I have a 1990 Mustang Gt Convertible...I took my friends advise and installed Mac 1 5/8 unequal length headers, underdrive pulleys, BBK X-Pipe with NO CATS, smog pump was taken off. In fender free flow air filter, Hot coil, aftermarket cap and rotor, and aftermarket cables. It still has the stock mufflers.

After installing all of this..the car has lost most of its low end torque. To back it out of the garage I have to accelerate it so it will pick up speed. If I downshift into 2nd..it gets really slow...On the highway...ITS GREAT...but this low end torque deal sucks...

I have been told everything, Install a 3:55 or 3:73 rear end to compensate...Take off the Mac 1 5/8" headers and go with 1 1/2" instead since it is a convertible and is heavier...some say...I should have never gone with the 2 1/2" X-pipe....

I DONT KNOW WHAT TO BELIEVE!!!!!!

HELP!!!

ASKERNIE
Ernie Fuentes

 

Get your car dyno tuned. It will cost you a bit, but theres a good chance your CPU is not reading the modifications correctly, and all that torque is waiting to be unleashed.

 

try disconnecting the negative battery cable for at least 10 minutes to clear the KAM (keep alive memory) in the ECU and then let it learn the new sensor readings and see if this doesn't help things out some. the headers and pipes are no way too big! I have the same size but equal length headers and didn't lose anything, gained instead.

 

Make sure there are NO leaks in your exhaust too, check them header bolts again...

 

Did you put the rotor on the way you took it off?
Is the fireing order correct?
And check your timing too.

 

The rotor can only go on one way.

Are you sure the tranny is ok?

 

just a ?....why put an x pipe and use stock mufflers all you did was choke off the exhaust......I would reset you tps, clean your electronics in your maf, check your timing and exhaust leaks..you did however do the right thing with the headers..and a good 3.90-4.10 gear will help a ton