hi could any one please shed some light on what is acceptable on boost settings,
the car is running std injectors plus 2 extra injectors on a greedy standalone unit, a walbro fuel pump(255) and a fuel pressure regulator.
it has a full stainless 3inch exhaust with no cat or baffles, and a front mount and pipercross cone filter. blow off valve, no enviromental rubbish, and a few other bits.
i have an apexi boost controller (electric) so i can manage it all fairly accuratly. at the moment im running std boost but would like to see what is possible.
thanks for any help.
also got a fuel air meter in the exhaust measuring the mixture ratios.
if its the stock turbo - then .85 bar should be OK for you
what if its not a stock turbo, i no the stock turbo will struggle, but what will the engine take if the fueling mixture is good?
if its not a stock turbo - then who knows
when i decatted mine i could hit .9 on the stock one and it was OK ( not sure how long it would last though )
the engine will prob take about 350 BHP with the fueling and cooling ( not sure to be honest ) - but its the turbo that you need to be aware of
have you got an aftermarket turbo ??
The stock turbo and intercooler are the limiting factors once you\'ve done exhaust and intake. As you\'ve done front mount intercooler, it\'ll be your turbo that\'s going to limit things.
I\'d say don\'t take it much above .8 bar unless you have some way of controlling ignition (retarding it) as you could run into problems otherwise. Fuelling is one thing, but you will have to retard at higher boost settings.
You will definitely need to do something with the wastegate if you\'re running stock turbo - you will be getting boost creep even now.
im running an apexi electronic boost controller which i throught reduced the risk of boost creep,?
is the point of retarding the ignition to prevent detenation? i so what can i do to do this?
thanks for all replys.
The boost controller will only control the boost in as much as it allows you to increase beyond spring boost.
With the boost controller off, and with the engine warm, take it up a hill in 3rd or 4th gear and see what happens to the boost pressure. If it reaches a maximum value and stays there then all is well, but most likely it will appear to reach a peak and then \'creep\' up from that point. You\'ll need to get the rev\'s up when you do this, and be in the highest gear you practically can be. Boost creep is basically where the wastegate isn\'t large enough to flow the additional exhaust gases past the turbine, and as it becomes overwhelmed, it will start to push the boost up.
You can get round it by either porting the wategate, reducing either the intake flow or exhaust flow (but that will lose some power) or by going for an external wastegate - you\'ll need a new manifold for that.
Ideally, the boost conroller will control the boost between the spring boost setting (about 6 psi on a stock turbo) and whatever the wastegate will allow at the top end. Go beyond that and you\'ll be back into boost creep again.
For retarding the ignition you\'ll need either a standalone ECU, or a piggy back device.
thanks for your explanation on boost creep,very usefull,