The reason is , I just had new custom exhaust dualed from cats back to a dual Magnaflow muffler then out dual tips. I lost some low end T/Q. I havent dyno yet but I can feel the loss of T/Q down low. It reved much faster before the new exhaust was put on, it screamed thru the powerband now it sputters trying to climb the powerband. The exhaust is much quieter than before the mufler was installed with new piping. So I have decided to try to free up some air by getting Crawfords hiflows but was wondering do you lose T/Q low? My exhaust was only 400.00 but I dont want to go backwards in power for sound. Will hiflows help?

 

Its been addressed time and time again. Exhaust mods will alter the torque curve. Attempting to figure out how for every potential combination is impossible.

 

I understand that , my point is I gained back pressure by adding a muffler , now will hiflow cats help with the flow or not worth the cost?

 

Yes. I believe that high-flow catalytic converters are a worthwhile bolt-on (I own a pair). Its just an educated guess but the new torque line will cross the previous one at about 2,500 rpm. In other words there will be a torque loss below 2,500 rpm but it is offset by a gain above 2,500 rpm. This seems to be a common experience.

A ECU tune may help this situation.

 

I will get a dyno this weekend , then probably order some Crawford cats have Doug install them. I just was trying to think of a way to get some T/Q loss down low from new exhaust. Thanx David you have been helpful.

 

you shouldn't have a tq loss from hf cats. i havn't seen a dyno to suggest htere's any loss anywher ein the band