Average boost pressure to achieve 300hp ?

[robster247]

So I've finally got the end in site for my turboed vts , but I'm not sure how much boost to run to achieve my goal of 300hp .

Obviously it's all forged, cammed, gt28 turbo, dta s40 . So I'm hoping it should be upto the job.

So the question in hand is what size spring to put in my trial external wastegate? I am using a turbosmart electronic boost controller so should be able to make slight adjustments through using that .

[AXracing]

It would very much depend on many variables. But if we talk a stock cc vts engine beefed up to high heaven with a few other tweaks for all that extra gass. Also you go ott on cooling your probably talking around 1.5 bar. Though that's a hell of a lot of boost so personal I would start a lot lower and work my way up.

[robster247]

It would very much depend on many variables. But if we talk a stock cc vts engine beefed up to high heaven with a few other tweaks for all that extra gass. Also you go ott on cooling your probably talking around 1.5 bar. Though that's a hell of a lot of boost so personal I would start a lot lower and work my way up.

Thanks for the reply,

Has a big intercooler, 13 row oil cooler and a alloy radiator with a 50mm core so should run cool. I am a bit worried about bay temperatures though as everything is rather tight in there .

I'll get on eBay and buy a few springs for the wastegate, starting from a bar upwards

[Chipwizards]

It's always better to start low and go up in sensible steps than start broken and try to work downwards.

An S40, good little ECU that it is, doesn't have knock control so your 'goal' of 300 will be very difficult to achieve with any degree of safety.

Monitor temperatures, especially exhaust temperature, very closely. Start extremely rich and gradually go leaner. Too lean and the bit of cylinder head between the exhaust valve seats will get too hot, go soft, and the seats can drop out - causing carnage.

Go sensible at first and run it for a while then do a leak down test. Keep an eye out for gasket breach between the cylinders because that's the weak spot when you push these engines.