How would an aftermarket LT1 intake with long runners effect the performance?!
10-15-2017, 12:05 PM
#121
Find a builder that KNOWS what he is doing and build a 396 shortblock for your LT1 engine. Convert it to 1.7 rockers and call it good. For the rpms you want, you'll be ecstatic. For California, you'll have zero issues with inspections. The reason I suggest 396 vs 383 is a good builder won't sacrifice ANY longevity to get even a bit more from the mod AND at little additional expense. I would take a 396 too. There is no replacement for displacement...especially in a street car.
There is a lot you can learn from smallest details of a build: How to build a block for maximum quench, considerations of cam overlap and how it can add power in lower/higher rpms, why 5.7" rods create more torque but 6" rods sacrifice little for less side-loading, etc... If you enlist a good builder (and there are a couple even in THIS forum), you don't need to know all that. All you SHOULD know is that a stroker kit is the answer to what you are looking for.
See you in two years!
There is a lot you can learn from smallest details of a build: How to build a block for maximum quench, considerations of cam overlap and how it can add power in lower/higher rpms, why 5.7" rods create more torque but 6" rods sacrifice little for less side-loading, etc... If you enlist a good builder (and there are a couple even in THIS forum), you don't need to know all that. All you SHOULD know is that a stroker kit is the answer to what you are looking for.
See you in two years!
You can feel the effect of a stroker kit in all rpms making it much more beneficial than a custom intake AND a custom intake isn't going to make you drool nearly as much. It's likely to make you think "Why did I spend all this money?". That doesn't mean it won't help in the lower rpm ranges just that the percentage bump will be subtle versus overt. When you spend $1000 on a mod, subtle is disappointing.
What I suggested for a build is the smallest Bullet cam (10-deg less total duration int/exh) than my cam...yet it has the same lift. My cranking compression has room to be higher so I know you COULD go smaller than me and gain more torque. I'm also sure you could gain torque from 1 5/8" headers vs 1 3/4"... especially if you were going to reuse the stock heads vs going aftermarket. I don't know the stock orientation of an LT1 cam...but if not mechanically advanced, you could shift it that direction. There was a member here who installed 1.7 rockers on an LT1 engine with good success. So....
The budget was of approaching this build is to install 1.7 rockers, keep your stock cam/heads and shove a stroker kit (as many suggested) underneath. To be honest, the bang-for-the-buck return on a custom intake probably isn't worth it (though I'm one of the first people that notices the sub-5k-rpm advantage of a longtube intake over a miniram/LT-intake). And, by advantage, I'm talking about if you rarely plan to exceed that level of rpms.
FWIW, my setup (which has a 214/214 .555/.555 112LSA cam, custom longtube intake, 383 w 1 3/4" headers and AFR 195 heads) fits your description). It can idle at stock rpms and it's more gas friendly than my 4x4 SUV that averages 15mpg city/hwy. It has 3.33 gears and doesn't NEED any more torque. My suggestion for AFR180 heads, smaller headers, and smaller cam come from knowing there IS room to get even MORE torque/responsiveness from a 383 setup. Of course NO ONE does that because they realize their "need" to build also includes the need for horsepower.
If you built EXACTLY the config I run (AFR195's/cam/383) and kept your stock LT1 intake, you would not be disappointed in the torque. There is night/day difference between my motor and an LT1. Again, I observed direct comparison between my config and a hotcammed LT1. My feels like a 427 by comparison. Having a Miniram (LT) intake on top would not take all of that away...not even half. And, having an LT intake saves you LOTS of money while retaining the much easier access to injectors.
Going back to what EVERYONE said, a stroker kit is the best option for you. With 1.7 rockers and a mechanically advanced cam (4-deg), you'd be where you want in terms of maximum driveability/mileage/emissions. You wouldn't have to deal with visual changes for California inspections because they wouldn't SEE anything. It would all be internal.
The budget was of approaching this build is to install 1.7 rockers, keep your stock cam/heads and shove a stroker kit (as many suggested) underneath. To be honest, the bang-for-the-buck return on a custom intake probably isn't worth it (though I'm one of the first people that notices the sub-5k-rpm advantage of a longtube intake over a miniram/LT-intake). And, by advantage, I'm talking about if you rarely plan to exceed that level of rpms.
FWIW, my setup (which has a 214/214 .555/.555 112LSA cam, custom longtube intake, 383 w 1 3/4" headers and AFR 195 heads) fits your description). It can idle at stock rpms and it's more gas friendly than my 4x4 SUV that averages 15mpg city/hwy. It has 3.33 gears and doesn't NEED any more torque. My suggestion for AFR180 heads, smaller headers, and smaller cam come from knowing there IS room to get even MORE torque/responsiveness from a 383 setup. Of course NO ONE does that because they realize their "need" to build also includes the need for horsepower.
If you built EXACTLY the config I run (AFR195's/cam/383) and kept your stock LT1 intake, you would not be disappointed in the torque. There is night/day difference between my motor and an LT1. Again, I observed direct comparison between my config and a hotcammed LT1. My feels like a 427 by comparison. Having a Miniram (LT) intake on top would not take all of that away...not even half. And, having an LT intake saves you LOTS of money while retaining the much easier access to injectors.
Going back to what EVERYONE said, a stroker kit is the best option for you. With 1.7 rockers and a mechanically advanced cam (4-deg), you'd be where you want in terms of maximum driveability/mileage/emissions. You wouldn't have to deal with visual changes for California inspections because they wouldn't SEE anything. It would all be internal.
10-15-2017, 12:12 PM
#122
Team Owner
Member Since: Oct 2004
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St. Jude Donor '05
Noone is going to make that intake, theres just no market for it.
396
10;1 CR
you will need a larger cam period. Just watch the overlap thats where you get caught up on smog your stocker wont cut it
port your intake
AFR 195 heads
Dougs shorties or equivalent
A real good set of cats and a tune
This will get you what you want and more
Dont need high $ parts to do this just good machining and a great balance job
396
10;1 CR
you will need a larger cam period. Just watch the overlap thats where you get caught up on smog your stocker wont cut it
port your intake
AFR 195 heads
Dougs shorties or equivalent
A real good set of cats and a tune
This will get you what you want and more
Dont need high $ parts to do this just good machining and a great balance job
Last edited by cv67; 10-15-2017 at 12:22 PM.
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Phoenix'97 (10-15-2017)
10-15-2017, 12:33 PM
#123
The market always changes, yes guys are inclined to pick the LS motor over the LT motor, but what if we could make the LT motor flow just as well as the LS motor and perform just as well as the LS motor? Competition is always a good thing in the free market.
If someone else won't ante up with this intake, I guess I will have to try, assuming I can find someone willing to build it and build it well not using sheet metal, and the cost will always be a factor. The reward may be worth it and for the second generation LT1 community.
396
10;1 CR
you will need a larger cam period. Just watch the overlap thats where you get caught up on smog your stocker wont cut it
port your intake
AFR 195 heads
Dougs shorties or equivalent
A real good set of cats and a tune
This will get you what you want and more
Dont need high $ parts to do this just good machining and a great balance job
10;1 CR
you will need a larger cam period. Just watch the overlap thats where you get caught up on smog your stocker wont cut it
port your intake
AFR 195 heads
Dougs shorties or equivalent
A real good set of cats and a tune
This will get you what you want and more
Dont need high $ parts to do this just good machining and a great balance job
Last edited by Phoenix'97; 10-15-2017 at 12:36 PM.
10-15-2017, 12:51 PM
#124
Race Director
Noone is going to make that intake, theres just no market for it.
396
10;1 CR
you will need a larger cam period. Just watch the overlap thats where you get caught up on smog your stocker wont cut it
port your intake
AFR 195 heads
Dougs shorties or equivalent
A real good set of cats and a tune
This will get you what you want and more
Dont need high $ parts to do this just good machining and a great balance job
396
10;1 CR
you will need a larger cam period. Just watch the overlap thats where you get caught up on smog your stocker wont cut it
port your intake
AFR 195 heads
Dougs shorties or equivalent
A real good set of cats and a tune
This will get you what you want and more
Dont need high $ parts to do this just good machining and a great balance job
Oh yeah...California doesn't allow longtubes, do they?
Again, I agree more cam and more "power" is the better option. Have you ever seen/known anyone that built a stroker UNDER a stock LTx topend? ... in California?
Have you ever known/seen anyone even MORE hell-bent on the sub-5k performance than me? This guy qualifies.
FWIW, it's hard (for me) to recommend "the whole enchilada" in times where pollution shows it's effects AND in states that highly defend/regulate against it. If someone ONLY wants low-rpm torque and may benefit from eliminating components toward that goal, why not list that option?
Having seen (over the years) what a handful of members accomplished under truly budget builds, I also tend to err on the side of finding THE PIECE that will accomplish a goal. TA built a setup similar to mine with ported stock heads and mild cam. Of course mine is bottled up compared to what it CAN do (sidepipes/intake). That doesn't mean it doesn't meet my daily driving goals and that the extra 70hp would represent more exposure for violation than function. It DOES mean there IS room (in an ideal sense) to build for more torque. Ron, we both know port velocity matters to the lowest rpm response. We also both know that bigger cams create more power AND can be manageable especially if we can "settle" for higher idle speeds etc...
From my standpoint, the real question is whether we "secretly" recommend building that extra HP into the equation so the owner is happier with the hwy horsepower...even if they didn't ask for it OR to suggest the absolute "ideal" for torque-production in 1000-2000rpms?
Truth be told EVEN AFTER 7 YEARS OF OWNERSHIP, I really do spend 90+ % of my driving in that 1000-2000 rpm range. The extra power and responsiveness simply don't require it. Plus "life" doesn't require every rev/shift to exhibit aggressiveness. Driving a sportscar is a clandestine exercise where you constantly look for lawful ways to enjoy excessive power while finding very few...unless you live in the country. I'm saying streetcar ownership is almost like moonshine running. You have something fun but have to keep it a secret more often than not.
Based on the occasional rare build (mine or TAs), I'm not convinced an owner NEEDS a bigger cam to power a stroker. I think it's well-advised if the owner lies on that horsepower couch and realizes they probably want more than they think. I also think the low-end "sacrifice" is negligible for the benefit of more power when you need it. I'm saying I agree with you but won't do so without qualifying why.
The following users liked this post:
Phoenix'97 (10-15-2017)
10-15-2017, 07:11 PM
#125
Melting Slicks
Oh yeah...California doesn't allow longtubes, do they?
Again, I agree more cam and more "power" is the better option. Have you ever seen/known anyone that built a stroker UNDER a stock LTx topend? ... in California?
Have you ever known/seen anyone even MORE hell-bent on the sub-5k performance than me? This guy qualifies.
FWIW, it's hard (for me) to recommend "the whole enchilada" in times where pollution shows it's effects AND in states that highly defend/regulate against it. If someone ONLY wants low-rpm torque and may benefit from eliminating components toward that goal, why not list that option?
Having seen (over the years) what a handful of members accomplished under truly budget builds, I also tend to err on the side of finding THE PIECE that will accomplish a goal. TA built a setup similar to mine with ported stock heads and mild cam. Of course mine is bottled up compared to what it CAN do (sidepipes/intake). That doesn't mean it doesn't meet my daily driving goals and that the extra 70hp would represent more exposure for violation than function. It DOES mean there IS room (in an ideal sense) to build for more torque. Ron, we both know port velocity matters to the lowest rpm response. We also both know that bigger cams create more power AND can be manageable especially if we can "settle" for higher idle speeds etc...
From my standpoint, the real question is whether we "secretly" recommend building that extra HP into the equation so the owner is happier with the hwy horsepower...even if they didn't ask for it OR to suggest the absolute "ideal" for torque-production in 1000-2000rpms?
Truth be told EVEN AFTER 7 YEARS OF OWNERSHIP, I really do spend 90+ % of my driving in that 1000-2000 rpm range. The extra power and responsiveness simply don't require it. Plus "life" doesn't require every rev/shift to exhibit aggressiveness. Driving a sportscar is a clandestine exercise where you constantly look for lawful ways to enjoy excessive power while finding very few...unless you live in the country. I'm saying streetcar ownership is almost like moonshine running. You have something fun but have to keep it a secret more often than not.
Based on the occasional rare build (mine or TAs), I'm not convinced an owner NEEDS a bigger cam to power a stroker. I think it's well-advised if the owner lies on that horsepower couch and realizes they probably want more than they think. I also think the low-end "sacrifice" is negligible for the benefit of more power when you need it. I'm saying I agree with you but won't do so without qualifying why.
Again, I agree more cam and more "power" is the better option. Have you ever seen/known anyone that built a stroker UNDER a stock LTx topend? ... in California?
Have you ever known/seen anyone even MORE hell-bent on the sub-5k performance than me? This guy qualifies.
FWIW, it's hard (for me) to recommend "the whole enchilada" in times where pollution shows it's effects AND in states that highly defend/regulate against it. If someone ONLY wants low-rpm torque and may benefit from eliminating components toward that goal, why not list that option?
Having seen (over the years) what a handful of members accomplished under truly budget builds, I also tend to err on the side of finding THE PIECE that will accomplish a goal. TA built a setup similar to mine with ported stock heads and mild cam. Of course mine is bottled up compared to what it CAN do (sidepipes/intake). That doesn't mean it doesn't meet my daily driving goals and that the extra 70hp would represent more exposure for violation than function. It DOES mean there IS room (in an ideal sense) to build for more torque. Ron, we both know port velocity matters to the lowest rpm response. We also both know that bigger cams create more power AND can be manageable especially if we can "settle" for higher idle speeds etc...
From my standpoint, the real question is whether we "secretly" recommend building that extra HP into the equation so the owner is happier with the hwy horsepower...even if they didn't ask for it OR to suggest the absolute "ideal" for torque-production in 1000-2000rpms?
Truth be told EVEN AFTER 7 YEARS OF OWNERSHIP, I really do spend 90+ % of my driving in that 1000-2000 rpm range. The extra power and responsiveness simply don't require it. Plus "life" doesn't require every rev/shift to exhibit aggressiveness. Driving a sportscar is a clandestine exercise where you constantly look for lawful ways to enjoy excessive power while finding very few...unless you live in the country. I'm saying streetcar ownership is almost like moonshine running. You have something fun but have to keep it a secret more often than not.
Based on the occasional rare build (mine or TAs), I'm not convinced an owner NEEDS a bigger cam to power a stroker. I think it's well-advised if the owner lies on that horsepower couch and realizes they probably want more than they think. I also think the low-end "sacrifice" is negligible for the benefit of more power when you need it. I'm saying I agree with you but won't do so without qualifying why.
With the 3:07 rear end, my LT-1 doesn't feel much different than a C5.
10-18-2017, 01:37 AM
#126
Race Director
I don't follow your point, Cool Runnings?
I should also add that owning a ZF 6-spd mandates some VERY low rpms on the hwy in 6th. But, we know that.
With my 214/214 single-pattern cam (under an IDEAL head for small cams stroker use), performance for the lowest 500 rpms (idle-1250 rpms) isn't quite as good as a stock 350. Even with the steeper ramps, valve opening is at least somewhat longer and (I'm going to assume), port velocity could be better -- for those rpms. That's DESPITE the STELLAR reputation of the Eliminator 195s.
TO BE CLEAR, I have zero disappointment with the idle/off-idle performance of my setup. However, there has been a build/two with 180s in the last 7 years (since my build). I don't recall specific statements, but I do remember some pretty awesome results...even compared to mine. Partly, it reinforced just how good AFR heads versus the competition. Partly, it made me wonder how much better those first 500 rpms would be had I made that choice. In asking myself that question, I ponder how often I troll in 1st/2nd threw local store parking lots versus THE NEED to blast beyond 5k rpms...which my longtube intake sucks at anyway. (Of course, there is PLENTY of head-snapping torque below 5k rpms, the pace getting to 5k rpms probably couldn't be any better (w/o FI/cubes/nitrous), and I've also wondered what MORE cam would be like...with another intake.)
For purely functional reasons, less cam is more if you REALLY don't want 5k-6k rpm performance. For purely bang-for-the-buck reasons, NOT choosing to put more cam with a stroker almost makes the choice feel "wrong". After all, if you're GOING to spend money on an engine build, why leave horsepower on the table?
No one NEEDS more off-idle torque than stock (unless towing). Just like no one NEEDS a performance motor to drive to the store. Most importantly, no one is terribly impressed by how many broke-down 18-wheelers you can tow at 1200 rpms with your sports car.
Understanding these points may help the OP decide if/why a build is even called for....especially in CA.
Of course I may be more curious than the rest to see what AFR195 heads and a stroker would do for an otherwise stock LT1. You can always open it up and install a performance cam afterward. If (with high-ratio rockers), the result was as surprising as I think, it would say a lot for the AFRs. Probably more than any other build IMO.
Of course, I've ALSO been waiting for years to see an AFR195 stroker build under a FFI intake. Had this combo not required an remote coil distributor, there's a better chance I would have gone that route. Plus, I wanted it to look stock (albeit polished stock) under the hood.
I've gotten over that and want to try an HSR one of these days. I've had one in my basement since 2010. Considering that Engine Analyzer projects it would "feel" like a 100-shot of nitrous, how can I NOT want to know what that would be like?
Pheonix97, if that last statement sounded intriguing AT ALL, rethink your build completely. BTW...If you search my ID, you'll find I actually started a thread about 8 yrs ago that asked the question "How much torque is too much torque?". Mostly, I was looking for the "tipping point" where 1st, 2nd, and possibly 3rd contained so much torque that you could spin tires with a ZF6. The thread MAY have gotten locked! LOL I think the answer was there's no such thing! LOL Considering modern HP levels, that conclusion is hard to argue with!
I should also add that owning a ZF 6-spd mandates some VERY low rpms on the hwy in 6th. But, we know that.
With my 214/214 single-pattern cam (under an IDEAL head for small cams stroker use), performance for the lowest 500 rpms (idle-1250 rpms) isn't quite as good as a stock 350. Even with the steeper ramps, valve opening is at least somewhat longer and (I'm going to assume), port velocity could be better -- for those rpms. That's DESPITE the STELLAR reputation of the Eliminator 195s.
TO BE CLEAR, I have zero disappointment with the idle/off-idle performance of my setup. However, there has been a build/two with 180s in the last 7 years (since my build). I don't recall specific statements, but I do remember some pretty awesome results...even compared to mine. Partly, it reinforced just how good AFR heads versus the competition. Partly, it made me wonder how much better those first 500 rpms would be had I made that choice. In asking myself that question, I ponder how often I troll in 1st/2nd threw local store parking lots versus THE NEED to blast beyond 5k rpms...which my longtube intake sucks at anyway. (Of course, there is PLENTY of head-snapping torque below 5k rpms, the pace getting to 5k rpms probably couldn't be any better (w/o FI/cubes/nitrous), and I've also wondered what MORE cam would be like...with another intake.)
For purely functional reasons, less cam is more if you REALLY don't want 5k-6k rpm performance. For purely bang-for-the-buck reasons, NOT choosing to put more cam with a stroker almost makes the choice feel "wrong". After all, if you're GOING to spend money on an engine build, why leave horsepower on the table?
No one NEEDS more off-idle torque than stock (unless towing). Just like no one NEEDS a performance motor to drive to the store. Most importantly, no one is terribly impressed by how many broke-down 18-wheelers you can tow at 1200 rpms with your sports car.
Understanding these points may help the OP decide if/why a build is even called for....especially in CA.
Of course I may be more curious than the rest to see what AFR195 heads and a stroker would do for an otherwise stock LT1. You can always open it up and install a performance cam afterward. If (with high-ratio rockers), the result was as surprising as I think, it would say a lot for the AFRs. Probably more than any other build IMO.
Of course, I've ALSO been waiting for years to see an AFR195 stroker build under a FFI intake. Had this combo not required an remote coil distributor, there's a better chance I would have gone that route. Plus, I wanted it to look stock (albeit polished stock) under the hood.
I've gotten over that and want to try an HSR one of these days. I've had one in my basement since 2010. Considering that Engine Analyzer projects it would "feel" like a 100-shot of nitrous, how can I NOT want to know what that would be like?
Pheonix97, if that last statement sounded intriguing AT ALL, rethink your build completely. BTW...If you search my ID, you'll find I actually started a thread about 8 yrs ago that asked the question "How much torque is too much torque?". Mostly, I was looking for the "tipping point" where 1st, 2nd, and possibly 3rd contained so much torque that you could spin tires with a ZF6. The thread MAY have gotten locked! LOL I think the answer was there's no such thing! LOL Considering modern HP levels, that conclusion is hard to argue with!
Last edited by GREGGPENN; 10-18-2017 at 01:40 AM.
10-20-2017, 08:41 PM
#127
What forum did you leave from with this conversation? Third gen by chance? Hope this helps you understand.
copy and pasted form 2007
I think that people who know what they are talking about were already informed of this news several years ago.
Obviously the restrictive stock 180cc LT1 23* heads are going to choke a 5.7L motor more than some free-flowing 200cc LS1 15* heads.
The more NA horsepower you make, the higher the torque curve and horsepower curve moves up.
Next thing you know, a stock L98 will make more low end torque than a 430 rwhp 236/239 .600/.600 Cam-Only LS1.
copy and pasted form 2007
I think that people who know what they are talking about were already informed of this news several years ago.
Obviously the restrictive stock 180cc LT1 23* heads are going to choke a 5.7L motor more than some free-flowing 200cc LS1 15* heads.
The more NA horsepower you make, the higher the torque curve and horsepower curve moves up.
Next thing you know, a stock L98 will make more low end torque than a 430 rwhp 236/239 .600/.600 Cam-Only LS1.
Last edited by pologreen1; 10-20-2017 at 08:46 PM.
10-21-2017, 02:20 AM
#128
What forum did you leave from with this conversation? Third gen by chance? Hope this helps you understand.
copy and pasted form 2007
I think that people who know what they are talking about were already informed of this news several years ago.
Obviously the restrictive stock 180cc LT1 23* heads are going to choke a 5.7L motor more than some free-flowing 200cc LS1 15* heads.
The more NA horsepower you make, the higher the torque curve and horsepower curve moves up.
Next thing you know, a stock L98 will make more low end torque than a 430 rwhp 236/239 .600/.600 Cam-Only LS1.
copy and pasted form 2007
I think that people who know what they are talking about were already informed of this news several years ago.
Obviously the restrictive stock 180cc LT1 23* heads are going to choke a 5.7L motor more than some free-flowing 200cc LS1 15* heads.
The more NA horsepower you make, the higher the torque curve and horsepower curve moves up.
Next thing you know, a stock L98 will make more low end torque than a 430 rwhp 236/239 .600/.600 Cam-Only LS1.
At the very beginning of this thread, I mentioned that I was "soul searching" on what to do with my motor. After honest advice, criticism, jokes, and then serious suggestions, I was left with the stroked option. However, a different thread (https://www.corvetteforum.com/forums...n-5-lt1-3.html ) directed me to the notion of satisfying my build by finding a way to bolt on an LS intake to the LT1 motor, which would require a custom head that works with the LT1 motor but can utilize the LS intake. The only problem, I doubt I will find someone who will make it. Then, after some searching around with the Bill Mitchell Racing SBC/LS hybrid motor, I came to the conclusion that the slight modifications which include raising the camshaft height up the block, would result in a disastrous build. So, while I took away some good knowledge, I am left with my LT1 block, but this could be a blessing in disguise in terms of a budget build.
I am concerned about my fuel economy with a 396 stroker kit using a very mild tow/mileage camshaft. So, I can start by leaning out the air-fuel ratio when the motor is dynotuned by the shop. Second, I need to restrict airflow by keeping the LT1 heads stock, keeping the current LS1 factory air box I am using, and lastly, to seriously consider using the factory TPI intake for the L98 and have a machine shop work it to make it bolt-on capable to my LT1 heads. The factory TPI intake will help to choke off airflow starting at the 3000 RPM range and more-so after 4500 RPM. This will also serve as "speed control" for my city driving having that 396 stroker kit. This is probably the best compromise that I can make granted the few options I have and working within the demands I have for this build. I will definitely upgrade my ignition to a coil over cylinder set-up, granted many guys claim it provided a noticeable idle improvement and slight power increase over optispark ignition system. Then, short of the custom long tube headers built for the peak RPM range, probably 3000 RPM dictated by the TPI intake, the rest of it will be refurbishing wire harnesses, replacing aged out components of the engine systems, and I really should have the radiator replaced with an all metal unit. Pretty much, a well budgeted build.
On a last note, the TPI intake will be a royal pain to fit in my engine bay when 9 inches at it's highest will put it right up to the cowl.
Last edited by Phoenix'97; 10-21-2017 at 02:48 AM.
10-21-2017, 10:10 AM
#129
I am just going to post this for my own future reference and the reference of others who are curious about this thread.
http://www.superchevy.com/how-to/568...e-vortec-head/
A Scoggin-Dickey TPI intake for the Vortec Head, this is promising granted the similarities of the Vortec head and the LT1 head. I may not have to come up with a means to add more material to an L98 TPI base in order to get it port matched to my LT1 heads. I am also curious as sin to know if it is remotely possible to utilize the TPI intake coolant passages and incorporate it somehow into the total reverse-flow cooling system, I am even trying to figure out how to reuse my LT1 throttle body with coolant passages on the TPI intake.
Yeah, it seems like a cluster **** and fitment issues should be on my mind, but I have time to plan this out, get more input and scorn from those who know better.
http://www.superchevy.com/how-to/568...e-vortec-head/
A Scoggin-Dickey TPI intake for the Vortec Head, this is promising granted the similarities of the Vortec head and the LT1 head. I may not have to come up with a means to add more material to an L98 TPI base in order to get it port matched to my LT1 heads. I am also curious as sin to know if it is remotely possible to utilize the TPI intake coolant passages and incorporate it somehow into the total reverse-flow cooling system, I am even trying to figure out how to reuse my LT1 throttle body with coolant passages on the TPI intake.
Yeah, it seems like a cluster **** and fitment issues should be on my mind, but I have time to plan this out, get more input and scorn from those who know better.
Last edited by Phoenix'97; 10-21-2017 at 10:11 AM.
10-21-2017, 04:06 PM
#130
Race Director
I am concerned about my fuel economy with a 396 stroker kit using a very mild tow/mileage camshaft. So, I can start by leaning out the air-fuel ratio when the motor is dynotuned by the shop. Second, I need to restrict airflow by keeping the LT1 heads stock, keeping the current LS1 factory air box I am using, and lastly, to seriously consider using the factory TPI intake for the L98 and have a machine shop work it to make it bolt-on capable to my LT1 heads.
....On a last note, the TPI intake will be a royal pain to fit in my engine bay when 9 inches at it's highest will put it right up to the cowl.
....On a last note, the TPI intake will be a royal pain to fit in my engine bay when 9 inches at it's highest will put it right up to the cowl.
Going through all this customization for a couple thousand rpms of grunt just doesn't seem worth if...ESPECIALLY if you're going to worry about every little drop of gas you'll burn. If you can't stand the thought of POTENTIALLY using 10% more fuel, don't do it. I'm here to say you won't if you're the saint you convey! LOL The reality is ANYONE would have trouble keeping their foot out of a "build". I think you will too -- which means you'll use more fuel!
Like I said, they made a few superram (TPI) bases specifically to mount a superram on an LTx. You could use a longtube plenum/runners instead. Or...find an FFI that was made for LTx (if they don't still make them). FWIW, I understood you to say the "standard" FFI would be too tall and may need to be cut down. I'm not so sure they are any taller than a stock TPI?
If you were able to use a stock TPI, I'd at least use large tube runners. Polo was making the point that air restriction can have a TORQUE restriction in lower rpms. Beyond that, it's going to be hard to help/advise someone thinking so far out of the norm. I'm sure EVERYONE is perplexed by a person worried about fuel costs but NOT about custom one-off intake work.
You are an enigma.
Last edited by GREGGPENN; 10-21-2017 at 04:21 PM.
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Phoenix'97 (10-21-2017)
10-21-2017, 04:48 PM
#131
As most readers (if not all), your concern about mpg and limiting air flow is counter-intuitive for any stroker/performance build. If you are THAT concerned, just don't do it. Plus, they have made FFI and TPI intakes configured for the LTx engine. Obviously we can't know your clearance issues but they are out there...though rare. (OTOH, you have plenty of time to hunt/shop).
Going through all this customization for a couple thousand rpms of grunt just doesn't seem worth if...ESPECIALLY if you're going to worry about every little drop of gas you'll burn. If you can't stand the thought of POTENTIALLY using 10% more fuel, don't do it. I'm here to say you won't if you're the saint you convey! LOL The reality is ANYONE would have trouble keeping their foot out of a "build". I think you will too -- which means you'll use more fuel!
Like I said, they made a few superram (TPI) bases specifically to mount a superram on an LTx. You could use a longtube plenum/runners instead. Or...find an FFI that was made for LTx (if they don't still make them). FWIW, I understood you to say the "standard" FFI would be too tall and may need to be cut down. I'm not so sure they are any taller than a stock TPI?
If you were able to use a stock TPI, I'd at least use large tube runners. Polo was making the point that air restriction can have a TORQUE restriction in lower rpms. Beyond that, it's going to be hard to help/advise someone thinking so far out of the norm. I'm sure EVERYONE is perplexed by a person worried about fuel costs but NOT about custom one-off intake work.
You are an enigma.
Going through all this customization for a couple thousand rpms of grunt just doesn't seem worth if...ESPECIALLY if you're going to worry about every little drop of gas you'll burn. If you can't stand the thought of POTENTIALLY using 10% more fuel, don't do it. I'm here to say you won't if you're the saint you convey! LOL The reality is ANYONE would have trouble keeping their foot out of a "build". I think you will too -- which means you'll use more fuel!
Like I said, they made a few superram (TPI) bases specifically to mount a superram on an LTx. You could use a longtube plenum/runners instead. Or...find an FFI that was made for LTx (if they don't still make them). FWIW, I understood you to say the "standard" FFI would be too tall and may need to be cut down. I'm not so sure they are any taller than a stock TPI?
If you were able to use a stock TPI, I'd at least use large tube runners. Polo was making the point that air restriction can have a TORQUE restriction in lower rpms. Beyond that, it's going to be hard to help/advise someone thinking so far out of the norm. I'm sure EVERYONE is perplexed by a person worried about fuel costs but NOT about custom one-off intake work.
You are an enigma.
Then lastly, this old post has only inspired my drive to put a factory TPI intake on my motor.
https://www.corvetteforum.com/forums/newreply.php?do=newreply&p=1577213703
Tuned Port
The TPI will never make big horsepower because of the very long total length runners to the backside of the Intake valve. The TPI does one thing better than any other GM style EFI intake system. TPI makes tremendous low end and midrange torque. A 240hp TPI will flat out smoke a 350hp LT1 from the early 70's. A 340hp TPI can have torque over 475 ftlb and be over 400 ftlb for more than 3000 rpm.
TPI design. Uses "shock waves" (harmonics) with tuned length runners that 'push' more air into a cylinder than that cylinder can draw on its own. You can customize the total runner length to take advantage of "wave tuning". The 4th harmonic is worth 4%. The third harmonic worth 7% and the 2nd harmonic is worth 10%. If going for the 2nd harmonic you will use all three boost rpm ranges. The stock TPI uses the 3rd harmonic range for its boost. Most are well aware of the boost that creates. It is best to have the runner volume roughly equal to the volume of the cylinder. This helps in the added boost in flow from the kinetic energy from the ramming of the air mass into the cylinder. If done right and with a good exhaust you can create up to 5 pounds of boost. Based upon stock intake runner diameter, a 350 produces peak torque (400 ftlb)at 3,427 rpm. To be effective, the TPI to a point HAS TO be restrictive. The same restriction to flow is what speeds up the air in the runners which contributes to the wave effect. This means that extra 20 or 30 cfm you get from hogging it out huge can actually hurt performance down low by means of port velocity though it can help it up top. Ignore flow numbers in the intake, and concentrate on using the right size and length. Best place to worry about flow numbers is in the heads.
http://www.thirdgen.org/techboard/tp...culations.html
The TPI will never make big horsepower because of the very long total length runners to the backside of the Intake valve. The TPI does one thing better than any other GM style EFI intake system. TPI makes tremendous low end and midrange torque. A 240hp TPI will flat out smoke a 350hp LT1 from the early 70's. A 340hp TPI can have torque over 475 ftlb and be over 400 ftlb for more than 3000 rpm.
TPI design. Uses "shock waves" (harmonics) with tuned length runners that 'push' more air into a cylinder than that cylinder can draw on its own. You can customize the total runner length to take advantage of "wave tuning". The 4th harmonic is worth 4%. The third harmonic worth 7% and the 2nd harmonic is worth 10%. If going for the 2nd harmonic you will use all three boost rpm ranges. The stock TPI uses the 3rd harmonic range for its boost. Most are well aware of the boost that creates. It is best to have the runner volume roughly equal to the volume of the cylinder. This helps in the added boost in flow from the kinetic energy from the ramming of the air mass into the cylinder. If done right and with a good exhaust you can create up to 5 pounds of boost. Based upon stock intake runner diameter, a 350 produces peak torque (400 ftlb)at 3,427 rpm. To be effective, the TPI to a point HAS TO be restrictive. The same restriction to flow is what speeds up the air in the runners which contributes to the wave effect. This means that extra 20 or 30 cfm you get from hogging it out huge can actually hurt performance down low by means of port velocity though it can help it up top. Ignore flow numbers in the intake, and concentrate on using the right size and length. Best place to worry about flow numbers is in the heads.
http://www.thirdgen.org/techboard/tp...culations.html
Last edited by Phoenix'97; 10-21-2017 at 05:08 PM.
10-21-2017, 07:53 PM
#132
Race Director
I trust you when you say that if I have a light foot most of the time the mileage should not drop as radically as I worry about. There is a problem I realized, I enjoy downshifting to slow down my car, it has it's uses and it gets the point across to tailgaters behind me when it is time to slow down for stopped traffic ahead. With a stroker, I don't even know how badly this could eat at my fuel with high rev down shifting.
When you decel, injectors aren't delivering fuel like you would with a carb. In comparison, they "shut down" which is one reason they get better mpg than 60's muscle cars.
Like I said, 15 city 25 hwy mpgs is about what to expect. OTOH, you could probably "hyper-mile" it to 20-35. LOL
10-21-2017, 08:58 PM
#133
New thought.... Get ready!
More cubes or power adder with taller gears = Way more torque and better gas mileage at some point.
Your move.
Seriously though how much is 50? lbft tq worth?even 100? which IMO some regular shop guy doing bolt ons is not going to be able to formulate. Maybe some guys out there know, but I think you are throwing money out the window.
This is interesting though.
More cubes or power adder with taller gears = Way more torque and better gas mileage at some point.
Your move.
Seriously though how much is 50? lbft tq worth?even 100? which IMO some regular shop guy doing bolt ons is not going to be able to formulate. Maybe some guys out there know, but I think you are throwing money out the window.
This is interesting though.
Last edited by pologreen1; 10-21-2017 at 09:02 PM.
10-21-2017, 09:08 PM
#134
I would like to run 295/50/R15 on the rear and 225/60/R15 on the front in either Center Line or American Racing wheels. The larger rear tires will make my rear axle behave as though I have a taller gear on it than my stock gear! So, there is no need to get too crazy with overdrive rear axle gears, and the wider rear tires should help to give me better traction control on the road surface, so long as I don't slam on the gas pedal. The vision I have is simple, to pass on the classic muscle car feel and look to my sports car and blend them beautifully. "We build driving excitement." "The muscle car lives." "When a Firebird dies, a Phoenix rises from the ashes."
10-22-2017, 01:27 AM
#135
I would like to run 295/50/R15 on the rear and 225/60/R15 on the front in either Center Line or American Racing wheels. The larger rear tires will make my rear axle behave as though I have a taller gear on it than my stock gear! So, there is no need to get too crazy with overdrive rear axle gears, and the wider rear tires should help to give me better traction control on the road surface, so long as I don't slam on the gas pedal. The vision I have is simple, to pass on the classic muscle car feel and look to my sports car and blend them beautifully. "We build driving excitement." "The muscle car lives." "When a Firebird dies, a Phoenix rises from the ashes."
DO IT! I want some lt1 LTR torque and I want a video or dyno to see what you created.
10-22-2017, 11:16 AM
#138
Team Owner
Member Since: Oct 2004
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St. Jude Donor '05
so have the tuner remove some fuel on decel; going "real lean" is a mistake . Bigger displacement or even a 350 with a bigger cam will use more fuel period there is NO way around it. You wont care once you have it
You need to ride in something similar to what you want thats the only way this will sink in. What youre ideally hoping for does not exist unless you buy a brand new one.
You need to ride in something similar to what you want thats the only way this will sink in. What youre ideally hoping for does not exist unless you buy a brand new one.
Last edited by cv67; 10-22-2017 at 11:16 AM.
10-22-2017, 12:28 PM
#139
so have the tuner remove some fuel on decel; going "real lean" is a mistake . Bigger displacement or even a 350 with a bigger cam will use more fuel period there is NO way around it. You wont care once you have it
You need to ride in something similar to what you want thats the only way this will sink in. What youre ideally hoping for does not exist unless you buy a brand new one.
You need to ride in something similar to what you want thats the only way this will sink in. What youre ideally hoping for does not exist unless you buy a brand new one.
Why the hell not try to make a stroker more fuel efficient for a daily driver?!
Post Edit: Before I forget, I wonder how low we can get away with idling the motor. Can we strive for 500 RPM or at least 600 RPM on idle? Every little detail!
Last edited by Phoenix'97; 10-22-2017 at 12:35 PM.
10-23-2017, 11:00 AM
#140
I am not aware of what the tuner can do with the technology of a 1997 LT1 PCM. This is certainly a thought, have the car tuned to remove fuel on deceleration! Again, I need to talk with him, the guy is an expert and he works with racers and casual racer/street drivers. He too may find my set-up odd as hell and my requests a bit on the absurd side, but he can work his magic to try to make a possible 396 TPI LT1 stroker with mild stock cam, a fuel sipper from idle, to go, and when decelerating.
Why the hell not try to make a stroker more fuel efficient for a daily driver?!
Post Edit: Before I forget, I wonder how low we can get away with idling the motor. Can we strive for 500 RPM or at least 600 RPM on idle? Every little detail!
Why the hell not try to make a stroker more fuel efficient for a daily driver?!
Post Edit: Before I forget, I wonder how low we can get away with idling the motor. Can we strive for 500 RPM or at least 600 RPM on idle? Every little detail!
Imagine the tuner time to make this work like you want. Imagine the tuner thinking WTF does this guy want me to do here?
My thoughts is buy a 1960's or 70's tow truck and have blast in the winter time with tons of torque, make a little money on the side for the gas consumption.