going to look at hopefull y my new g40 :-)

Started by benh999, December 20, 2009, 04:54:46 PM

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Nick_S

One thing i noticed and worthwhile bearing in mind if you are staying with the G40 blower; don't go bigger bore than 2.25" on an exhaust system.
I've recently installed one of the PPP systems which is 2.5" at the downpipe exit. Having stepped up directly from a 1.75" system, i have lost 1 psi of boost. Mine already has a very well flowed BVH cylinder head which was giving 9psi boost on the OE bore with a 4 branch, now gives 8psi with the PPP system (65mm toothed pulleys). Car certainly feels more laggy low down now than it did. I could fit a bigger blower of course to get max output, but i'll try tweaking a few things before i go down that route.

hayesey

you've lost 1psi of boost because more air is getting consumed by the engine as the exhaust isn't causing as much of a restriction.  So 1psi less back pressure in the inlet manifold = more power. :D

Yoof

Think you've got some wires crossed Nick...


Yoof

P.S- It's good to know our systems flow more than stock  ;)

Robin


Nick_S


Robin

really? how does it feel like a turbo?

btw where is my sodding breakfast coolant boy?

Nick_S

Quote from: Robin on December 21, 2009, 09:07:15 PM
really? how does it feel like a turbo?

btw where is my sodding breakfast coolant boy?

Power delivery.

That was your ethylene glycol special liquid breakfast.

Robin

really? have you driven a turbo'd Polo before?

Nick_S

Nope, just a fezza RST and Nissan Silvia petrol engine wise.

Robin

can't really compare it to a turbo'd polo seeing as you not driven one lol.

comparing the lader to the turbo is a massive difference, yes i know your's is not the standard lader set up but the difference between the 2 can't be as big as the difference from the lader to the turbo, the turbo feels VERY VERY much like a lazy GT engine until it comes on boost then its frantic after that.

i can see why you say yours boosts later but the turbo boosts alot higher in the rev range than the lader on any set up.

Nick_S

Thats like how mine behaves, don't notice any positive boost pressure until about 4.5k then its a rampant mo fo.

Robin

Quote from: Nick_S on December 21, 2009, 09:38:32 PM
Thats like how mine behaves, don't notice any positive boost pressure until about 4.5k then its a rampant mo fo.

really? that high up???? that will be shit for road use! no boost no boost no boost no boost no boost no boost then 8 psi of boost!

Robin

also if it only gets into boost at 4.5k that means you have 2.5k max to go before you have to change gear!

you sure you not driving a diesel?!

Nick_S

It don't need lots of boost low down when its as torquey as hell off it. Engine was built with high boosting in mind, so i'm not all that surprised ;D 8P box on at the moment don't help to compare acceleration/gear changes, but 1st and 2nd are pretty useless :D