Exhaust Question

[jamesvx]

I have a 3 inch Wortec cat back. AAS said they would make me some headers and sports cats for a good price. Is it worth it? Is there a difference in sound, a difference in performance? And is there a noticeable difference in loudness? Cheers

Edited by jamesvx on Thursday 8th January 17:45

[mv6]

Yes,yes,yes,and yes.AAS did mine in November.Go for cutouts too!

[jamesvx]

What do you mean by cut outs? Also as the cat back is 3 inch would it be best to get the headers and cats 3 inch too? What exhaust do you have on? Or did they make the cat back for you also?

[r8black]

Hello
With a decent set of headers and decatted it'll sound more like a NASCAR when booted mine does

[jamesvx]

I did fancy decats but I don't think AAS will make them and they said it's too much of a pain to swap them over for mot's

[r8black]

jamesvx said:

I did fancy decats but I don't think AAS will make them and they said it's too much off a pain to swap them over for mot's

Just get your existing cats gutted and find a friendly MOT station when it's due

[jamesvx]

Would it not be better to get decats made and keep the standard cats just incase?

[r8black]

jamesvx said:

Would it not be better to get decats made and keep the standard cats just incase?

Possibly but decat pipes mean no cats on show underneath so it's obvious to any examination that they have been removed which is illegal,

Gut existing and they still sit in situ underneath, still illegal though

[jamesvx]

Could do that but would I not gain more from making the rest of the system 3 inch? As the cats are 2.5 and the cat back is 3

[V88Dicky]

My Monaro has a full AAS system, from engine block to tailpipes, including some hi-flow cats (100cpsi iirc) and a pair of QTP electric cut-outs.

Here's what cut-outs are, on a C5 'vette.

http://youtu.be/2TrycvqeEmY


So it's basically quite loud and rumbly or incredibly loud and NASCAR like


AAS quality is superb and they're a very knowledgeable bunch of blokes. Proper petrol heads too.

[jamesvx]

Didn't even know what cut outs were until now! I've been doing a littl research and people have said it can sound like an exhaust leak when closed? So if I got headers and sports cats done it will sound better and louder, and if I got the cut outs done it will be even louder again?! Does it sound better again or do they take away the lovely v8 note?

What did you pay AAS for your exhaust/cut outs etc, I take it you got the full system done by them? I already have the cat back

[V88Dicky]

jamesvx said:

Didn't even know what cut outs were until now! I've been doing a littl research and people have said it can sound like an exhaust leak when closed? So if I got headers and sports cats done it will sound better and louder, and if I got the cut outs done it will be even louder again?! Does it sound better again or do they take away the lovely v8 note?

What did you pay AAS for your exhaust/cut outs etc, I take it you got the full system done by them? I already have the cat back

There shouldn't be a leaky sound unless they're not shut properly and mine have worked fine for the past 18 months or so. Just an occasional spray of oil on the spindles is enough to keep them free.

I've had the exhaust since 2009 I think, paid about £550. Headers and cats came in at around £1200 a year later. The cut-outs were part of a big service which included strut top mounts / bearings and other stuff, not sure how much they were. I'd imagine they're about £400 fitted.

Nice to see another northeast owner btw

[ARAF]

Our cutouts don't close properly, but for the price they were, we'll put up with it.

[mv6]

My cat back is a Magnaflow for a Pontiac GTO that I "adapted".Will get AAS to replace the cat back with one of theirs this year.AAS quality is superb. Headers and sports cats give a nice deeper grumble, but once the cut outs are opened it is pure NASCAR as has been said. Great fun!!!

[blue666uk]

I don't have cut-outs, just headers, 200 cell cats and Wortec cat-back with no silencers - to be honest, that's chuffing loud (though not quite in Goldies league yet), and when booting it, it does sound pretty Nascar-esq enough for me!
On mine, idling and low revs, it's very purposefully meaty, but 3K rpm plus, very Nascar like. I would say the volume is already at 11 for day to day, cut-outs you couldn't use all the time, the dial gets turned to 15 for those! But, open road, away from plod and built up areas - very fun........(from experience of hearing other peoples' cut-outs)

[jamesvx]

Do the cut outs give more performance? Or do you lose performance with them open?

[R8VXF]

jamesvx said:

Do the cut outs give more performance? Or do you lose performance with them open?

Higher flow rate should give better performance. YMMV

[stigmundfreud]

no the cut outs do not add any performance

If you are booking in AAS get on the phone now. I am booked in for April but made the call in October - they are that busy

[THUNDER STORM]

ARAF said:

Our cutouts don't close properly, but for the price they were, we'll put up with it.

I presume you know that some cutouts like mine have to have a slight tap on the close switch at end of closing. This is due to the torque of the motor winding up and when released winds back to slightly open valve.

With a bit of practise it comes natural and works every time.

The only other problem could be loose screws on butterfly valve, or it is left open for ages in the loud position allowing for carbon deposits to build up on closing face of butterfly.

Use it and maintain it and no probs, end of lecture

Ade

[ARAF]

THUNDER STORM said:

I presume you know that some cutouts like mine have to have a slight tap on the close switch at end of closing. This is due to the torque of the motor winding up and when released winds back to slightly open valve.

Yes, our old Badlandz ones were like that. These are Chinese ones, that were less than a third of the price, and are one-touch, so you don't get that option.