scoobyboy555

Bit of information needed please - ive already got an afterburner vortex rear box, a cat bypass centre section and want to get a decat downpipe - do they really make 'that much' difference and - most importantly - do they make the car sound even better??

Andy

Its a scorpion decat pipe I want too - by the way

scoobfan

It will make a difference otherwise whats the point !

The turbo back pressure is reduced allowing it to spool up quicker
and the car should produce more power due the the reduction.

That said, maximum benefit will only be found after a remap.

As for sound, it will produce more of it !!

And if your lucky....... spit 3 foot flames out the back, Nice.

Rob

hoskib

iTrader: (1)

do they make a difference? yep quicker turbo spool up, wastegate noises, louder scooby rumble. downside is you won't pass an MOT without your centre cat back in place.

total **** to fit aswell as you'll break off most of the nuts holding it to the turbo.

make sure it's got a twin dump off of the wastegate or an open mouth design or you may as well not bother! do a search for some pics if you're not sure what they look like.

scoobfan

Good point hoskib,

Go for the bellmouth design, it should start at 3" and reduce to 2.5".
Unless your car is producing above 350bhp 2.5" will be fine, with the
3" I believe you loose some back pressure required to keep the turbo
spinning effectively.

Take a look on www.scoobyworld.co.uk for some ideas.

Rob

scoobyboy555

The Scorpion one has a single outlet which is the same diameter as the rest of the pipe? havent checked the size but looks like 3"?

scoobfan

Souns like a bellmouth so great !

You need to check the other end now to make sure it's 2.5"
and not 3" otherwise it won't mate properly to your centre section.

Rob

scoobyboy555

Cool, ive just checked with my mate and it is 2.5" at the other end. So hopefully sould be okay? When you say fitting it is an **** - is it fiddly or is it really a total *******?

I work for a garage so can get it up in the air - just wondering about those studs breaking - want the car ready for the Ace Cafe next wee

Cheers for the help by the way

scoobfan

The studs shearing or rounding off are the biggest issues,
the most painfull though are the skinless knuckels !

My advice would be to leave the car at your works garage
over night and spray all the studs with some penertrating
fluid such as WD40, this will make it alot easier to remove.

The reason I say leave it at the garage is that you don't
want to drive it as the turbo get very hot causing the spray
to dry out and also causing expansion of the joints making it
harder to release.

Rob

Red Rocket 11166

Got a Scorpion on mine,works well.

Give the nuts and bolts on turbo a good soaking with WD.

I also lagged mine from the turbo to just under the car. If you decide to lag do it before you fit pipe.

Cheers Red.

scoobyboy555

Thats great advice - does the Scorpion make much difference to the noise and does it pop and bang on the over run??

Me

furrydice79

im not too clued up on all this guys,,i have a MY05 sti, at the mo i only have HnS backbox,, which cat should i remove for better performance gains

cookstar

iTrader: (6)

Overall the downpipe gives the most gains IMHO of course

cookstar

iTrader: (6)

Im assuming that your STI is non PPP, as they will have put a sports cat in place of the downpipe already

furrydice79

MY05 sti (nonPPP),,,, ?

so yer sayin i should replace the downpipe

cookstar

iTrader: (6)

I only have an 02WRX but noticed a huge difference when i had the downpipe changed, havent had a re-map yet but should see much more gain when i have

furrydice79

ok cookie, thanks alot, thats exactly the answer to my Q.

which one to get though?? hhmmm