what would you need to do with an 87 iroc 350 to beat a 97 z28 6spd assuming they both hooked up? i might get an 87 and i'm planning on bumping the compression up to about 9.8:1, full exhaust and as big a cam as i can with the stock computer.

 

You can run a pretty big cam with the stock computer (if you tune your own PROM for it). If you are talking about running the biggest cam in a TPI motor that you could actually get away with the stock chip, then I would go with the Comp Cam's XR264HR-12.

Get that cam, make sure you put decent valve springs on your heads, port match your intake, and a good set of headers and you'll give that LT-1 all it wants and then some!

 

a well driven 6speed LT1 can go high 13s 100% bone stock. there have been a few documented cases of them going as low as 13.6 when powershifted.

my GFs 120k mile 94 Formula, which is an auto, went 14.0 at 100mph before we did anything to it. then after cold air, a catback, and some DRs it now goes 13.4s at 102mph

LT1 cars have good potential... problem is most of the people who own them cant bring it out

 

A small shot of N2O will more than handle him! In moderation with the proper tune will not hurt the engine either.

 

what about 041 heads, i have a set of them but i don't know what the compression would be and if there better than the l98 heads.

what is the CC of the l98 heads? the 041s have been milled to about 58cc.

 

BTW, tpivette89, how does the bottom end torque on the l98 or 350tpi compare to an LT1? i see you have a few of each.

 

I'm currently building a TPI 355 for a buddy of mine's 91 RS.

specs:

10:1 compression
XR264HR-12 cam
Mildly ported Iron L98 heads
port matched TPI (plenum to base)
24 lb. injectors
1 5/8 edlebrock shorties
700r4 with S-10 convertor
3.23 posi rear
Flowmaster exhaust
Custom PROM

I'm realistically expecting high 12's - very low 13's with this setup. I'll post results as soon as his car is done. But I expect it to rip a stock LT-1 car a new one on the street with the above combo.

 

wasn't 97 the first year for LS1?

 

yeah, i think so, for the vettes.

 

Correct. The LS1 started in the f-bodies in 1998. The L98 makes more low end than the LT1 but not by much. The LT1 really wakes up after 4500rpm where as the L98 falls flat. A full exhaust and intake is all you should need on an L98 to hold off an LT1.

 

i out run all types of lt1 with a allmost bone stock tpi i have long tubes headers 3in ex. a 458 lift cam cold air box corvett alum. heads off of a 88 tpi 1.6 roller rocker arms and my eng. is a non roller cam i have 327 gears and stock at with stock stall i run 13.31 105mph and cut a 1.91 60 ft. and i am selling my car if anyone is wanting a 86 trans am very very clean 2nd owner i am wanting 5500obo have all rec. on what i have invested have 7000 in car.

 

Your car is a full second faster than a stock L98. You have tons of mods and your times are way ahead of any stock LT1. You are definately not close to stock. You have a great bruiser there that shouldn't have problems with most cars on the street.

 

thanks i do not no why my runs as good as it does the poeple i run with say its a feak eng and i am stupid to want to sell it but i love to buy cars poeple say are not fast and i do the little things to show them that oldschool tpi is just as good as a ls1 or lt1 my next project is my new grand national

 

your need to run the o41 heads it is a lot better head than the l98 head but if you dont i would like to buy the o41 from you i have a set of l98 vett alum. heads mybe you would like them better

 

my old z28 had no problems with LT1s i had an 88 L98,hooker headers,2.5"y pipe,pulleys,ram air with cut boxes,t5 trans,3.27 gears,jegs torque arm,17x9.5 w/bfg285/40/17s ran 13.77@104 at 2250' most LTs up here were runnin 13.9s...

 

My setup pulled LT1s pretty good...kept up pretty close to the LS1s...like shifty said, stock tpi runs out at about 4500, so you want mods that maximize your midrange and upper end torque

 

so, if i went to about 9.8:1 compresion, full exhaust, HSR(a little farther down the road though), and a bigger cam i should be able to beat the hell out of LT1s?

 

should not be a problem,personally i feel you should shoot for the Ls1 numbers cause you will be spending the same chedder so play the throttle game(sand bag)

 

Don't worry about compression ratio so much. Just keep the stock ratio. You can make lots of power at that level and not have to worry about running premium fuels. You will only need about 260rwhp in a thridgen to beat LT1's. They aren't that great. Why are you so set on beating LT1's? With the set-up you want, you should be able to run with LS1's all day long.

 

i'm shooting for an LT1 becuase my brother has a 97 Z28 and its got good power for the street but not crazy and i know it'l beat just about any average **** burner out there.

it was funny when he raced an integra(i think a VTEC something) a friend has. he thought it was fast and would leave us behind so he started to pull away(buzzing real loud). my brother hit the gas(without downshifting at about 60mph and around 2000rpms) and passed him like he wasn't even on it.

BTW, what kind of gas milage would you think i'd get with close to 300rwhp, OD and something like 3.42 or 3.73 gears?

 

i have an 89 l98 ta,bone stock the car ran 14.00 at 98 mph my buddy has an 97 lt1 z28,he beat me by 3 or 4 cars,then i just put headers on thats all,and ran right beside him

 

to 90 mph then walkage took place :lala:

 

its hard to give an accurate comparison cause my TPI Vette is slightly modded, while my LT1 Vette is stock. ill try though

if you look at the #s of each "Vette" motor, the LT1 actually makes peak torque SOONER than the L98. however, the L98s peak torque #s are higher than the LT1s:

L98 hp: 245 at 4400rpms
LT1 hp: 300 at 5000rpms

L98 tq: 345 at 3200rpms
LT1 tq: 330 at 2400rpms

the L98 cars i have "feel" faster cause the power curves are peaky, while the LT1 seems like the power peak never arrives cause the torque curve is so flat. however, stock for stock, the LT1 would have been faster (even though it didnt feel like it was)

the weird thing is that alls i did to the old L98 Vette was open up the exhaust and lightly siamese the plenum - runner openings in the TPI intake and now it will easily pull the stock LT1 Vette on the big end. it may not rev as high, but it definately walks it from 60 - 120mph. theres about a 2 - 3 mph difference between the 2 cars in the quarter

 

very ture well said