Installed Intake, midpipe; I notice an enormous loss in torque!
 

After driving about a month stock, my intake and midpipe were put on right about a month ago. I have noticed an enormous drop in 1-3k rpm torque. In the higher RPM's I notice a huge pull differance (gain in HP). But for normal driving, losing probably 15 lb-ft in the lower rpm's is insane (just a rough guess). I may consider going back to stock, or just adding a B&B cat-back.

Do you guys think my B&B cat-back would make up for the torque loss, or would you suggest going back to stock. I DO notice a big hp differance in high rpm, but for daily driving I dunno.


Troy J.

that makes sense wouldn't the midpipe increase back pressure therefor the loss in torque?

I believe the midpipe would decrease back pressure......less restrictive. Anyone correct me if I'm wrong please.

Would adding a cat-back increase the torque, or make it even worse?


Troy J.

It would cuase a loss in lower range like you are saying...but midrange should be awesome as well as top end.

Be easy on the throttle during low rpm's and you won't bog it so much...then roll-in quickly as your mid range kicks in....then shift.


Hope I've helped:)

Instead of putting everything back to stock, remember that you changed 2 things at once. It is hard to tell which one is really the culprit. I would replace one thing at a time to see what the effect will be.

Hmmmmm this bring back memories of past discussions. Sound familiar Rotorygod?

Listen to Rotarygod.
Pull the intake and try again.
Intakes on the RX-8 are worse than useless.

I agree with MazdaManiac and rotarygod ...

Dropping backpressure from a full aftermarket exhaust is known to sometimes cause a drop in low-end torque in exchange for hp on the top-end. The mid-pipe frees things up more than a cat-back will on the 8. The same can be said of intakes on the RX-8...

Pull the intake and see how it rides.

I forgot to mention that I put the intake in roughly 1 week before the midpipe. I noticed a little bit of a differance for the better in the high rpm's. I have a custom titanium heat shield on mine, so it does soak up heat. When I put the midpipe on, that is where I noticed the low-end loss. But I think I am going to just keep it on, we go to the track next weekend; so that is where it will really shine.


Troy J.

I actually suspected as much, but you get some pretty decent gains from the mid-pipe, so I hesitated to mention it directly.

Be sure to include a light-weight flywheel in your upgrades... recent reviews say that this has a lot of bang for the buck.

What are you doing driving at 1k-3k anyway... ;)

Also lost huge amounts of torque with a high flow cat and midpipe. Watched a stock RX8 fly away from me at 20 MPH in 2nd gear. And I thought my Borla and midpipe would make me king...

What I tend to wonder is what we expect when upgrading the performance with aftermarket accesories. As was stated, there are several discussions around here re: the drivability aspects of certain mods. I have stated in almost every related post that there is a power loss below 4K but a major boost in all areas above that. In addition, with the full-length exhaust and intake setup, Jeup will see full gains above 7K. I will offer this much: my 8 accelerates from 70 to 145 mph MUCH quicker than before my mods were done and the low end loss helps it to hook up when drag racing. Power is of no use when it is wasted by heating the tires instead of moving the car. I picked up 1.3 seconds in the quarter mile with another car I once had by swapping the trans/converter combo. It felt slower off the line but that was deceptive.

Charles

It shouldnt effect it much at all.