Fabspeed Exhaust -- Too Loud?

[Johnny Danger]

If anything is causing a loss of low end and midrange torque in Jhandy's vehicle, it's the 100 cell cats. In the past, I experimented with different cell counts. And the use of 100 cell cats resulted in a loss of back pressure; especially when they were located mid stream.

[Allen K. Littlefield]

Originally Posted by Johnny Danger

If anything is causing a loss of low end and midrange torque in Jhandy's vehicle, it's the 100 cell cats. In the past, I experimented with different cell counts. And the use of 100 cell cats resulted in a loss of back pressure; especially when they were located mid stream.

Since I am keeping the stock header and cat configuration, I wonder if I will experience 'de-tuning' with the Charlie Chan muffler and my secondary cat delete pipes? Would make the case for adding the secondary cats again with the CC muffler to eliminate loss of backpressure and consequent 'de-tuning'?

AKL

[Johnny Danger]

Originally Posted by Allen K. Littlefield

Since I am keeping the stock header and cat configuration, I wonder if I will experience 'de-tuning' with the Charlie Chan muffler and my secondary cat delete pipes? Would make the case for adding the secondary cats again with the CC muffler to eliminate loss of backpressure and consequent 'de-tuning'?

AKL

The short answer is no . Both the oem muffler and secondary cats are very restrictive . The Charlie Chan muffler should increase flow a bit, at the same time maintain effective back pressure, and provide better sound (subjective) .

[Allen K. Littlefield]

Originally Posted by Johnny Danger

The short answer is no . Both the oem muffler and secondary cats are very restrictive . The Charlie Chan muffler should increase flow a bit, at the same time maintain effective back pressure, and provide better sound (subjective) .

This leads me to ask, what exhaust system did you end up with and did it require a new chip program in order to make it all work?

AKL

[Johnny Danger]

Originally Posted by Allen K. Littlefield

This leads me to ask, what exhaust system did you end up with and did it require a new chip program in order to make it all work?

AKL

I stuck with the principles of the oem header/pre-cat configuration by having M&M Exhaust in Germany custom fabricate a set of headers and cats using longer, 2 1/2" diameter equal length primaries that flow into a merger collector with HJS 200 cell tri-metal cats. The muffler is a custom cat-back with 2 1/2" diameter inlets and 3" outlets from 9ff, along with secondary cat deletes . It was a tremendous improvement over the oem system; albeit a very expen$ive one . And the sound is just ripping ! Almost to the extent of the Fabspeed race exhaust .

p.s. I did have the ecu re-programmed, however, it was not required .

[ocoeeboxster]

Ok ordered off eBay $299 free shipping .

[jhandy]

Johnny,
The headers with 100 cell cats are very free flowing and when combined with the secondary delete and the muffler, there was not engough backpressure.

Low end torque was fine with the cat deletes and muffler, the headers where the problem. replaceing the OEM muffler fixed the issues, and it is easier to change than the headers.

[ocoeeboxster]

Originally Posted by jhandy

Johnny,
The headers with 100 cell cats are very free flowing and when combined with the secondary delete and the muffler, there was not engough backpressure.

Low end torque was fine with the cat deletes and muffler, the headers where the problem. replaceing the OEM muffler fixed the issues, and it is easier to change than the headers.

Is the m22 ss a basic bolt on for the non s cars or will there need to be some modified install done?I got a shop that will do the install for $200 as long as it doesn't get complicated.

[jhandy]

bolts right up. Taking off the OEM is the time consuming part. Some people do it without taking off the bumper. Tried that once, have the knuckle scars to prove it. Its possiable, but taking off the bumper will save time.

[Johnny Danger]

Originally Posted by jhandy

Johnny,
The headers with 100 cell cats are very free flowing and when combined with the secondary delete and the muffler, there was not engough backpressure.

Low end torque was fine with the cat deletes and muffler, the headers where the problem. replaceing the OEM muffler fixed the issues, and it is easier to change than the headers.

I agree with you in so far as 100 cell cats are a bit too free flowing for street applications . Moreover, the ecu has to be re-mapped in order to avoid CEL's, and keep the vehicle OBD II compliant . With that said, the combination of a freer flowing cat-back , along with deletion of the secondary cats, in my experience reduced back pressure to the extent that low end and mid range torque suffered . This deficiency was remedied by switching to 200 cell cats, along with some exhaust reconfiguring .

[ekam]

Originally Posted by Johnny Danger

If anything is causing a loss of low end and midrange torque in Jhandy's vehicle, it's the 100 cell cats. In the past, I experimented with different cell counts. And the use of 100 cell cats resulted in a loss of back pressure; especially when they were located mid stream.

Good call. Afterall no one can explain why the Maxspeed cats have side-entries instead of a straight design. I've never seen that on any other aftermarket performance cats period.