Project: RS2 ABY

[prj]

Still limiting boost immediately after gear-change above 6krpm apparently, obviously not quite making target boost but needs to be tweaked for the new WG anyway.

Probably max pressure exceeded code in ECU. I think it's over boosting on gear change.

[KaraK]

Still limiting boost immediately after gear-change above 6krpm apparently, obviously not quite making target boost but needs to be tweaked for the new WG anyway.

Damn.. so it's back to where it was at the 'Ring last year then?

[prj]

I think there are multiple issues here.
I am pretty sure at least part of it was the broken wastegate and is fixed with the new wastegate.

I am also sure the ECU will behave incorrectly with the new wastegate and there can be short overboost and possible limp mode.

As to "not making the designed boost pressure", I want to see that from an ECU log, not from someone looking at a boost gauge, that would be much more useful to me.
There can also be issues with N75 positioning that can cause such behaviour, but regardless, I will sort it out.

[Sonic]

Probably max pressure exceeded code in ECU. I think it's over boosting on gear change.

I'd write that bin file to a fresh chip but seeing as you'll be with the car soon enough...

Damn.. so it's back to where it was at the 'Ring last year then?

Yes, but that's no bad thing as it runs perfectly... it's just need a tweak and it'll be at 100% rather than 99.9%

[Sonic]

I think there are multiple issues here.
I am pretty sure at least part of it is different wastegate.

Unquestionably the new WG will need sorting out with the map.

It has a 1 bar spring in it now, although i expect i'll have a fistful of springs we could fit.

[A80Avant]

Unquestionably the new WG will need sorting out with the map.

It has a 1 bar spring in it now, although i expect i'll have a fistful of springs we could fit.

If you can remember what was your wastegate pressure before then the spring to use needs to be exactly the same, ie wastegate pressure of 0.4 bar for example otherwise the ecu will not cope with the higher Arlington pressure, overboost and as prj says go into a cut

[prj]

If you can remember what was your wastegate pressure before then the spring to use needs to be exactly the same, ie wastegate pressure of 0.4 bar for example otherwise the ecu will not cope with the higher Arlington pressure, overboost and as prj says go into a cut

There are other parameters to a wastegate other than cracking pressure as well.

Some examples:
Response to duty cycle
Travel
Size

[Sonic]

Needless to say i wont be hammering it until it's tuned for the new WG (apart from a log to confirm the boost "sticking" issue on gear-change).

[A80Avant]

There are other parameters to a wastegate other than cracking pressure as well.

Some examples:
Response to duty cycle
Travel
Size

indeed, which would alter the response to the interim DC of the N75

[Sonic]

Picked up the S2 from VRS last night, and boy does it feel good to be boosting up correctly again

Just the gear-change issue to resolve with prj in a couple of weeks when he's over, and he has a couple of likely candidates for the problem.

[A80Avant]

Don't drive it!
You know what's going to happen. Once Dmitri comes the damn thing will work brilliantly and he wont be able to replicate the problem!

[prj]

Don't drive it!
You know what's going to happen. Once Dmitri comes the damn thing will work brilliantly and he wont be able to replicate the problem!

It won't in this case. I am pretty sure I know exactly what's wrong now.
Before it was very complicated, because the wastegate was also causing issues, so there were multiple issues together.

I will confirm this with my data logger, fix it and then make a writeup if this is indeed the case.
The boost is more or less fine I think, this should be something much simpler

[Sonic]

Don't drive it!
You know what's going to happen. Once Dmitri comes the damn thing will work brilliantly and he wont be able to replicate the problem!

It's pretty repeatable and i intend to get a log of it occurring this week.

It won't in this case. I am pretty sure I know exactly what's wrong now.
Before it was very complicated, because the wastegate was also causing issues, so there were multiple issues together.

I will confirm this with my data logger, fix it and then make a writeup if this is indeed the case.
The boost is more or less fine I think, this should be something much simpler

Absolutely - having fixed 2 problems (wg sticking and the inlet hose boost leak), this is the only thing remaining. Far easier to troubleshoot now!

[prj]

Guessed the problem correctly. It had an adjustable cam pulley on it, and the hall sender window was on the ragged edge.
Meaning when I mapped it and the timing belt was new the issue did not manifest itself, however, as it got more miles on it and the timing belt stretched somewhat (naturally), there was just enough belt slap on gear change to trigger the ECU hall sender fault condition.

Because it was there for a very short time, the ECU retarded the ignition timing and temporarily cut the boost, but did not log a fault.

JP has adjusted the camshaft pulley now, and it's perfectly fine. The 0.5 bar problem is gone.
I gave it a small checkover as well, and it's running spot on.

[Error404]

Good detective work guys, and a good result. Andy you must be pleased with it now?