I have an MY99 and plans for a Tek3 and new exhaust with a sports high flow cat. I was thinking of having the sports cat in either the downpipe or the centre but can't decide.

I'm assuming either set up would get me through the mot but which one is likely to give the best performance?

Does anyone have any experience or a view?

Mark.

I'm looking for one as well, but ideally in the downpipe!

Why, well I want to run it with a HKS Hiper exhaust which has a specific centre section! And I don't like the idea of a cat (which will be quite big) hanging down the centre of the car, especially as there are lots of speed bumps by me!! :o

Mark

I've just fitted a 3inch turbo-back exhaust with high flow sport cat in downpipe. Result was extra 20bhp/20lbft at the wheels measured with deltadash raod dyno :D

I can't imagine a full decat would have made a lot of extra difference. Not sure if a centre cat would be worse than this, but would be suprised if it was better.

GO FOR IT! ;)

Simon

PS Feels a lot quicker/smoother too

[Edited by SiHethers - 3/27/2003 2:48:18 PM]

Downpipe cat is most common. Makers include Graham Goode, Haywood and Scott (via scoobyworld), APS, MRT, and several american type people. MRT will guarantee that you will pass emmissions with their system, but I'm not certain about UK distributors. I have the APS system with sports cat on my MY02 (hence no MOT yet); great quality, nice noise but less drone than most, 284bhp with fairly mild mods.

The only sports cat centre I can name is the Power Engineering one, although I have a nagging feeling there was someone else too.

If you really want to go emmissions friendly, I see no reason you couldn't match a Graham Goode/H&S downpipe with a PE centre, and have two sports cats. ;) May cost a bit, but give good flow and emmissions you could inhale (disclaimer - don't try that at home!)

I think the GGR jobbie is a sleeve fit - so it's all or nothing! Although I'm probably talking poo here...
Centre should, technically be the better place for flow purposes, but I'd have thought it's rather more likely to get damaged there (at full heat & go through a puddle? Hmm...)
I had (well, still have in the loft...) a PE catted centre. Definately more restrictive that no cat at all, but less restrictive than a not-so-good BB. ie, the centre cat was noticeable (fueling-wise) with a 3" DP & BB as to a 3" straight-through centre, but on the H&S 3" to 2.5"DP & TSL (2.5")BB, the cat in or out made little difference (to the fueling, & hence power & stuff). Not having a RR in my back yard - well, not having a back yard at all, to tell the truth - measurements are a little hazy!

Thanks for the replies everyone.

Simon. Does the turbo spool up quicker with the sports cat or is it about the same as the original? What make exhaust have you got?

Thanks. Mark.

Yes, most definately, it spools up a lot quicker :D :D

I'm now getting 1 bar of boost in 4th at 2500rpm. All round the car drives better, particularly the pickup from low revs. It now pulls smoothly from 1500rpm/30mph in 4th. Note that I do have a Dawes Device to aid spoolup more :rolleyes:

I got it supplied and fitted by Graham Goode Racing in Leicester, for a wallet-busting £1000 :eek: but is well worth it IMHO ;)

And I got them to exhaust wrap the DP too.

If I was clever, I would be able to post my road dyno graphs. But I'm not, so I can't. If you download the demo version of the software from Ecutek I could email the files to you so you can see for yourself.

Simon

Scoobyworld (H&S) - £425.53+VAT = £499.99 + delivery (same price for 2.5" or 3")
Jap Innovations - £478.80+VAT = £562.58 + delivery (MRT 3" only)
GGR - £395+VAT = £464.13 + delivery (3" only)

MRT (Direct) - AU$884.01 (approx £295) + £60 (guess) + £35.50 (10% duty) + £68.34 (17.5% VAT) = £458 (approx total delivered!!)

Email from GGR:

The GGS 605 should mate up without any problem to the HKS Hiper Muffler. This is a 3" diameter pipe which goes down to the a standard size and flange.

[Edited by Andy Tang - 3/28/2003 1:19:39 PM]

[Edited by Andy Tang - 3/29/2003 4:20:21 PM]

Power Engineering - T75 centre section with cat: £365+VAT = £428.88

75mm (3") system, but no good for me as I want a downpipe one!

If you're going for a full system anyway, the APS with cat is a fairly good value option. Unless you want something that gives you a headache on the motorway, in which case it isn't a good option!

hi,

just wanted to make a slight correction - our downpipe (made for us by Hayward and Scott) with integrated hi-flow sports cat is £499.99 inc VAT not £646.00

thanks

Wendy
www.scoobyworld.co.uk

Apologies Wendy, I was going by the price that was emailed to me by H&S!