GolfGTIforum.co.uk

Model specific boards => Golf mk4 => Topic started by: Screech16v on 29 January 2013, 23:55

Title: Larger exhaust more boost ?
Post by: Screech16v on 29 January 2013, 23:55

Since replacing my exhaust I have noticed I have more peak boost was .8 bar  now over .9,old exhaust was standard mk3 16v but there was a section that was 2"  :shocked:. I now have a 2.5 stainless system decat and 3"downpipe how come I now have more boost? surely the exhaust wouldn't determin boost pressure would it? :undecided:

Title: Re: Larger exhaust more boost ?
Post by: golfyste on 30 January 2013, 05:46

Not 100% sure but it might be that because there is less back pressure it is spinning the turbo up quicker and just spiking a little higher due to it being easier to spin......maybe  :laugh:

Title: Re: Larger exhaust more boost ?
Post by: Granta Gti on 30 January 2013, 07:23

Mine seemed to do it when I fitted the eBay :" system I think it peaks quicker and then tails it back down. Cause it's doing it quicker and less restrictive it flows better and has more boost initially.

Title: Re: Larger exhaust more boost ?
Post by: Prawny on 30 January 2013, 08:29

less restriction, allows the turbo to work more, 0.8 - 0.9 bar isn't a huge jump, I'd say it's more than possible.

Title: Re: Larger exhaust more boost ?
Post by: Dalo Harkin on 30 January 2013, 08:44

It's the downpipe that does it, bigger downpipe = turbo spooling faster  :wink:

Title: Re: Larger exhaust more boost ?
Post by: Screech16v on 30 January 2013, 20:13

Thank you for the replies ,it does seem to have a bit more tourque low down also.