PHILYB

Going to be fitting a decat down pipe soon. its a magnex one
What do i need to remove under the bonnet to get in?
what is there to remove around the turbo, heatshields etc. is it a long job to fit??

regards phil.

zhastaph

You only need to remove the IC and the heat shield.

It will look like you can get away with not removing the IC, but believe me it'll end up coming off in the end.

The first time you do it it'll take you a good afternoon, once you get good at it you should be able to get it down to about 3 hours

The best advice I can give is the evening before you're planning to do it, douse the heat shield bolts in as much WD40 as you can and try to get it in on the bolts round the DP as well.

Other than the joys of getting the welded bolts undone it's not a too bad a job.

Dark Blue Mark

Dont shear anything or you will be in the crap! Some will be very stiff.

Some people on here can change a DP in 30 mins apparently

It will take a number of hours on your first go as Zap says.

Have you got new gaskets?

MB

PHILYB

Cheers chaps,

once i have the pipe fitted is there any need to trim the turbo heatshield? is the magnex pipe any good?

regards phil

Dark Blue Mark

You will need to trim it a fair bit, as the Magnex is a twin dump and quite wide at the top. It is a very good pipe and well made. I got 260 bhp with a full magnex sys on a UK MY99.

I would be careful on the P1 though, your car basically has an STi fuel map, so decatting it may cause some fuelling issues on boost. I would definately be fitting a Knock Link first. Worth looking for other P1 owners on here, with some experience on decatting.

MB

scoobynutta555

furiously touching wood here Ive decatted my P1 3 years ago and it hasnt blown up yet. I suspect now that i have said it, it will happen

No other engine/ecu mods.

PHILYB

have u got a knock link on your p1 mate?
what does the knocklink do?

Dark Blue Mark

I would try the search but there have been numerous threads on P1's going bang with decats,and some non modded ones too. Basically, your P1 is similar to a MY00 with the well known dicky MAF sensor, which has caused numbers of engine failures.

The P1 didn't recieve any ECU remapping by Prodrive, so Subaru used the STi map which is for a higher grade fuel. I think they stuck the Broquet thing in the fuel tank as a half effort to cure it

So, given plenty of MY99/00 cars have gone bang from the MAF sensor leaning out the mixture, the P1 will be at more risk anyway because of its fuel map. When you decat the car, this may increase the problem as the fuelling cant keep up. I had the problem on my STi after decatting.

This is what ive heard from previous posts, and someone like Bob will have to confirm this.

Regradless, a Knock Link is abolutely essential on any scoob IMHO. o a search on them, but they have saved many an engine from going bang.

MB

scoobynutta555

No knocklink as yet, thinking about it though. Considering that more than a few standard P1 engines have blown up, and at less mileage than mine, I'm either quite lucky or there's a bit of a scare going around about decatting. I have decatted all the imprezas i have owned and have never remapped or fitted a knocklink.

Having said that remapping is probably the wisest move to try and counter your engine blowing up, but its something i haven't done in 6 years of impreza ownership. I will remap knoclink when I upgrade the engine when the warranty runs out, ie front mount etc.

Knocklink is a device which measures 'noise' in your engine and detects if your engine is 'detonating'. It uses a series of lights, green for ok, red for detonation detected. Red is generally a bad sign

Dark Blue Mark

Yep, listens to a specific frequency which det produces.

You can happily decat a Uk spec car and not have it remapped and it will be ok, but I would still advise a KL. Decatting an STi / P1 is a bit differet and you have to be a bit more careful.

MB

PHILYB

OK CHAPS THANX 4 UR THOUGHTS. GUNNA HAV 2 PRICE UP A KNOCKLINK NOW ME THINKS!!

REGARDS PHIL

zhastaph

Take heed of DBM's advice on the KL (both of you), the first thing I did when I got my MY99 STi was fit the KL and she woz detting like a b1tch This woz a combination of knackered MAF and the decat causing the boost to go way over what the car was designed for. There's no doubt at all that if the car had been left like that it wouldn't've been long before something went pop

As far as concerns the engine on a P1 it is an MY99 STi full stop.



Zap??!!?!?

Dark Blue Mark

Oops Just looked like Zapstaph when I first read it

I shaln't do it again

MB

zhastaph

Mickle

I've got a P1 and had various decat downpipes over the years. The only one I've had trouble with is the magnex, it knocked against the gearbox. The HKS and Hayward & Scott one's were both fine.

PHILYB

mickle, do u hav a kl on your car mate??

what sort of money is a kl?? best place/ price to get one from??

regards phil.

Dark Blue Mark

BR Developments, £150.

MB

PHILYB

contact details please mate 4 br developments.

regards phil