So I took my stock 305 IROC to the track for the first time yesterday. The ONLY thing it has that isn't stock is a TPIS big mouth manfold that the P.O. put on it but kept stock runners(stupid, I know.) Well I have to say, I'm slightly disappointed with what it ran.

Best run was a 15.77 with a 60' of 2.19. The 60' was pretty much the same every time, but the 1/4 time fluctuated from 16.0 - 15.77.

I thought It would do more like low 15's maybe even high 14's but I guess not. Now I'm gonna start the quest for better times. I already have headers and a y-pipe I haven't put in yet, and want to get some high flow runners for my high flow base. I was reading about all the "free mods" you can do and might try them but I'm not expecting 1/2 a second for gutting out the air box.

Here's a picture just cause:

 

Thats about online with what I've seen through SEVERAL 305 TPI cars, so don't feel bad.

Headers, y-pipe, k&N, bump the timing up to 10 * initial and you will gain quote a lot...

1/8th mile I started at 10.5's. With gears, stll converter, headers, camand ported stock stuff(SLP runners) I got it down to bottom 9's 1/8th or low 14's stock.

THEN I sprayed a 150 shot into the 12's!

 

Sharp iroc!

What headers did you buy?

Expect to drop 2 or 3 tenths if you can still hook up the same.

 

Flowtech shorties, and also a flowtech muffler. Also, how much should cold air help? This time it was about 95 out, and next time should be some night passes at about 75 or less.

 

Cold air will help a bunch, gotta have that engine BREATHE!
Take out the spare tire, and back seats next run, if you didn't already. (you can put them back in after racing)
The stock 2.73 gear, to a 3.xx gear would help a lot as well.

 

Service codes tell me it's a 3.42 gear so that's probably fine. As for the back seats, that seems like a lot of work for not that much weight reduction.

 

Rear seats removal consists of 4 bolts, not hard to remove, but your right, not much weight savings there.

 

Yeah, easy to take out and put back in, it isn't much, but it isn't much work for an extra few pounds.

 

Have a timing light? Bump the timing... TRUST ME

 

Do you have any time slips still? If so would you mind posting them. I'd like to see the numbers. I also have a mostly stock 305. Mine only has the magnaflow 3" catback and k&n drop-ins

We have an 1/8 mile track near by and I think I was in the same ball park time wise on the 1/8 as Nuff last time I ran it. I'll be at a 1/4 mile track in the morning,.. not sure if it will be open to test and tune but maybe I'll see how slow I am there.

 

I can't scan them so I'll just post the numbers.

Best run:
REACTION: .0855
60 FT: 2.1995
330 FT: 6.4774
1/8 ET: 10.0645
1/8 MPH: 68.07
1000 ET: 13.0839
1000 MPH: 78.41
1/4 ET: 15.7788
1/4 MPH: 86.66

All of the other passes are pretty much exactly the same just a little slower from crappy RT's and 60ft's.

Oh yeah and I've never mentioned this baby is pushing 171,000 on the original motor.

 

Just took it again this weekend and picked up some time. All I did was take off that cat (which was only like 8 bolts) and it picked up more than half a second!

Weather was basically exactly the same as the day I took it in October(gotta love Arizona.)

Anyways I don't have the slips near me but I can remember some of the times:

60FT: 2.10 (previously 2.20 ish)
1/4 ET: 15.20 (Previously 15.77)
1/4 MPH: 89.something (previously 85-86)

I'm thinking 14.99 is easy with the headers I've got waiting and some cooler weather.

 

must be the sea level and air and temp where you live. mines a 87 305 tpi. i have headers, full 3" flomaster exaust delete pulleys and k&n drops runnin 15.5s at 86-87 mph

 

The track is at about 1190ft above sea level and it must have been at least 85 if not hotter this weekend when I was making passes. I do have the big mouth intake manifold but stock sized runners and throttle body so that might be giving me slight gains.