IAN

iTrader: (3)

I video taped my wastegate trying to trace the no boost and lag issue during full throttle runs. (Taped the camera into the engine bay LOL)

Funny thing is that I see the wastegate responding instantly and gradually going fully opened. I thought that the apexi AVCR holds the boost off and once you hit target boost it opens it up. What's with this opening up right away? Should it not be an on off function? This was set to run 14psi but I only can reach 5psi. I think the spring may be set to 5psi or more. (10psi spring installed)

Any answers?

Thanks,
Ian

jreynish

iTrader: (2)

Ian,
Is your diaphram inside your wastegate cracked or ripped, I was having the same issue as you... and then I bought a new diaphram and replaced it... and now I can get to 15psi.

IAN

iTrader: (3)

Don't think so. I had this problem last year. Pulled it apart and it looked fine last year. Maybe I did not look at it well enought. Its brand new. Maybe 2500KM on it.

Thanks for your input.
Ian

maxcooper

The wastegate should never be simply on/off, even with a boost controller installed. The wastegate should be open just enough to maintain the desired boost level, which means that it has to be able to move continuously from fully closed to fully open, stopping anywhere it needs to inbetween.

Is your wastegate stuck partially open, even when it is at rest (and should be completely closed)?

-Max

maxcooper

The wastegate should never be simply on/off, even with a boost controller installed. The wastegate should be open just enough to maintain the desired boost level, which means that it has to be able to move continuously from fully closed to fully open, stopping anywhere it needs to inbetween.

It does seem odd that it is opening at such low boost levels, though. Usually the EBC should try to keep it closed until right before you hit your target boost.

Is your wastegate stuck partially open, even when it is at rest (and should be completely closed)?

-Max

Carl Byck

Based on the Propoganda produced by the manufacturers of EBCs, there thould be ZERO signal to the WG until the target is reached, at which time the EBC bleeds off minute amounts of boost allowing the turbo to hold a specifific level longer than if the WG went full open.

That said, the "duty cycle"/Gain/whatever the manufacturer calls it, determines how close to that Ideal situation you get. This is why the boost curve/HP on a ~30 psi run is a near vertical line, where the identical set-up on a ~15 psi run is a gradual curve. Virtually all modern EBCs have some form of "fuzzy logic", that causes them to try to "predict" when max boost will be reached. The better the EBC(and larger the solenoid), the closer you can get to the ideal(higher duty cycle on the boost solenoid) described above. Basicly, the size of the valve on the solenoid of an EBC is far too small to react in the ideal fashion described, therefore, it bleeds off boost in an effort, not to "overshoot" the pre-set level. I have no idea why nobody markets an "electronic WG", basicly an EBC/WG all in one, with the proper size relief valve, but until someone builds such a device the compromise will always exist. Carl

maxcooper

Even without an EBC, the wastegate doesn't just go full open. If it did, your boost would drop substantially at that moment. Any kind of wastegate control system MUST be able to operate the valve over a range of "open-ness". You might need full open at your torque peak with a wide open exhaust -- anything less might give boost creep, depending on your setup. But really, you probably don't want to be that close to the edge of boost creep, so your system may never need the wastegate to go full open. And if it went full open at 3000 RPM, your boost pressure would drop like a rock. The control system needs to be able to open the wastegate maybe halfway at 4000 RPM, then almost all the way at 7000 RPM and then start to close down again to maintain your desired boost level as you continue to rev the engine out.

The duty cycle of the EBC solenoid varies to maintain the right amount of pressure on one or both sides of the wastegate diaphragm. It does not mean that the wastegate is opening and closing like a mad little flapper.

I suppose that it might be possible to get rid of the traditional pneumatic wastegate actuator and spring and replace them with an electrical solenoid that could be duty cycled by an electronic controller to control boost a little more precisely. However, there are some significant challenges. It would probably beat the hell out of the valve seat and wear out quickly to duty cycle the valve, though perhaps a stepper-motor could be used instead of duty cycling. The failure modes would be ugly since you would probably have to choose open with no/low boost or closed which would pop your engine quickly, unlike the run-on-spring pressure failure mode (at least for some kinds of failures) of the traditional design. I guess you could use a spring, but then the power consumption might go up pretty substantially, which would add to the cost and thermal issues. It might be very difficult to get a solenoid that is strong enough and fast enough -- this sounds expensive. And finally there is the hot environment, though perhaps the solenoid could be remote-mounted and use a rod to control the gate like many internal wastegates do.

I've never been very satisfied with how well my boost pressure holds, so I do see some room for improvement over the current systems. But I bet most issues with the current systems could be tuned out with various tweaks (hard, short, large diameter control lines, etc.), a good EBC, and someone that knows how to tune the EBC effectively.

-Max

maxcooper

IAN,

Since your wastegate seems to be opening sooner than it seems like it should (I'm still not certain, but this seems to be worth investigating), how about using a hand pump to test what pressure it cracks open at? And then perhaps review your boost control system plumbing to see if something is fouling up the operations there.

-Max

IAN

iTrader: (3)

Max,

Total pulled everything off again. Wastegate is fully closed.

But!

Here is how I had it plumbed in. This is the rear or the UIM starting from the top down to the buttom.

1: This went to the LIM nipple under the cold assist start. (middle of LIM) Cold assist removed. Gizmo is capped.

2: Airbleed to NC on apexi solenoid to the side of the turbonetics WG (would this not always open the WG regardless?

3: OMP

4: Idle control thermowax. this is on the throttle body?

The other side to the APEX AVCR solenoid (COM?) went to the top of the WG.

I did go look at a Turbonetics 60-1 turbo on a honda civic. Brand new it spins and feels the same as mine so I'm beginning to wonder if its something else.

I removed the FMIC and looked for leaks. NO leaks. That is a big job

Thanks guys,

Ian

IAN

iTrader: (3)

Also It has the silver spring installed in the WG. THis is good from 7 to 9psi.

This should be good for 15psi???

I think the WG was adjusted for the buttom end of the boost. But still should boost more then I was seeing.

maxcooper

That sounds right. I don't know why it isn't working.

In simple terms, this is how to plumb the AVC-R and an external wastegate:
1. manifold pressure to side of wastegate (the WG port that will open the gate when pressure is applied)
2. manifold pressure to NC port on AVC-R solenoid
3. NO port on AVC-R solenoid vented (not plugged, nothing attached)
4. COM port on AVC-R solenoid to top of wastegate

The AVC-R should supply full manifold pressure to the top of the wastegate during spool-up to hold the wastegate shut. That's how the EBC works -- by controlling the pressure in the top of the wastegate.

I saw a thread on here about someone having their ignition timing all messed up that caused really slow spool and poor boost reponse in general. Have you checked your timing maps, and verified that your actual timing (tested with a timing light) actually matches what your map says it should be?

-Max

NewbernD

iTrader: (1)

Have you tried just running on spring pressure to troubleshoot? If you have a 10 psi spring installed you should be able to hit 10 psi with just one vacuum line running from the turbo outlet to the side port on the WG.

IAN

iTrader: (3)

This car was tuned by steve KAN

maxcooper

So that means the numbers in the map are probably good (unless they got screwed up since then).

The next question is whether the 10 in the map gives 10 degrees of actual timing, or if your crank angle sensor has come loose and you're really getting -12 degrees instead. I would expect that comparing numbers are at idle with a timing light with a map watch would tell you if things are working properly.

-Max

IAN

iTrader: (3)

Weird. Seems backwards. I have this installed this way and my AVCR manual states so. This is pissing me off. I wonder whats up with this.

maxcooper

What seems backwards?

-Max

IAN

iTrader: (3)

The fact the AVCR holds it open to till it it reaches the boost. BUt this makes it fail safe. Since if the AVCR fails it will fail closed allowing the boost too the WG.

thank again max for your help.

I think I have T'd in the airbleeds together to the WG so maybe this may be the problem with boost.

Ian

maxcooper

The boost controller holds the wastegate closed until you hit full boost. Open wastegate = no boost. Closed wastegate = give me boost!

The AVC-R boost controller holds the wastegate closed by keeping the solenoid open (activated), thus supplying full boost to the top port of the wastegate.

It's probably a good idea to study how the boost control system works (or is supposed to work) in detail. It will help you troubleshoot. If you want help, post some pictures that clearly show how all the boost control hoses are routed.

Be aware, though, that a boost controller can't give you less boost than your spring pressure. Since you are getting less boost than your spring pressure should be giving you, that tells me pretty clearly that you have a problem that is not related to the electronic boost controller. You might still have boost controller problems, but you've got at least one other problem that is causing your boost to be less than your spring pressure.

-Max

eViLRotor

iTrader: (2)

*edit*

IAN

iTrader: (3)

Thanks max,

I understand the concept. Previous to my stock setup it worked fine. Just problems with this new setup.

And for some reason I just hooked it up per diagram and never bother to think how it work. For example i always thought that you would use the solenoid inbetween the wg (side connection) to hold boost from going to the wastegate to open it up. Then the solenoid would open up at the preset boost opening the wastegate.

That said it is hooked up via apexi instructions. http://www.apexi-usa.com/documentation.asp I did have the airbleed nipple between the primary injectors T'd into the WG so I wonder if that could produce the uncontrollable boost and lag?

Thanks,
Ian

I think all of this aluminum dust has severly affected me!

maxcooper

There's more than one way to control a wastegate, but using both ports on an external gate seems to be the most popular method, and is probably the best (but that's just a guess).

I am not sure what you mean about the air bleed nipple.

The strange part is that if you have problems with the wastegate control hoses, you normally still can't get it to boost less than the spring pressure. That makes me think there is something else wrong with your car besides the air hoses that go to the wastegate. Screwed up ignition timing, massive boost leak, wastegate not air-tight at rest, wastegate spring too weak, etc. seem like possible causes. I know you have investigated some of these already, but I would turn my attention away from the wastegate control hoses until this root problem is solved. Once it is fixed, you might find that your boost control system works perfectly.

-Max

maxcooper

Another possibility: no valve seat for the wastegate. It happens:
https://www.rx7club.com/showpost.php...6&postcount=26

-Max

IAN

iTrader: (3)

Valve seat? As a whole the thing cam assembled. The valve justs rests on the body as far as I can tell.

The last option for me is pull the turbo out. But I went to a local garage and felt there 60-1 turbo. It spun as freely as mine and had the same play and this one was new.

I can't find a boost leak. Even then a small hole should not be noticed?

thanks max your a ton of help.

Ian

maxcooper

Oh yeah, that's right your wastegate has a captive valve with the seat built into the wastegate body.

These are the things I would do next if it was my car:
1. See what pressure the wastegate cracks open at (pressure to side port, watch for valve lifting off the [internal] seat).
2. Check the ignition timing.

-Max

chuck8313BTSDS

Just a suggestion, make a plate to cover your waste gate exhaust port. Take the car for a 4th gear pull. 4th gear will allow the boost to climb slowly. You sould be able to boost 1 bar easy. If you still can't build 1 bar then it is not your waste gate or boost controller. I was having boost ploblems once and did this. I ended up leaving the waste gate exhaust port closed about 25% to get the boost I was looking for. My thought was my 4lb spring with the boost controller would not hold the valve closed because there was to much back pressure in my exhaust manifold above 20psi.
Like I said, just a thought
chuck