4 Bar Fuel Pressure Regulator

[Lee172]

Had a look in the search bit but cant find anything for 8ls..

Do you need a 4 bar regulator to go to stage 2 ? Some places i have called say you do some say you dont but i cant understand why?

Also about performance exhausts, a few tuners say the s3 one is ok for stage 2 if you get a sports cat/decat.. is this true?

 

[Alex C]

from what ive heard the exhaust flows ok, its the downpipe that restricts it i think, may be proved wrong tho

 

[Welly]

Had a look in the search bit but cant find anything for 8ls..

Do you need a 4 bar regulator to go to stage 2 ? Some places i have called say you do some say you dont but i cant understand why?

No, you don't IMO.

The reason people say that you need one is that more fuel will come out of the injector hole if the pressure is higher. Basically, using a 4 BAR FPR, you can eak some extra flow out of the S3 injectors. Extra fuel that you don't need for Stage 2. IIRC Stage 2 Revo was the one that required a 4 BAR FPR.

S3 fuel pumps, especially after having run 80K+ at 3 BAR, will not like having the pressure required upped to 4 bar, and normally pack in. Packing in fuel pump/weak fuel pump = lean condition. Bad.

Also about performance exhausts, a few tuners say the s3 one is ok for stage 2 if you get a sports cat/decat.. is this true?

Some may say this, but they normally add 'at the VERY least' afterwards. If you haven't ever seen the layout of an 210/225 downpipe, then you won't understand the problem. It's crap. Discussion over.

I would always say to replace the downpipe over anything else. The OEM downpipe will give you higher EGTs and consequently higher under bonnet temps. Not to mention make it hard for the gasses to escape from the engine.

Downpipe FTW.