The title say it all... When we launched at a light, I was in front for a while, but when he hit his 4, he pulled away (slowly). I have a 305TPI GTA. I just bought it... I had a hard time too with Honda Civic SI... Let's say I have 500$ to put on my car, where should I put it to make it faster? It is completely stock. I want modifications that will afect the performance in all the power band. I don't want to compromise let's say the low end torque etc... I want performance in all the band. Thanks and sorry for my bad english I'm a Canadian

 

exhaust/headers. after just that u will notice a good diffrence.

 

What year GTA? Automatic? Miles on 305?
Without any information to go on, I would suggest doing as many free modifications and cheap modifications listed in the tech articles in addition to a tuneup. That will be a start.
It will be an uphill battle with a 305, but it can be done.
Exhaust is a great start to improving performance!

 

I had no problem beating the Civic SI that some goon at my school drives. He's got an intake and exhaust, I only had an exhaust. I got the auto and his was stick. Maybe the little car was worked?

 

Why does everyone tell the newbie to get headers? Got any dyno results to show what he's going to gain after he spends that $600 in parts and labor? No offense but I think there are a lot better mods for that money. I did this stuff because I got my 350 butt kicked by a 305 guy who did this, so I copied it.

Advance your ignition timing to 10 degrees-$20, ~10hp
Cold air intake with good air filter- $150-250, ~ 7hp
Rip out that crappy long TA intake tube and buy
a few feet of 4" AC duct from Home Depot, $20, ~ 5 hp
Underdrive pullies if you don't care about
dropping 1/2 a volt, $100 ~ 7 hp
Port your plenum (free with 2 hrs and dremel) ~ 5 hp
Good plug wires (several to choose from), $150? ~ ?
3" catback exhaust, $250-500 ~ 8hp


By the way I didn't look but if you have 2.73 gears they suck bad. Get at least 3.23's or steeper if you plan on lots of mods down the road.

Then you'll have traction issues and it's time to start doing stuff there.

The only other things my car has is an aluminum driveshaft and the smog stuff is pulled off but you may not want to do that.

 

Stay away from underdrive pullies, too many horror stories already to start another one

Build your own Cold Air Intake instead of spending $150+ on an SLP intake, just search the boards and you'll finds tons and tons of info on how to make one.

Def do a tuneup before anything which is on the main page of the boards under the tech articles as well as the freebie mods like porting your plenum.

once the car is all tuned up and in good runnign condition, thats when you should upgrade your exhaust to notice the most gains.

 

i've said this a million times before, weight reduction is probably one of the best ways to increase your acceleration rate,. i would start w/ spare tires, extra junk (especially under the hood, like a/c if you live in a cold climate, cruise control, etc.). sound matting like under the carpet and underhood. and various other thing. best of all it's free!

 

It's a 1988 Pontiac Trans AM GTA all original with a 305TPI, automatic transmission, 165 000km (don't know how it does in miles, I think it's 105 000). I will take the car to a shop to do the mods 'cause I'm not too good in mechanics stuff yet.

 

well for a tuneup def don't take it to a shop, it can be done easily in your own driveway/garage with a decent assortment of tools. Headers and Catback you might need the help of a shop but before that definitely do the tuneup which consists of

oil change
oil filter
check TPS sensor
check IAC sensor
air filters
change all the fluids on the car
spark plugs
spark plug wires
Distributor cap and rotor
ignition coil

that should be a good start and its definitely doable for any level of DIY mechanic. If your'e having trouble you could always ask on the boards or pick up a Haynes or Chilton's manual just to provide you with some guidance

 

Buy some tools and do a tune up. Save your money to fix things when they break, it will happen.

 

Unless you're very rich, there is pretty much no way you can pay to have a thirdgen modded and have any hope of actually making the car faster. 99% of the mechanics out there have absolutely no interest or ability when it comes to modifying performance vehicles. They are parts swappers, nothing more. And they're often not even very good at that.

 

Dumb question, is that 10 degrees BTDC, mine stock is set at 6 degrees BTDC. Thanks.

 

Yep, 10 deg. BTDC.

 

I've raced an all stock 305 GTA automatic once. It was pretty slow compared to my 350 powered car.

https://www.thirdgen.org/newdesign/tech/tpimod1.shtml

https://www.thirdgen.org/newdesign/tech/mods2.shtml

I suggest reading these. Get started on learning how to work on your own car...wether your rich or not.

 

The 305TPI auto's had the so called peanut cam correct?
Tha'ts your biggest draw back. Don't know if you want to get into cams just yet but a l98 or lt1 cam may be your best bet at this point. While you're at it, change the timing chain as well which has probably never been done and is stretched to **** at over 165,000km's.
After learning exactly how stupid the local mechanics are around here when it comes to f-bodies, you'll start investing in tools like I did over 6 years ago.
Our cars are a dream to work on in light of what other **** is out there.
Don't be afraid to learn something and if you break it - chances are Canadian Tire has one in stock. Another great feature of thirgens!!

 

Nitrous will add the most power for the least amount of money, but you run a higher risk of damaging the motor.

If you have 2.73 gears, I can almost guarantee that a 91-92 V6 firebird can beat you, until the firebirds speed limiter kicks in.
Gears will be the best mod right now if you have 2.73 or 3.08.
Get some 3.42's. If you happen to have a 9bolt rear, gears will cost a little bit more, but worth it in the long run.

 

His car will have the 3.27 rear gear in the 9 bolt version.
www.9bolt.com
From my recollection, no GTA got the peanut cam. But you don't know until you check the lifts or take out the cam.
A cat-back exhaust, and removal of the catalytic converter if possible would be my recommendation after a tune up.

 

My 1985 305 TPI has the same cam that was put in the earlier model 350 TPI cars.

 

the 305's with the l98 cams were 5 speeds, i believe only the auto's got the peanut cam

 

only autos got the penut cam- .350/.381 is the lift of it, i'm planning on the ramjet cam, $135 .450/.481 w/ 1.6 rockers
thats a nice jump imo. also get a catback, afpr, new intake, port the plenum, tune up, and good tires and your car should pick up about 35hp. then headers and head work along w/ port the base, then u will have picked up 75hp.

 

Good list, don't forget the fuel filter . My friends '91 RS was choking to death on a filter that had been on there since who knows when. Easy to change and cheap to buy too.

 

I remember when i changed the filter for the first time. Damn, the fuel on the tank side was brown rusty coloured!!!
1 change them every 10,000kms or so now.

 

Well it might be because there may be not money in it. Well if comes to working on cars you are going to do what makes you money. The part about part swappers is a joke. It takes more to work on a car then part swapping. If that was what working on cars was all about we whould not have to have so much money wrapped up in tools.

 

Man i raced my friends precidia and stomped him. he got a hole shot cause i lite them p off the line. maybe a good tune up will help. after that g into preformance. eveyones right do the free stuff first. CAI, Port, siamese runners, will get u good start

 

Just have a note to Zepher. I have a formula 88 305 tpi 2.73 gears auto and no way a 91-92 v6 could take my car any which way. I have a buddy who has the crappy 3.1 and I completely dust him. All I have done is built my own ram air and raised the timing to 12 and use 93 octane. I know I don't have the greatest combination with the tpi but everyone acts as if its slow. I havent been to the track but I can tell you that I can beat alot of cars in a race. Im not trying to say that I'm beating any LT1's or LS1's but my formula still kicks some a** for an older car.

 

It is possible the OEM rear gears are 2.77 (Borg 9-bolt), like mine. I don't see it as a drawback, since my top end is well over 145... Yes, that's a 305.

 

3.27 or 3.08 for auto equiped GTA. Yet to hear of a GTA with 2.77
www.gtasourcepage.com

There is also the possibility it came stock with a Dana rearend.

If the SPI label is still inside the console, GW6 is the code for 3.27 gear. GM3 is for 3.45 (manual transmissions only)
Y11 is for the Dana rear. Don't recall code for 3.08 or 2.77.
Could just look under the car and check the tag if it's still there.

Horsepower ratings for auto. equiped 305 GTA for '88:
190 hp @ 4000 rpm; 295 torque @ 2800

 

Thats a new one on me. To the best of my knowledge, the Dana 44 was an over the counter race rear end, and never factory equipped on 3rd gen f-bodies.

According to my GM Production Options book:

RPO: Years: RPO Description:

Y11 1990-1992 10.50" Ring Gear, Dana Rear Axle


That kinda looks to me like a truck differential option.

I could be wrong, but according to everything I've read over the years, the Borg-Warner 7.75" ring gear Australian 9-bolt was the beefiest differential we could get on our cars from the factory. If a Dana was in fact available, is there anyone here on the forums thats has one in their car from the factory? Just curious.

Dave

 

FREEEEEEEEEEEEE MODDDDDDDDDDDSSSSSSSSSSSSSSS

 

The Anvil,

I got that information from www.gtasourcepage.com
A reliable source. Take it for what its worth.

 

According to the GTA Source Page, Option Code Y11 is the 'Package, V.I.P Plus', which jibes with my GM RPO book. ("interior ornamentation"). Y11 meant various things over the years, but no sign of it meaning a Dana rear end in the f-body.

If you can show me the link concerning Y11 meaning the Dana rear end in the f-body, I'd like to take a look.

Thanks.

 

http://www.gtasourcepage.com/88RPOFigures.html

Y-11 Ring Gear, 10.50 diameter, Dana Rear Axle - 3,308