Running with wastegate open and compressor side not plumbed in
Turbo Mini Forums

As i collect bits for the new turbo EFI build i was thinking i could fabricate my exhaust manifold and fit it with the turbo but run the car with the wastegate fully open and the compressor side left t air (but plumbed into some pipework and a air filter to avoid any debris damaging the compressor).

Does anyone know if running like this is likely to damage the turbo? I'm assuming it will rarely spool up to any sort of speed but just wanted to check.

The reason for doing this is so that i can test operation of different aspects piece by piece. E.g. i'd ensure the dual lambdas are functioning at this stage. Then after i'd be able to add the inlet manifold and run N/A before closing the wastegate and joining up pipework.

1275 N/A Sprite, 998 T2 Turbo Mayfair
1275 EFi Turbo

I have thought about this on running in for initial set up, but with no load on the compressor, i'd expect the turbo to overspeed, even with the wastegate full open

If you plumbed it all up and just left the wastegate open then it shouldn't overspeed. Would be a restriction though.

Wastegate fell open on van once when e clip pinged off. Drove ok but was dog slow.

If something is worth doing, it's worth doing half of.

What you could do is take the core out of the turbo and fit a blanking plate to the exhaust housing and just fit the exhaust housing. It would save damaging the rest of the turbo and having to pipe it up.

Or blank the compressor outlet (preferably a cap with a small hole) to allow it to spin up but not overspeed which it shouldn't if the wastegate is also wired open.

Schrödinger's cat - so which one am I ???

If the wastegate is fully open I wouldnt worry too much. Just drive it sensibly and it wont do it any harm

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

great, thanks chaps

1275 N/A Sprite, 998 T2 Turbo Mayfair
1275 EFi Turbo

Just a thought

surely it would not be possible to overspeed a turbo by running with the compressor open as the engine would not get produce anywhere near as much exhaust gas as it would when its running loaded up, therefore be unable to serously speed the turbo up.

Just my logic so feel free to shoot me down

On 4th Nov, 2011 minimole23 said:
Just a thought

surely it would not be possible to overspeed a turbo by running with the compressor open as the engine would not get produce anywhere near as much exhaust gas as it would when its running loaded up, therefore be unable to serously speed the turbo up.

Just my logic so feel free to shoot me down

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will