Hello all, I installed an AVCR today, and I cannot control the boost. In a nutshell I believe everthing is set correctly, and I need a lighter wastegate spring(have 15 psi spring now). Boosts to 15 psi w/ controller off.
AVCR is;
initiallized
FB is 2 1 1 1 1
boost 1.0 bar
duty cycle 30%
car select 4 4 /
ne points 3000 3500 4000 4500 5000 5500 6000 7000
sensor voltages are correct
turbo is a small TO4 (.60/.85ptrim)
street ported
Can anyone help me with this?
Thanks, Carl Byck

 

Carl:

It might be that you hook up the solenoid valve wrong. Did you follow the instruction closedly? If you hook it up wrong, the wastegate is not going to open at all becuase the solenoid valve is blocking the boost going to the wastegate chamber. Check that first before you figure out the AVC-R setting.

If you turn your AVC-R off, you should only see the wastegate spring rate of 15 psi. If you still see 26 psi, it's definitely the solenoid valve.

Chuck

 

"Boosts to 15 psi w/ controller off." Been there.... What about the spring Chuck?

 

Carl,

Up your duty cycle. I never had mine that low (30%) and have it acutally be able to control boost in time. Start at 50%+. My last setting has right around 49-64% depending on my boost setting and RPM range.

Tony

 

With all due respect Badog, That's the wrong direction. A higher duty cycle will create higher boost. I have an AVCR on my 97TT supra, so I have plenty of experience adjusting it. The external wastegate is the only thing I haven't dealt with before. Do you have an external wastegate? If so what spring is in it, and what boost are you running? Thanks, Carl

 

Carl:

It's also possible that the vacuum lines you have are too long. Keep them as short as possible. wastegate spring shouldn't have anything to do with it.

Chuck

 

not sure how you have solinoid hooked up. but there is a difernt port for external wg. when going from stock twins to single, i hade to change from the hoses going in a 90* angle to going straight in and out of the solinoid. does that make any sense? the one port not used for the stock wg, is the one needed for external wg.
is this what chuck was saying already?

 

Everything is routed correctly, I am going to shorten the "COM " hose to the wastegate a little. I did find that we had plugged the unused port on the solenoid, hopefully that's it. The reason I thought spring was the problem is that the directions say to use a spring that allows you to control max boost at a 70% duty cycle. this implies that the spring does make a difference. The instructions do not say what to do with the unused port in a wastegate configuration, but with an intergal wastegate they say to leave "NC" open to the atmosphere. so logically when you go to the external wastegate, you should leave "NO" open. I'll go for a drive in a couple minutes, hopefully no more 1.8 bar runs They are fun but not healthy. Carl
BTW Chuck, I'd like to check out your ride when its convenient

 

The plug in the open port was the problem. Thanks for every ones input, Carl

 

Carl,

About the spring ... most bc's claim that they will only be able to control boost to about 2x spring pressure.

As for the hose routing, it has been too long since I had the AVCR to comment specifically. In general, most external poppet wg's can be config'd in two very different setups and modern bc's will have separate modes the user must select to accomodate the line routing. The first will use two connections on the wg, the bottom is routed to turbo out pressure tap and the top is routed to the bc. The bc will have a turbo out pressure source that it uses to apply pressure to the top of the wg to hold it closed, the amount of pressure applied is controlled by the solenoid and it's vent to atm, hence the need to not plug off the vent (sometimes this is internal to the solenoid box and not visible, makes sure noone can plug it by mistake).

Second will vent the top of the wg and plumb the bottom wg tap to the bc. The bc will have a turbo out pressure source that it uses to apply pressure to the bottom of the wg to open it (opposed by the wg spring). The amount of pressure applied is controlled by the solenoid and it's vent to atm.

This may make more sense if you blow through the various taps on the solenoid. You can also hook up a pressure gage to the various lines, go drive, and really see what your bc is doing. Gotta be a bit geeky to do this last one.

Sorry for the longish post, but I've been playing with my bc and external poppet style wg. Having issues holding boost when rpm's exceed 6500 rpm, also trying to maximize boost response. Went to 14 psi spring and now converting from first to second config as above.

 

I am Bad , I am sure. No problem.

Only time I used my AVC-R was on the twin setup. That is what worked for me back then.

 

I was just going to tell you about the NO port and you found the problem yourself. That's cool. You can run 26 psi on pump gas and the engine is still ok so far? That really amazes me. My car should be done in about 1 week. I will take my friend's car that has almost the same setup as my car to the dyno on 2-17-03 to ATP at Fremont for dyno tuning. Let me know if you want to go together. Talk to you later.

Chuck

 

Actually, whenever I try something new, I use 100 octane, thus I still have a motor A Monday would be tough unless it's later in the day. I still need to get a hold of the correct o2 sensor for my wideband, ESP since I don't trust the one at ATP(unless they have just replaced it). Also I planned to have my Haltech Guru on hand, and he is only available saturdays. I may come down anyway, and see what I'm making now. I did some 1.4 bar pulls tonight, and the car feels good. I am pretty sure I am going to end up with a bigger turbo ultimately since at 1.4 bar the car is fast, but entirely controllable(looking for that brink of disaster power) on 235-40 Toyo RA1s. There is an adapter that HKS makes to allow you to clear the frame rail with a larger turbo using their cast FC manifold. If you can, could you find out if they still make it, and what it costs? Hope to hook up soon, best regards, Carl

 

I looked at the HKS catalog, I can't find the adaptor you are talking about.

If you can make it on Monday, that will be great. I will let you know what time we are going. Later.

Chuck