Akra X-Pipe Torque Dip

[a5m]

Looking at installing an Akra X-Pipe. Have been reading about the torque dip that some experience and trying to understand what this exactly feels like in day to day driving, particularly in a manual?

Say you're at an intersection waiting to turn left and are rolling forward in 1st at idle, then hit the gas to go. Does the car hesitate? Is there a delay, then it suddenly lunges forward?

I know this is a very specific scenario but curious to know how it behaves on a manual car, and if a tune is absolutely a must to fix it/can fix it.

[CamasM3e93]

I have a catted valvetronic xpipe with a forward X that is said to experience the same issue, installed on a 6MT and a stage 2 bpm tune. I could ascertain a torque dip coming out of a stop under moderate acceleration when it first went onto the car, but it quickly disappeared. The sensation was similar to waiting on old turbos to spool. I assume that the car’s adaptations adjusted to the equipment. Car pulls linearly now.

I don’t like this particular X, however, because the cats hang down too far and I can rub on speed bumps. The car isn’t lowered much at all. I digress.

[a5m]

Originally Posted by CamasM3e93

I have a catted valvetronic xpipe with a forward X that is said to experience the same issue, installed on a 6MT and a stage 2 bpm tune. I could ascertain a torque dip coming out of a stop under moderate acceleration when it first went onto the car, but it quickly disappeared. The sensation was similar to waiting on old turbos to spool. I assume that the car’s adaptations adjusted to the equipment. Car pulls linearly now.

I don’t like this particular X, however, because the cats hang down too far and I can rub on speed bumps. The car isn’t lowered much at all. I digress.

That's exactly what I'm trying to describe, like turbos waiting to spool, where you apply throttle and nothing really happens. But if this happens from 0 mph then it's a bit dangerous, like when making left turns with fast moving traffic.

I'm concerned the Akra will behave similar to a forward X, because of the 'H' crossover it has at the front. Hoping someone with one can chime in.

[RugbyBro]

With any forward bridge like the H on the Akra or a forward X on other pipes, you need a forward H / X specific tune to correct for the change in scavenging.

Mine is from Randy @ Epic who specifically tunes (adjusts cam timing) for the forward bridge. He very specifically asked me what mods were on the car and adjusted the tune accordingly prior to sending it to me. Post tune, it pulls everywhere with no torque dips.

[a5m]

Originally Posted by RugbyBro

With any forward bridge like the H on the Akra or a forward X on other pipes, you need a forward H / X specific tune to correct for the change in scavenging.

Mine is from Randy @ Epic who specifically tunes (adjusts cam timing) for the forward bridge. He very specifically asked me what mods were on the car and adjusted the tune accordingly prior to sending it to me. Post tune, it pulls everywhere with no torque dips.

What X-Pipe are you running? Did you experience the specific scenario I described above?

I know Randy is the man, and I've spoken to him. Thing is I'm selling the car soon so don't want to shell out $800 on a non-transferable tune if I can live with it and it's not difficult/dangerous to daily drive.

[RugbyBro]

Originally Posted by a5m

What X-Pipe are you running? Did you experience the specific scenario I described above?

I know Randy is the man, and I've spoken to him. Thing is I'm selling the car soon so don't want to shell out $800 on a non-transferable tune if I can live with it and it's not difficult/dangerous to daily drive.

I'm running an alibaba sourced titanium forward-x pipe with high flow secondaries and resonators. My car came with an Alpine Stage 1 originally and pre Epic Stage 2 there was a little drop in low end torque going to the Forward X. Post-tune there are 0 issues, definitely a bit peppier in the low and mid range compared to my friends' cars with Stage 2 but standard X.