silvercl55

I just replaced my cat with he magnaflow x pipe and went 3" back to the mufflers. It seems to be raspier then i thought espically than the videos i heard. But the more important thing is it seems to be alot slower espically fro
1st gear on the highway it seems to be quicker but i cant really tell. Can someone give me any suggestions or reasons of what it could be or what i should do to fix this. Im thinking the computer might just need to adjust adjust to the new system. Any help would be greatly appreciated. Thanks

wawy

You may have freed up too much back pressure and possibly lost some low end power (torque). Perhaps the ecu will adapt somewhat but if it doesn't then you may have to look at getting a custom ecu tune....

Exotic-metal55

You are being fooled by the lower pitched sound. You did not loose HP or TQ from doing that small mod.. Super charged engines need exhaust out quickly. YOur stock manifolds create TONS of back pressure..

ATKM5

Drive it! After 300 miles or so, the ECU will adapt! I had the same set-up on my E55....

silvercl55

Did you have the same situation with yours. it seems like at low gears it takes a min to take off and feel like at first it lags. on the highway iot seems like it really moves quicker with a more steady flow in the power band it doesn't seem to pull as hard but I get up in speed alot faster than before. Could this possibly effect the temp on the car i don't know it it's me or not but it seems to run a lil warmer. a lil below the line between the middle of the one from the 80 and 120 if that makes sense. Any insight would help i'm about to put it back to stock and call it a day with messing with this thing.

ATKM5

Before you put it back to stock, please give the ECU a chance to adjust. I felt like I lost power as well, but after driving it, the sound became better, the car felt much lighter on its feet (revved much easier IMO). I also installed green filters after that and the two went together really well. I don't have the dyno sheet anymore as I got rid of the car 2 years ago, but I remember that my car produced 432 rwhp with the exhaust and filters... Baseline was 418 rwhp.

Hope this helps, but like I said, just drive it for 300 miles or so on this set-up! Let me know how it goes!

silvercl55

thanks for the advice. it's making me very hopeful. I was about to give up on the car. lol...I've been also researching a little on if there is anything on the cheaper side to do to help performance as well. I know we own very expensive cars and nothing is cheap but within reason. Maybe a couple hundred to few hundred dollar range.

ATKM5

Yeh I hear you...

So far, for the 55K cars I found that the best upgrades were:
Johnson CM30 Pump - 150$, the car was able to use it full pontential
Sec Cat + Res Delete - 200-300$, 10 rwhp gain
Green Filters - 150$, 4 rwhp gain
I think ASP pulley is still good buy for $800, but an ECU tune is highly advised to support it and thats where it gets pricey. Although LET offers an ECU tune for $800 I hear, I bet all the above + ASP + LET ECU will put you at 490 rwp....

I wish gains with the 63 were that easy... lol