need advice

[chuck88]

I have an 88 GT and I want about 300 hP.
Current mods GT 40 upper/lower Lower is ported
65 mm Throttle body
shorty headers, hiflow cats, H Pipe, dynomax exhaust
Cold air intake
3:55 gears

The mech. dyno tuned the car and I have 240 hp & 300lbs torque

Now the car is backfiring. He did correct the surguing idlke and stalling problem. (I plan on going back)

He says I might have to much intake.

Could this be true?
If so which intake do you guys recommend the mech. suggested a cobra intake.
is this a good choice?

should I go heads & cam ($2500)?
mass air conversion?

I am son confused


chuck 88

[Coolbreeze]

I would keep the intake in preperation for a set of heads & cam. Once you get a set of good flowing heads the intake will be right...Then with heads and cam you should be at the 300HP mark you want.

[tommyinla]

should I go heads & cam ($2500)?
mass air conversion?

if you do go heads and cam, you'll have to convert to mass air. speed density doesn't deal well with major engine mods...

[gtsr515]

Well if you have a GT-40 intake the only reason to go to a Cobra intake is that it can be ported, If you want a new cam you must convert to Mass-Air, or you will have big driveability problems.

Forget about horsepower figures and concentrate on traction, If you've got stock suspension, no sticky tires and the like, 300 horsepower wont mean anything except on a roll on the highway.

Jay

[fiveohpatrol]

300 horsepower wont mean anything except on a roll on the highway.

Wow, something I actually agree with you on!

FYI, the cobra and the GT40 intakes are almost identical on the inside, and on flow rates. So let your mechanic know that so he doesnt try to tell other people wrong information.

Did your backfire start right after the dyno tune?

Have you checked timing and fuel pressure?

[302 LX Eric]

There are guys on this site that have had good results with mods and speed density (88workcar, Dark 5.0, et al), however, I would take the lazy way out and convert to mass-air. Sure, it might cost you a few HP, but it will accept just about every mod you throw at it.

I agree with the comments above about the GT-40 vs. Cobra intake.

E

[srv1]

Originally posted by chuck88
I have an 88 GT and I want about 300 hP.
Current mods GT 40 upper/lower Lower is ported
65 mm Throttle body
shorty headers, hiflow cats, H Pipe, dynomax exhaust
Cold air intake
3:55 gears

The mech. dyno tuned the car and I have 240 hp & 300lbs torque

Now the car is backfiring. He did correct the surguing idlke and stalling problem. (I plan on going back)

He says I might have to much intake.

Could this be true?
If so which intake do you guys recommend the mech. suggested a cobra intake.
is this a good choice?

should I go heads & cam ($2500)?
mass air conversion?

I am son confused


chuck 88

Is that 240 at the wheels?

[chuck88]

The back firing reocurred after the dyno tune I stopped by pushing the fuel pressure way up (48).

Yes that was 240 hp at the wheels.

Do you guys think a mass air conversion will solve the problems?

Chuck88