Arrow PCM high flow cats Corsa exhaust review.

[Darius]

I recently installed the Arrow PCM, metal matrix high flow cats from Partsrack and Corsa mufflers on my ACR. For those who want to put Corsa's on the ACR they will NOT fit with the supplied tips. They are too short for the stock ACR bezles. You will have to cut off the stock round tips or have some round ones made. The stock tips are round, corsa's oval just like all the pre acr's. The sound is so much better, now I feel like I'm driving a Viper again. It's raspy, high pitch and just sounds awesome. Especially when you let of the gas, although it gets a bit annoying at times. Like leaving your house late at night you have to push the clutch in and coast to not piss of the neighbors, or it's pop, pop, pop! For performance I feel like I lost a little bit of low end torque. I noticed that right away. It revs higher with the pcm but on the track where I used to hit the rev limiter I find myself shifting when I feel like the motors at it's peak and I rarely hit it with the pcm.

I came out of turn 11 at Laguna with Todd, Venom V here and I was right on his bumper. I thought I got at least as equal of a exit as he did and I was amazed as he kinda pulled away from me a bit. I did have a passenger but I thought for sure I would reel him in a bit but I didn't. I was also running a race gas mix, well over 93. I'm starting to think the pcm works best with the stock exhaust. I know the pcm makes a difference. I've raced Rapidrezults when we both had out Ta's and he would pull me by at least a car length from a 2nd to 4th gear run. Makes me think the motor likes a bit of back pressure. I didn't do headers because I didn't want to worry about the burnt up 02 sensor wires. Maybe all the power is in the headers and the stock mufflers are fine? Either way I'm happy. Car sounds like a beast.;)

[donk_316]

Im confused... Arrow PCM means you don't need 02 sensors or cats. You're leaving so much on the table without using headers. I have seen people running ARH, no cats and stock cat back.
or is it an emissions issue where you live?
Everyone says the Corsa sounds the best. No surprise there.

[Darius]

Im confused... Arrow PCM means you don't need 02 sensors or cats. You're leaving so much on the table without using headers. I have seen people running ARH, no cats and stock cat back.
or is it an emissions issue where you live?
Everyone says the Corsa sounds the best. No surprise there.

I've just heard a lot about the o2 sensor wires burning up and the cost factor as well. I'm sure I might do headers in the future. I've come to the conclusion that the power is in the headers and not ditching the dual cats and stock exhaust.

[FLATOUT]

Anything over 95 octane and you'll actually start to lose a bit of power, couple that with the passenger and that might have been what you noticed. Stay between 93-95 and you'll be in good shape.

[mjorgensen]

I've just heard a lot about the o2 sensor wires burning up and the cost factor as well. I'm sure I might do headers in the future. I've come to the conclusion that the power is in the headers and not ditching the dual cats and stock exhaust.

Darius,
You should heat wrap all the wires and many other things in the Viper if you are tracking, go look through Chris's ACR and you can see all that we heat wrapped for him. If you do headers just be prepared to go the extra mile with the wrap and you will be fine. I also believe that a car is better with 1 HF cat in place, but won't start that debate here. The headers though are a big boost compared to the PCM only, on the 13/14' cars the PCM was worth average 29rwhp on a stock car, the tune later and on the 15/16' cars is better and the gains were about 20rwhp, when you add headers you gain another 30-35. The PCM will work best in the heat at a good 95 octane would not waste the money to go higher, pretty much acts like you are retarding timing at that point. Another thing to consider is miles each car has, there is about 20+ hp left on the table until it is fully broke in (1500-2000+ miles).

Glad to see you out having fun with that beauty.

[Darius]

Anything over 95 octane and you'll actually start to lose a bit of power, couple that with the passenger and that might have been what you noticed. Stay between 93-95 and you'll be in good shape.

I was mixing 101 with 91. I think I probably ran one full tank of 101 though as the car used a half tank every session.

[Jack B]

Another thought on octane, the octane stoic number and % oxygen affects the power more than the octane itself. You can have two different brands/series of gas with similar octanes, however, the stoich numbers and oxygen content can be way different, therefore, affecting the TRUE airfield ratio.

if you use 50 % GT260, it has a minor affect on the tune.

L

Anything over 95 octane and you'll actually start to lose a bit of power, couple that with the passenger and that might have been what you noticed. Stay between 93-95 and you'll be in good shape.

[GTR>Viper]

go look through Chris's ACR and you can see all that we heat wrapped for him.


Anywhere to get heat wrap install details or pics? The most in-depth info I can find from threads is to cover 02 sensors, clutch lines, and vent tube.