Boost Control

mouse · Post by **mouse** » Tue Aug 14, 2007 11:46 pm

What wastegate duty for low engine speeds and loads would be recommended for a subaru road car if running open loop control?

RickS · Post by **RickS** » Wed Aug 15, 2007 3:26 pm

Hi

For low engine speeds and loads i would suggest you don't close the wastegate it makes the driveability of the car a lot easier at low speeds as you don't keep getting big chunks of boost, i wouldn't start closing the wastegate until you hit 1600 - 1800 rpm.

I hope this helps, it is probably something worth experimenting with.

Phil

mouse · Post by **mouse** » Wed Aug 15, 2007 9:26 pm

Cheers Phil.
But under low load conditions at say 3000rpm thare may be little boost available, small throttle changes may be required to maintain speed on the open road, but no boost needed. Would it be more efficient to have the wastegate open, or closed so if a fast throttle applied boost may come on sooner?

RickS · Post by **RickS** » Thu Aug 16, 2007 9:56 am

There may be little boost avaliable but you may as well use it, If you close the wastegate perhaps 70% then the boost will help the car maintain the speed, you have to take account of greater rolling resistances and drag at higher speeds.

This will also keep the tubo spinning and therefore enable boost to build faster when required.

I hope this answers the question.

mouse · Post by **mouse** » Sun Aug 19, 2007 10:16 pm

Cheers for that

I'll give it a whirl.