Guys,

I'm looking at a JDM header and I want a back box (muffler) and a test pipe to go with this, I have spoken to someone at Powerflow (Company in the UK that makes Exhaust systems for people who turn up at thier door), I was hoping to match the pipes all the way through from header to back box with 2.5 inch piping but the guy said there would be no extra gain by using bigger bore pipes from the CAT onwards and it could affect back pressure and make the car loose power as opposed to any gain. He said for said that 2.5 inches are for cars with turbos.

I this guy talking out of his tail pipe or not?

I was looking at some back boxes and noticed the connection pipe on the rear of the back box is about 2 1/4 inches or so, does this mean the bottleneck will be there or is this too close to the tail pipe to notice? Should this be 2.5 inches too or not?

I have seen pictures of a wire/sensor around the CAT area, does the ITR have one if so how can I get past this problem with the test pipe I wanted?

Thanks

 

Question part one: Go with 2.5" from the cat all the way back.

Question part two: The wire/sensor is the secondary O2 sensor. If you run a test pipe, the ECU will throw a code, however there won't be a loss of power - you'll just become good friends with the CEL.

EDIT: Now that I think about it, I'm not certain that your C6 has an OBDII ECU (someone help me out). If not, the sensor/wire in the cat. may be a temperature sensor as in JDM cars, and there shouldn't be a problem running the testpipe.


[Modified by Padawan, 7:23 PM 7/23/2002]

 

This is getting a little hardcore for my knowledge, if the ECU throws our a code, does this mean a light will light up when I start the car?

Also, whats the sensor measuring and why?


Bedtime for me, back in the morning.

Thanks.


[Modified by Black Sheep, 12:33 AM 7/24/2002]

 

Can any other of you guys help?


Thanks.

 

If you're going to get an JDM header, then the best thing you can do is to get a full 65 mm exhaust. That's because all JDM headers have a 65mm collector. Don't listen to that Powerflow guy.
Just tell him the collector of the header is 65 mm OD.

Do you have one or two O2 sensors? If you have only one in the header (OBD1), then you won't have any problems with testpipes...The CEL won't light up.

Do you have an UK ITR or imported JDM ITR?
I know that Euro ITRs are OBD1.


[Modified by DutchITR1689, 11:31 AM 7/24/2002]

 

I knew I could count on you Dutch! thanks for the input, problem is I don't even know what the sensor is for let alone know how many I've got, I have seen pictures of this but can't remember from what car.

 

If you have a real Euro ITR, you won't get any CEL codes. I'm almost certain for UK ITRs. Don't know about JDM ITRs...




[Modified by DutchITR1689, 11:53 AM 7/24/2002]

 

If it a Eurospec ITR it will only have the sensor in the header! Mine is like that too

 

Mine's the UK one, thanks all the help guys.

 

But when doing the 65mm B-pipe u must find a muffler with a 65mm inlet am I correct??