Can someone explain the nitty gritty pros and cons of each? I assume the LT1 will flow a little better and probably has a much wider powerband, but really how much of a power difference is there?

I'm asking because I was planning on the Lt1 conversion, but a friend of mine has decided to give me a deal on his AS&M runners ($200). I figure I can get the runners and port my plenum and stock base, and then if I decide to, I can upgrade the heads and cam at a much later date. But for now keep it pretty stock with exhaust mods, suspension, and maybe a TC.

The only real advantage I can see right now with the LTR setup(besides price) is that it should be more computer friendly, since it'll still have EGR, and it won't really need a custom chip burned (although it would still be nice.)

I guess the install would probably be a lot easier with the LTR setup too.

Decisions decisions, please help. Thanks again everyone. -Brian

 

Advantages of a LT1:
- capable of breathing up to 7000+rpm
- One piece manifold

Disadvantges of a LT1
-Not emissions legal
-Lost of a little torque on low-end


Advantages of TPI
- Unbeatable torque
- Emissions legal

Disadvantages of TPI
- Not capable of supporting High RPMs and high horsepower levels

I'm sure I forgot alot of stuff but its all that I remember off hand.

 

Go with the LT1 and don't look back, you'll be much better off. Get good heads and a good cam to match when money allows. If you want to stay on the "mild" side, get an LT4 HOT cam. If you want to really fly, get the Comp Cams 306. Either way, you should find someone who can burn PROM's or learn to make your own.

 

1. With the gear ratio you have and stock heads and/or stock cam; your car will NOT be faster with an LT1 intake.

2. Like you said, the LT1 allows room for growth. When you get heads and a cam the gains will come in leaps and bounds.

3. So, you have to evaluate where you want your car to be in a year or two.

 

Oh, I would think you could get by with the stock chip. I ran my car with a stock chip and I ran fine. I even have good heads and a little bit bigger cam. Not to say it was ideal tuning, though.

 

Really? No increase at all with an LT1 intake???

 

The stealth ram is supposed to add like 60hp at top end to a motor with stock heads/cam. Why wouldn't the LT1 intake perform atleast close to that?

 

Go tell that to glenn

 

You probably will get HP. I did not say you wouldn't. I said I do not believe your car will get faster given your current gearing, heads etc. Maybe throw on an LT1 and a set of 3.73 and you will definately see a gain.

Yes, you will lose a bit down low. There is no denying that.

 

I should correct myself and say that the LT1 moves the peak torque at a higher rpm than the tpi. I think i got it right now.

 

More HP + Wider powerband = No increase in acceleration?????

I'm not saying you're wrong, I just don't understand why. I realize stock gears, cam, and heads are far from optimal but still...

 

That stealth ram dyno was a freak of nature.No one that has the stealth ram has yet to dyno 60hp its I have it and it does move the power band higher up but NO 60hp.If I cant pull any good numbers this year next year Im trying the LT1.

 

Wow, and here i thought LT1s made peak torque @ 2400rpm, 800rpm LOWER than TPI cars.

Think of TPI as pitching a tent pole in the powerband in the 32-3500rpm range. More torque there. Less everwhere else. Seems almost like long curved runners are a flow liability on the low end due to lack of velocity stalling the air charge, as they are off the top where they also choke the airflow. I know i have lost no low end torque/driveability (as experienced with the converter clutch locked since i have a converter) since swapping to a siamesed base. So much for the idea that TPI is some kind of boon to driveability. Then again, coming from a carbed background, i knew that was BS to begin with...

 

thanks for for clarifying that up for me Ed. I had the right idea but just no techincal details.

 

Ok, maybe the LT1 peaks sooner. I did the swap. Whatever it is the TPI had more torque hands down. It would spin the tires violently from a roll. The LT1 will do this but with less ferocity. I am not truly sure about the LT1 having a larger power band, just higher. Look, you take a stock 240 HP 1990 L98 camaro. I would assume it runs the 1/4 at 14.5 with 2.77 or 3.23 gears. Now, take a 1994 275 HP camaro Lt1 auto and place 2.77 gears in it; I would assume very similar et even though a 35 hp difference, stiffer chassis, etc. Start modding and the performance gains will become clear.

It is sort of like the guys that take a stock L98 an stick a 600 holley on top hoping to rule the streets They end up with the same torque (higher rpm) more HP ( higher rpm) and little to no improvement over the L98 quarter mile performance.

 

Nope,, it's "marketing"
This was cut from a previous post:
--------------------------------------------------------
Here's the chassis dyno results!
Car is an automatic 1992 5.7L Camaro. Car is bone stock except cat back.

We added the stealthram and a Holley billet 58mm throttle body. That was the only changes. I don't think the throttle body makes much of a differenece at this power level.

This data is for 3rd gear RWHP on a dynojet.

RPM Stock HP Stealthram HP Diff
3400 190 175 -15
3600 200 188 -12
3800 209 198 -11
4000 210 204 -6
4200 212 210 -2
4400 213 223 +10
4600 214 234 +20
4800 210 240 +30
5000 198 239 +41
5100 184 238 +54
5200 174 237 +63
--------------------------------------------------

See,,, it added 63 horses at 5200 rpm. In reality it added 26 peak vs peak and lost 23 lb/ft torque at 3400 rpm (doing the math). I'm assuming this was a stone stock TPI with an unported plenum as well.

 

So there's no point in switching to the LT1 intake unless you're going to change heads &/or cam at the same time?

 

Swapping to the LT1 intake on a relatively mild stock car probably won't help ET out all that much. Putting it on a car with at least a nice converter (or a 5 spd) though and the gains would probably be pretty significant. In the grand scheme of things, HP is what really moves the car, and actually having a useable powerband out to 5k or so is a lot more useful than torque at 3200rpms.

 

Well, I guess my choices are between:

LT1 intake
Pro Lightning heads
LT4 hotcam, CC305, or custom grind

Ported Plenum
AS&M runners
SCDK base
Vortech heads
ZZ-4 or LPE cam

Ported plenum
SLP or AS&M runners
Ported stock base
Heads- Pro Lightning?
Cam?

I think I'll keep doing research before I jump into anything. I definately don't have the resources to do intake/heads/cam all at the same time. Maybe for now I'll get some Hooker Long Tubes...

 

I have avoided this post because I don't feel like fighting. But, I can tell you from personal experience that my car is faster with a Miniram (and mildly ported Aluminum heads). But I am running the stock cam. It has more torque down below and a ton more up top. Better car overall.

One key thing I've done is worked very extensively on my tuning. My car was very well tuned with the L98 intake and fairly well tuned right now (though it is now put to bed for the season).

The combo you chose will have a lot to do with "where the power comes on". A bigger cam is going to make a LOT more power at the top and YES I will loose some torque. But, I would have lost torque with the TPI setup and a bigger cam too.

Your question is to do the intake by itself, and I can say from experience that you will notice a better top end for sure. And if you do a GOOD eprom, you will probably improve your et's (though not much ... but now you have the potential to take advantage of future mods). I will say that your engine will be more fun to drive when you discover there IS some more power past 4,500 rpm. My car now makes good power past 5,500 rpm - not just "revving the motor" like the TPI did.

TPI cars DO need to have all three (intake/heads/cam) addressed before serious power will be obtained. And as a stand-alone mod, doing just ONE of the three doesn't really do much either.

YES, it is more prudent to do all three at once, but if you DO plan to do future mods, the ONE thing about the LT1 intake is that it sure will be a lot easier to get the intake off again in the future.

I also recommend you start learning how to burn eproms if you want to get the optimum power out of your combo. Don't make the mistake a lot of guys do...do a TON of mods first and THEN decide to learn about eprom burning. It is a lot harder then, because you don't even have a "base" to work with. You are more concerned on just having the car run "half-assed" rather than "optimal".

 

Thanks Glenn, I think that's what I needed to hear.

Thanks for all the comments everyone.

If you've got any more, go ahead and post em.

Thanks again

-Brian