Can the factory TPI intake be reduced in height by shortening the runners?
#1
Can the factory TPI intake be reduced in height by shortening the runners?
I can't help but think that the TPI intake could sit a good inch or two lower in the rear if the connecting runners were shorter by the necessary amount. Is this possible or am I dreaming?
Last edited by Phoenix'97; 10-21-2017 at 04:25 PM.
#3
Well, oddly enough, to get a shortened TPI intake mounted to a Vortec head adapted base to fit on my LT1 motor in my F-body Trans Am. Yes, some additional modification will be necessary but it could very well work quite nicely.
#4
I read somewhere that the Firebird has a different plenum than the Camaro and Corvette. Has to do with the lower hood line on the Firebird. That there is also a lower H.P. rating for the Firebird because the lower plenum presents a restriction over the Camaro / Corvette part. I've never confirmed any of this, just recall reading it years ago.
This is at the front, so won't help you with the rear. Cheers.
This is at the front, so won't help you with the rear. Cheers.
Since I am creating a "torque monster", I now need to tame all that torque for daily year-round driving by deliberately detuning by restricting air flow and denying cold air. I will try to find a way to get my LT1 throttle body with coolant passages to work on the TPI and to seal off it's coolant passage drains underneath the base to try to flow coolant from the throttle body through the base of the intake and connect it to the rest of the coolant system. Also, I will look into getting a "tasteful" cowl hood that is better constructed to fit like a factory hood. I love the current hood on my car, but let me explore my options.
Last edited by Phoenix'97; 10-21-2017 at 08:57 PM.
#5
I think that is what Siameseing did? I don't even remember.
You have to go back in to the 90's google searches. TONS of people did serious TPI mods
This vid shows some interesting stuff sine you are in to intakes. He ports and flows them.
You have to go back in to the 90's google searches. TONS of people did serious TPI mods
This vid shows some interesting stuff sine you are in to intakes. He ports and flows them.
Last edited by pologreen1; 10-21-2017 at 09:08 PM.
#6
pologreen1,
There is no need to Siamese the TPI runners with my build! I do, however, need a machine shop to bend the runners a bit more to lower the ends by one to two inches to help me snug up the top of the intake with the base of the intake. I don't even need to have them cut out a segment of each runner! I just hope I have some clearance so that if I have to, I can take apart the intake to access and replace the EGR valve underneath. Worst case, the custom shop needs to cut out a notch in the cowl to give me an extra half-inch.
There is no need to Siamese the TPI runners with my build! I do, however, need a machine shop to bend the runners a bit more to lower the ends by one to two inches to help me snug up the top of the intake with the base of the intake. I don't even need to have them cut out a segment of each runner! I just hope I have some clearance so that if I have to, I can take apart the intake to access and replace the EGR valve underneath. Worst case, the custom shop needs to cut out a notch in the cowl to give me an extra half-inch.
Last edited by Phoenix'97; 10-21-2017 at 09:17 PM.
#7
Team Owner
Member Since: Oct 2004
Location: altered state
Posts: 81,242
Received 3,043 Likes
on
2,602 Posts
St. Jude Donor '05
Youre going backwards man. You were told the perfect solution in your last thread ie Cubes. Starting to wonder who this really is
#8
I told you, this is a daily driver! I have no business trying to show off like a butt head trying to egg on an illegal street race. I get the max cubes with a 396 stroker kit but as per my requirements to tame that power, I need the TPI intake to do it's thing and cut into the high power band. Further actions on my part are the deliberate reduction in airflow which means I keep my stock 170cc heads, I don't dare change the rocker rollers from 1.5, and I make sure my intake air is as warm and less dense as I can get it! I will make use of custom long tube headers but a blockage will exist with those California catalytic converters! Even Iso-Butanol will have the emission of Nitrogen Oxide which causes breathing problems and the more air sucked in, the more Nitrogen Oxide produced and that is where the overkill Cali Catalytic converter comes in.
Also, during the winter months, I will spend lots of time idling and struggling in deep snow, I need to reduce the power of my motor. The final tune of this motor when constructed will attempt to lean out the air-fuel mixture to a safe level, so even though I lose power, I still have plenty enough torque to have my fun. It is counterintuitive, but I am not building a race car here!
Last edited by Phoenix'97; 10-21-2017 at 10:00 PM.
#9
Zen Vet Master Level VII
#10
Sometimes going backwards instead of forwards will lead you to where you want to go. I still have yet to determine if I can squish the TPI intake an inch, preferably two, in order to get it to fit. It looks like it can be flushed down more to the fuel rails, again this depends on whether or not those runners can be compressed enough to lower the upper portion of the intake.
So, why is everyone so dead set against a TPI intake on a 396 stroker LT1 build? I have my reasons but if you have your opinions, explain to me why it is a bad idea?
So, why is everyone so dead set against a TPI intake on a 396 stroker LT1 build? I have my reasons but if you have your opinions, explain to me why it is a bad idea?
Last edited by Phoenix'97; 10-21-2017 at 10:59 PM.
#11
Race Director
#13
Team Owner
Well, the game plan so far is a 396 stroker using just my mild camshaft currently in the motor. I figure with the stroker kit, why bother with a tow cam, and with the TPI intake I already have my choke off point, to ensure that all that power is restricted and with it the bonus of reducing airflow which will translate into better fuel efficiency when I max out at the higher RPM range.
I told you, this is a daily driver! I have no business trying to show off like a butt head trying to egg on an illegal street race. I get the max cubes with a 396 stroker kit but as per my requirements to tame that power, I need the TPI intake to do it's thing and cut into the high power band. Further actions on my part are the deliberate reduction in airflow which means I keep my stock 170cc heads, I don't dare change the rocker rollers from 1.5, and I make sure my intake air is as warm and less dense as I can get it! I will make use of custom long tube headers but a blockage will exist with those California catalytic converters! Even Iso-Butanol will have the emission of Nitrogen Oxide which causes breathing problems and the more air sucked in, the more Nitrogen Oxide produced and that is where the overkill Cali Catalytic converter comes in.
Also, during the winter months, I will spend lots of time idling and struggling in deep snow, I need to reduce the power of my motor. The final tune of this motor when constructed will attempt to lean out the air-fuel mixture to a safe level, so even though I lose power, I still have plenty enough torque to have my fun. It is counterintuitive, but I am not building a race car here!
I told you, this is a daily driver! I have no business trying to show off like a butt head trying to egg on an illegal street race. I get the max cubes with a 396 stroker kit but as per my requirements to tame that power, I need the TPI intake to do it's thing and cut into the high power band. Further actions on my part are the deliberate reduction in airflow which means I keep my stock 170cc heads, I don't dare change the rocker rollers from 1.5, and I make sure my intake air is as warm and less dense as I can get it! I will make use of custom long tube headers but a blockage will exist with those California catalytic converters! Even Iso-Butanol will have the emission of Nitrogen Oxide which causes breathing problems and the more air sucked in, the more Nitrogen Oxide produced and that is where the overkill Cali Catalytic converter comes in.
Also, during the winter months, I will spend lots of time idling and struggling in deep snow, I need to reduce the power of my motor. The final tune of this motor when constructed will attempt to lean out the air-fuel mixture to a safe level, so even though I lose power, I still have plenty enough torque to have my fun. It is counterintuitive, but I am not building a race car here!
#14
Team Owner
#15
OK. So this is a daily driver. Why again do you need a 396 motor for a daily driver? We get it. No race car. Why do you need to limit the air going in to hamstring the motor? Isn't that what the "gas pedal" is for when it opens the throttle blades? If you want it in snow, you should not have a 396. I'd go for no more than a 5.0L. A 396 will not run well in the snow. So exactly what are you using it for? Doesn't sound like it needs a 396 build even.
#16
The brick wall is real when senior members of this site are giving you bad advice for a future build. Then again, I drive my 5.7L in the snow with non-snow dedicated tires every year. What saves me is the manual stick shift, you couldn't pull it off in an automatic. So, with a light foot and detuned motor with a stroker kit, I probably could handle winter driving, but I need studded deep tread truck/suv tires on the rear.
I though you refused to stroke it, and wanted to keep your lt1 block and put a different intake on it?
I have not seen bad advice only opinions. it's your car build it how you want.
It's obvious to me you are not new to this information from you past posts that show your understanding for how an engine works and what options are out there and that is why you came out of left field with this option.
Lets unTrump this build and tear the wall down. Lets get back to building a lt1 torque monster with a custom intake and cam in it.
I want to see this build happen and see the results for the offspring sake so they know how to build these things in the future.
#17
Race Director
The brick wall is real when senior members of this site are giving you bad advice for a future build. Then again, I drive my 5.7L in the snow with non-snow dedicated tires every year. What saves me is the manual stick shift, you couldn't pull it off in an automatic. So, with a light foot and detuned motor with a stroker kit, I probably could handle winter driving, but I need studded deep tread truck/suv tires on the rear.
Also, during the winter months, I will spend lots of time idling and struggling in deep snow, I need to reduce the power of my motor. The final tune of this motor when constructed will attempt to lean out the air-fuel mixture to a safe level, so even though I lose power, I still have plenty enough torque to have my fun. It is counterintuitive, but I am not building a race car here!
You want more low-end torque (so much so that you don't just describe the tuning of a long-runner intake as helpful, you talk about it like some beneficial noose around the throat of a motor). The reason(s) you are hitting brick walls and/or criticism is because some things aren't well thought out. Or...they are based on misconceptions you may have with tuning, power, AFR, etc...
When I was building a motor, one of the best posters I remember was a guy who told you how it was...or even laughed at stupid thoughts I made. It gave me a clue to learn more, think of better questions/angles and be more intelligent with my posts. Consider that approach rather than complain about senior members.
You're also talking about wanting more torque -- while also saying you want LESS to deal with snow. Can't you see you are talking out both sides of your mouth?
No one "leans out a motor" to safe levels. They set it up for ideal running condition. I'm not in California, but I've done enough learning/tuning to know lean idle isn't the optimal situation (unless you just absolutely have to). I'm pretty sure the sneakiest/best tuners could alter a tune for "inspection" but run it -- the way it NEEDS to be -- the rest of the time. Hot and/or lean conditions create NOx so your comment about leaning didn't make sense to me.
How is having more torque going to help with snow conditions? It won't...you'll just (be able to or) have to upshift to a higher gear to avoid spinning. I suppose you could "detune" it for winter but I wouldn't do that. Tune it for stoich and be done with it. For WOT, you can tune for max torque and avoid USING IT when weather conditions don't permit.
I replied about your downshifting habit/technique in the other thread and you ignored it. Ignoring comments and/or having the ability to support your position/goals/etc...is the basis of any debate. If what you want can't hold up to scrutiny, your knowledge isn't strong enough yet and/or your plan is flawed.
Quit complaining. No one has insulted you. Just as you have an opinion about what you want to do, people who have BUILT cars have their own. And, they may have more experience.
I don't think it sunk in what I was telling you about getting better throttle (off-idle) throttle response with your current intake. 396 stroker torque with the right cam will provide all the tire-burning torque in 1st and 2nd you can use. In fact, you won't be ABLE to avoid tire spin with WOT in those 2 gears (in lower rpms).
If you THINK you need more torque in 3rd, you don't realize what the higher rpms of 2nd can accomplish AND have the HIGHER torque (multliplication) of gearing. That's what your current intake provides without the headaches of the unknown.
I'm CERTAIN everyone's goal is to save you money...especially when you could build the stroker first (with a cam favoring torque), then STILL come back and find/fashion a longtube intake LATER if you think you still want it.
Finally, since I don't see any active cold-air intake for your hood, I question why you couldn't modify/alter the hood if you end up wanting a taller intake. Unless you have some rare collectible (which you haven't indicated), you should be willing to modify the car as necessary. Some "odd" intake is bound to offput any future buyer vs an alteration in the hood...especially if it could ultimately provide a cold air source.
Since you have two years to consider a build, take a breath and think about some of what's been said. Also consider budget planning. Assuming you have limitations (and I'm guessing you do), look at bang-for-the-buck options in a build. If you do, I can tell you right off the top, a custom TPI intake won't fit that criteria. It will cost too much and not deliver enough of what will be happy with.
I already told you I'm one of the few "torque monster" builds here. I started out with a stock TPI and the notion/worry the government might someday expand California emission's law to other states. So, I wanted to keep mine closer (looking) to stock....just in case. Even with all my torque goals, I can assure you I would have tried a stroker/cam/header combo BEFORE considering spending ANY money on the intake (except self-porting). If I lived in California, I definitely would start with modifications not easily seen.
#18
I have made it very clear that this is a daily driver! I have made it very clear that this car will be driven year-round which includes deep snow driving with lots of idle time! This is where my emphasis on fuel economy comes into play, you don't want a car that chugs fuel when idling, especially in the heart of winter if you get stranded somewhere and you need that car's heat every so often to help you survive until help comes, but that is the most extreme situation. So, why do I want to have a stroker kit put into my car then? Well, some senior members read everything I posted about the TPI intake, my unwillingness to go lower with my rear gear ratio, and my other wants for this build and suggested stroking the motor but to use the stock mild camshaft. Okay, I was willing to bite at the idea, but then the additional performance enhancements started to pile on and as you said greggpenn, more power means more air and more fuel. Think about the power I will have with a bare stock LT1 using a 396 stroker kit? Long before I was only asking for a camshaft upgrade, like the Crane 227, with necessary airflow increases, to meet my goal to bump up power production, however, this is where I stumbled upon the TPI intake and figured it would help me gain additional lower end torque and mid-range power while sacrificing high end performance, which I never use for my daily driving. SO, I am now combining both ideas but for the stroker, which will certainly produce more power than the Crane 227 set-up I had in mind, I now need to reduce airflow to balance out fuel consumption and get it on par with that set-up. So now we run into comments by senior members who can't, for the life them, understand my reasoning for what I am doing!
Greggpenn, can't you see I am trying to strike a balance between your proposal and what I really seek for daily driving? My Trans Am is no winter garage queen! I tried initially to keep her garaged during the winter while I drove my then automatic 6-cylinder Firebird in the winter but I was only working low end wage jobs and I couldn't afford it after 2008. So, my crown jewel had to become my one and only and with experience I realize that stick shifts are VASTLY SUPERIOR than automatics in the snow, and I still drive with all wide tires from the WS6 package! There is a benefit to "snow float" with wide tires on our cars! Driving in the winter in my F-body is a horrible challenge, especially on the cheap with nothing but performance all-season tires. That will change when I have the money to get dedicated big and wide snow tires with studs for the rear and skinnies on the front.
Yeah, I forgot there is a marginal increase in NOx if you lean the fuel out. Then again, that is why I plan on using the California catalytic converters. Furthermore, the engine builder and dynotuner will have the final say on just how lean the fuel mixture can get. He can provide me the power curves from before, and after and he can give me the final honest answer on whether or not my set-up is worthwhile. Again, everything rests on whether or not I can shrink the TPI intake down by hopefully 2 inches which will then require the cowl to be notched out by 1/2 an inch to give me the last bit of clearance that I am going to need. Otherwise, the LT1 intake must stay.
This will be my one and only car, I am not even going to consider a winter beater Honda Civic. The downside to driving your spring/summer toy is that you now must adapt your diving to deal with fall/winter! So, if I build this car as a stroker, a stroker she shall be for the winter! Now, don't regard me as some idiot who can't handle driving a V8 in the winter snow, I have nine years under my belt and you can include the difficulty of driving an 18-wheeler in the snow, both heavy loaded and empty! In winter your car burns more fuel from colder ambient temperature on start-up, the extra time spent idling in creeping traffic, and the work the motor must do to propel a car from a dead stop in winter snow! This is why fuel economy with the stroker kit has me worried and this is why my set-up will run warm less dense air using the LT1 coolant heated throttle body to trying to run coolant through the TPI base and then running a coolant line from the TPI base to where the LT1 throttle body hose would have connected to.
I never encountered this comment so I wasn't ignoring it! My downshifting is very safe, very calculated for driving conditions, and it helps to slow my car down when braking is not necessary, and sometimes downshifting slows me down better than gradual braking from higher expressway speeds.
Can you blame me? I am only used to driving a stock LT1 Trans Am! Switching over to a 396 stroker set-up will be quite the adjustment, and it will remind me of the day I stepped up to an LT1 from my former 3800 Series II 6-cylinder. I have respect for V8s and a stroker kit won't be any different. However, after my many years of driving, I realize I don't hardly ever top 5000 RPM when I feel the need to let loose! So why in God's name do I need to reach 5000 RPM and even surpass it with the full power of a 396 stroker for daily driving? Part of what I do requires timing and judgement to avoid blowing past the speed limit of the area, and that average is 45 mph on a straightaway. With a 396 stroker I won't be gunning it that long, so it makes more sense that I use the TPI intake to choke off that power and force me to downshift to get that power back. THIS CONTROLS THE POWER OUTPUT FOR MY BUILD AND DAILY DRIVING CONDITIONS!
I am not doubting you. I am grateful that you have inspired me to step-up to a stroker. Now I can have my powerful motor, but with it, I run into problems. There is more responsibility on my end because now I will have a very powerful street driver and the temptations that come with such power are severe. So, I feel the need to restrict that power, for my sake, for my daily driving needs, and for maintaining a healthy balance of fuel consumption with power. So, can someone with a TPI motor chime in and tell me that this stroker motor is a bad idea or great idea for all the variables being considered?
I have no intentions of selling this car. I doubt very much GM can ever produce a F-body in the shape of my current car that looks just as good as the Corvette. "Boxy curves" for a pony car is what is the rage now, and such cars are hard to differentiate from regular low end street cars, there is no originality or distinction. Furthermore, I am a Firebird guy, unless Chevy adopts the Firebird and offers a cosmetic option to give you a Chevy "Firebird" with Trans Am package, and those next-generation streamlined flip-up lights with a low tech interior with no computer screen in the dash, I won't be interested in the least! Besides, I am trying to build my own car, a Phoenix.
First off, I don't live in California, I live in New York, but our emissions standards are now following California with the exception of visual inspections. Even so, I am sure our mechanics wouldn't obey it as they own cars with long tube headers and some form of "illegal" modifications. I am going above and beyond using Iso-Butanol in my motor in the future, and then to use California catalytic converters with a performance exhaust set-up! If anything, my car will be emissions friendly!
Last thing, you had a TPI? Do you still have that TPI intake or did you convert to an LT1 intake? I am still trying to find a video of a TPI motor reving past it's "choke" point to understand why it is so bad? A former GM engineer on LS1 tech commented about the TPI intake as a means for meeting the emissions and fuel economy mandates of the 1980's. This is only more reason for why this conversion on my motor for my build is such a good idea. My notion of "performance" is vastly different from everyone else's.
Like I said in the other thread, you have some learning to do with regard to fuel injection. And...there are more contradictions for you to consider.
You want more low-end torque (so much so that you don't just describe the tuning of a long-runner intake as helpful, you talk about it like some beneficial noose around the throat of a motor). The reason(s) you are hitting brick walls and/or criticism is because some things aren't well thought out. Or...they are based on misconceptions you may have with tuning, power, AFR, etc...
You're also talking about wanting more torque -- while also saying you want LESS to deal with snow. Can't you see you are talking out both sides of your mouth?
You want more low-end torque (so much so that you don't just describe the tuning of a long-runner intake as helpful, you talk about it like some beneficial noose around the throat of a motor). The reason(s) you are hitting brick walls and/or criticism is because some things aren't well thought out. Or...they are based on misconceptions you may have with tuning, power, AFR, etc...
You're also talking about wanting more torque -- while also saying you want LESS to deal with snow. Can't you see you are talking out both sides of your mouth?
No one "leans out a motor" to safe levels. They set it up for ideal running condition. I'm not in California, but I've done enough learning/tuning to know lean idle isn't the optimal situation (unless you just absolutely have to). I'm pretty sure the sneakiest/best tuners could alter a tune for "inspection" but run it -- the way it NEEDS to be -- the rest of the time. Hot and/or lean conditions create NOx so your comment about leaning didn't make sense to me.
How is having more torque going to help with snow conditions? It won't...you'll just (be able to or) have to upshift to a higher gear to avoid spinning. I suppose you could "detune" it for winter but I wouldn't do that. Tune it for stoich and be done with it. For WOT, you can tune for max torque and avoid USING IT when weather conditions don't permit.
I replied about your downshifting habit/technique in the other thread and you ignored it. Ignoring comments and/or having the ability to support your position/goals/etc...is the basis of any debate. If what you want can't hold up to scrutiny, your knowledge isn't strong enough yet and/or your plan is flawed.
Because the right cam and stroker will provide ALL the torque you need. This notion of choking off higher rpms to save gas makes it sound like you (otherwise) won't have the self-control to let off in the higher rpms where you don't want/need power AND where you don't want to burn more fuel?
Finally, since I don't see any active cold-air intake for your hood, I question why you couldn't modify/alter the hood if you end up wanting a taller intake. Unless you have some rare collectible (which you haven't indicated), you should be willing to modify the car as necessary. Some "odd" intake is bound to offput any future buyer vs an alteration in the hood...especially if it could ultimately provide a cold air source.
Since you have two years to consider a build, take a breath and think about some of what's been said. Also consider budget planning. Assuming you have limitations (and I'm guessing you do), look at bang-for-the-buck options in a build. If you do, I can tell you right off the top, a custom TPI intake won't fit that criteria. It will cost too much and not deliver enough of what will be happy with.
I already told you I'm one of the few "torque monster" builds here. I started out with a stock TPI and the notion/worry the government might someday expand California emission's law to other states. So, I wanted to keep mine closer (looking) to stock....just in case. Even with all my torque goals, I can assure you I would have tried a stroker/cam/header combo BEFORE considering spending ANY money on the intake (except self-porting). If I lived in California, I definitely would start with modifications not easily seen.
I already told you I'm one of the few "torque monster" builds here. I started out with a stock TPI and the notion/worry the government might someday expand California emission's law to other states. So, I wanted to keep mine closer (looking) to stock....just in case. Even with all my torque goals, I can assure you I would have tried a stroker/cam/header combo BEFORE considering spending ANY money on the intake (except self-porting). If I lived in California, I definitely would start with modifications not easily seen.
Last thing, you had a TPI? Do you still have that TPI intake or did you convert to an LT1 intake? I am still trying to find a video of a TPI motor reving past it's "choke" point to understand why it is so bad? A former GM engineer on LS1 tech commented about the TPI intake as a means for meeting the emissions and fuel economy mandates of the 1980's. This is only more reason for why this conversion on my motor for my build is such a good idea. My notion of "performance" is vastly different from everyone else's.
#19
Team Owner
Member Since: Oct 2004
Location: altered state
Posts: 81,242
Received 3,043 Likes
on
2,602 Posts
St. Jude Donor '05
#20
You can buy an L98 motor (entire engine) fairly cheap and much easier with a whole car wrapped around it.
Lot's of guys love the torque it makes to about 4,000RPM; 1985 technology was the best for some......
However, someone with much better advise than you got here from the knowledgeable senior members can tell you how to shorten the runners from the L98 intake to make it fit under your custom hood; and get that backside distributor hole filled in and make it fit on your later model LT1; eventually make you a happy member.
Someone here certainly has good advise on taking an LT1 F-body; upgrading to the earlier technology and grafting it on while making sure it fits under their LS1 hood; come on guys!!
Keep em coming! These threads are entertaining!
Lot's of guys love the torque it makes to about 4,000RPM; 1985 technology was the best for some......
However, someone with much better advise than you got here from the knowledgeable senior members can tell you how to shorten the runners from the L98 intake to make it fit under your custom hood; and get that backside distributor hole filled in and make it fit on your later model LT1; eventually make you a happy member.
Someone here certainly has good advise on taking an LT1 F-body; upgrading to the earlier technology and grafting it on while making sure it fits under their LS1 hood; come on guys!!
Keep em coming! These threads are entertaining!
Last edited by 856SPEED; 10-22-2017 at 02:07 PM.