I installed the AVC-R a few weeks back. However, I'm having real difficulty getting rid of some boost spikes.

 

The unit was relatively easy to configure for two boost levels of 0.8 bar and 1.0 bar and went into self learning mode. However, I can't get rid of initial boost spikes. It's hard to explain this one so I've knocked up two graphs which I've attached to this post.

 

The spikes are overshoot spikes where the boost first rises. After that, the boost is very stable. The boost appears like the first graph I've attached. I've tried reducing the start duty to get rid of the spikes but that just makes it go like the second graph I've attached. This is no use at all as I end up on reduced boost for most of the rev range.

 

I've tried disabling/enabling gear based learning. I've played with start duty, feedback speed, etc, all to no avail.

 

Has anyone successfully set one of these up to dial out these spikes? If so, any suggestions would be very welcome as would details of your settings.

 

Cheers

 

Mike

 

Graph 1

 

Graph 2

Hi Mike, self learning is considered not to work on the AVC-R on a twin turbo, mine kept creeping ever higher. I've completely disabled it and just set it manually, been pretty close to the mark ever since given the odd change due to climate. Might be worth checking for boost leaks too as I'm sure these will play havoc with your settings.

 

Cheers

 

RobH

Trust me I am no expert on this, but as far as I know the self learning mode does not work with dual solenoid/turbos - you have to do it manually. It's a shame because I installed one of these in an MR2 Turbo and it was an absolute breeze with the automated features.

The main self learning function is for the duty cycle at different RPMs and it appears to have learnt this very well. The graph of duty cycle vs RPM has changed quite considerably under the self learning and it now gives a perfect steady boost once the target level has been reached. I.e. It boosts very briefly to between 1.05 and 1.15 bar then settles down to 1 bar. It sticks almost perfectly to 1 bar right up to the red line.

 

My problem is due to this initial overshoot which I've tried overriding the other self learning stuff to control (i.e. start duty, gear based learning, etc). However, none of the parameters seems to be able to sort it out.

 

Surely someone else has got one of these fitted. What are your findings and/or settings?

 

Cheers.

Is the pressure sensor definitely mounted correctly? Most I've seen MUST be mounted vertically, with the pipe coming out from the bottom. Also where have you attached the vac pickup too? If its the passenger side of the plenum then thats where the pickup is for the fpr and has the solenoid which will affect its reading. How long are the hose runs? Are they equal lengths from the t-pieces? It sounds like the boost controller is struggling to respond quickly enough - this could still be a setup problem though...

 

CheerZ,

 

Andy

When I spoke to Phil of C&S Woods, he told me that installing it is one thing but getting it set up makes all the difference and is probably the hardest part of it.

 

He told me of some one he knew in West Houghton who installs things like this and more importantly sets them up for you.

 

Stuart

Mike,

 

I have the AVC-R on mine and have absolutely no spikes! and it's in self learning mode... does sound like it's struggling to adapt like Andy said. What % gain are you using? I think mine's on 62% for 1 bar - I can check my other settings when I get back if you like.

The pressure sensor is located as in the attached picture. It is mounted vertically and the hoses from the turbos, etc, are all of equal lengths.

 

The green arrow shows where the boost monitoring connection is made. The red arrow shows where the line is t-pieced with the pressure sensor line going towards the bulkhead. The blue arrow shows the pressure sensor mounted on the bulkhead.

I can check my other settings when I get back if you like.

If you would mate that would be good. My duty cycle for 1 bar ranges from 46% at 3000rpm to 63% at 6500rpm.

If you would mate that would be good. My duty cycle for 1 bar ranges from 46% at 3000rpm to 63% at 6500rpm.

 

That graph looks like a typical control system with too much gain. I'k not familiar with that particular boost controller but does it have a gain setting?

I have asked on TT.net and they said put it in self learn and after 3-4 runs in 4th from 2000rpm to red line it works perfectly.

Mine was always a little like that - I put it down to boost leaks but I've spoken to a few people now who think it's an AVC-R trait full stop.

 

These might be the same people who don't realise it needs setting up properly, 'course. :D

 

I used to get boost wobble - fixed that by playing with feedback speeds. Never got rid of the spike though, and it used to catch me out on turn-out. :eek:

 

I also found it was dicky after a reset until you'd really smacked it hard three or four times, like Stu says!

Mike. If you pop it down here mate. Chris will have a look free of charge. He sets those units up in his sleep mate. If you either bell me or pm i will give you a time.

 

Cheers

 

Johnny