Wastegate Movement? Video taped
 

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

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.

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

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

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

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

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

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

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

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.

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

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.

This car was tuned by steve KAN

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

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.

What seems backwards?

-Max

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

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

*edit*

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!

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

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

-Max

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

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

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

Ian, do you have a regulated air compressor?
if so jack up your car, get the hose connected to the side port on the wastegate, and slowly raise the pressure on the regulator starting at 5psi and watch to see when it "starts to open" and when it is full open. see if that in any way collaborates your readings while driving.this is also a effective way to check for what spring you have.

Any update Ian?
Car going to be ready for Rotary Revolution?

Nope. Doubt it.

But I did clean up a few things.

Moved one vaccum line. Doubt that is the cause of the problem. But I am bolting everything together and see if it changes anything. Also redid the angle of the turbo and FMIC tubing and also modified the bumper to fit cleaner. Better then last year. ETC ETC/

I did strip the second 02 bung so I need to retap it.

I might just drive the car the way it is. I guess the motor will hold up for awhile with only 5psi :)

IAN, what are you running for boost control?
Also did you try the Regulated Air compressor trick, this will confirm the function of your wastegate, as well as the stiffness of your spring.

I don't have a air compressor.. I took apart the wastegate (AGAIN) and confirmed the spring and diaphragm. All looks ok.

I am using an APEXi AVCR.

Thanks,
Ian

well, if you happen to be in a place that has a regulated air compressor, make use of it. ;)
P.S. I am having a similar problem with my Profec B I only get 5 psi. But I have found that the Profec B II keeps ressetting after I turn it off. but if I redoo the settings, it works like a charm.

maybe you dont have the constant wire hooked up so it remebers your settings..

just dont connect your EBC to the wastegate, and keep the boost line on the side of the WG. Drive it and see if makes a difference

I don't want to pollute Ian's thread, so could you possibly PM me what you mean?
Thanks
Jeffrey

no worrys. Its a related question.

no worrys. Its a related question.

^^ I think this is a good idea and is easy to do. Take the EBC out of the system and see how it runs. At this point, I really don't think there is a problem with the EBC, since an EBC should only allow you to run more boost than spring pressure, and you are getting horribly slow boost response and low boost generally, which are not things an EBC is designed to "fix".

I also like the idea of completely blocking the wastegate (sandwich a plate between the gate and the turbo manifold) and then (carefully!) roll into boost in high gear to see what happens. If you don't build boost quickly, you have a problem with the tuning, engine, or turbo, and not with the wastegate or wastegate control.

-Max

How does it reset?
I know mine resets the revlimiter. So, I have to press 'h'i--'low'--'hi' to get it back to my settings...

nope the hi settings keep just reverting back to the Stock Greddy settings, and As soon as I input the correct settings it works like a charm... but the lo settings do not errase so I don't think that I have it incorrectly wired up... because I am certain 99.9% that I wried it up correctly.

update.

The whole car is back together again. no leaks etc.

4260rpm = 4.3psi
4960rpm = 8.5psi
6220rpm = 9.9 psi

this was on the spring tension only. (10psi spring)

It must be the turbo!

I need to see someone else with a T04B 60-1 in person so I can see what it feels like having a working unit :(

...or it might be tuning.

It seems weird that the turbo could cause that without any noticable damage. Have you removed the turbine housing (you often can't see damage with the housing installed) to make sure the turbine blades are still there?

-Max

I had the turbo removed and brought to adp turbo last year. Visually they said the turbo was fine. This year I checked the turbine housing again. Looks fine. I might just have to buy another CHRA. But those things are expensive :(

Tuning was done by steve kan so the cars tuning should be fine.

Thanks,
Ian

Did you take the turbo to adp (ATP?) because you were having the same problems you are having now? If so, it sounds like there is nothing wrong with your turbo and you should look elsewhere for the true cause before spending money to replace a good turbo.

I mean check the turbine blades. To do so, you need to remove the turbine housing so that you can see the ends of the blades. Your car seems to be working too well for the turbo to be broken in some invisible way. But you might be missing some turbine blades or have some other damage that could be detected visually with the housings removed.

There was a post on here recently where the owner found that their timing was about 10 degrees retarded from what his ECU programming was set to because of a mechanical issue with the wheel on the pulley. My point in relaying this story is that even though you might have good numbers setup in your ECU program, a mechanical issue may cause the actual timing (or fuel delivery) to be different from what the numbers say.

If it was my car, I would do these things next:

- remove all the hoses from your wastegate and (carefully) try to build some boost in high gear -- it should stay shut and build boost quickly -- be sure to let off before overboosting

- try a plate (sheet metal with two holes drilled in it) to completely block your wastegate -- this test is designed to determine if your wastegate is leaking when it is "shut" -- it should do the same thing described above, be sure to let off before overboost

- remove turbine housing and look at the turbine -- are the blades all still there? Look at the compressor wheel (also with the housing removed, so you can really see it), too.

- find some way to make 10 psi of pressure (a Motive PowerBleeder brake pressure bleeder bottle can do this, and is also my favorite way to bleed brakes http://motiveproducts.com) and experiment with your wastegate a bit -- remove it from the car and see how it responds to various pressures supplied to the side port

- find any exhaust leaks you might have

- look for a dead rodent or other major restriction in the engine air flow path (intake pipe, ic pipes, intercooler, manifold, exhaust) -- for instance, do you have a restrictive IC from a moped, or an IC pipe that is nearly pinched shut?

- check timing with a timing light to verify that ECU settings and actual timing match

-Max

Ian,

speaking of dead rodents blocking ic pipes:

I know that this sounds stupid, but a frind of mine left a cotton shop towel stuffed in his IC piping, it blew down to his intercooler, and blocked off over half of his FMIC made for some really weird boost problems before he admitted defeat and let me look at it.

(He drives a nissan silvia with the sr20det, and didn't want a rotorhead touching his precious piece of shit).

kenn

Lol thats funny, because it happend to me with a shirt that I had put over the afm. This was when my car had an n/a motor. I put it over the afm and forgot about it, I turned the car on and it idled fine, but when I would drive it, it felt like a blown motor. I remembered I had the shirt on there but I thought one of my friends removed it. Anyways I found the after I took the motor out. That was on the top of the "stupid shit that I've done list".

Anyways Imma see if I video tape my turbo, to see how long it stays spining after I spin it manualy. Your turbo should be similiar.

Max,

Thanks for all of your help. I have spent way to much time and to many posts in regards to this.

I was going to bring this turbo to http://www.adpdist.com

I completely tore apart the turbo last summer to see if there was something wrong. Nothing was noticeable.

I am running a Greddy VSPL FMIC. Timming was checked three times and also at the dyno were we noticed that the turbo would not start to act until 4500rpmish.

I will be playing with the car alittle bit today to see if I can get anywhere with it :)


Kenn-chan

Everytime I had it apart I covered the wholes so I believe there should be nothing in it.

Here it is. The audio sucks ass as this was taken with a digicam. But you can hear when the engine stops running.

http://www.putfile.com/media.php?n=Picture-1027

Kenn-chan

Everytime I had it apart I covered the wholes so I believe there should be nothing in it.[/QUOTE]


thats exactly how my friend got it sucked into his, he stuffed the rag in to stop trash from going in the hole! currently hesays that one of his buddies that helped him probably left it in there, but who knows, its an easy check Ian.

kenn

Spins fine. No idea what mine looks like. I did last year with the car running hold the nut and stopped the turbine from spinning.

P.S Don't try that. Good way to possible loose a finger.

supposedly, you are supposed to hold the compressor wheel for like 5 sec for the initial install to let the oil run through the turbo. I never did that but w.e.. Actually the video was for you to evaluate your own turbo. If it spun like mine then you have some mysteriose forces actin on the spool time. But if it stops spining immediately after shutting the carr off, or if it takes a lil bit for it to start spinning when you start the car, then its either a manifold or turbo problem...