More specifically, what would an 86 IROC with a 305 TPI and a 700R4 run in the 1/4 mile? I may have a chance to buy one, and am pretty excited, but would like to know what kind of a platform I would have for modding the engine. My goal would be mid 14's, where do you think the car would be bone stock, 70K miles, runs fine. Thanks for your help in advance, venture any guess you would have based on any kind of experience.

 

Depending on rear end ratio, Someplace in the 15's

Mid 14's are definately attainable, But not with the Peanut Cam

 

I've seen members in my car club with stock 305 TPI's run high 15's maybe a mid 15 on a cold day. You want mid 14's here is the plan to get there.

Headers $300
3 inch exhaust $230
NO CAT
Port the intake $50 (supplies needed to do it)
Ram Air system $40 (tubing and clamps)
K&N Filter $35
Fuel Filter $5
Posi-Rear End $250 used if you can find a good one

among other things...

 

What kind of car do you have right now dmair5_0? 5.0 ?

 

right now I got a 91 Firebird with the might L03. Great car, very good condition, but I'm kinda stuck as far as performance goes. Have always loved the IROC's, so maybe this is the one.

 

the cam in those is weak. that should be the first thing you should do for it. If you get new heads or can port the stock ones at the same time as doing the cam that'll help quite a bit too. I've run 14.8 with my 305TPI. still on the stock heads and cam. just exhaust and AFPR. see specs below.

Hodge

 

if u have an LO3 expect 16's or high 15's...

 

my best with my 86 iroc 305 tpi was 15 flat at 91mph and that was with headers, no cat, catback, shiftkit, 3.23 and goin off of idle

 

I just ran a 14.74 @ 92.84mph.
My mods are in my sig.
I am running a stock 305 prom which is hurting my performance.
I also need an AFPR badly, as well as a gutted cat with a straight pipe through it (muffler shop wouldn't put on my gutted cat when I had my exhaust put on, so I had to buy a new hi-flow one).
I have 152,000 miles on my motor which was originally an LG4, just slapped the TPI parts on it.

 

With the peanut cam my 86 IROC ran a best of 14.77et around 93mph.I suggest cam first if you want to get mid 14's.I did it the hard way and did cam last.Don't waste your $ on other mods till you get that peanut cam out.
BD3:hail::bowtie:

 

86 TA, BONE STOCK 305 peanut cammed, 2.77, 700r4
15.92 with 103,000 miles. I thne change the intake piping to 3" flexible alum. ducting and went 15.62.

Need mods are 225/50/15 BFG GForce DR's and a 3.27 rear end.

 

well if you consider the stuff i did to ny car in my sig you can see what you might have to do to get in to the mid 14's
i ran an 14.86@89.54 at the track with haveing to feather the gas out of the hole and if the posi in my rear worked i could lauch much harder and actualy use my 2500 converter and im sure i would be in the mid 14's

well my car is an 89 with a bigger cam then you have also
this sould give you an idea

 

well with the GForce Drag Radials in 225/50/15 I went a best of 15.29 @ 87 mph today, dropped just over 3 tenths. Tonight I'm about 3/4 of the way through swapping in a 3.27 rear end.

BTW with the DR's at 24 psi and launching at 1600 rpm, flashing to 2300, or just going all the way against the converter @ 2200 rpm, they never barked or even spun.

I'm hoping for 14.99x with the new rear end. Then I'm gonna add a Summit Cam 204/214 .420/.443 over then winter.