First time is was at the track i ran a best of 16.2, which is just about right on the 86 ta right out of the factory, whichi i think it was tested at 16.3.

Now i put on slp headers to catco cat and american thunder catback and ran a best of 15.3, so i gained 9 tenths of a second, the 60 foot times stayed about the same. Oh yea, i also gained 7mph. I have lcas sitting in my gargage right now i need to put on and maybe get sub 2 60 foot times.

I did have more tire spin off the line when launching at 1500rpm so i dropped it down to about 1200rpm and that helped but i still couldn't get them lower than my first outting.

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1986 Trans Am
305 TPI
"If it's not one thing, it's another!"
http://www2.hanover.edu/hierlmeier

[This message has been edited by 86Trans Am (edited May 31, 2001).]

 

Cool, nice performance gains!!

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89 RS

Looking For:
87 IROC-Z28 350 TPI

 

holy ****!!!

------------------
Webmaster: www.IROC-Z.org

 

Post this message on the TBI board, with attn to "ONEFINE8T9". He, for some unknown reason, thinks that exhaust won't help a stock motor. (?!)

Anyway, good mod, and great results!

 

Great improvement..... Still shouldn't the car be sub 15's with those mods? How many miles?

 

i put a full exhaust on and lost 2 tenths.

 

Keep in mind this is the peanut cam, the worst cam GM has ever put in a car....

I have full exhaust
ported plenum
home made air-intake with k&n
airfoil
msd cap/coil/rotor/wires ac rapidfire plugs
ss subframe connectors
emissions removed
afpr

and the car weighs with me in it 3800 pounds, no i am not fat, i weigh 150

any body else think this thing should be faster? I have never messed with the timing, tps, egr, or any other sensors or relays.

Is bumping the timing up a couple degrees worth while procedure or a waste of time?

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1986 Trans Am
305 TPI
"If it's not one thing, it's another!"
http://www2.hanover.edu/hierlmeier

 

Your right about the cam. I swaped a LT1 cam into my 87 what a diff. I was going to do headers next but I bought the 350 to build insteed. Here are all my times.


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87 Z28 305 TPI, Auto, LT-1 cam (@.50 418/430, 194/199, LSA 111), roller timing set, 2.73, Gutted air boxes, K & N fillters, Dyno Max 3" cat back, 8.8 mm spirals, air foil, BFG Drag radials, and 170* Stat.
Old Best 15.414 @ 87.47.
new best 15.006 @ 89.55.
w/ drag radails 14.72 @ 92.1

“Fallen But Not Forgotten”

 

You're running right where you should. You didn't mention your rear end ratio but if it's a 2.73 you're actually doing pretty good. Exhaust is always the first place to go for power on a TPI F-Body after you use all the free mods up. The factory manfilds and y-pipe are a joke. And after a decade or so of hard use your cat could have been a little "congested"...

Yes, bumping your timing up a few degrees will help quite a bit if running a stock chip. Bump it from 6* (stock) to 10* and you'll pick up a solid tenth and 1 MPH.


[This message has been edited by Damon (edited June 01, 2001).]

 

My 91z 305 5-speed ran a 14.874 @94.55mph w/only a slp catback. Stock 3.42s and all. Derrick

 

my car ran a 14.874 @94.55mph w/only a slp cat-back. Stock 3.42s and all. And that was w/a 2.3 60'. Derrick

 

I replaced the stock LG4 exhaust w/ 1-5/8 Summit headers, and custom 3" exhaust w/ a Magnum race muffler (its way to loud) but improved by .5 !!! I have timeslips and witnesses!

------------------
If you live in Southeastern US, check us out!
South East Thirdgen

GM Master Tech
ASE Master Tech + L1
Savannah, GA

'87 Trans Am
S/D TPI retrofit including functional PassKey,
22# injectors,
Whatever chip I feel like burning,
JET AFPR, Ported Plenum,
TB Coolant Bypass, Custom Cold Air,
SSM SFC, KYB Shocks, Boxed LCAs, Wonder Bar,
8mm Accel wires,
Flowmaster Exhaust,
16" GTA rims,
Corvette Servo,
3.73 Posi
4wheel Disc Brakes

'97 Bonneville SSE

 

86 Trans Am, I have a dealer poster from 86 that has a red Trans Am with you wheels on it. I would have sent you an email, but its not listed on your profile. If you are interested in it, send me an email at Teletubbie98_99@yahoo.com


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89 Trans Am Turbo 3.8L All stock 43,000 miles #1053 of 1555

Past Thirdgen:
86 Trans Am w/ built 355TPI with SLP goodies and too much other stuff to List. One sweet *** car, wish I would have had a good enough Job to pay insurance on three cars so I could keep it, but for a 89 Turbo Trans Am w/ Low miles, I think I made the right choice!

 

You know, anymore, i'm not even sure what gears i have. My dad, who ordered the car in 1985 seems to think it has 3.23's, but after reading some of the stuff on the board i'm begining to wonder if they aren't 2.73's. I have looked for the stamp on the axle tube but couldnt find it. All i know is that at about 70mph, i'm at about 1800-2000rpm, closer to 1800.

Oh well, installed my poly/rod ended lca's today, of course it rained.....

plus my transmission decided it didnt want to go into 4th again for awhile...

------------------
1986 Trans Am
305 TPI
"If it's not one thing, it's another!"
http://www2.hanover.edu/hierlmeier

 

with that kind of rpm they definitly must be 2.73 gears. sounds like a pretty good gain for that mod.

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'92 firebird t-tops
305tbi,670cfm tbi, 2 1/2" Dynomax catback, 9x3 K&N open element

 

1800 RPM at 70?!?!
When I'm at 70 I'm well over 2500!
Count your blessings, with gas at $2.15 a gallon here in NY.

Gotta love 3.70's!

------------------
1980 Camaro, '88 Police 350 engine, Headers, full exhaust, completely redone, my baby!
1988 Iroc-Z L98, MSD 6a, Accel coil, K+N's, Airfoil, Coolant Bypass, Flowmaster, Gears, Late model Bose, I like the 80 better

 

i have to confirm that exhaust work does help but i had to put in a afpr to get full effects. these are the times on my car for reference. 87gta L98 ran 15.21 bone stock.. after complete exhauste 1 3/4 headers high flow cat and flowmaster it ran actually slower at 15.26. checked car over and found i was lean. put in afpr and ported plenhiem and now just ran 14.81.. i think it should be a little lower but i have major wheel spin now off the line. running basic street tires which do not stick worth a damn. after new skins it should be interesting to see if i can lower it some more.

 

Throw a quarter in the top of your FPR if you don't already have an AFPR. Cheap way to shim the FPR and up pressure a couple lbs...

------------------
Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray