Started twisting my MBC to get more boost, and no matter how much I throw at it, it stops at 0.7 bar and then falls back to 0.6-0.65. I've peaked at 0.9, but that was a once-in-a-lifetime thing it seems.

Hence, I need a stronger actuator, so I can get more pewpew. Considering getting one from ebay, but we all know the "you get what you pay for" rule at ebay.

Any tips on a universial 10-11 psi actuator I can put on the GReddy fan? Or a PnP one for that, I just fear issues with fitment and a price out of the ordinary. With a universal one, I can make the bracket myself, and know that the result is good enough.

 

Trying to find pics now. I'm running one from an FM1 (just a straight-armed actuator) with the rod length adjusted and an aluminum bracket I made.

Gimme a minute.

 

I can get pics of mine too, I reused the stock bracket after cutting it off the oe actuator

 

Coolio.
Got any tips on where to buy a new one too? ^^

 

FM, as a pricey last resort to finding a decent used one. FM1 actuator.

https://www.miataturbo.net/showthrea...reddy+actuator

In that thread Joe Perez and I detail our setups. I've since replaced my actuator bracket with a sturdier one. Lesson learned - don't design in a stress concentration.

https://www.miataturbo.net/showthrea...reddy+actuator

 

The FM one isn't really expensive, so I'll probably go for it.
Quality > Price when it comes to parts pushing my boost to the end of what it can do.

Having a 9-11 psi actuator gives me the opportunity to go for 15 psi, and then achieving my goal.

Reading the thread, I would like to point out that I have the feed line to the wastegate post TB, so I have no pressure loss over the IC, compared to BC/gauge pressure. I'll probably move it to the other side of the TB, but it will never be at the turbo housing, since it doesn't provide stable pressure.

Thank you very much for the tips.
I feared I would get shitflamed for asking about this, but my imagination when it comes to forum searching is just awful.

Seems I'll end up getting the FM actuator with the rod end, and then adjust it to fit.

 

Suggest changing the MBC out or trying a stiffer spring in yours. I can get 15+ psi using the stock Greddy wastegate with the MBC in-line.

 

Right now there's no signal reaching the actuator since my BC is set to close, and the wastegate still opens at 10 psi. If this can be changed by doing adjustments the boost controller, then I would like to know how

It seems like the actuator weakness is pretty much individual, and getting 15 psi with the OEM actuator is rare. You making it, doesn't mean I can make it

 

Ben had his EBC tables at 100% IOT hold boost to redline with the Greddy actuator, IIRC.

 

Helper spring

 

^^ Not a bad idea. The trick is all the trial/error to get the spring thickness and length just right. I have a eye bolt and bracket setup that I made in a box somewhere with a mixture of different springs that I tried out and one I settled on. The switch to MBC made it unecessary, but if your wastegate is too weak even with the MBC, this could help.

 

Have you tried shimming the wga where it attaches to the comp housing? I inserted about 5mm of spacers under my last 16g actuator so that it kept a higher pressure on the arm/flapper, and was able to bump up from a flat 22psi to a peak of 32 fading to 27psi at redline. I tried a range of 2-8mm and 5 seemed to suit my needs at the time, so you might play around with thickness as well. Just be ready fuel-wise for the boost pressure to ramp up higher before settling out if you shim it a lot.

 

Got my MS set on a boost limit of 200 kpa, so I won't go up in flames if it goes too high. And the mapping is set fairly rich, so no worries for the mix
Gonna try shimming it, but I would prefer getting a better actuator in the long run.
I work on my car with mx5-t and Inglar, and redneck solutions don't go light in there

Some also recommend shortening the actuator arm to increase the pressure, but it's more work then to buy a new one and adjusting a mounting bracket and arm. At least compared to what you get..

After testing a little more, it seems it randomly peaks at 0.9 bar on rare occasions, and then settles at about 0.6. Usually though, it peaks at about 0.7, and then settles at 0.6. From what Inglar said when he was in the passanger seat though, was that the boost pressure halted at 0.5-0.6 first, then went up to 0.9, and then went down to 0.6 again.

What seems weird, is that the acceleration seems go to poopers around 5k rpm, and it doesn't feel like there's any power left. Is this a common problem resulting from the actuator issue, or is it just me feeling the car like less powerful because the boost pressure isn't rising anymore, and there's no power INCREASE over 5k rpm?

 

Interesting, I have no issues with mine holding rock steady at 15psi, I agree that it could a luck of the draw thing. What down pipe are you using? Regarding the car stop making power at 5k rpms should not matter thats its not adding boost, my car isn't adding anymore boost after 3900rpms just maintaining it. I would look at the tune probably timing if the AF's are on target.



Here is my boost plot from last dyno. 15ish psi you can kinda see how the boost comes on and holds. The haltech is controling boost I also have a artech down pipe that has a divorced wastegate.

If your running stock ignition it will be gamble if it will be enough for that boost pressure. I am switching to a GM truck coil setup.

 

I've got the GReddy downpipe..

A/F is looking good, taking a leap here, but I'm fairly sure I'm at about 11 when I floor it. The timing map is VERY conservative, so we might have a look at tuning it a bit.
Gonna take a buddy for a spin and see what he thinks, the power loss might just be my head pulling tricks on me.

 

get a new DP stat! its going to be hurting your power.

 

Pretty limited options with the turbo location?
Or are there other downpipes that fit the GReddy setup without altering the car?

 

Yes Abe at artech can build them he built mine.

 

Begi DP fits mostly ok.

 

What is the price range on these?
Was hoping to run with the current setup though.. ^^

At least I've got the solution for my actuator issue