91 z28 305tpi & 5 speed

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Sep 26, 2000 | 08:02 AM

mikemat

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Joined: Jun 2000

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From: harper woods michigan u.s.a.

91 z28 305tpi & 5 speed

I bougght this car used it has a flomaster muffler and 2/1/2" tail pipes it also had astage 3 chip but dealer took it out. I replaced it with a hypertech thermomaster chip. My problem is,whats the stock horsepower? I can not get tha anwesr from anybody.I tried the dealer,cheverolet customer service,ect... ,but nobody seems to know.

Sep 26, 2000 | 08:43 AM

Brian Shaughnessy

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Joined: Jul 1999

Posts: 216

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From: Saugerties, NY, USA

Car: '89 Formula

Engine: 355 TPI

Transmission: T56

Axle/Gears: 3.70 9 bolt.

Single cat conv. = 205 hp. Dual cats = 230.

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'89 Formula - Thunderchicken - 355 Vette L98/T-5/3.45 9-bolt/black/t-tops - the fun car!
'90 GTA - The GTA - 5.0 LB9/TH700/3.27 9-bolt/black/t-tops/tan leather - the cruiser.

Sep 26, 2000 | 11:42 AM

IrocManiac

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Joined: Apr 2000

Posts: 213

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From: Ok, USA

220 I think for the single cat and 230 for the dual cats.

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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."

Sep 26, 2000 | 03:18 PM

Kevin91Z

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Joined: Jul 1999

Posts: 10,950

Likes: 26

From: Orange, SoCal

Car: 1990 Pontiac Trans Am

Engine: 355 TPI siamesed runners

Transmission: Tremec T56

Axle/Gears: 12-Bolt 3.73

Brian is correct. 205 HP for a 90-92 305 TPI with a single catalytic converter, and 230 HP for a 305 TPI with dual cats.

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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=-