Ok Ive got a few question guys and Im hoping yall can help me out here...First of all...Which engine would be easier to install the 350TPI or the 350LT1? Second, which of the two engines would I be able to get more HP out of? Third, Which one is better on the miles per gallon? Oh, and I think Im gonna keep both in FI mode. Thanks alot guys!!!!!

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1992 Camaro RS 3.1L
T5 Manual 5 speed
Open Air Intake
Z-28 Exhaust

 

Well my guess is the 350TPI has to be easier to install since some thirdgens came with a 350tpi but no thirdgens came with a lt1...I doubt there is much of a difference in gas mileage..in stock form there isn't that much horsepower difference between a 350tpi and 350lt1

[This message has been edited by TwicK91 (edited October 23, 2000).]

 

LT1 is a TPI motor. L98 would be easier to understand. I'd say complete- each would be worth what you'd pay

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91 RS W/carbed 350, Vortec heads, performer rpm, Comp cams Xtreme energy 280 grind. BFG Drag radials. 3.42 posi,Corvette servoed 700r4, ****ty stock converter
13.24@104

 

I don't know what was meant by the L98 being 'easier to understand'.

If you're starting with a V6 then either swap will be just as complicated and almost equally expensive.

Some LT1s (93 only)are batch fire like the L98s, but the majority (94-97) are sequential fuel injection which makes them more efficient and a little cleaner than the old batch fire method.

If you're going to really modify the engine then either one is good to start with since either will respond well to different mods.

Stock for stock I would lean towards the LT1. It gives up a VERY LITTLE torque on the bottom end but FLIES at high rpm and loves high compression. IF you wanted to run nitrous on the car I would suggest changing the factory hypereutectic pistons out for something forged and step up the compression from 10.2 to 11 or so. The reverse-flow coolant system cools the heads first which is what allows higher compression. One guy I know, Bob, is running 12.1:1 on his '94 Z. The fact that the heads are aluminum and flow MUCH better than an L98's are another bonus for the LT1 in my book.



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1991 RS LT1
every imaginable bolt-on, ungodly LT1 355, and 12 pounds of intercooled boost on it's way in '01

2000 C5 Coupe
black/black 6-spd, optional polished rims, first run 13.056 @ 109.52 stock

"So what DOES the back of a Mustang look like?"

 

I'm with Brett on this one. Hypothetically if you're starting with nothing, or a v6, or a carb/TBI 305, the labor involved in putting a L98 or LT1 in is virtually the same. LT1 gives you more power right off the bat. With head porting and a cam change, your car now FLIES! TPI has built in restrictions. It's a torque monster, but quits making power above 5000 RPM. LT1's have great midrange power and great top end power, not as much power in the lower RPMs but that's the design of the intake (But don't get me wrong, there is still plenty of power, just not as much when compared to a stock TPI, but if you were to upgrade the cam or heads in the LT1, you now will have more power than the TPI in all aspects) Another reason why an LT1 would be more cost efficient is if you want to make TPI to make great power, you either need to port it extensively (expensive) or you need to purchase a new intake (superram, miniram = VERY expensive) and now you'd only be MATCHING the power of an LT1! You'd also need new heads, instead of just porting the stock ones to get major power. All in all, an LT1 is a hands down better swap into a thirdgen who needs a new FI intake and a 350 anyway. Another thing to remember is that you can get a LT1 rather cheap, like $1500-$2000 for a complete setup including PCM and all. $1500 - $2000 doesn't even cover what a miniram costs!

I hope I don't sound that I don't like the L98 because I really do! I like both engines very much, but if your pocket changed is going to be greatly affected, why not just go for what makes more sense economically, right?

 

Although my knowledge of the 4th gen drive trains is limited, i do know that i agree with brett and mark. if your doing an upgrade from a carb/tbi/v6 to a lt1 or a tpi system, the work is going to be basically the same. I feel that the lt1 is going to give much more room to work with, being that when it comes to mods, its will be more responsive right off the bat. the induction on the tpi is more restrictive and only good for low end torque, and trust me, its like hitting a brick wall at 4500-5000 rpm on the tpi.

All in all, considering the factors you have presented in your question, and with out a little more info, a LT1 i think is going to be more to your advantage...

Steve

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86 Firebird, LG4, t-tops, 2.73 open rear, SLP 3 inch cat back exhaust, catco cat.

Gonna be sellin the 86 in the spring to hopefully get an 88-92 formula 350, and supercharge it!! (amoung some other sweet mods)

My Webpage- Battle of the birds, My own Thirdgen Page, still under construction, http://www.geocities.com/soares711/index.htm

88 Firebird Formula- deseased 2/9/99- 305 TPI, SLP 3 inch exhaust, SLP Intake runners, SLP cam, 3.45 BW disc brake posi, WS6, NOS, and all that good stuff, 13.8 on the motor, 12.89 on NOS and slicks! Hit by what else!?!? a FORD EXPLORER!!!!!!

 

Thanks you guys! I was thinking along the same path but wanted your advice. I think Im gonna stick with the LT1. Sad thing is I passed up one that would have cost me $300. Only thing I know that was wrong with it was that the heads were warped. Im thinking maybe the block was cracked too. But dont know for sure. Any ways, before I could get my hands on it the guy sold it to someone else for $250.

About the LT1...I can get a crate one for $3,300 out of Next Gen. Is that to much for one? And I dont know what year engine would be better. Im thinking 95 to 97. And wouldnt the T56 be easier to bolt up to the LT1 rather than the TPI??? Thanks a bunch!

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1992 Camaro RS 3.1L
T5 Manual 5 speed
Open Air Intake
Z-28 Exhaust

 

TPI bolt up? You mean the 5 speed should bolt up fine to your car, but it probably won't hold up to the power, of any V8 engine at that. You should change the tranny.

 

LT1 my friend...

I think you'd enjoy it a lot more...

Eric

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Red '85 Z-28 w/'94 Vette LT1 w/'93 Z ECM
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Red '85 Z-28 w/LB9
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I said that the T56 (not the T5) would bolt up to the LT1 since thats what the tranny is made for. Sorry that I confused you.


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1992 Camaro RS 3.1L
T5 Manual 5 speed
Open Air Intake
Z-28 Exhaust

 

If you can get an LT1 with a 6 speed out of a 92-93 Vette, go for the LT1. If not, get the L98 (350 TPI). The 92-93 LT1's are faster than the later LT1's, even with just the single cat (probably due to intake design and batch fire). The Vette's LT1 also makes 300HP, has the tranny you need (that T5 wont work), and the computer with harness you need, and the accessories drop right in. The accessories out of a Camaro/Firebird wont fit in your car without mods.

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1985 Z28, Jasper Class 1 350, Edelbrock Performer intake, Dual snorkel air cleaner, K&N, Edelbrock headers, Catco 3" cat, Hooker 3" cat-back, Richmond 3.73's, Transgo shift kit, JET Stage 2 chip, Hypertech coil, Lakewood LCA's, Powertrax locker, SSM subframes, Centerline Auto Drag's

 

but like in summit where it says u can get a cold air intake (for example) for a 94-97 camaro or firebird, would that same thing work for the 92-93 vetter lt1???

 

The only reason the Vette motors were rated at 300HP and the F-body motors were rated at 275 is because the Vette's have a better exhaust system. Other than that they are the same motor. Actually if you put a LT1 Vette and a LT1 F-body on the same dyno back to back the F-body will make more power (at least everytime I have seen it done) because it is a lighter car. Vette's have to be rated more to justify the price. You wouldn't want to go out and pay $40,000 for a car knowing that you could have gotten the same performance out of a $25,000 car but the truth be known... lol you can!