Anyone have factory claimed 1/4 mile times for
305 TBI auto - ? I think Low 16's
305 TPI auto - ? I think Mid - High 15's
305 TPI stick - ? I think Low - Flat 15's
350 TPI auto - ? I think Mid - High 14's
I only want info from what the factory claimed or your best stock run.
Thanks guys



1991 Firebird LO3 Best Et. 16.64 Bone Stock w/95,000

Ran a guy with an L98 Iroc and he went 14.8 at 96 with just a cat-back. This was a pretty slow night for everyone so i would assume he could have gone 14.6-14.7!

the factory doesnt put out 1/4 mile numbers

Yes they do in the brochures, or the dealers if u wanna get technical. I personally saw them once.

Ide really like to see that brochure because they dont publish 1/4 miles times or advertise them. The only thing similar they give out are hp and torque numbers. The 1/4 mile times are for the magazines.

I actually think i got the link to a brochure for an original iroc off this site, and it said 14.5 1/4 time

Anyway what do the magazine's claim. There probably just as good.

GM does quote 1/4 mile and 0-60 times. look in the sales media on this site...

https://www.thirdgen.org/newdesign/b...brochure12.jpg

https://www.thirdgen.org/newdesign/b...TurboTA_Ad.jpg

The first one isnt even a brochure, the second one just says 0 to 60 in under 5.5 seconds. It's impossible to give accurate 1/4 mile times on these cars because each car is slightly different and so are the drivers and location as well. Ever seen a commercial for a car that advertises 1/4 mile performance?? No, Thats because its impossible to state what each perticular car will run. You can probably get base line performance for a certain car by looking at magazine times like motor trend or a similar magazine, but I bet if you bought 2 magazines that tested the same car they would both get different times. That is why auto companies do not advertise 1/4 mile times. They may give a general statement to market the car like 0 to 60 in under 5.5 seconds, but they can not give accurate 1/4 miles times. It's just not possible. There are way too many variables involved!

1988 iroc-z 5.7 camaro all stock except dynomax muffler and k&n filters i ran roughly 14.7's

1988 formula 350: air foil and flowmaster muffler, k&n. best run was a 14.45

1991 formula 350: air foil and k&n best run was like a 14.5 but i think i can get it down to like 14.3's with a good 60 foot..

i took the a/c out, took the a.i.r stuff out, 180 stat, going to straight pipe the cats and i will run at a track to see what it can do now, i suspect low 14's because i beat a friend who runs low 14's a few days ago... i just need to be able to hook up better..

My old 85 Iroc was supposed to run 15.2 with its 305 TPI. But, that time is from a mag. I think that I once G(ay)-Tech'ed my car and it was like 14.3 or something.

I believe the magazine was probably the better time, that was about right for a 305 TPI.

305 TBI auto - ? I think Low 16's
305 TPI auto - ? I think Mid - High 15's
305 TPI stick - ? I think Low - Flat 15's
350 TPI auto - ? I think Mid - High 14's

looks good....except the l98 will be a mid 14 and the 305 stick will be at its heels..ive raced plenty of SD l98 cars and i take um outta the hole every time...and at about 70 they start to come by...i loose a half car by 100

my best stock run for my 91 lb9 t-5 was a 14.7@94

but after a fartmaster, k&n, ported plenum and a better launch i got a 14.2 out of it...but then i blew it up...

remember though, the fast LB9 5 spd cars are the ones with the g92 option or the 350 cam. the 86 LB9 t5 still got the peanut cam...

fastest ive ran is a 16.7 all stock (well, my cat is bout rusted off!)

1983 Z28
305 4bbl
T-5 gearbox
133,500 miles

That 14.7 run is awesome dude. Im thinkin about gettin one.

yea i forgot to mention that...i have the "fast lb9"

in 91 there were only 164 cars with the lb9 and mk6 and g92

14.7 is quick for what it is..hell a 14.2 is lt1 speed

my 305TPI is down to 14.8.. it's not stock, but just thought I would put it up here..

Those are some nice times, with a few more mods you could be knocking on 13's doors.

Thank you.. Many more mods to come in very near future.. Making it a 335 stroker with torquer heads good cam ported&polished plenum.. and some other goodies like afpr better injectors etc etc...

305 TPI's are starting to grow on me especially manuals

25th....yea it would of been cool to get my 305 in the 13's...but im almost ready to put in a 406..and im goin for some fast 11's

the lb9 cars are fairly quick but once u start modding then you dont get the results youd get with a bigger motor...

personally i'd rather go with a LB9 and a T-5, than a L98 and a 700R4. Sure the L98 has a torque and slight horsepower advantage, but i'd ALWAYS take a stick over an automatic. Autos suck *** compared to a stick.

I see so many of your kind out there its so funny, expecially when they get *** raped off the line by an auto with a converter.

Auto with converter. Once I break my T-5 that's what I'm doing.

got a 3800 stall converter on my nova with a 400 turbo trans, talk about throwing you back in the seat!!!

auto and convertors are defierntly the way to go....

but if u get your stick to hook on slicks then itll be even off the line...

i saw a guy with a zr1 launch of the limiter with slicks and yank the wheels and shifted to 2nd before they dropped....absolutly awesome

the problem is, a few times hooking with slicks in a stick car and bye bye rear end, then bye bye tranny.

thats very true...

99 times out of 100 the rear and tranny fail due to shock not the power going through them,

an auto car with a big converter transbrake and that stuff has the drivilive loaded..while the stick car doesnt

put a line lock on the stick car and bring out the clutch just enough to take the slack out and to mesh up the gears..so when the light goes green you side step the clutch...you still dump it but you dont have the shock because the driveline it tight...
the clutch will take the abuse instead of the trans and rear