Installed Over pipe,no more low end torque?

[sierra]

Originally Posted by Sniper2606

The sound is awesome

Sounded good at idle, similar to a Nameless axleback but when it picked up there was nothing much there. Lots of air and a little bit of attitude trying to get out but without much success.

[Jesse]

i honestly felt a minor decrease in low end with the overpipe. with the ecutek tune it all feels better / more smooth now.

[swift996]

How restrictive is the OEM over pipe anyways? I can't imagine getting much of a gain given it's compact compartment to fit in.

[sierra]

[quote]

Originally Posted by swift996

How restrictive is the OEM over pipe anyways? I can't imagine getting much of a gain given it's compact compartment to fit in.

A picture is easier to understand some times.
It would be if I could post it!!!!!!
[IMG]http://*************/forum/attachments/f16/5596d1372715617-nameless-performance-exhaust-image.jpg[/IMG]

[pepe]

you lost power at low rpm to install frontpipe decated resonated envidia?

[continuecrushing]

we have low end torque?

[Poodles]

Originally Posted by Shutter

we have low end torque?

Compared to an RX-8 or Miata, yes

[KoolBRZ]

Originally Posted by Sniper2606

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

The stock AVCS valve timing is tuned for much higher resistance and back-pressure. The ECU adjusts the A/F ratios automatically, (learning), but it doesn't adjust the valve timing, so when you change the resistance of the intake or the exhaust flow you need to re-tune the valve timing to compensate.
I use an OpenFlash Tablet and RomRaider software to adjust the tuning on my car, and it never ceases to amaze me how much difference tiny changes can make. The OFT off-the-shelf tunes for stage 1 and stage 2 have changes to the AVCS tables because stage 2 tunes are for cars with headers and less restriction in the exhaust.
You haven't mentioned any header. Are you still using the OEM header on your car? If you're not planning on getting a tune, or an OFT right away, I've just reinstalled my catted front pipe and immediately noticed how much more low-end torque I got back. I also average about 2 MPG better overall.
The best mileage and performance is still going to be with proper intake and exhaust valve timing and an unrestricted intake/exhaust, but I just haven't learned how to properly adjust the AVCS tables yet, so I put the OEM Catted front-pipe back on to temporarily give me better torque and mileage.

[pepe]

I changed only the rear muffler (top speed axleback) and apexi of substitution with oem air box .... necessary adjustment to your comment?

install the envy frontpipe thought silenced without catalyst .... this change would need the setting you said?

Thank you very much!

[KoolBRZ]

Originally Posted by pepe

I changed only the rear muffler (top speed axleback) and apexi of substitution with oem air box .... necessary adjustment to your comment?

install the envy frontpipe thought silenced without catalyst .... this change would need the setting you said?

Thank you very much!

I also have the top speed axleback. Changing that alone reduces back-pressure, but still barely within the tolerance of the stock tune. When you also removed the restriction of the Catted front-pipe, you went outside the efficiency range in the stock ECU. The OEM ECU is setup for restricted airflow of both the intake and exhaust. You changed both the intake and exhaust restrictions when you replaced the air filter, muffler, front-pipe, and over-pipe. A good tune will bring the ECU back into the efficiency range, producing better power, torque, and mileage.

[pepe]

frontpipe not even install. I'm thinking about it, just frontpipe without overpipe.
Frontpipe + axleback ..... ecu reprogramming necesary?

[pepe]

very thanks for your responses

[pepe]

you lost power at low rpm to install frontpipe decated resonated envidia?