88GTAinRI

I need some opinions. I have a completley stock GTA (20,000 miles) and have been considering all kinds of modifications. I plan on the following. SLP 1 3/4" headers, porting stock intake, superram, Crane compucam 214/220 duration .452/.465 lift, AFPR, 2800 stall speed converter, MAC cat back system, strut tower brace, frame connecters, rear gears?, and a B&M megashifter. I need some ideas for the following. I need a good flowing head for everday street use as visits to dragstrip will be occasional. I am unsure what size combustion chamber too use and have no plans of building a stroker motor. I don't want to raise compression alot, to keep my options for a supercharger open for the future. Do I need a bigger throttle body with head change and superram, and does all this added airflow affect air flow sensors readings? Does AFPR give the extra fuel needed or should I consider bigger fuel injectors? Has anyone found a good PROM for these cars? I have had nothing but problems with them in the past. Anyone have part numbers for gears needed to calibrate speedometer after installing 3:73's? Is the ceramic header coating worth the extra bread? Thanks for your help and opinions of my project.

Hank O.

AUTOGON350

iTrader: (8)

If you do heads and cam you are going to need an intake that will support that added airflow. The TPI is great for low end tourque but drops off in the high end. There are many ways to overcome this like aftermarket runners and base manifolds, but I would suggest you look at the TPIS miniram intake if you are going to do new heads and cam. (tpis.com) It seems to support the increased airflow very well. Its easy to work on and I know there are a few companies making chips for it. It uses all GM stuff too. I have not heard a bad thing about it yet. Do a search on the Board archives for it. I know a guy here in town that was running one with ported heads on a 350 and stock cam and he was going 12.8 in the quarter. I know from first hand experience that if the TPI isnt opened up enough you will be dissapointed plus the long tube runners, superram setup is expensive and still kind of hard to work on. I tried running the stuff in my sig below with a stock TPI and it was not good. The heads and cam killed the low end and the TPI design killed the high end so the result is slow. The 2800 stall is a great idea and a lot of those cams like the high ratio gears. You will need a custom chip for sure. I tried to run mine with a stock chip and it ran but I had to keep one foot on the gas at all times to get it to idle and it ran like crap. I had great good luck with a custom prom I got from ed wright. I believe the website is fastchip.com or fastchips.com. You should search the Board Archives for advice on heads. I am happy with my sportsman II heads from world castings even though they are a little wild for street. They only cost $700 complete with 2.02/160 valves and roller tip rockers. I belive they were the 72cc combustion chambers. Compression is like 9.5:1 on a 350. As far as the header coating you are probably going to get lots of mixed opinions on that. I have heard that it gets beat up bad during installation which does not surprise me considering the engine compartment. I have not dealt with the coated ones myself because the're like 3times the price.
I have also read that the stock throttle body is good up to 330horses.
24pph injectors should be good Ive seen equations for calculating injector sizes for different horse power requirements on this site before but I dont remember where. Ask around.
thats my little bit of advice hope that helps out.

iroc22

What year is the GTA? there's a huge difference between the MAF cars and the MAP ones. 64cc is the stock combustion chamber size. There's a huge range of heads on the market. How much are you willing to spend?

72cc on a 350 will not produce a 9.5:1 compression ratio, unless you are running domed pistons, about 10cc.

88GTAinRI

I just ordered the following:
World Product Sportsman II Lite heads 74cc straight plug
SLP cam 51006 218/224 @ .050 .495/.502 lift
SLP Headers 1 3/4 stainless steel
Summit steel 1.5 roller rockers
Comp Cam hardened push rods
Summit pushrod guideplates
BBK 52 mm throttle plates
BBK AFPR
MSD 6BTM boost timing control system
MSD blaster SS coil
Dynomax high flow catalytic converter
MAC cat back exhaust system
Auto meter pillar gauge pod
Nordskog digital fuel pressure gauge
Nordskog digital boost gauge
B&M megashifter for Camaro & Firebird console
Edelbrock strut tower brace

Found a superram, new, for a sweet price! Haven't ordered yet.

Need:
wires. undecide which ones yet. I've had the Accell 300+ in the past.
MSD 8366 distributor
3:73 gears and speedo calibration
2500-2800 stall speed converter
SUPERCHARGER
Custom burned PROM
air foil
Time to install all of this stuff!
Aftermarket intake? Or port the hell out of stock?
Remove MAF screens
Frame connectors
CD player and speakers


The heads are on backorder until middle of July. that sucks. Not sure which supercharger to run yet. Still doing some reading.

I noticed alot of peole read post but didn't respond. I must have asked too many questions! Thanks to everyone that did respond and sent me their ideas via e-mail.

Hank O

gtabadboy

Just watch your compression for the heads when you get the supercharger. You will need about 8:1 compreesion so that your blower performs good. Check the specs on the blower you want to buy so that you dont have to mess with the heads and pistons to reduce compression when you buy the blower. I made this mistake and got so frustrated when the car was slower with the supercharger. I sold the paxton to my bro for $400.

urbman

Wow 20k miles...
Sell it to one of the resto guys...
Buy something errr less pristine to hack on
save this one

AJ_92RS

My thoughts exactly.

That car is worth more now (as well as easier to sell) than if you were to build it up. Hell, I'd pay $10K-$12K for a car like that, if I had the money.

I wouldn't be afraid to add bolt on parts, but I'd also keep the original parts. That way it'd still be worth something when (and if) you were gonna sell it.

I can also guarantee that you'd win more shows if you left it stock. Can you say "Trophies"?

AJ

88IROCs

Some thoughts:

- aren't the Sportsman II Lite heads made of aluminum? If so, that and those huge chambers are really going to hurt your top end(lack of compression). If your worried about adding boost, most of the supercharger manufacturer's make kits to work with the stock heads' compression. The boost in these kits range from 6 - 8 psi, and it's usually good for approx. 100 hp. If these heads are made of aluminum, order them in a 58 - 64cc chamber, which should give you between 9.25 - 10.00:1 CR.

- CompCams makes a cam with the exact same specs as SLP's, but charges about $100 less. This cam is a good one for a normally-aspirated, stock compression TPI. For a boosted motor you'll want something with less overlap(especially a boosted motor with low compression).

- an afpr should be used to fine-tune the fuel flow. If you need to go more than 5 psi over the injector's rated pressure(usually around 43.5 psi), you should get larger injectors.

- nobody, living hundred's of miles from you, is going to burn the perfect PROM for your motor. Hell, some of them can't even burn a 'decent' chip for a stock motor. Get your butt over to the "PROM" forum and learn how yourself. This is truely one of those times when: "If ya want it done right, you'll have to do it yourself". Besides which, your F-body owning friends will be envious of you, and those Fox-body guys will have another reason to hate ya

- I noticed you aren't changing anything between the TB and the heads, there's a potential for a bottleneck there. I'd definitely consider an Accel SuperRam base. Check with Cruzin' Performance: they occassionally put these up on eBay for a Buy It Now of less than $400. Maybe they can get you a deal. You might also want to consider larger runners - SLP's are great for the price and AS&M's are better if price ain't a worry.

- don't overlook the chassis and suspension. With sfc's, tube LCA's and a stiffer torque arm, you can probably lose around 0.5 sec, without needing additional horses. Adjustable shocks are great for dialling it in at the track and making it comfortable for the street(this matters to an old fart like me). Mild lowering springs(1.00" - 1.50") will also help with weight transfer at launch and during cornering, without making you deathly afraid of speed bumps.

- the jury is still out on whether header-coatings make an appreciable horsepower gain, but it definitely lowers underhood temps. Lower temps underhood usually means you can run more boost safely.

88GTAinRI

The sportsman II's are out. They are on backorder and everyday they give me a later and later date of shipment. I bought the Dart Pro 1's. I do plan on keeping all the old parts that I take off to make sure car could be made original again by turning a few bolts. I just added a mega shifter and bought new shifter trim piece I had to cut to make transition, wrapped old shifter and cable up, and put them in storage. I also ordered a new pillar piece because of modifications made to existing one for gauges. I WILL NOT be "hacking" car as Urbman put it. All bolt on modifications are street and smog legal (for the most part). I will be making mods between the t/b and heads. I bought the Superram and Accel base manifold from Cruizin performance. The guy there, Rich, was great and would recommend him to anyone. I have read the chip burning posts and "how to" and it all sounds foreign to me. I think once I try it, hands on, it will make more sense. I will definately try to find all out I can about custom PROM making. Thanks to everyone for posting there techniques. Anyone in New England area thats wants to show me how, I'm buying the beers. Chasis mods will probably come next spring after the long winter nap. A modified car can win trophies too! Thanks for your replies. I learn something new on this board everyday.

Hank O.

urbman

No offense intended
In my universe hacking means
"skillful modification"

88GTAinRI

None taken. I work for a new car dealership, so "hacking" is a nasty word. I like "skillful modification" much better.:rockon: