What did the L98 F-bodies run in the 1/4 back in the day? Fully stock, nothing at all done to anything. Like they just rolled out of the factory?

14.7 - 14.9 around there depending on the total pakage of the car.

Mine used to run on average 14.3 on good days. I used to get ticked off because I got beat by every Buick Regal Grand National on the block.. That doesn't happen anymore..



I think I spent too much to get ahead though.

90-92 run a bit harder
91 z 14.2 @ 99mph stock 5.7, A4 virgin..
92 z 13.6 @ 105 mph stock 5.7 w/5spd and 3.42(was an A4 car)
gotta love sea-level and a damn good track H.R.P.

mid to low 14's with the later years L98's

how is that possible to have lsx block with gen I parts?

wow, for older cars they still keep up with some of the boys of this era

It isn't.. I did that on another channel because some kid was telling me he was able to do it. So, in 2 minutes, I changed my engine too.. I didn't realize that it would change every thread though until now. I know the LSX requires special heads but, I figured if he could make it up, So could I.. Just didn't figure it would change my stats on all threads.

Please do not get mislead,my numbers were at sea-level....
my 88 iroc ran 13.3s at Houston Raceway Park
here in vegas at 2600' it ran 13.7
mod list.
stock 88 350
stock fuel pump power wire was bypassed and wired through a 30A relay to supply the pump using 12 guage wire(BIG HELP)
crane afpr set at 44psi
svo 24lb inj.
ported plenum
hooker headers
2.5 y-pipe(no cats)slp muffler
pulley kit
87 T-5 manual trans,ws6 alum.drive shaft
9 bolt rear w/3.27s
17x9.5 rears w/bfg comp TAs 285/40/17
jegster tq arm (best mod EVER)
jegster sfc(best fitting on the market)
all smog associated componets were still functioning minus the cats.
13.77 @ 104 1.8 60'
TPI tq w/manual trans sweet combo!

I remember seeing an old magazine article being posted up a long time ago of a showdown between the 87 L98 Iroc vs the 87 Grand National. The Iroc ran in the very low 14s and the Grand National was in the 13s. It would be great if somebody saved that.

like they said befor the 88-89 formula(s) ran high 14s and with a good driver and tires they could muster a low 14 90-92 formula 350 cars could get mid to low 14s and I have "heard!!!" of a few squeaky high 13s

I have a test artical that showed the 88 formula 305 tpi 5-speed running 14's as well right out of the box. back in the day it was good but keep in mind gm had many cars that would still take our f-body's look at the 442 w41 olds calais in 91 (N/A quad 4 N-body) ran in the mid to upper 14's as tested! which for a FWD 4cyl back then was very fast and had to **** off a few f-body owners

So what CAN they run? What mods net what ET's? I am wondering if my L98 is even gonna be worth rebuilding, I am going from a 12 second 4 banger, to a 91 t/a L98 A4, is it even worth dumping money into go fast parts, I am considering getting rid of it and starting with a better platform.

So what mods add what.

the best mod to do is get hedders ans full exhaust(i like the heddman or hooker shorties.)
L98 ported heads(alum)2.00 1.56,7/16 studs 1.6 rockers Non Self Aligning
hard pushrods
double roller chain
LPE 219/219 560 112
2600 stall,big trans cooler
custom performance chip
Holley Stealthram
30lb inj
58 mm throttle body
3.42 gears(max)
this should get ANY 3RD GEN in the lo 12s

So what about without the Holley stealth ram, and with stock 3.23 gears, and maybe a little bit smaller cam. That's about the setup I am going with.

depending on how much smaller the cam is,i can still see you running in the mid to high 12s. two things to consider TQ does not require a bunch of gear and tunning,tunning,tunning,is IMPERATIVE(be sure your distributor is in perfect working order and has NO slack)

Mine ran bottom 14's completely stock. With nothing more than the cats cleared out and a little extra timing it went in the high 13's. I haven't even messed with the fuel pressure yet, but a new motor is on the stand, still trying to decide which way to go, LTR or otherwise.

I am also at sea level and it has made its fair share of passes at HRP.

My 91 Formula 350 TPI auto. ran a 14.19 @ 98 mph stone stock with 40,000 miles on it. I bought it brand new in March 1991

I ran a 14.8 when I was bone stock. That is with 2.77 gears, a 2.2 60ft, older ignition components, and some leaky injectors.

I'll let you know this spring

I'll be testing a stock 91 Formula L98 with nitrous. I'll post results with 50,75,100 increase. should be fun

prediction based on experience^^^^^^^^
91 Formula 350(lightweight)
NA should run 13.9-14.1 (sea level)
100 hp jets 13.0-13.2
150 hp jets 12.6-13.0 traction is a factor here!
you will get a rush on the 150 shot! i used autolite 25 spark plugs w/.032gap