Nick_Scooby

Interested in a decat downpipe, the centre cat is already decatted with a 3" system.

Once I get the Decat downpipe, the system will be straight through, no restrictions, when will the power increase be most noticable (hoping to increase acceleration from stand still), and how much louder is it likely to be, I already have the nice burble , will it just make the burble louder?

Hope someone understands me
thanks

borat52

I upgraded the turbo with my downpipe so can't say how much extra power was down to the turbo and how much was downpipe.
Will make burble noticably louder but not massively, you get the biggest increase in exhaust noise with a new backbox which you already have. Still downpipe is said to give 10-15 extra break and make spool up faster so its well worth it in my opinion. You may want to consider a downpipe with sports cat, no MOT problems, though they are a little pricey @ £300.

bulbsubaru

iv put a decat down pipe on mine dident notice a big gaine in power but the sound is sweet!

ALi-B

iTrader: (1)

Most of the gains are noticed on off-boost and when the turbo spools up - at few hundred rpm lower than current, and it also responds a few milliseconds quicker when you put your foot down at higher revs.

Max bhp power isn't what it's all about, it just makes the engine/turbo more flexible across the the rev range. Worth it imo.

Nick_Scooby

I know people aren't too bothered about 0-60 times, but with a stop watch I'm 5 seconds dead, will this decat downpipe lower this time?

ALi-B

iTrader: (1)

Yup, you'll lose a few tenths (providing fueling is ok, and you don't encounter any overboost issues)

rmtypeR

I went from a std exhaust system on my Type R (catted downpipe, resonated centre section and sti backbox) to a full 2.5" decat. I can't say I noticed any difference in turbo spool (either reduced lag or power coming in at lower revs) - although it may just be that I wasn't paying attention before!

The difference I definately noticed though was more power at the top end. In standard form the power felt flat above 6k rpm, where as now it pulls stonger until at least 7500rpm.

Apparently with a decat you're also supposed to be able to hear the turbo spin up more, but the extra noise from the exhaust completely drowns that out now on mine!

Nick_Scooby

Am I likely to cause problems by fitting a decat downpipe?

sifly

Ive had a ninja sportscat downpipe fitted and is a great mod pulls alot harder abit more noise and you hear the turbo spin up and the standard dump dumping i would recommend it mate thats on a 95uk with panel filter mid decat and backbox done before.

rmtypeR

One definate problem is you'll fail the MOT! (Although I've read posts on here where people have passed even with full decats).

The other possible problem that I'm aware of is that decating will make the engine run leaner than before... therefore increasing the chances of it detting. Obviously imports are more at risk of this than UK models as they are already running on lower octane fuel than there were mapped for. If yours is an import then I would definately recommend a remap (which isn't cheap). Or at least fit a Knocklink as otherwise the only way of knowing if your engine is running too lean could be when the engine fails!

Nick_Scooby

Yes it is an IMPORT,
How much is a remap roughly and where can I geta knocklink, and how much do they cost?

rmtypeR

If yours is a 99 or later model then the std ECU can be remapped = ECUTek. generally around £700 I think.

If yours is older than 1999, then the best route is a complete replacement ECU, Apexi Power FC being the usual choice. Generally cost around £800-£900 for supply, fit and map.

As far as knocklinks go, about £150 I think. You need the display itself and sensor. BRDevelopments is one place I know that sells them, they had a groupbuy a few months ago...
http://bbs.scoobynet.co.uk/showthrea...ight=knocklink

~DrEaM~

a decat downpipe will make the turbo spool up quicker...

scoobfan

If your car is a WRX ,I wouldn't worry too much about a re-map just because
you have replaced the downpipe.

They run quite rich anyway, so won't suffer from leaning out.

Now if your car was a Type R or RA that would be different.

Rob

pk4rney

im hoping to get a full 3 stage custom on the one im getting hopefully it will be a uk turbo will decating it make it run leancause i dont wanna risk it if it does, if so how can i make it run more rich. p.s where is good for exhausts cause ive heard bad things about poweflow.