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-   -   Installed Over pipe,no more low end torque? (https://www.ft86club.com/forums/showthread.php?t=36825)

Sniper2606 05-17-2013 06:28 PM

Installed Over pipe,no more low end torque?
 
I recently installed the FT86 over pipe on my brz matching it with the q300 and catless pipe, right away ive noticed that i lost the nice low rpm torque the car used to have, i did noticed the car pulling better on 4th, 5th,6th gear which i enjoy but im trying to figure out where the low end torque went?

Thanks

zoomzoomers 05-17-2013 06:39 PM

That's interesting you say that. Do you have any other mods? It's common that most bolt on mods are geared toward the higher end of the rev band, but to be able to actually "feel" the loss is surprising.

wheelhaus 05-17-2013 06:44 PM

Did you disconnect the battery for any reason? The ECU may be in it's learning phase, which can feel sluggish.

MightyMeeple 05-17-2013 06:48 PM

Quote:

Originally Posted by wheelhaus (Post 942375)
Did you disconnect the battery for any reason? The ECU may be in it's learning phase, which can feel sluggish.

^^^^What he said. I've seen several posts here describing what you have experienced until they either:
a. reset the ECU via disconnecting the batter
b. giving the ECU time to "re-learn" on its own

Keep us posted on how it turns out!!!

RedLeader 05-17-2013 06:49 PM

As with most all NA cars, the more you open the exhaust, the more low end torque you lose. Exhaust back pressure helps scavenging, which is why going to a less restrictive, wider exhaust pipe in an NA car (from the 2.25 factory to a full 2.5 with no cats, resonators, and all straight through mufflers) will gut your low end but give you a much better top end.
It IS odd that you can feel it after a single piece, but not impossible. Rumor has it that it takes a 10hp/10 ft-lb change to be noticed, but I've never tried it.

Sniper2606 05-17-2013 07:30 PM

I'll give the ecu more time to understand, don't wanna restart ecu and have my radio settings all jack up again

Hopefully once I installed the vortech sc kit I can get that torque back

mad_sb 05-17-2013 08:06 PM

Quote:

Originally Posted by RedLeader (Post 942390)
As with most all NA cars, the more you open the exhaust, the more low end torque you lose. Exhaust back pressure helps scavenging, which is why going to a less restrictive, wider exhaust pipe in an NA car (from the 2.25 factory to a full 2.5 with no cats, resonators, and all straight through mufflers) will gut your low end but give you a much better top end.
It IS odd that you can feel it after a single piece, but not impossible. Rumor has it that it takes a 10hp/10 ft-lb change to be noticed, but I've never tried it.

This is an old myth. The reason larger exhausts often loose low end torque is because of reduced velocity which hurts scavenging, back-pressure does not help scavenging it hurts it.

http://www.gomog.com/allmorgan/exhaustbackpressure.html

OP, i certainly did not notice a loss in torque when i installed my nameless over / front pipe. My guess is you may be running a little richer than before but i don't know what front pipe you have.

Sniper2606 05-17-2013 08:27 PM

Quote:

Originally Posted by mad_sb (Post 942538)
This is an old myth. The reason larger exhausts often loose low end torque is because of reduced velocity which hurts scavenging, back-pressure does not help scavenging it hurts it.

http://www.gomog.com/allmorgan/exhaustbackpressure.html

OP, i certainly did not notice a loss in torque when i installed my nameless over / front pipe. My guess is you may be running a little richer than before but i don't know what front pipe you have.

I have the invidia catless pipe with q300

RedLeader 05-17-2013 08:32 PM

Quote:

Originally Posted by mad_sb (Post 942538)
This is an old myth. The reason larger exhausts often loose low end torque is because of reduced velocity which hurts scavenging, back-pressure does not help scavenging it hurts it.

http://www.gomog.com/allmorgan/exhaustbackpressure.html

OP, i certainly did not notice a loss in torque when i installed my nameless over / front pipe. My guess is you may be running a little richer than before but i don't know what front pipe you have.

Wrong verbiage, same effect; my mistake. Loss of exhaust scavenging causing a loss of low end torque.

Also, thank you for posting the link to that article, I was looking for it earlier but couldn't remember where I'd seen it. Now I can bookmark it for later when this question inevitably comes up again.

SmsAlSuwaidi 05-17-2013 08:35 PM

Quote:

Originally Posted by Sniper2606 (Post 942583)
I have the invidia catless pipe with q300

how do you like the sound, we are debating running it on a new frs that we just got !

charged86 05-17-2013 09:03 PM

Quote:

Originally Posted by SmsAlSuwaidi (Post 942598)
how do you like the sound, we are debating running it on a new frs that we just got !

I have the same with sniper but with motiv overpipe. My car had the same feel. Give the car same time to react and adapt

jflogerzi 05-17-2013 09:43 PM

I agree your AFR is probably a bit rich now. Its time for a tune :)

SmsAlSuwaidi 05-17-2013 09:46 PM

Quote:

Originally Posted by charged86 (Post 942660)
I have the same with sniper but with motiv overpipe. My car had the same feel. Give the car same time to react and adapt

sound wise how is it ?

Calum 05-17-2013 09:49 PM

Quote:

Originally Posted by RedLeader (Post 942390)
As with most all NA cars, the more you open the exhaust, the more low end torque you lose. Exhaust back pressure helps scavenging, which is why going to a less restrictive, wider exhaust pipe in an NA car (from the 2.25 factory to a full 2.5 with no cats, resonators, and all straight through mufflers) will gut your low end but give you a much better top end.
It IS odd that you can feel it after a single piece, but not impossible. Rumor has it that it takes a 10hp/10 ft-lb change to be noticed, but I've never tried it.

Nameless saw more power everywhere with a 3 inch exhaust vs a 2.5 inch.


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