Boost Issue

[ratter]

have you logged throttle position or torque control ?

If the ECU is shutting the throttle the boost will drop off like your chart assuming you are logging it from the manifold side of the throttle blade

[DesFlurane]

Using Rev2 with Iphone and KiwiPLX.

Not sure Ratter as to where it's getting the readings from.

The revs seem normal for a first to second change, just the loss of boost.

I guess the question is whether the problem is in the tune or a mechanical issue.

Would an EBoost fix the issue?

IH8TOADS, yes your graph shows an interesting top end ;-)

Limited on the PID the KiwiPlx can pick up, but will have a look at throttle position, fairly certain it doesn't read torque control.

Thanks.

[IH8TOADS]

I think you have more than one issue. I gather you have no cat....which probably explains why boost rises with rpm, either that or the tuner is trying to create a linear power curve.

I know sweet FA about the ZF but start with ratter's suggestion as you should be able to log TP as a minimum. If it's gearbox / torque calibration related, I'm sure someone has experienced this before.

There's excess manifold pressure there on gear changes and that's your biggest concern. The tune looks to be set-up for 15psi so if it's hitting 20 - 22psi that's going to lean the AFR's badly. Don't worry about an eBoost yet, that won't fix your problem.

Readings should be coming from the manifold side. Interesting that it logs actual boost...must auto subtract baro pressure and convert to psi.

[djkice]

The kiwi wifi has throttle % as well woooo so it should work for ya

I love the kiwi wifi, it helped diagnose an intermittant fault with boost in third gear. dumb w/g porting

Edited 16/12/09 07:33 AM by djkice

[DesFlurane]

Here's a quick squirt on to the motorway today.

Throttle 100% when the boost cuts.

throttle.rtf

[our06t]

that point when its at 100% you are revving at 5600rpm that's your rev limiter I would say cutting in it has pulled all your timing out as well as boost , and I hope that manifold pressure is not in psi it reads 34 at stages?

Edited 17/12/09 12:45 AM by our06t

[IH8TOADS]

Manifold pressure is inches of mercury. Was that a boost cut or a gear change? You hit 6341 rpm in the other log. The fact that there's 8 degrees timing tells me it's under peak load when you see that 20psi spike so mechanically speaking the wastegate is shut when it should be open to lower boost.

If you have a look at this graph it happens at 6000rpm twice...probably 2nd and 3rd gear. 1st gear can see you past the limiter so our06t maybe onto something. It's interesting that it changes at such high rpm in drive? Is there anyone else with a ZF that can describe the rpm changes in drive?

[tab]

Holding the accelerator flat with a ZF will rev it right out even in drive, will go over the standard rev limit if it's in a good mood (if everything is OK, engine/trans/ambient temp, wind direction, day of the week etc.)

[our06t]

yeh BA FG a little different but not that much and the BA had an extremely variable rev limit anything from mid 5 to low 6k as tab said depending on it's mood

[DesFlurane]

It's a gear change, that data is from the drags.