What Suites Pacey 4001's

[Abacus]

Its finally time to change the exhaust. I'm about to get LPG installed, and I want the headers to go on beforehand. I'll also be getting the Crane 2031 that's been sitting on the shelf for the past year fitted.

I've decided on Pacemaker 4001s. That bit is settled. What isn't settled is what to put behind them.

I want mid-range torque and I'd prefer a single pipe to dual pipes because of the cost difference.

I've read on these forums that the standard cats don't flow too bad, so I don't see the need to go for hi-flow cats. Like I said, I'm after mid-range torque, not max high rpm power, so I figure the standard cats should be fine. Please correct me if I'm wrong.

P***es me off that I've got to put cats on at all, seeing as the car is going to LPG. Apparently its the law.

So the only real question seems to be the size of the pipe. I'm getting different advice regarding 2 1/2" or 3". What should I do?

[Casper]

2.5 inch is going to be the best bet in the end. Tried and tested.. and not "book me" loud.

[Abacus]

Originally Posted by Casper

2.5 inch is going to be the best bet in the end. Tried and tested.. and not "book me" loud.

Thanks for that.

Reckon something like this would do the job? Can't really ****** about the price.

http://stores.ebay.com.au/Online-Per...dZ2QQpZ3QQtZkm

[Abacus]

Oh for crying out load - profanity checker is even picking up b-i-a-t-c-h.

Sigh.

What a pain in the bottom.

[loxxr6]

Originally Posted by Casper

2.5 inch is going to be the best bet in the end. Tried and tested.. and not "book me" loud.

Out of curiosity, if a 3" exhaust is ok for a 4L, why would a 2.5" be the best bet for an 8 ?

I'm not disputing your advice just curious.

[JC]

Originally Posted by Casper

2.5 inch is going to be the best bet in the end. Tried and tested.. and not "book me" loud.

Casper - yes for an I6, but on a 5.0? single 3" minimum. Stock XR8 system is twin 2", so single 2.5" will be too restrictive - especially with the crane cam. You will definitely need at least single 3".

The way to control volume is with mufflers, not pipe size. One in the middle, and a short resonator/hotdog at the back and the noise will be legal. I only have one muffler on mine, and it's probably/possibly legal. LOL.

The 4001 are a better choice than the 4006 if you want to retain low end torque, but seriously, 2.5" is just too small for anything other than a stock E series V8.

[Casper]

Originally Posted by loxxr6

Out of curiosity, if a 3" exhaust is ok for a 4L, why would a 2.5" be the best bet for an 8 ?

I'm not disputing your advice just curious.

Honestly, I personally still think a straight 3" cat back is too big for an NA I6. If it wasnt for Stiddy's car showing no ill effects from it I would have simply said that but its not the case. A 3" system seems to work just fine on the NA I6 (although way too loud) but I still think the 2.5" is optimum.

As for v8's, no idea to be honest.

[JC]

Originally Posted by Casper

2.5 inch is going to be the best bet in the end. Tried and tested.. and not "book me" loud.

Oops..double post. Damn BigPond going down all the time!

[Casper]

sorry guys, just realised abacus is driving a V8.


3" all the way for a V8.

[JC]

Abacus' car is a 5.0 V8 - so 3" is the only way to go (or pick up someone's old XR8 twin system - pretty sure there's one on ebay for around $50.)

[JC]

Originally Posted by casper

sorry guys, just realised abacus is driving a V8.
3" all the way for a V8.

Will you stop posting at the same time as me? LOL. We're both making each other look like we're arguing then agreeing!!

[Abacus]

LOL.

OK, so its 3" then!!!

[Casper]

3".. I agree with JC :P

[JC]

No, I insist, I agree with Casper! 3".

Now having settled on 3", you WILL get good torque down low from single 2.5", but it will run out of breath about 4000rpm, and will struggle to the red-line. 3" is the compromise size that still gives good punch down low, but it keeps it going right to red-line.

[Casper]

Originally Posted by JC

No, I insist, I agree with Casper! 3".

no no no, after you JC, 3"... just as you said