How would an aftermarket LT1 intake with long runners effect the performance?!
10-11-2017, 09:16 PM
#21
Yes the TPI intake is "old technology" but I now have an "old motor" that has been replaced by the LS family and even the new LT family. For lack of being a rich guy, and having a car in dire need of tear down restoration and modification, I am best salvaging the motor and transmission I have but finding out a way to make it more "fun" to drive in terms of what I feel is "fun".
10-11-2017, 09:19 PM
#22
I am not the first person, nor shall I be the last, to inquire about a bolt-on TPI style intake for the LT1 motor. My car is a daily driver and right now I am soul searching with what I want to do with the motor. I don't need a suped up race car with 4.10 rear gears and an aggressive camshaft with ported heads and upgraded valvetrain and the whole nine yards! I do, however, want more low to mid-range torque that I can feel immediately and that gives me an enjoyable daily driver that is fun to launch from green lights or aggressively accelerate where safe to do so in the city. I have no intention of butchering my motor to try to fit and fabricate a stock L98 TPI intake. I do, however, intend to seek out a company that can make this custom intake that is a genuine bolt-on with all necessary sensor attachments and emissions controls. However, I need expert advice on whether or not a dedicated LT1 intake with long runners will be detrimental to the motor or not. I assume the CPU can handle the adjustments with the intake and as far as driving below 5000 RPM, there shouldn't be any problems but again this is an LT1 and not an L98 with a different fuel injection design. So, am I correct in my logic that this intake will give me the low to mid-range "umpf" that I am seeking, or do I have it all butt backwards?!
Thank you for your comment and answering my question. Yes, I understand that I could be paying a pretty sum to have a legit and reputable business produce a possible one-off TPI style intake that is a direct bolt-on for the LT1 which is also low enough to clear the hood and fit any other LT1 vehicle. Then again, I stand to spend lots of money doing the other thing by focusing on increased air flow and more power production on the top end, and with the rear gear. I can always get a price quote and decide if I am willing to take that step. Who knows, this could provide a new product for the LT1 community if anyone is interested. For the driving I do which is quite tame and necessary for the unpredictable and dangerous bumper-to-bumper city driving, I really can't go all that fast so why put in a lower rear gear when my stock gear is really perfect for the driving conditions. This is why I want every bit of low end to mid-range torque that I can get, to intentionally optimize my LT1 for this power band. I may not be quick at the track but I can have my fun at the green lights.
Now I am getting overwhelmed with the diverse opinions! I have thought about a motor swap, especially the 2014 LT1 or even the 2015 LT4. The problem is, IT WILL BE EXPENSIVE to not only buy a turn-key crate engine but the transmission to accompany it, the ECM that my car will need, the modifications required to get it to fit my car, and even to wire everything up to my stock gauge clusters. Those thousands of dollars on a mere intake, and a custom grind camshaft are far more economical by comparison! Despite the LS family of motors being the "superior" motor to get, I have grown attached to my LT1. I love the way it sounds with the Magnaflow exhaust I have on it and frankly speaking I still feel that there is more I can do to improve upon this motor. It may never compare to the newest LS or even the next gen LT motors, but my goal is to produce a torque monster for daily driving, something that will allow me to use my factory rear gear ratio for better economy and yet have enough low end grunt to throw me back in my seat during aggressive acceleration from a stop.
Now, I am not expecting to make breakneck low end to mid-range torque from this intake alone. I realize I will need the necessary custom grind camshaft to do this. However, I won't need to go into mild porting my heads or concerning myself with more air flow from my motor so this build should be comparable to what I would spend to make myself a decent track car. Again, for any company to take on this task of developing the right long runner intake for my car, some research and development is going to be required. However, this is where I am hoping that the company which produced the FIRST aftermarket TPI intake can also make a bolt-on version for the LT1. If this can not be done, then I may be crazy enough to find a company to fabricate me a cross-ram stack EFT throttle body intake which will have the necessary plumbing to my factory air box and which must have the same emissions control attachments and PCV system as the LT1 intake. There was one company that expressed interest a way back when I was asking around about such an intake before. The cross-ram EFI throttle body intake produces instant low end to mid-range power but starts to fall behind when compared to the LS intake at high RPM. Even so, such an intake is ideal for my build.
Now, I am not expecting to make breakneck low end to mid-range torque from this intake alone. I realize I will need the necessary custom grind camshaft to do this. However, I won't need to go into mild porting my heads or concerning myself with more air flow from my motor so this build should be comparable to what I would spend to make myself a decent track car. Again, for any company to take on this task of developing the right long runner intake for my car, some research and development is going to be required. However, this is where I am hoping that the company which produced the FIRST aftermarket TPI intake can also make a bolt-on version for the LT1. If this can not be done, then I may be crazy enough to find a company to fabricate me a cross-ram stack EFT throttle body intake which will have the necessary plumbing to my factory air box and which must have the same emissions control attachments and PCV system as the LT1 intake. There was one company that expressed interest a way back when I was asking around about such an intake before. The cross-ram EFI throttle body intake produces instant low end to mid-range power but starts to fall behind when compared to the LS intake at high RPM. Even so, such an intake is ideal for my build.
So if you are just new to cars or something I don't know but here are the main principals to building an engine to your style.
Extreme intake runner lengths create extreme peaks and limits.
Do you know the runner length of the TPI torque monster compared to the LT1 intake?
Do you see the nice torque curve considering all the other options for the motor?
A crosssram has never been the greatest intake. EVER. 60's and up people still tinker in hopes and come up short.
Now if you like a crossram that much user c409 here has made some old ones EFI and maybe he can make you an LT1 version or have it made.
So far other than custom one off purpose built intakes to fit the exact desires and needs of cam and heads etc the LS platform just works.
You can look at the lt1 2 ways. It is either about as good as it can get from the factory so build off it, or it really has it's limits of options compared to gen1 SBC.
If it's not trolling here, I advise you to ride in some different cars. You have some major misconceptions and exceptions f what performance parts do to cars.
You say you are not expecting break neck, but you don't understand you will not likely feel much difference at all except a wallet 2k light for a custom intake, that compared to an lt1 will either be built to rev to the moon and your motor can't or will make all low end barely more than lt1 and be out of breath as the other honda civic blows by you.
Plain and simple your looking in the wrong place to improve your performance and taste.
Post your intake fabricator if you do this and keep us posted.
If I were you and had your hard on for mid range I'd get a IDF crossram intake fabbed to fit the lt1. Then the heads and cam and exhaust become the limits. Oh yeah and your gears will be wrong too if most likely.
It's been done on l98. I wanted it, nobody would tune it. Ended up half car half fuel injection.
The following 2 users liked this post by pologreen1:
6SpeedTA95 (10-11-2017),
Phoenix'97 (10-11-2017)
10-11-2017, 09:22 PM
#23
Team Owner
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St. Jude Donor '05
call ken at FIRST maybe he can find a way to make one work for your car
with a small cam and just some porting your car will really wake up. Know its not what you want but as long as someone doesnt overdo it youll like the results. Too many are after some big # and the head gets too big in the meantime thats not what you really want. Just a thought.
with a small cam and just some porting your car will really wake up. Know its not what you want but as long as someone doesnt overdo it youll like the results. Too many are after some big # and the head gets too big in the meantime thats not what you really want. Just a thought.
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Phoenix'97 (10-11-2017)
10-11-2017, 09:24 PM
#24
I do not have a C5 and the motor in my car is definitely the LT1. There is a reason I am here, for better opinions and technical know-how instead of trash talking posts about how "dumb" my planned build is. Not everyone wants to make their car a certified strip race car. I just want more go power from stops without killing my factory rated fuel economy, performance I can feel during a tame aggressive launch from a green light for some thrills.
Yes the TPI intake is "old technology" but I now have an "old motor" that has been replaced by the LS family and even the new LT family. For lack of being a rich guy, and having a car in dire need of tear down restoration and modification, I am best salvaging the motor and transmission I have but finding out a way to make it more "fun" to drive in terms of what I feel is "fun".
Yes the TPI intake is "old technology" but I now have an "old motor" that has been replaced by the LS family and even the new LT family. For lack of being a rich guy, and having a car in dire need of tear down restoration and modification, I am best salvaging the motor and transmission I have but finding out a way to make it more "fun" to drive in terms of what I feel is "fun".
The LT4 and LT1 physically look the same other than some minor cosmetic badging changes.
10-11-2017, 09:28 PM
#25
This project won't be happening anytime soon. I am just seeing what options I have, seeing what others think of my proposals, and trying to figure what I will be able to do and how best to achieve the performance that I am seeking.
Yes, I am naive about cars and what I know is what I have read. I do know that I don't want to build a track car, I think I am trying to build a performance daily driver using the knowledge that I have to try to get there, wrong as it is or not. I just feel that my LT1 is lacking in torque from idle to my limit of 5000 RPM. So, again, I need to figure out what I can do to build this motor the right way and achieve my goal.
Yes, I am naive about cars and what I know is what I have read. I do know that I don't want to build a track car, I think I am trying to build a performance daily driver using the knowledge that I have to try to get there, wrong as it is or not. I just feel that my LT1 is lacking in torque from idle to my limit of 5000 RPM. So, again, I need to figure out what I can do to build this motor the right way and achieve my goal.
10-11-2017, 09:31 PM
#26
Please check the year of your car again. 1997 they no longer put the LT1 in the Corvette. They still put it in the F Bodies but not the Corvette. The last year for the Corvette was 1996, but only in automatic trim. 6 Speed cars in 1996 were LT4 cars. Any chance you can post a picture of your car and a picture of the engine for us? That might help.
The LT4 and LT1 physically look the same other than some minor cosmetic badging changes.
The LT4 and LT1 physically look the same other than some minor cosmetic badging changes.
10-11-2017, 09:31 PM
#27
Also, I'll add, I have extensive experience with TPI cars and LT1 cars and LSx cars. I've owned all of the above...and have had extensive experience with various mods on various cars through local car groups and friends over the years.
I like the L98 because of its nostalgia and it looks super cool. But for drivability INCLUDING torque I prefer the LT1. Throttle response on the L98 I always felt was impressive, that was already mentioned inn this thread, but beyond just barely tipping into the throttle at MOST engine speeds the LT1 is a better engine. It breathes better across the rev range EVEN down low. There's a brief period where the L98 makes more power but its pretty narrow. Additionally there are MANY options for making an LT1 erase any positives an L98 had in terms of performance.
From someone who has owned and modded numerous cars and has been around this hobby for a long time now, I would advise against a custom intake. Finding something off the shelf thats different or working with what you have makes the most sense for the goals you've expressed.
If you just want something super different, again that's a an altogether different agenda then drivability and low/midrange performance. I know you said you don't like revving your motor much and if that's the case buy a cam that suits the profile for the LT1 that you have.
But try to get us some pics of the car perhaps we can help with the confusion.
I like the L98 because of its nostalgia and it looks super cool. But for drivability INCLUDING torque I prefer the LT1. Throttle response on the L98 I always felt was impressive, that was already mentioned inn this thread, but beyond just barely tipping into the throttle at MOST engine speeds the LT1 is a better engine. It breathes better across the rev range EVEN down low. There's a brief period where the L98 makes more power but its pretty narrow. Additionally there are MANY options for making an LT1 erase any positives an L98 had in terms of performance.
From someone who has owned and modded numerous cars and has been around this hobby for a long time now, I would advise against a custom intake. Finding something off the shelf thats different or working with what you have makes the most sense for the goals you've expressed.
If you just want something super different, again that's a an altogether different agenda then drivability and low/midrange performance. I know you said you don't like revving your motor much and if that's the case buy a cam that suits the profile for the LT1 that you have.
But try to get us some pics of the car perhaps we can help with the confusion.
10-11-2017, 09:33 PM
#28
I registered this name more than ten years ago when I had an LT1 Trans Am. I no longer have that vehicle and am hoping to jump back into the C4 market soon.
10-11-2017, 09:42 PM
#29
Sure it may be an LT1 but then its not a 1997. If it's a 1996 and a 6MT then that means you have an LT4. I can't recall all the differences between the LT4 and LT1 in terms of power off the top of my head. I do remember thinking driving a couple of them that they felt a touch down on the low-end vs the LT1 but made up for it above 4000 rpm. If you have an LT4 car that could explain why you may feel a bit more of a difference below 4000rpm? I'm shooting in the dark here...
I registered this name more than ten years ago when I had an LT1 Trans Am. I no longer have that vehicle and am hoping to jump back into the C4 market soon.
I registered this name more than ten years ago when I had an LT1 Trans Am. I no longer have that vehicle and am hoping to jump back into the C4 market soon.
10-11-2017, 09:48 PM
#31
I already have the skip shift disabled. It was driving me nuts and I fail to see how it is an "improvement" when it sounds like you are lugging and grinding the motor in fourth at 30 mph!
10-11-2017, 10:04 PM
#32
Team Owner
Pro Mechanic
Where do you live?
I HIGHLY suggest that you use this forum to find an owner, local to you who has an LT1 w/gears or a stroker/383 LT1...go drive it. Then you'll know that you can save several thousands on a custom intake that won't do what several hundred on gears or stroker kit will.
I HIGHLY suggest that you use this forum to find an owner, local to you who has an LT1 w/gears or a stroker/383 LT1...go drive it. Then you'll know that you can save several thousands on a custom intake that won't do what several hundred on gears or stroker kit will.
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6SpeedTA95 (10-11-2017)
10-11-2017, 10:06 PM
#33
Where do you live?
I HIGHLY suggest that you use this forum to find an owner, local to you who has an LT1 w/gears or a stroker/383 LT1...go drive it. Then you'll know that you can save several thousands on a custom intake that won't do what several hundred on gears or stroker kit will.
I HIGHLY suggest that you use this forum to find an owner, local to you who has an LT1 w/gears or a stroker/383 LT1...go drive it. Then you'll know that you can save several thousands on a custom intake that won't do what several hundred on gears or stroker kit will.
10-11-2017, 11:54 PM
#34
This project won't be happening anytime soon. I am just seeing what options I have, seeing what others think of my proposals, and trying to figure what I will be able to do and how best to achieve the performance that I am seeking.
Yes, I am naive about cars and what I know is what I have read. I do know that I don't want to build a track car, I think I am trying to build a performance daily driver using the knowledge that I have to try to get there, wrong as it is or not. I just feel that my LT1 is lacking in torque from idle to my limit of 5000 RPM. So, again, I need to figure out what I can do to build this motor the right way and achieve my goal.
Yes, I am naive about cars and what I know is what I have read. I do know that I don't want to build a track car, I think I am trying to build a performance daily driver using the knowledge that I have to try to get there, wrong as it is or not. I just feel that my LT1 is lacking in torque from idle to my limit of 5000 RPM. So, again, I need to figure out what I can do to build this motor the right way and achieve my goal.
What gears?
What trans?
Coupe or vert?
I ask, because of gear ratios that matter even stock. Also idle to limit is 6k. It might not be healthy from what you describe.
Also you might want to check compression etc or race someone at a track, sounds like a beat dog from what you describe.
Unless you have a real hunger for power and don't know it...
Now for the race car talk you keep mentioning... Gears and mods don't mean race cars, it means performance improvement.
People these last few generations like to pretend they have race cars. They don't. They just race them or just throw money at them.
Nothing wrong with mods, that is what you want to do too.
Mods make better performance not race cars.
many 10s of thousands of dollars make race cars. Any schmuck can throw parts at a regular car and pretend. Any schmuck with cash can run 11's these days. Those are not race cars.
Now for the mods, it's not like the old days with a 3speed auto having 4.56 gears in them and a quadrapuke or whatever on it people were driving around to be cool.
You have a geared trans, EFI, computer tunability, and should be able to be very streetable with mods.
Now what is your goal?
hp?
tq? (not going to make a big difference on a 350)
Stop light times / drag times?
Options
1. heads, cam, intake porting, rr's, headers, gears,
2. n20, s/c, turbo
3. Drive it or sell it
4.post pics of ground breaking technology intake that came 20 years too late
10-12-2017, 12:21 AM
#35
Team Owner
Pro Mechanic
Although I don't advocate going this route (I advocate a stroker), HERE is a cheapy mid-length runner intake.
10-12-2017, 09:50 AM
#36
Where do you live?
I HIGHLY suggest that you use this forum to find an owner, local to you who has an LT1 w/gears or a stroker/383 LT1...go drive it. Then you'll know that you can save several thousands on a custom intake that won't do what several hundred on gears or stroker kit will.
I HIGHLY suggest that you use this forum to find an owner, local to you who has an LT1 w/gears or a stroker/383 LT1...go drive it. Then you'll know that you can save several thousands on a custom intake that won't do what several hundred on gears or stroker kit will.
10-12-2017, 10:04 AM
#37
How long have you owned it?
What gears?
What trans?
Coupe or vert?
I ask, because of gear ratios that matter even stock. Also idle to limit is 6k. It might not be healthy from what you describe.
Also you might want to check compression etc or race someone at a track, sounds like a beat dog from what you describe.
Unless you have a real hunger for power and don't know it...
Now for the race car talk you keep mentioning... Gears and mods don't mean race cars, it means performance improvement.
People these last few generations like to pretend they have race cars. They don't. They just race them or just throw money at them.
Nothing wrong with mods, that is what you want to do too.
Mods make better performance not race cars.
many 10s of thousands of dollars make race cars. Any schmuck can throw parts at a regular car and pretend. Any schmuck with cash can run 11's these days. Those are not race cars.
Now for the mods, it's not like the old days with a 3speed auto having 4.56 gears in them and a quadrapuke or whatever on it people were driving around to be cool.
You have a geared trans, EFI, computer tunability, and should be able to be very streetable with mods.
Now what is your goal?
hp?
tq? (not going to make a big difference on a 350)
Stop light times / drag times?
Options
1. heads, cam, intake porting, rr's, headers, gears,
2. n20, s/c, turbo
3. Drive it or sell it
4.post pics of ground breaking technology intake that came 20 years too late
What gears?
What trans?
Coupe or vert?
I ask, because of gear ratios that matter even stock. Also idle to limit is 6k. It might not be healthy from what you describe.
Also you might want to check compression etc or race someone at a track, sounds like a beat dog from what you describe.
Unless you have a real hunger for power and don't know it...
Now for the race car talk you keep mentioning... Gears and mods don't mean race cars, it means performance improvement.
People these last few generations like to pretend they have race cars. They don't. They just race them or just throw money at them.
Nothing wrong with mods, that is what you want to do too.
Mods make better performance not race cars.
many 10s of thousands of dollars make race cars. Any schmuck can throw parts at a regular car and pretend. Any schmuck with cash can run 11's these days. Those are not race cars.
Now for the mods, it's not like the old days with a 3speed auto having 4.56 gears in them and a quadrapuke or whatever on it people were driving around to be cool.
You have a geared trans, EFI, computer tunability, and should be able to be very streetable with mods.
Now what is your goal?
hp?
tq? (not going to make a big difference on a 350)
Stop light times / drag times?
Options
1. heads, cam, intake porting, rr's, headers, gears,
2. n20, s/c, turbo
3. Drive it or sell it
4.post pics of ground breaking technology intake that came 20 years too late
I have owned my car now for 10-solid years.
Rear Gear Ratio: 3.42:1 stock
Transmission: 6 speed manual
Coupe
First off, how is it not healthy to produce power from idle to 5000 RPM? This is well below the computer RPM limit and furthermore lower RPM won't wear down the valve-train with constant high rev driving.
Second, I don't have the money to oblige the notion of racing in my car with a 20 year old transmission that is showing signs that it needs to be replaced along with a recent replacement of my stock rear gears. My girl is a daily driver and if I do take her to the track in the future, she is going to run nearly stock with the modifications I have outlined.
My goal? I care not for horsepower because I don't do a lot of high rev driving which is where HP numbers are produced. Since my daily driving is within the operating range of idle to 5000 RPM, I best focus on the torque production of my car at this power band.
Modifications? Again, I have a nagging feeling that I should keep persistent in the long runner intake because it is optimized for the power band that I am focused on, and per my research, long runners on an intake improve torque production despite suffering from lack of air flow at higher RPM usually beyond 4500 RPM but if I limit myself to 5000 RPM anyways for my daily driving, this is no major loss! So, I am focused on the intake, I need a custom grind camshaft emphasizing torque production from idle to 5000 RPM, and in some respects this would also qualify as a "fuel economy cam" which is all the more better for my notion of "street performance". If the heads could benefit from mild porting, then sure, lets tack that on! All that is left is the exhaust which my motor is currently using aftermarket short tube hooker headers with emissions hook-ups. The short headers are supposed to be good for low end torque production and while I do notice a slight umpf after their install, I want more torque umpf to get me going from a stop.
I have no intention of selling my car, I am too in love with the styling and frankly, I can improve upon her with all around LED lighting both exterior and interior.
Last edited by Phoenix'97; 10-12-2017 at 10:09 AM.
10-12-2017, 10:08 AM
#38
Safety Car
https://www.nookandtranny.com/Info_LT1.html
http://www.hpsalvage.com/lt1.htm
1997 Corvettes did not have an LT1 engine. Camaros/Firebirds yes, Corvettes, no. From the factory, a 1997 Corvette had an LS engine. Putting a LT1 in a C5 would entail as much changes as putting a LS based engine in a C4. Changes to the motor mounts, C-beam, torque tube, transaxle etc etc etc.
http://www.hpsalvage.com/lt1.htm
1997 Corvettes did not have an LT1 engine. Camaros/Firebirds yes, Corvettes, no. From the factory, a 1997 Corvette had an LS engine. Putting a LT1 in a C5 would entail as much changes as putting a LS based engine in a C4. Changes to the motor mounts, C-beam, torque tube, transaxle etc etc etc.
10-12-2017, 10:25 AM
#39
Team Owner
Pro Mechanic
Yes, I want more torque but this is within the parameters of keeping this car within it's fuel economy rating and keeping it emissions compliant for daily driving. I really don't think I am asking for the world in trying to maximize torque production from idle to as far as 5000 RPM.
You hadn't mentioned fuel economy as a criteria earlier (or I hadn't seen it) so that is new news. But I would not hesitate on a stroker (or gears) for a second, if I had your goals. Look at the power curves graph I posted earlier; what is the long runner intake getting you? 10 lbs of tq...at most. For thousands?
What's a stroker kit going to get you? 30 lbs? (way more if you add a little cam) For hundreds. So which is the more sensible direction?
I agree. Spending what you will have to spend for a long runner intake to gain 10 or so lobs is not really "being real"...IMO. Especially when:
1. You can spend way less to get way more gain in tq
2. I've already posted a graph showing how the short runner LT1 makes more low RPM tq than the LTR, L98. The LTR intake only works good in the narrow RPM range for which it's tuned; in the L98's case, the MID RANGE (not low end) of ~3200 RPM. At 3200 RPM and in the looks department, it's a winner. Everywhere else, it's a loser.
Last edited by Tom400CFI; 10-13-2017 at 11:16 AM.
10-12-2017, 10:35 AM
#40
Team Owner
Pro Mechanic
I have a nagging feeling that I should keep persistent in the long runner intake because it is optimized for the power band that I am focused on, and per my research, long runners on an intake improve torque production despite suffering from lack of air flow at higher RPM usually beyond 4500 RPM but if I limit myself to 5000 RPM anyways for my daily driving, this is no major loss
Last edited by Tom400CFI; 10-12-2017 at 10:37 AM.