I have a 87 GTA with a 305.. I really thought it was a 17 sec car at best. Well I just can back from test and tune and it ran:

60' = 2.156
330 = 6.503
1/8 = 10.100 @ 67.78
1000' = 13.261
1/4 = 15.907 @ 83.05

This was in drive. I did not get to run another pass because something happened to the photo sensors at the track and they had to call it a day.

I have to admit that I have not driven at the track in about 10 years so I was a little nervous and did my burnout in reverse I still managed to pull a .738 R/T LOL

Anyway I am wondering it that is right for a stock 305 car?

This is more like my before run. I want to see what it will do at each stage of building. My next thing is exhaust.

 

that is kinda low et and mph. prob needs basic tune up. those figures sugest your making less than 200hp. is it a 5-speed? well i guess it has to be , since it is a gta that has a 305. i think it will run a 14.9 - 15.20 with everything in proper order. check to make sure the timing is correct and the plugs are good. i think you can do better. my completely stock 350ci gta ran a 15.0 on its very first pass. after we fixed the timing and put new plugs and filter in it , it ran a 14.5. work with it .

 

No it's an automatic. I also have new plug wires, plugs, ECT...

So you think that was slow.. Now I have to go look at more stuff. I never did check the timing when I did the tune up because I cant seem to find my timing light. I think my sisters husband still has it.

My main goal is to do all my mods to this engine and the last mod I will do will be a 350 with all of this engines mods on it. (I just hate to waste this engine it only has 56,000 miles on it.)

 

man for a GTA those are slow times, you should be low 15s

 

sounds right, I would have figured a mid 15sec 1/4 time

 

from a L98? are you serious?

 

if you read what he said.... he is running those times with a 305 LB9

 

LOL oops my bad! i was thinkin somthin else! sorry man, hahaha that was dumb of me!

 

no problem, I also agree with ya that if it was a L98 GTA it should run low 15's

 

15s seems high for a L98 tho :shrug:

 

GTA's are heavy, though. They'll do worse then a regular Trans Am with the same motor and trans. Not TERRIBLY worse, but still. Does your car have T-tops? The previous owner of my car (L98) said he did 15.5, but he had crummy tires and I haven't a clue what his maintenance program included. I wouldn't be suprised if the car needs a huge tune-up, even though it seems to run okay.

 

No t-tops.. I will get some pictures up soon and put a link in my sig.

This car has about every option I can think of but the original buyer did go for the LB9 with an automatic tranny. Not what I would have done but I was not there when he bought it.

It ran the 15.9 in drive also with a full tank. I am changing the exhaust this weekend and I think that should be worth a few 1/10's or at least some MPH.

With any luck I will learn how to do my own computer chips this winter so next summer I can slap in a 350 or even better a 383. I am very new to TPI (This is my first TPI car) so I will stick to my experimenting on the 305. At least for now.

Thanks for all your feedback.

 

My 87 t/a with the lb9 and 700r4 ran a 15.88 my first time at the track.I think I could have gotten a little better time though.Mine has t-tops and a full system in the back.

 

are auto 305 lb9's really mid high 15's??

some 5 speeds are in the high 14's so will an auto really take off a second?

i wonder what a L98 with T5 would do....... i hate GM for not figuring out how to do that.

 

Yeah, so much for corporate wisdom. I have an Edelbrock cat-back, not sure what the actual effects are on my times, I've never ran the car for the 1/4 mile. Sure is quiet now... What cat-back are you getting? Can't wait to see some pics. Leather seats, too?

 

It is a hooker cat back that I ordered and yes the seats are leather.

 

I had considered Hooker seriously, but finally decided on Edelbrok due to the tip apperance, they look exactly like the ones that came with the car. I didn't want bling bling 3" chrome on an otherwise stock car.

 

Please remember the intake track on 87 pontiac TPI's were terribble...88 is when they went to the better flowing elbows.
I think you car needs a serious tune-up...i would think 15.5's@87-88mph a little more realistic taking the poor intake setup into consideration.
upgrading exhaust is good...but even upgrading to a stock intake setup from 88 up models would help...get a cold air setup on it to compliment the exhaust...check your timing..some thirdgen's (like mine) timing was a bit off from the factory 6*setting..bumping it to 10-12 *gives a nice little gain...

 

LOL yea I dont like them at all and dont plan on using them. I hate anything that changes the appearance of the car.

I did talk the wife into buying me a lap-top and the stuff needed to burn chips for Christmas. I actually need a laptop anyway for business. Do you guys think it's a good idea to put a bunch of mods on this 305 and then buy a 350 or 383 or should I change the engine first. The engine is low miles so I really hate to just scrap it but at the same time... I am thinking 1.6 roller rockers for my next move. They seem to add power for a small price. (They are cheap on ebay)

Thanks for the info about the 87 TPI's I thought they where all the same. When you say elbows are you talking about the runners or something to do with the intake? Sorry about that question but I am new to this.

 

I just recently sold an 87 GTA. mine was an L98 though and it wasnt stock. it had SLP runners, headers and SLP cat-back. mine ran a 14.5 @ 95 with 145Kon the odometer with no rebuild.

 

I think the decision is ultimately yours to make. It sounds to me like you wanna take this car and do it up a little. If you ask me, try to sell off the 305 while you still can. Maybe trade (and some cash) for a 5.7. Yes, many of the bolt on parts you slap on a 305 can be slapped on a 350, but do you really want to go through all that time and trouble? I wish I had done that years ago when I had my original 305 tpi. It was a fun little screamer, but stepping into the 350 is a whole new ballgame.