You GReddy guys all should replace your wastegates
 

http://i24.tinypic.com/2rzz62r.jpg

this is Rappadan's boost curve. Upgraded to a wategate actuator off a 300zx twin turbo. it bolted right up but had to be extended an inch.

but as you can see it's probably the best spoolup I've ever seen on a Greddy kit. Stock motor, turbo tony DP, 3" exhaust, MBC no helper.

how did he go about extending it? i have a serious problem with wastegate flutter on my greddy.

that's pretty much what mine does too...
17 psi by 4300 rpm or so in 3rd according to tonight's datalog.
His boost is nice and steady though.

Wheres the instructions?!

It's not so much the spool up, but i haven't seen any better on a MBC. but the way it holds boost and doesn't spike is a substantial difference.

On the same MBC preload he was spiking hard to 12psi and dropping to 8psi by redline. Such is very common with all the Greddy kits as you are well aware.

Did he pull this actuator from a junkyard car, or is there a known source of reasonably-priced new wastegate actuators for these cars? The last of the 300ZXs came over in, what, '96? I'm a little hesitant about sticking a 12 year old actuator on the car.

I'm tempted to try out one of the wastegate actuators offered by ATP Turbo. While some creativity might be required in terms of mounting and attachment, they have a couple rated in the 12-14 PSI range. Actually, I'd prefer to keep the MBC and use one with a lower rating, so that my WI failsafe mechanism continues to work.

his buddy pulled them off turbos they pulled. But regardless, replace it with anything, the GReddy actuator sucks ass.

Yeah, the stock actuator is a PITA. With a TurboXS MBC and a smallish helper spring, I've gotten the system to be fairly stable between 10-12 PSI, however there is still a noticeable spike.

Actually, this particular unit at FM looks attractive. It's a Gerrett piece, not terribly expensive, has a straight threaded rod, and a low base boost point so that I can keep the failback to low boost mechanism I've built. The ones that Forge makes look really nice, but a tad pricey...

I wonder if you could fab this to fit:

http://cgi.ebay.com/ebaymotors/T3-T4...spagenameZWDVW

http://www.flyinmiata.com/dealoftheday/index.php

Should be easily be able to make this work .... $30, the price is right.

Probably, but I want something with a lower base pressure. My water injection system has a failsafe mechanism such that whenever there is no pressure in the waterline at the injector, a solenoid is open which bypasses the MBC. This way if the system ever fails, the turbo will make no more than base boost. With the stock Greddy actuator, this used to be 5PSI. Adding the helper spring increased it to about 8. I want to go back to something with a lower base boost to regain some of that functionality "just in case."

... And interestingly, the FM Deal of the Day is this wastegate actuator: http://www.flyinmiata.com/dealoftheday/index.php

Looks perfect except for that oddball rod. Wonder how hard it'd be to modify that...

im thinking about getting it also but im just not sure if it can be easily modified to use on the greddy kit.

I'm not getting it out of FM hatred, but I'd bet it can be made to work easily enough.

You can extend or shorten any rod by cutting it and tapping the ends and using threaded joiners. If it needs to be longer just get a piece of rod that is the same diameter. Also, if it's too long you can just use short lengths of tubing to shim the mounting bracket. I've done this shit a few times.

Personally, I have no FM hatred. Unfortunately, I also have no die set that I can use to thread that rod.

I think I may buy the other one, with the pre-threaded rod and the studs to attach a mounting bracket.

Aw, hell. I broke down and ordered the DOTD wastegate. I can't pass up $30. The money saved lets me go to Harbor Freight and purchase a proper Tap & Die set. :bigtu:

hacksaw and JBweld is all you need dude. :gay:

Braineack FTL.

Ha, I was going to offer to do it for you, but getting your own tap/die set works too. :bigtu:

I relish any opportunity to use the act of cheapskating on a project as an excuse to purchase a new tool or tools. I sometimes lament that my Greddy-based turbo project has ended up costing me just as much as a complete Bell kit, but that figure includes all the ancillary bits that I picked up along the way- a full SAE open-end wrench set, a new angle grinder, a tablet PC, a ratcheting air-wrench, etc... And it's all Harbor Freight, so while it ain't the highest quality stuff it's adequate for the frequency with which any particular tool is used. I think this is the one I'll get: http://www.harborfreight.com/cpi/cta...emnumber=39424

Heck, if each die only lasts a single use, that'll more or less justify the purchase price.

That actuator on FM's site was the deal of the day a few weeks back and I called and asked if it could work with the Greddy kit. I was told "probably not without welding it." Let us know how it works for you as I am still considering it. At 5psi, my Greddy is doing OK for the time being, but I'll need one eventually.

More info on this thread:
http://forums.miataturbo.net/showthr...light=actuator

Buy 2 and send them to me. I'll make them work and send you 1.

I'm not planning to weld on it. My thinking right now is to create a new mounting plate to go on the compressor which will then attach to the mounting plate which is on the WG. It looks like there is enough space for a couple of #8 screws.

As to the rod, the offset may prove beneficial. There is some definite side-load on the rod in my present setup. It'll probably take some trial and error but I'm hoping there's a sweet spot on that rod somewhere that makes everything line up. I will probably cut it off at the end of the straight section in the middle and thread it for an additional straight rod to make the requisite length.

The stock Greddy WG can is fine at 5 or 6PSI, but it starts to have trouble at higher boost levels. Even with a good MBC, it's apparently not strong enough to hold boost at high RPM and high load, so you have the situation where boost builds up to whatever your MBC's set level is (say, 14PSI) and then once the WG has cracked open slightly, the can cannot seem to hold it steady anymore, so boost drops.

Ben, just call FM and buy one. They're not evil people.

i've had my eye on that ebay one for a while, i really just want to hold 15psi to redline and be reasonably stable. does anyone know how long the stock greddy wastegate rod is without having to go out and measure?

yo,
its rapper checking in. I was waiting for you(scott) to make a post.

For all you that are wondering i actually had to lengthen it almost 2" probably. the way the bracket was offset. The greddy mounts flat. I got a wastegate acutator off an t25 from a 300zxtt. mounts up fine. Fits close to the head/valve cover. And it holds boost nice...

That set is SAE, I think you'll need metric. I've got the metric set, had it for about 15 years. It comes in handy once or twice a year, haven't broken a tap or die yet. Worth the price to have it around when needed.

I haven't bought it yet, but I'm assuming that since Garrett is a US company, the rods they use are of SAE-friendly diameter. The end I put on it will be custom-fabbed anyway, and SAE hardware is easier to find.

But we'll see. It's supposed to be here on Thursday, and I'll measure it then. Got a couple other projects that need finishing first- one is to mount a '94+ seatbelt-tower brace in such a way that it does not interfere with seat travel. More welding...

http://cgi.ebay.com/ebaymotors/T3-T4...QQcmdZViewItem

Would this work?

Define "work". Can you make it work (well)? Yes. Will it bolt up? Probably not.

I figured you would cut the shaft, die both ends, and insert a threaded coupler. Done.

Well, the shaft on that WG can looks like this: ---\___/---

Whereas what I need is more like this: ---\______

We'll just have to see when it arrives. Probably not going to happen this weekend as I've got plans, and then I'm out all next week.

I just did the measurements extra well, did not tap/thread the shaft and all i needed was 2 small washers to set the preloaded tension on it. It felt like the same tension i had on the greddy that was tightened all the way

I'll look into it probably when I upgrade the downpipe and exhaust.

Well, I finally got that new WG can installed this weekend. It's the one with the kink in the middle of the rod, and is rated for 5 PSI.

Here's a shot of the new can next to the stock Greddy can. Obviously, some fabrication will be involved. FM claimed to clay that it would not fit without welding. Well, I didn't have to break out the MIG welder, but the angle grinder and drill press got a decent workout.

For one thing, note the positions of the mounting bracket relative to the vacuum nipple. Mounted in the same orientation as stock, the nipple nearly hit the head, no way a hose would fit on there.

http://img265.imageshack.us/img265/8...ebysidegw6.jpg



First, I cut off the folded-up part of the new WG bracket, then I notched it to clear both the head and my breather filter. Next, I cut the rod into three pieces, sectioning it at the third and fourth bends (the one closest to the can being the first). I discarded the middle piece, and threaded the ends of the two remaining pieces. They were exactly 1/4", so I used a 1/4-20 die. A pair of hex couplers and a piece of 1/4-20 straight rod, and I now had a WG with an offset and adjustable rod, which improved the fit dramatically, allowing me to mount the can very close to the compressor body:

http://img164.imageshack.us/img164/9872/topviewgq4.jpg


Then I fabricated an adapter bracket to mount the new can onto the compressor. Relative to the mounting of the Greddy can, this one is rotated a bit more than 90° counter-clockwise, so that the bracket faces up. In the process of notching the can's attached bracket for clearance I lost one of the two mounting holes, so I re-drilled a new one very close to the body of the can. Here's a shot from the front showing some detail on the bracket:

http://img91.imageshack.us/img91/3662/frontviewrx8.jpg


Using a hand-operated pump, I extended the rod by about 3/16" before screwing everything together, to pre-tension the WG somewhat.

And the results? Well, I'm not as impressed as I'd hoped I'd be.

With the MBC bypassed, the system makes a steady 7 PSI. Not bad.

With the MBC in, I'm still getting some spike. Or more precisely, some droop at higher RPMs. This morning I drove up a long hill, in 5'th gear, at WOT, at about 60 MPH. The system held a rock-steady 13 PSI. But blitzing through the gears in a more realistic fashion, I'd see the boost initially go up to 14 PSI and then gradually droop down to about 12 PSI. (I'm basing this on eyeballing the mechanical gauge, as the logging PC is not in the car right now.)

It's definitely an improvement. The old setup, even with the spring, had slightly more droop, and produced a slightly higher pressure with the MBC (I consider this a bad thing, since electronically bypassing the WBC is my failsafe for the WI system)

I'll probably keep it. Just wish I could have gotten that nice rock-steady line that Brainey posted initially.

Maybe it needs a little more pretension? Still that is some nice work Joe.

I could try increasing the pretension, however that will also increase the "base" boost- ie: the boost when the MBC is bypassed.

I'm a bit nervous about that owing to the fact that I'm relying upon the ability for the system to automatically drop boost in the event that my WI system should ever fail. (the presence of pressure in the WI line closes a pressure switch, which powers a solenoid, which closes the bypass around the MBC. No water pressure = no activation of solenoid = base boost)

If somebody wants to send me a GReddy actuator I can see about making a replacement. If you don't mind making your own bracket I could sell them to you guys for $100 (retail on a bracketless WGA is $150). I can build them with 5-10, 9-14, 14-18 or 19-24 psi springs. Lifetime warranty blah blah blah.

Joe I get the similar boost action after adding in the MBC on my internally gated t3. It's rock steady (after I added the helper spring) with actuator only. Add in the "diy MBC" and I see nearly a 2 psi fall after peak boost. The helper spring DID reduce that fall by nearly 1 psi with MBC installed. Is the MBC causing this peak and drop? It looks like it to me.

It's hard to say, since I have not adjusted / spring either WG can to achieve 13PSI all by itself. I have always tried to aim for a 2-stage system, with "full" boost activated by the operation of the WI system.

But I can say that the lower levels of boost I've achieved without the MBC have always been stable, whereas the higher levels of boost achieved with the MBC have not.

I'd be happy to send you mine, but I wouldn't recommend that you use it as a gold-standard. The fit of the stock Greddy WG can is non-optimal in my opinion.

A question for you however- I have seen some WG cans that have two vacuum nipples. Typically one is connected to the boost reference and the other left exposed to atmo. I presume that this second one is equivalents to the vent hole found on the most WG cans.

Question is this- with a dual-fitting WG can, could I potentially achieve my goal (two switchable boost levels) by adjusting the WG to achieve full (13PSI) boost when the second nipple is exposed to boost, but to fall back to a lower level when the second nipple is left open to atmo? (switched by the same pneumatic solenoid I'm using right now as an MBC bypass)

That is correct. All of our WGA are dual-port capable, although they ship with a grub-screw in place of the second port.

The best way (for spool) is to bleed off the reference to the primary/top port and send that to the bottom or to send ALL of the pressure to the bottom with nothing to the top. This way there is no boost to open the flapper prior to full boost.

I just changed my wastegate actuator vacuum source from the port on the turbo to a ported nipple on the intake manifold and that made a BIG difference in responce and how it held boost. To anyone that is trying to make there greddy hold boost better DEFINATLY do that. It took 3 minutes to do and made alot of difference. And make sure the WGA has its own vacuum source that is big too.

Absolutely that makes a difference, I went through all that a while ago - the issue seems to be restrictive intercooler and piping.

If you run it in the manifold, the turbo spins a LOT, all the time. Basically, let's say it's a miata and not a drag car, and there's a sort of... "curve" in the road. In this case, you might only give it "partial throttle". Basically, you only want 2-5 psi in the manifold, but the wastegate sees there's work to be done, and flows all the exhaust through the turbo.

Then you're turbo spools to about a billion, and you have exhaust restriction, hotter intake charge, heat soak the intercooler (which you'll want cold when you get out of the turn and floor it) etc. The only advantage is you get like 20 psi waiting for you outside the throttle plates - the downside I guess you could blow off hoses.

Anyway, I put my signal right in front of the throttle plates - after all the restrictions. That way the 3-5 psi drop (measured) across the intercooler is compensated for, but the turbo only presents the desired pressure to the throttle plates, to be used or not, as needed.

Pics:
http://abefm.smugmug.com/gallery/1164235#54351370

BTW - I spent quite a while explaining this to the folks at FM. They eventually conceded that I was correct. It makes sense when you think about it, there is a flow dependent pressure drop across the IC. So you'll get a bigger boost droop at high flow (be it RPM or boost based).

In an IDEAL world (since I like the crisp tip-in of having too much pressure in the IC piping, I want to run TWO MBC's, one in the manifold at my target boost (say 12 psi), and one in front of the throttle plates a bit higher so I get that huge inrush of air when I touch the gas (say 15 psi) to keep the turbo from overspooling and the wastegate from having to find a new, zen-like center once you DO open the throttle, since then it's only a small change for it. But I haven't tried this set up yet, so I can't say how it will work.

BTW, I have an intercooler/piping (FMII) for sale with this "mod" already done. Cheap! :-P

Also, manifold references can kill diaphragms in wastegates...

Really? Any idea what the mechanism is? Rapid fluctuations is all I can come up with, but it's a pretty weak idea. Interesting.

Abe- that's an interesting idea and I think I'll try it. Although it seems obvious, I'd somehow failed to consider that boost drop across the intercooler is in fact a function of flow volume.

My hesitation to do something like this earlier was based upon Corky's recommendations. Specifically:
I'm not sure I understand PAT!'s concern as to the death of the diaphragm.

Let me know how it goes- I only have my theories and the one data point - my own car, which worked well. My feeling is that in the manifold, there IS going to be a lot more heat - not the initial spike he's talking about, though I guess it's a small issue) but the build of up the turbo trying to put 50 psi into the IC piping trying to force 10 psi past your partially closed throttle.

I should clarify- I'm going to try post-IC, pre-TB, not the manifold.

considering the relitively low boost amounts i'm running, 7-8psi. And having a decent size front mount intercooler. I think the benifits of having a manifold sourced wastegate is the way to go. I think everyone should try it at least, cause its so easy and makes a nice differance.

Where's the benefit? The main reason I put it ahead of the throttle plates was listening to my turbo spool as fast as it could go, and avoiding heatsoak, at part throttle. I guess it sounds good spinning like that, maybe it's worth going slower/getting knock for, but is it worth the turbo rebuild? I'm dramatizing a bit, but I really think you'd want to concider having the signal pre-throttle.

heres a read.

If you can come up with a EBC that doesn't suck, best of all. Take it off the compressor outlet. I'm curious to see how much heat you get by taking the signal at the other side of the intercooler. It's an easy test to run, read the turbo outlet temps and move the line around.

For that matter, you could measure heatsoak by seeing how much the IC outlet varies in the two modes.

I really don't see it hurting you on the other side of the IC piping, you're talking, oh, milliseconds there. Running at part throttle you're really heating this air you're not even using.

Anyway, this is getting beat to death.

Rapid fluctuations is mainly it. When tied to a constant pressure source the opening and closing of the actuator is pretty smooth. But when referenced to the manifold the moving assembly is sucked upwards much quicker and the diaphragm takes a beating when it slams into the upper part of the actuator body. Also, in some actuators, its possible for the diaphragm to lift, partially or fully, off of the perch that connects it to the rod. This can distort the surface of the diaphragm and created wrinkles or high points... we get far more warranty claims on set-ups with the actuator tied into a manifold reference.

I know I'm resurrecting an ancient thread but I guess I have an ancient turbo set up.

Would this actuator be an acceptable replacement for the one people complain about on the GReddy? REV9 GT Series Adjustable Wastegate Actuator 5PSI T25 T28 G25 GT28 Turbo Charger | eBay
(Do I need to stick with a 5psi actuator if I'm going to use a MS2e and Electronic Boost Control? Is there an advantage to going up to a 7psi Actuator?)

To lengthen I could just use one of these, right? https://www.z1motorsports.com/forced...od-p-5345.html

Trying to get all my potential issues shored up before I have Savington dyno tune my MS2e / GReddy setup at the end of the month. I really don't want to have issues holding boost during the tune and then switching out parts later that will screw everything up.

Hello?? Is this thing on?

Can anyone answer my question about switching around wastegate actuators?

Is the GReddy one inherently bad or was the improvement because the 300zx tt actuator is set to 7psi and its stiffer spring makes it more consistent?

Braineack , Ben , Joe Perez , Curly ??

I have an ancient blow off that came with one of the earlier (c.1999) FM2's. There's no diaphragm in it. I used to have to pull it apart and clean it every few months as it would gum up.

Later, I moved it closer to the throttle body, and rotated it. We're something like 8 years later and I haven't cleaned it once. To be fair, that's probably only 30k miles, still, I've been happy with it. Never any repairs to diaphrams. It may be slower, but I'm not sure it is. Look at Synapse Engineering's valves - they can open in under 20 ms, so pistons aren't all bad. :-) They are a little spendy, though.

for now I'm just running a recirculating eom Bosch blow off valve. My issue is building boost with stock GReddy wastegate actuator. I think it is cracking open on partial boost. I hadn't driven it yet with the MS setup (still finishing that off). I'm sure the EBC will help but I didn't want to show up at the dyno for tuning and have to fight with the wastegate actuator and waste my money.

I found this one that is a little higher psi (7.5) with a curved actuator that should put everything in a better location on the cocked turbine housing.
Kinugawa Adjustable Turbo Wastegate Actuator Subaru IHI VF30 VF34 VF35 0 5 Bar | eBay

It's not pretty, but if you're creative and on a budget (and it's accessible, I'll admit, I don't know what the part you're working on looks like) you can use a helper spring. I did that on that FMII's wastegate, it worked for years.

https://www.miataturbo.net/attachmen...ine=1465069732