Header and O/R H Pipe install, and now no bottom end?
06-02-2009, 09:14 PM
#1
Thread Starter
Join Date: Jul 2008
Location: CA
Posts: 8
Header and O/R H Pipe install, and now no bottom end?
Hey what's up, so I installed a Hooker super comp set of headers and O/R H Pipe this weekend. Now it seems like my car has no bottom end. It's an 87 converted to MAF, with just bolt ons such as underdrive pullies, BBK CAI, 93 ecu and MAF, 2 chamber flows, stage 2 shift kit and 3.73's. Now am I just too anxious too notice results, and will it take awhile for the ECU to reprogram itself? Or what's going on?
Seems like it had more power before! UGH!
Seems like it had more power before! UGH!
06-02-2009, 09:25 PM
#2
4th Gear Member
Join Date: Aug 2007
Location: Texas
Posts: 1,788
An exhaust needs back pressure. The cat-converters and crimped 2&1/4" provided extreme backpressure while being slightly restrictive. By adding free flowing tubing and no converters you have essentially given yourself more power, but at a higher rpm. When I took off my stock H-pipe I noticed a dramatic loss of low end torque. But now I have two cats and I regained my lost torque.
06-02-2009, 10:07 PM
#4
4th Gear Member
Join Date: Aug 2007
Location: Texas
Posts: 1,788
Without opening up the wallet there is not much to do. You could bolt on some highflow cats or maybe swap your gears for some lower ones like 4:10's. It doesn't help your cause that you have a hp/trq robbing AOD.
06-02-2009, 10:57 PM
#6
2nd Gear Member
Join Date: Feb 2008
Location:
Posts: 461
I had an 87' GT auto years ago.Forget what gear it had.I installed an offroad H-pipe and a Flowmaster American thunder axle back and man did it sound mean but lost EVERY OUNCE of low end it really never had.My bad.
06-03-2009, 06:44 AM
#8
1st Gear Member
Join Date: Feb 2009
Location: Exton Pa.
Posts: 76
pipes
Sell the H-pipe and install an X-pipe you will get back about 10% Tq did you advance the timing after the install? Unless you have a stroker motor or forced induction your mods are too small for that big exhaust. Time to add a blower or turbo.......
06-03-2009, 01:23 PM
#9
Thread Starter
Join Date: Jul 2008
Location: CA
Posts: 8
I guess you are right with over doing the exhaust with what lil I have so far, I do plan on rebuilding the motor at some point a 347 with high hopes. No I didn't advance the timing. I tried that before with only getting the dreaded pinging it seemed at 12-14 deg and yes I run 91/92 only.
