Hi guys, I guess I'm pretty new here so maybe this isn't the correct place for this question, if not I'm sorry. Anyway I am looking to purchase a stock thirgen with a 350tpi engine. I prefer a Formula or a GTA. I had a 87 GTA with a 305 about 8 years ago and It ran mid 15's at about 88 mph. Nothing crazy but it was a fun car to drive. Now I am wondering what is easier to get into the consistant 13's, 87-90 or the 91-92 engines. I've heard the major difference is the later don't have a MAF sensor meaning mods require tuning more so that with a MAF sensor. Since I am hoping to achieve 13's with mostly bolt on parts which would you reccomend. Also is it possible with bolt ons. I'm currently looking at a 91 GTA, 91 Formula 350, and a 88 GTA. All of them have the 350tpi engine and are around $3000.00-3500.00. They are also stock with only a few little mods. So I guess what do you guys think?

Thanks in advance for your time!

- Zack

 

Welcome to the board. I think the easiest way to go fast for cheap is with a carburator. I know, the TPI looks cool and makes lots of low end torque, but if you are on a budget and want to go fast, 350+carb+good heads = fast! You can do it with a TPI for sure, but it will cost you. I have also heard that suspension mods are a big part of the puzzle for making these cars run hard as you lose a lot of power through body flex...and boy do they flex!! And you are right about the MAF. Because it measures airflow, and many of the mods improve air flow (either in or out), the computer is able to make more out of the mods because it can better measure the effect of them. A MAP is more primitive, it essentially only tells the computer how far your foot is into the pedal...that's it. But MAFs can limit airflow somewhat...probably not enough to make a difference for 13's, but I'm not sure. Hopefully some of the better EFI guys will wade in on this. As far as bolt on stuff, its just like any other engine....more air in+more air out+more fuel to feed the more air = more power. Most guys to exhaust mods, intake mods, and then bump up the fuel to make the most of the first two. I think usually you need to do the intake, fuel system and tuning all together. And search through some threads, there should be TONS of stuff on this.

 

A 350 TPI can easily get into the 13's with bolt ons. Slap a carb on and you basically ruin all the nice driveability of a fuel injected car. Get a Walboro 255 lph pump to start with redo the entire exhaust (headers back) and get sticky tires, this'll give you a good base line on what you'll need after that. TPI cars are all over the place, one will run 13.9's, another will run 15.0's. You really want to start with a 1990 plus MAP car, the MAP system is superior to the MAF system on Thirdgen Camaro's for alot of reasons and 13's should be a bit easier to get but you WILL need to learn tuning if you want to take it much further. Good luck on the build I'm sure you'll get where you want.

 

13's are pretty easy to getto with TPI. I would go with a newer speed density system. Yes it requires more computer tuning but with this site it becomes alot easier.
Building on what 1991CamaroRslow said I would put in new injectors and a good cam with a little headwork(heads only good to about .480 lift) And start your tune with the Super_AUJP V4 prom that you can download from here Check the diy prom boards lots of good stuff and Moates.net to get the equipment.
also some LCA's and LCArb's to help launch the car.With that you shouldbe well on your way.

 

I know a few people that got 350 MAF car in the 13's with bolt on. You figure you are starting at a 14.5ish car to a 13.9? Do the exhaust, header back, AFPR, port the plenum, get LTR's and base plate and you are mid 13's on a crappy tune and still get fuel injection reliability. Later a cam and heads will boost your torque but remember, most tpi systems lose steam after 4500 rpms so you may need to go stealth ram later for upper end power.

 

i had a 89 305 tpi motor in the 12s but it had a cam so it wasnt exactly all bolt ons, but a 350 with a little work should go 13s easily

 

I only have 1/8 mile tracks around here. But what I was running in the 1/8 is fairly close to 13.8/13.9 1/4's.

At the time I had some weight savings mods, full exhaust(block back), tune, modified air intake, A bit of suspension, 3.23 gears. Stock plenium, stock runners, sock FPR, stock injectors.

Its not all motor. Its everything.

 

Wow thanks alot for the responses. I am getting excited about this future build/restore. I'm glad to see this forum has great members that are happy to help out the newbies. Now I just need to decide on which car.

- Zack

 

Get the Formula if it's in good shape.

 

I think with only 3.73s, good tires, headers back and a
good chip tune,temp ect, that 13.9 is very achievable.

JMHO

Later

 

The 91 formula would be the fastest box stock bc its lighter then the GTA's
However if you want the cumfort too The GTA's would be the way to go. They have alot better interior then the other firebirds do. Its a great setup but adds more weight that if you don't need or want will slow you down

My vote the Formula

 

The formula also has a 3.73 rear in it already with an auburn posi if I remember right. I like the clean look of the formula's also. I'm still going to take my time and look at all the avenues. I will have a car before the fall though.