Is this normal

[turbulance_cressida]

Hey guys yesterday was the first day i drove my 1j single turbo supra to the exhaust shop.so while driving there the car moves beautiful with no boost with open downpipe. The car was able to rev out at 75k before the exhaust. So while driving back home the car feel lazy a bit and not reving pass 7k. Today i wanted to plug up the two wholes in the downpipe 1 for the o2 and the other for the aem wideband.my mods are pt70,550c,arfp,safc,96 twin fuel pump. So my question is it normal to have the motor not able to rev out as well as it did before the exhaust is put on?oh yea the car is not tuned at all.

 

[86_sports_1jz]

an exhuast system shouldn't affect how high you can rev... it maybe your tach or ecu cuz i remember mine sometimes reving to 73 and sometimes only 68, more than likely its your tach

 

[turbulance_cressida]

Cool thanks

 

[supra90turbo]

75k?! That's incredible! F1 cars are only turning 20k!!

 

[RacerXJ220]

When I tune for open downpipe, then put the exhaust on, I will run richer, and lose power because of it. My turbo needs more time to spool.

When I put the exhaust on, and tune it, then take the exhaust off, I run so lean I have to back out of it and put the other tune on.

My exhaust consist of a three foot section of pipe with a magnaflow straight through muffler that ends under the passenger seat. Not a lot of piping, and still a good deal lost in spool.