Decat Difference

[mbayley77 0]

Well after trying to trawl through SIDC website I cant find any really useful information about how much difference a full decat will make to my classic import STI.

 

So here I am on the only forum which i believe has any honest technical knowledge without constantly bragging.

 

realistically am I going to get much of an improvement in throttle responce and acceleration by fitting a decat pipe (downpipe and center section)?

 

Also, is the noise going to be much different - also running a Hayward and Scott backbox.

 

Sorry again for the non pug thread but just want an honest opinion before doing all the work.

 

Thanks

 

PS - I will get my bloody 205 on the road again this year and hopefully see some of you guys at Combe

[pugrallye 0]

scooby owner here...

yes cat removal makes a difference, even prodrive kits remove 1 cat in their PPP kit (the second one) and yes it makes the exhaust louder, well would say throatier as you get 'more flat four', if you only remove the second one and car is completly legal and will pass any MOT

A full Decat will make it slightly louder still as you only have the back box to silence it.. if you have an H&S backbox, it wont be as loud as say a vortex or blitz NUR system, I dont find it too offending too be honest unless on full throttle

Edited April 11, 2007 by pugrallye

[mbayley77 0]

Cheers for the reply.

What about the throttle response? Any better?

[pugrallye 0]

yes it is better,spools up faster and has a bit more life in it (it isnt going to do wonders for the old 0-60 but turbo kicks in say 300-500 rpm sooner), as they tend to strangle the car somewhat, would seriously take the walbro and remap route too though at some stage, as it really makes the car into a weapon (not the scooby owner coming out, lol just honest advise)

Edited April 11, 2007 by pugrallye

[maturin23 10]

Another ex-scooby owner here.

 

I had a UK MY99 - first thing I did was get a decat, and to be honest it gave a slightly noticable improvement in spool-up and a small increase in top end pull and throttle response, but all really marginal changes. It was most noticeable due to the fact the BOV was more audible.

 

In short - worth doing but don't expect massive results.

Edited April 11, 2007 by maturin23

[pugman211 0]

Another ex scooby owner! Definately do it!!! the main reason i found, is the OE turbo down pipe has a blanking plate on it from the turbo. When i put on my magnex decat, it had a seperate pipe on it allowing all the trapped gases from the turbo to be released quicker - hence quicker spool up/ down and throttle response.

 

What year STI is it??

[pugrallye 0]

Another ex scooby owner! Definately do it!!! the main reason i found, is the OE turbo down pipe has a blanking plate on it from the turbo. When i put on my magnex decat, it had a seperate pipe on it allowing all the trapped gases from the turbo to be released quicker - hence quicker spool up/ down and throttle response.

Err.... thats for the wastegate, you will see negligable increase in spool up by changing the flange design! (HKS for instance still leave it blanked!)

[mbayley77 0]

Its a 1995 STI Version 2.

[WildCards 0]

I fitted a decat pipe to my Legnum, I didn't really know what to expect before it went onother than it'd be louder.

 

It was louder, and I found the car was alot more willing to pull through the mid range although it seemed at the expense of low down torque. I have no experience of Scoobs, but i'd imagine you'd get similar results.

[mbayley77 0]

Thanks everyone. Ill try and report on what its like when I get it all done. Maybe a before and after sound clip as well. if anyones interested of course.

[zeolite 0]

If you want any Scooby info ask Squirrel555 in the scottishscoobies section. What he doesn't know, nobody knows.