I finallyyyy am getting an IROC!!! What are you guys thinking for possible 1/4 mile times? Here is the info

1988 IROC-Z

305 TPI w/40K on rebuild
Rebuilt 700R4 (stock)
3.42 Richmond Posi Rear
Edelbrock TES Headers
Hi-Flow Cat
Flowmaster Cat-back
Accel Cap, Rotor, Wires, and Bosch Plugs

Any estimates (I will be using street tires)? Any also any suggestions for racing my IROC down the 1320 for the first time?

- My immediate plans are pulleys, tranny cooler, and shift kit.
- After that a Stealthram and suspension next.
- Finally I'd love to built either a forged 334 stroker or get a whole new block and do a 383 stroker with heads, cam, etc (which leads to many more necessary mods...)

Any suggestions for me?

P.S. I have been on this board reading and posting for a while and I have learned quite a bit. Finally I get to be part of it in real life...can't wait!

 

I dunno about the stealthram on that 305, even with a 335 stroker mod. Maybe if you had the heads to support the RPM's needed to get power out of it.

On a guess for what you have right now I'd say a mid to low 15 second pass. I don't know what elevation you are at though so that could vary. Its still got the peanut cam, headers and a few other things won't change that much.

 

If you get a really good light, I'd guess 15 flat. Gear and headers/exhaust will make some difference even with the 305. Probably decent on gas too.

 

I beg to differ on that one. Headers, cam, rockers, intake manifold, upper plenum, any form of head work (port/polish, new heads..); any form of said items, put into combination of any type, will get you 14's; if all mods said are done, expect 13's. Easy.

 

I am refering to bolt ons, leaving the stock long block alone. Without porting/changing the cam and heads he won't gain much. Specially because he has the peanut cam in his motor.

The peanut cammed 305 TPI doesn't stand to gain much from bolt ons because the camshaft is so small. about .384" lift at most, and less than 200* duration @ .050".

Maybe with a bigger cam, but its shady to say. I don't see him breaking into the mid or low 14's without a cam.

 

The 305 TPI doesn't take well to add ons due to it's cam? I did not know that. I can see the trueness factor behind that.. but I guess I never really took that into consideration. BUT.. w/ JUST a cam, he should be lower 14's. I would think that everything else that I mentioned, he should be NEAR 13's w/out the cam.. but DEFF. in the 13's WITH the cam.

 

The cam specs for the 1986-1992 305TPI/auto cars are as follows.

.350"/.383" lift (w/1.5r), 178/194 duration @.050", on a 109lsa.

A VERY tiny cam compared to the 1985 TPI, 1987+ 305/manual and 350/auto cars.

1985 - .403"/.415", 202/206 dur @.050", 114lsa.
1987-1989 305TPI/M5, and 350/A4 - .415"/.431", 207/213 @.050" on a 117lsa.
1990-92 SD TPI 305M5/350A4 - .413"/.428", 202/207 @.050" on 114lsa.

 

Start with that stealth ram intake, the TPI setup makes gobs of down low torque but leaves you high and dry up top,but I wouldnt take the stock bottom end over 5500-5800. The TPI systems are crazy restrictive once you get an engine with potential for power, but they look cool. As for the heads, if you wanna do a stocker, see if you get ahold of some L98 heads and port those with about a 475 lift or so, that should but your torque numbers close to 400+ with a little over 310hp+, along with the bolt ons could see more. With a 3.73 gear and a stall of about 2800 rpm, should net you some times to run down a LT1 or a poorly driven LS1. Then be careful with the tranny, the 700R4 is weak and expensive to put a performance build on. With that you should be low 13's or borderline 12's.

 

I would think the Stealthram would be an absolutely **** poor choice for a 305 with the stock heads and peanut cam, you simply will not be able to take advantage of the extra power the Stealthram could produce up high over TPI, and you'll actually lose power down low. Poor, poor choice IMO without some supporting mods alot more significant then 3 or 4 bolt ons.

And I'd skip the 334 noise, if you're going to spend that money build a 383 or just stick with a 350, then the SR would be a good choice...

Anyway, a mild cam and the bolt-ons you have with some intake porting work for good measure should make the 305 run significantly better...

I had a 204/214 dur @.050, .420/.442 lift cam in my 86 IROC's 305 TPI with TES Headers and 3.42s and free mods (ported plenum, shimmed FPR to up pressure, home rigged cold air, etc) and it runs/ran pretty darn good for a 305.

 

Dont quote me on this but I believe you need a speed density car for the steath ram. I know my 86 Iroc is not speed density, not sure about the 88. I thought it was 90 and up cars only.

 

Any year thirdgen can use a stealth ram if the base matches the intake bolt angles.

MAF or SD, a TPI car can run a HSR no problem. All of the electronics swap over, injectors fit into the new rails. Everything works.