I've thought about external but until I rebuild I am already close to where I want to be with this setup on the stock block. I put the turbo smart boost t back on and sure enough I overshot my target again. So I have one of those Home Depot built mbc that a guy gave me with my fm intercooler. I tested it on a bicycle pump and it work like the turbo smart but flows more air. I'm gonna try this and if it doesn't work I'm going to give the ebc another shot. I might also add I over boosted with the turbo smart in 70 degree weather at 13 psi vs 11.5 that I was hitting at 45 degree temps on the wastegate alone.

Good lookin' out. Downpipe is still in the works - Inner rice boy debating with reserved adult to recirc or pretend my heap of shit is a gt4
http://i49.photobucket.com/albums/f2...5.jpg~original

In my experience, I couldn't find an mbc, that resolved boost spike. I just found a spike that didn't scare the shit out of me. A new actuator helped a little, I've always had a little bit when running small framed turbos, it's just how it is. Porting was the best aid for me. This is all my experience though... I just made sure my fuel was capable of handling the spike. A little factor of safety aided my mind and I dealt.

I think it's just time to turn the boost up....

I vote for bigger toybeau.

Yesterday I hooked up the DIY EBC and even with it in the fully open position I hit over boost. WTH haha. Im thinking about builing a diy boost boost controller that allows for more air to flow through it so I have more resolution. I am also preety sure my boost gauge is off a little cause when I hit overboost it says 16 psi but in MS its at 13 psi so I am just gonna keep playing with it. I did a vd yesterday with my friend and It said Im at 225hp and 203ft/lbs at 8psi. I know that probably off but I been playing with my spark map a lot and doing a lot of logs and according to my ass the power feels good. I dont have a boost controller hooked up currently but I am running the wastegate right before the throttle body and that has help tremendously with the fluctuations. Hardly ever over shoots but as soon as I put on the boost t it will overshoot then settle or if I add the EBC it will spike even with the valve fully open.:facepalm:

What helps most is aiding flow out of the wastegate orifice... an ebc may seem to aid, but it doesn't change the fact that your exhaust air is still going to flow out of the least restricting orifice w/ the wastegate flap open. Even when you port will still spike a little w/ an internal gate.

Ex. My subaru is internally gated with the OEM actuator it is around 6-7psi, my car is electronically set to 10psi... On warm days it's pretty solid, but it will still spike to 13 and even 14 on a very cold day. Every small framed internally gated car I've owned does this to a degree.

We'll I think I've done everything I can as far as porting to aid the wastegate flapper to open. I think now its more a matter of ajusting air flow to the actuator (me thinks). The wga doesn't have issues opening with no bc and fluctuations are very very minimal. However as soon as a boost controller goes on such as the boost t it will spike. I this has a lot to do with true restrictive flow of the bc. I notice for example on the boost t one end has a very tiny hole causing restriction. I'm so close to my targets that I think I'll just piece together a mbc that flows higher and slowly crank it up. I'll probably sell the boost t and diy ebc.


EDIT Also I am going to do some research but I wonder how much location has to do with how the mbc responds. So Maybe if I move it closer to the coldside vs close to the WGA.

What if you tune in EBC?

I put the EBC fully open and overboosted like crazy. Not sure why.

Do you have a bike tire pump that is accurate at low pressures? Out of absolute stupid curiosity, what happens when you run 4~5psi to the WGA?

15psi opened mine right on up.


The flaw is clearly in the boost controller.

Did you change back to the original wastegate can?

Mine opens up just like Erat posted. I notice that if I pump 4-5 psi and let it sit the WG will slowly open up but if I apply 15-20 psi( One hard pump) it will crank open just like in the video Erat posted. What I did was removed the shedder valve adapter and the bike pump hose slips right over top the waste gate. I then got creative and used a T with one end open so I could use my thumb to hold and release pressure.


The adapter mount for the FM WGA went missing in my garage so I haven't switched back but the kinugawa opens at the same pressures as the FM WGA.

https://www.miataturbo.net/attachmen...1&d=1390419734

Heres a picture of my EBC settings just for reference. Maybe Im doing something wrong.

Are there any instructions or an easy way to swap out the the spring in the WGA for a KINUGAWA for a higher tension one? I'm having a problem installing the higher tension spring without the gasket fouling where the bolts are supposed to go. Only have 1 set of hands available at the moment to do it - mine and the gasket keeps sitting where the bolts are supposed to go. I can't get the bastard in the grove.

I also wish I knew about the boost creep on the 2560 before the 2nd rebuild on my MSM. Detonated to shit cylinder #1 after 1st rebuild due to overboost and not paying attention to the boost gauge!

disregard. Stopped being a pussy and figured it out

Yeah the 2560 sucks donkey dick at overboosting with a 2.5 exhaust without a cat. However can easily be corrected by porting the IWG. Theres a couple write ups. I was scared at first but its very easy to do. I didnt port the flap hole just created a valley to help air transition to the WG flap.