How can I get my 89 GTA to break into the 13's? It has an L98, 700R4, and 3.27 gears. I ran a 14.85 @ 93mph bone stock. Does this sound right? I want to hit 13.99 just once. What do I need to do to accomplish this without using NOS or supercharger? Also, I'm looking for a ballpark figure as to how much it will cost. Its time to eat some Crustangs!

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1989 GTA, L98/auto, t-tops, Black w/ grey int.
Ran a 14.85 @ 93.4 mph BONE STOCK

 

Also, it has 108,000 miles on it. I dont want to rebuild it. I am however going to pull the heads to put in valve seals and take a look at the bores. Is there any head porting I can do myself? If so, does anyone have pics or any instructions on how to do so?

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1989 GTA, L98/auto, t-tops, Black w/ grey int.
Ran a 14.85 @ 93.4 mph BONE STOCK

 

Start with your bolt ons. I would get an exhaust, headers, with Y pipe, cold air intake, tpi airfoil, and a custom chip that should put you there.

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TPI 305,
Gutted airboxes,
gutted MAF,
K&N filters,
Corvette Servo.
14.9@93mph

"Speed kills, wanna live forever, drive a Ford."

 

Just to give you some hope check out my times and mods below. Keep in mind I've never even had the valve covers off.
I'm planning on a new intake and runners along with a new convertor this year to put me in the mid 13's I hope.

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350 TPI, 700R4(rebuilt), K&N's, MSD 6AL, Headers, Flowmaster, 160* stat, airfoil, MAF screens cut out. 13.88 @ 101.18 mph

 

Much the same as above:

Adj FPR
K&N Cold Air Induction
Air Foil
160 Degree Thermostat
JET Fan Switch
SLP 1 3/4" header/y-pipe kit
Gutted cat or Random tech converter
3" Cat-back-recommend Flowmaster (only cuz it's what I have
3.73 Ring & Pinion (If you have Posi)
Weld-in Subframe Connectors (do this first)
Lakewood Air Bag w/about 11PSI of air in right rear spring for traction w/street tires
Vigilante or B&M 2200RPM stall Converter

This should put you (not overestimated) at 13.8's or better, I'd guess right around 13.5's, but once again, don't over-estimate, I'd guess traction will be your biggest problem. Good Luck!



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Dan Young
1995 Z28/M6
Groton, CT

1985 Z28/A4
(Prospective purchase)

 

I know a fellow in an 89 IROC that ran a 13.5 with Catback, Ypipe, Headers, Ramair, 3.73 and a Custom Burned Chip I do believe he may have rebuilt his engine aswell.

 

After you've done all of the above suggestions, pull out the back seat, spare tire, carpet, tire change tools, cigarette lighter, ash tray...anything to make the car lighter.

Get some wide masking tape and tape over any gaps that might cause drag at high speeds. The car will look like hell, but that bit of weight reduction will make a difference.

 

Here's my recipe for the 13's.....
By the way, my car is an 88 GTA with the same engine, tranny, and gears as yours and has about the same mileage. Your times sound right for a stock gta, what was the weather and altitude?

I ran a 14.33 over a year ago with the following mods:
Flowmaster cat-back
ported plenum
underdrive pulleys
TransGo shift kit
Accel ignition
Hotchkis panhard rod and LCA's

Since then I've ported the plenum even further, added SLP intake runners, Performance resources chip, and a homemade cold-air kit and the car feels MUCh stronger! I know I'm in the 13's now, but haven't gotten a chance to get back to the track to prove it. I also have headers and y-pipe and an airfoil waiting to go on over the winter.

If I had to do it over again, here's the route I would take:
Headers and y-pipe (Edelbrock TES)
Cat-back (either gut your cat or get a high flow one also)
port your plenum and build yourself a homemade cold air kit.
TranGo shift kit (may not make you a whole lot faster but it's just too much fun not to do)
SLP runners
Performance Resources chip or custom one.

The runners, chip, and headers will set yu back about $300 each, the cat-back's a little cheaper, shift kit is about $50 and the porting and cold air kit is free or close to it. this should get you into the 13's, as long as you can get traction and have decent waether.

Dave M
88 GTA

 

Well hell, thanks for all your replies. I guess I know my mission now. Gotta get this baby moving. Also I forgot to add a little exhaust situation. I have an exhaust off like an 83 or 84 T/A with the two little crossflow mufflers with the 2 1/4 inch pipe from the cat all the way back. I think you guys know what I'm talking about. This has to be killing my times right? BTW, I ran my car at about 90 degrees outside temp in Phoenix with a 2.0 60 foot time.

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1989 GTA, L98/auto, t-tops, Black w/ grey int.
Ran a 14.85 @ 93.4 mph BONE STOCK

 

Hey, remember... an aftermarket cat-back would still free up some hp and be WAY less restrictive

 

Check the link in my sig, to my mods list.

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West Coast GM Shootout 2001!
1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.25 @ 107.18 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-

 

Not to dissuade you from doing some head porting, but you don't have to remove the heads to do the seals. When I do mine I'm just going to crank each piston to TDC when I do the seal - that will keep the valve from falling into the cyllinder.

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89 Iroc-Z LB9 305 TPI auto 2.73 posi:
3" Dynomax "cat" back,K&N filters, TB bypass, 3" pipe in place of cat, cleaned and flow-matched injectors, 180' thermo, mild ignition mods, synthetic oil, kicker sound system, soon to attempt engine swap...

 

That sounds good. I know I dont have to remove the heads to do valve seals, but I was just wondering about any porting I can do at home to free up some horsies. I do have a tool to keep the valve held up in place. It works off an air compressor. Do you guys think a cam would help me any?

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1989 GTA, L98/auto, t-tops, Black w/ grey int.
Ran a 14.85 @ 93.4 mph BONE STOCK

 

I have decided to rebuild the mighty mill. I think im going to go with an aftermarket cam. Do you know of any that are emissions friendly but will help propel my beast that much closer to the 13 second mark? THX

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1989 GTA, L98/auto, t-tops, Black w/ grey int.
Ran a 14.85 @ 93.4 mph w/ 305 exhaust (2 little crossflow mufflers), descreened MAF, TB coolant bypass, and casting wall ground down behind throttle plates.

 

The ZZ4 cam is pretty mild but with .510 lift on the exhaust might interfere w/ retainer to guide.

 

If you're having traction problems, your best bet is probably a SS Adj. torque arm. Talk to some people who have them about before&after performance and I think you'll be sold on it like me! After subframes and a rebuild, that's going to be my next suspension mod - that lakewood bag in the spring is also a great idea.

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Base: 89 Iroc-Z LB9 auto 2.73 posi
Exh: 3" Dynomax muffler, 3" Pipe in place of cat
Ign: Accel 300+ wires, cap&rotor
Fuel: Cleaned and flow-matched injectors, afpr, !air pump&diverter valve
Sound: Clarion deck, Kicker speakers and amps
Suspension: KYB Shocks, BMR Strut Tower Brace
Misc: TB Bypass, Synthetic Oil, Flexlite Transmission cooler,
free mods, hopefully engine swap and 4th gen seats in the works...

 

100 shot of nos should do the trick

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1982 Camaro Z28

should be running 11's this spring...we'll see
Check the website for progress http://members.fbody.com/Pro82Z/