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How would an aftermarket LT1 intake with long runners effect the performance?!

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Old 10-15-2017, 11:30 AM   #121
GREGGPENN
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Thank you many times over for essentially laying the groundwork to mention these components to the engine builder and custom shop in the not too distant future. I said before, I plan to finance this as if it were a car loan and essentially this is an attempt to recreate the 1997 LT1 Trans Am WS6 into a new car. I plan to hold on to this car for as long as I can as my daily driver and as such it will be built for this purpose. Yeah, the projected amount for the engine build is hefty and considering what Ken at FIRST will ultimately create for me, if he can manage an LS style intake that bolts on to the LT1, and then working in emissions device locations, MAP sensor and the PCV valve location, which I could have it moved to a valve cover like on the L98. I am just saying, I have looked into swapping the 2014 LT1 or even the 2015 LT5 into my car and the combined cost for the turn-key motor, the necessary transmission, the ECM to run the motor, the electronic throttle kit, and other goodies I need to swap this motor into my F-body and the necessary work to get it all to fit with the wiring required to get it to work with my factory gauge cluster, this engine build with custom intake will end up costing less!

So, if I have to save my LT1 motor, how do I improve the motor to make it more enjoyable, to give me my seat of the pants launches from lights without destroying my average fuel economy and to be safe to drive during the winter requiring a feather foot and literally having an experience of becoming "one" with the car and feeling everything that it feels and knowing when to slow down or when you are losing traction, just like my truck driving days! Greg, thank you again!

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.

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.

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!

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Old 10-15-2017, 12:05 PM   #122
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Originally Posted by GREGGPENN View Post
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!

I was thinking if am going for a stroker kit, why not go to a 396, and you answered the question already! I am projected to have two more years in college if all goes well and then the time to pay back my student loan but I am attending low cost colleges anyways without room and board, so it may be another year or two before I have that paid down with double installments.
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Originally Posted by GREGGPENN View Post
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.
I know I can get by with my stock intake, but to satisfy curiosity, I would really like to see an aftermarket bolt-on long runner intake made for the LT1 and realizing what the LS intake is, maybe it is time that we have such an intake made for the LT1, and the following better flowing aftermarket heads for the LT1 will come after. If I am holding on to this car, why not reinvent the wheel to make my motor seem newish like a version of the LT1 that GM engineers wanted to be put into production but couldn't make that call.


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Originally Posted by GREGGPENN View Post
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.
Thank you! I am drooling in my mind thinking about what this motor is going to turn out to be, thinking that I can have my cake and eat it to, in terms of my definition of "performance".
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Old 10-15-2017, 12:12 PM   #123
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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

Last edited by cuisinartvette; 10-15-2017 at 12:22 PM.
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Old 10-15-2017, 12:33 PM   #124
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Originally Posted by cuisinartvette View Post
Noone is going to make that intake, theres just no market for it.
That won't stop me from inquiring and getting a projected cost necessary to make a possible one-off LS style intake for the LT1 that is a direct bolt-on, that uses all sensor and emissions components from the LT1 intake, and that will fit under the cowl of the fourth generation LT1/LS1 F-body Firebird/Camaro.

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.

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Originally Posted by cuisinartvette View Post
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
Thank you. I have time to research and submit these proposals to the engine builder and tuner, along with the custom shop that will work on the rest of my car and the other subtle and updated modifications I wish to have done to my car.

Last edited by Phoenix'97; 10-15-2017 at 12:36 PM.
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Old 10-15-2017, 12:51 PM   #125
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Originally Posted by cuisinartvette View Post
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

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.
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Old 10-15-2017, 07:11 PM   #126
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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.


With the 3:07 rear end, my LT-1 doesn't feel much different than a C5.
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Old Yesterday, 01:37 AM   #127
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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!

Last edited by GREGGPENN; Yesterday at 01:40 AM.
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