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horsepower tv 6/5/04 03 cobra, re-program & pully. 491 HP !

I just watched the horsepower tv episode where they have a stock 03 cobra and do some mods to it. Stock they measure 364 ponies at the rear wheel. Comes down to about

418 at the crank which confirms what numerous other people have seen; Ford underrated the 03 cobra. Then they reprogrammed the Cobra with a hypertech programmer. This added another 43 ponies (total of 407 hp at the rear wheel or 468 hp at the crank) Then they changed a pully from 3.5 inch to 3 inch. Bumping up the pressure from 8psi to 12psi. This resulted in an increase of only 8 hp ? This seemed low to me. Not sure why it did not come out higher than that. They also reprogrammed the on board computer with the hypertech to reflect the pully change. After that they changed the pully to 2.8 inch diameter which resulted in a 12 hp increase. In the end they ended up with 427 hp at the rear wheel which means 491 HP at the crank ! Still impressive numbers for the small investment.

They also mentioned the defective driver side cylinder heads that Ford installed. Any heads with a date before nov-1 2002 can be defective and can result in a tick. He also said they have a bad design which will result in overheating (which I had not heard of before) You can check the date of the heads by looking right under the master cylinder, there's a sticker on the head with the date on it. Mine had

11/12/02 pfew. there is a recall out for this (voluntary) so check it out.

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Reply to
Rein
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Thanks for the tip. I watched it, today. It was particularly interesting when they said that the Hypertech programmer would not update the profile if it determined that the engine had pre-Nov'02 heads. If it did, you would have to call Hypertech, tell them you've had the head updated, and then they would give you a bypass "code" that would allow programming.

I went to the Hypertech website but couldn't see any mention of this restriction. I'm gonna call them about it.

They said that the Hypertech profile was optimized for stock intake and exhaust components, and that it might be risky to reprogram a car that had non-stock CAI and/or catbacks. They implied that the engine might run too lean with the update and without stock intake/exhaust.

The show also claimed that reprogramming would NOT invalidate the factory warranty. I wonder if Ford shares their beliefs?

Bob '03 Cobra coupe

Reply to
Bob

- snip

The instructions that came with the Hypertech Power Programmer III for my S-10 also stated that it did not void manufacturer's warranty. They did advise that you should de-program the computer when taking it in for service otherwise the non-factory specs would cause problems when the tech hooked up their computer.

bill Car: '64.5 Mustang: 260 V8, 3 sp, factory a/c, SVO cam, Performer intake, Holley 390 cfm carb, Pertronix, Hi-Po exhaust manifolds, 1.5" front & 1" rear drop, Jacobs wires, Torq Thrust D's

Guns: Colt AR15, Sig P220, Moss. 590A1, Marlin 70P

Reply to
bill

"bill" wrote

So, it won't void the warranty, but you gotta remove the programming before Chevy sees it. Hmmmmmmm.

Anybody else smell fish?

Reply to
66 6F HCS

Does your cobra have pre 1/2002 heads ?

hmm, makes sense. I'd have to ask about that since I have catbacks.

I doubt it. If they re-program it so it leans out too much at higher rpm's you could risk a lot. In case the motor blows due to something like that I am sure they won't cover it.

I've heard the Cobra is pretty rich at higher rpm's (on the safe side) and it wouldn't surprise me if hypertech leaned it out a bit to get these numbers. Would be interesting to see the air/fuel ratio from one of their dyno runs.

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Reply to
Rein

Well, my truck's been reprogrammed for 2 years with no ill effects. Hypertech states (as I mentioned before) that if you don't remove their tuning specs. that the service dept. computer will read the changed specs and indicate out of OEM tuning ranges. Basically causing the service dept. 'puter to indicate incorrect specs. and then you get the phone call from the "service advisor" saying you need X dollars of work to "fix" your vehicle.

Remember the factory builds the cars and computers to be as fuel efficient as reasonable to fulfill their government required total fuel efficiency.

Running lean wouldn't be a problem as you need to burn _more_ fuel to increase the horsepower with no other "go fast" goodies added to the engine/car.

bill Car: '64.5 Mustang: 260 V8, 3 sp, factory a/c, SVO cam, Performer intake, Holley 390 cfm carb, Pertronix, Hi-Po exhaust manifolds, 1.5" front & 1" rear drop, Jacobs wires, Torq Thrust D's

Guns: Colt AR15, Sig P220, Moss. 590A1, Marlin 70P

Reply to
bill

not exactly. The 03 cobra's are tuned on the SAFE side, not fuel-efficient. They are tuned RICH at the higher rpm's to prevent detonation. This also means you are not getting the max hp out of them. Too much fuel will reduce hp.

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Reply to
Rein

True, wasn't aware anyone was running their vehicles rich. I would have thought that would cause emission testing problems. But if it's only at high rpms that wouldn't be a problem during testing I'm guessing.

bill Car: '64.5 Mustang: 260 V8, 3 sp, factory a/c, SVO cam, Performer intake, Holley 390 cfm carb, Pertronix, Hi-Po exhaust manifolds, 1.5" front & 1" rear drop, Jacobs wires, Torq Thrust D's

Guns: Colt AR15, Sig P220, Moss. 590A1, Marlin 70P

Reply to
bill

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