29 replies to this topic

[Ivor]

Finally ready:
390bhp
350lbft torque

Should be exciting
Collecting Monday

[KurtVerbose]

Where's it been?

[Ivor]

Where's it been?

On holiday in Norfolk at Courtneys

[hairy]

Couldn't they squeeze another 10hp out of it? 400 sounds so much better!

[KurtVerbose]

How much did it have before?

 

Be interested to hear how you find it.

[Cavturbo]

That will be fun Ivor enjoy. Would love to hear the full spec.

Edited by Cavturbo, 19 June 2024 - 08:05 PM.

[Ivor]

How much did it have before?

Be interested to hear how you find it.

About 260

[Ivor]

That will be fun Ivor enjoy. Would love to hear the full spec.

I'll dig it out

[Cavturbo]

Thanks would be an interesting comparison to see how things have moved on since mine was built by them 10 + years ago. Back then Courtenays were recommending Garrett Turbos which mine still has fitted.

[oblomov]

Would it be rude to ask how much?

[Ivor]

Would it be rude to ask how much?

Yes more than another car
Not all was to do with the upgrade, new rad fitted,new fuel tank, issues taking the car apart etc

Edited by Ivor, 21 June 2024 - 06:12 PM.

[oblomov]

When Courtenay started doing stage 4 upgrades, there was (as I understand it) an unaddressed problem in that when the throttle was feathered, the turbo would continue to boost causing back pressure on the turbo/flutter.  This was caused by the fact that the throttle is fly by wire as opposed to a mechanical (wire) connection) and the ECU was not able to catch up quickly enough with what was going on with the throttle.  I had to install a top hat with a take off to a Forge bleed valve which in turn has to feed back in to the air intake after the AMM so no air is lost to the system, otherwise again, the ECU would be confused.  On cars like yours, how is the problem addressed these days?

[Ivor]

Amazing, that's exactly what it's doing. Do you have any more details on what you did, where you got the top hat from etc

[Ivor]

Didn't have the issue with my mmg stage 4 so don't know what's wrong / been changed

[stevieturbo]

When Courtenay started doing stage 4 upgrades, there was (as I understand it) an unaddressed problem in that when the throttle was feathered, the turbo would continue to boost causing back pressure on the turbo/flutter.  This was caused by the fact that the throttle is fly by wire as opposed to a mechanical (wire) connection) and the ECU was not able to catch up quickly enough with what was going on with the throttle.  I had to install a top hat with a take off to a Forge bleed valve which in turn has to feed back in to the air intake after the AMM so no air is lost to the system, otherwise again, the ECU would be confused.  On cars like yours, how is the problem addressed these days?

 

 

Sounds like a fairly typical problem with a vent to atmos dump valve on a setup with a MAF. You cannot dump already metered air, and expect things to behave normally.

 

That's not a DBW or any throttle problem

[Ivor]

Thanks both

[joshua]

With the stalling issue in mind I spoke with Courtenay last year about the fact my car was mapped 10+ years ago and suggested there might be an improved version by now . Their answer was not really.
Does this problem occur with this stage 4 and a Garret turbo?
My car does not vent a dump valve to air it has a recirculation valve but can flutter away happily and throttle modulation is not great at times.
I always presumed the problem was some kind of pressure feedback loop?

[Cavturbo]

Yes my Garrett VXT does this. I have learnt to drive around it on the road and doesn't do it very often now.

[Ivor]

Interesting, thanks all, when I was running it in I said it had this flutter, Courtney said that's what it does, must be a fix you'd have thought

[Ivor]

My stage 4 only did it if there was a vacuum leak