The_Judge

Last year I had the open neck downpipe with splitter, as part of a Group Buy. I also had the 3.5" tailpipe silencer at the same time, leaving the stock centre section with cat on my MY00 UK Turbo. I was well impressed, and couldn't stop grinning every time I put my right foot down, performance and noise-wise. I stuck with that setup right up until yesterday...

I'd been thinking about a full de-cat for ages, but never got round to doing anything about it, as the hype on here surrounds the downpipe de-cat moreso than the centre section de-cat. After doing a bit of digging for prices, I phoned Ian, and couldn't believe how reasonably priced their centre section was compared to the others. I knew how good the quality would be due to the 2 exhaust components I already had. So I ordered it. It was delivered within a couple of days (as prompt as ever), and fitted yesterday.

All I can say is WOW. Tickover isn't much different, but you can tell the exhaust note has something else to it. Part throttle acceleration, and even WOT below 2500rpm, you could liken her to a nice respectable lady, well spoken, well educated, good job, etc, someone to take to meet your folks. Good wife and future mother material.

But WOT above 2500rpm, and all ******* hell breaks loose. She turns into the sort of woman your parents warned you about, a snarling, growling, man eating *****, who'll eat you up and spit out what's left of you... unbelievable noise. I know others have posted on here about the Blitz, Firestorm, Afterburner Vortex, etc. Here's my vote for Hayward & Scott.

As I said, before I was grinning every time I put my foot down. Now, I can't stop laughing! And there's definitely more performance there than I was expecting. Certainly torque-wise anyway. Seems to rev more freely as well. But then when you look at what you've taken off, and how restrictive the cat itself was, it's no wonder really.

Anyway, I've babbled on and on for far too long (as usual ). Basically, anyone thinking about doing this mod, stop thinking about it and just do it. You will NOT regret it, trust me. Incidentally, I had my MOT (obviously prior to the fitting of said centre section ) and it passed the gas analysis relatively easily. Didn't have to warm her up first either. Dunno whether that helps anyone or not...!

So big thanks again to everyone at Hayward & Scott.

Ade.

jjones

what induction are you running?

what precautions have you made against running lean?

NelsonUK

Good job mate

I too am a complete H&S convert.....their system is just amazing

I got the H&S *original* Scoobysport Down Pipe and 3.5" Rear Silencer and ran with that and the Prodrive ppp Decat resonated centre for best part of 2 months. I was impressed with it then BUT I took the plunge a few weeks ago and went for the H&S Afterburner Decat (Again) Non resonated centre....OMG that was what it needed. As you say it is just such a naughty sound (sorry that is the only way I can describe it). I did in fact turn up to a mini Scooby meet at the weekend and all other owners were in awe of the sound of the H&S.....and couldn't believe the noise it made from a 3.5" tail....size ain't everything you know Anyway I too have been rambling on but I TOTALLY agree with the Judge - H&S rocks the sound is pure BLISS, my stereo doesn;t get used much now !! oh yea and I too have owned a scoob with HKS, Vortex, prodrive fitted

The_Judge

Full spec at moment...

Stock turbo.
Stock TMIC.
Stock AE802 ECU.
HKS FCD.
GBE MkII @ ~17psi.
Stock induction tract with STi panel filter.
Samco Intercooler Hoses.
Full H&S de-cat.
NGK PFR7B plugs.
Always run on Optimax (soon to be Optimax + 1ml/litre NF Race).
Knocklink (no activity worth mentioning).
Autometer AFR gauge (happy lambda and MAF sensors).
Autometer boost gauge.

The_Judge

Nelson

jjones

why the octane booster is there is no KL acitivity?

(curious)

The_Judge

I was running it at ~18psi and was getting worried at the occasional red flash at 3500rpm in 4th or 5th. Turned it down to 17psi, and no more flash. But I know the Millers made a difference to BP Ultimate (before I was converted to Optimax), so I'm just trying out the NF with Optimax. In theory, shouldn't I get more ignition advance? Maybe not loads, but there should be some improvement? And for £2.17 per fill-up, it's worth a try. If not, then I haven't lost anything. Well, £13...

Daz_WRX

how did you get it to 18 psi do you have a boost controller? i have a full decat on my 97 wrx import and i only acheive 12 psi?

The_Judge

Yep, that's what the GBE MkII is

I forgot to add HKS FCD to the list... will do that now.

minor_threat

Ade, I'd love to go full de-cat! Which bit will you put back on before the next MOT, will it pass emissions with just the centre section?

The_Judge

Yeah, an absolute bonus that my centre section cat is good enough to pass! Didn't like the thought of having to put the bloody downpipe cat back on, but had it with me just in case... How old's yours? How many miles done?

minor_threat

LOL! I wouldn't want to have to put the downpipe cat back on in a hurry! I have a MY00, 70k, currently with magnex 6x4 backbox. I want to de-cat the downpipe next and was wondering whether the centre section would be enough to pass an MOT. 3 cats is crazy!

The_Judge

3 cats? Don't you mean 2...?!

Mine hasn't done 40K miles yet, so I don't know if one that's done 70K would be OK. Worth the risk though...

wrxsmo

My H&S downpipe & centre are sat on the floor of my office awaiting fitting this week ! (& now I'm all the more excited )

zhastaph

Ref the KL activity your getting above 17 psi, you may want to add a fuel pump and reg to your list, I believe (other's may support this or tell me I'm talking complete twaddle ) that the stock fuel pump simply runs out of go at about 17 psi, once you start going above this, fuel pressure at the injectors actually drops, causing less fuel at a time when you really want more.

The_Judge

wrxsmo - You're gonna love it. What silencer you using?

zhastaph - I'd heard that as well, somewhere. But my AFR gauge seems happy enough at the point of the flash, so I'm not too sure. Will be able to prove one way or the other when I stick some NF in at my next Shell visit. If I still get the flash, then as you say, new pump and reg. If I don't, even better. Problem is as soon as I get a better pump and reg, I know full well my shopping list will suddenly contain a better turbo and a Tek3... and I really didn't want to go that far! Mind you, I never intended on buying everything I've bought up to now either... I suppose it's just natural progression. Once you upgrade something, you suddenly find something else needs upgrading to support it. And before you know where you are, you're getting close to the "new gearbox and clutch" territory...

StiX

iTrader: (4)

Yes, is for me anyway: MY95 with full-decat (afterburner/Ninja). Centre section replaced with standard last month and new MOT.

wrxsmo

The car already had the H&S back box on it when I bought it hence my reason for sticking with H&S

The_Judge

Nice one. One thing's for sure, losing both cats at the same time, it's gonna be LOUD in comparison to what you have now...

minor_threat

LOL! I can't wait to do this, however I fear my insurance company (elephant) is not going to like it as much as me.

wrxsmo

I've gone for the silenced centre section so to (hopefully) not upset the neighbours (too much) when leaving early in the morning

The_Judge

I gave up caring about the old cow who lives next door to me a long time ago. Miserable old trout. But as I say, it's not really any louder on tickover and low revs. If I blasted up or down the road though, I don't think they'd be too impressed. Besides, there's a chap who lives down the road who's got a blue classic Scoob, with what looks like a Ninja silencer. When he drives past, that reverberates around the houses more than mine...!

Oh yeah, one more thing. Driving into work this morning, I managed to set off 3 car alarms!!! I dunno, simple things eh...

StiX

iTrader: (4)

My 5 yr old son heres me coming home from miles away, and thats practically on tickover going over our ****ty speedbump infested road

The_Judge

I guess the Ninja is a bit of a louder beast than the H&S...!

stevie 1

hi lads i have an 03 wrx ppp could anyone tell me if i change the exhaust and decat ,would i have any problems with feuling or the way it runs was thinking of haywood and scott .

StiX

iTrader: (4)

I don't think it'll affect fuelling at all. The boost will be upped a bit due to reduction of back pressure and you'll have a fait bit more bhp - about 25-30 with full de-cat

StiX

iTrader: (4)

Just noticed you already have PPP, so I'm guessing your power gain will not be as much - does a PPP still retain both cats?

Scoobsterboy

Hey Judge, nice one. I also run a full Decat Hayward scott system it rocks. quick question for you, I noticed you are using a manual boost controller did you set this up? I was told by a garage that If I wanted to run one I would need to have the car rolling roaded and possibly mapped!!

Cheers Simon

MY00 Turbo 2000

stevie 1

i beleive the main restriction is the cat that is in the front downpipe but some say if i remove it effect the way it runs ,ie for the worst,not to say it will ruin my warranty so unsure what to have fitted to get a nice exhaust note.

StiX

iTrader: (4)

I have a classic with both cats removed, afterburner (made by H&S) front and centre and ninja backbox. Runs as sweet as a nut. It is the first mod people seem to do to release more horses on classics and newage, so I'd be surprised if it makes the car run badly sometimes?

Do a search and there are a lot of peeps who love the change in sound, better breathing and consequently more bhp - I'm no expert but I've done a lot of reading/research and can't remember anyone saying that removing cats makes the car run badly?