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-   DIY Turbo Discussion (https://www.miataturbo.net/diy-turbo-discussion-14/)
-   -   Well, I HAD wastegate creep... (https://www.miataturbo.net/diy-turbo-discussion-14/well-i-had-wastegate-creep-9514/)

t25miata 05-03-2007 03:06 AM

Well, I HAD wastegate creep...
 
I just installed my DIY MBC! Big it up for Braineack's FAQ! :bowdown:

Sheesh, it changed things a bit! When I first put it in it was a little tight and I didn't drill a hole in the back, so it was spiking to 10 and settling at around 7 PSI. I took it out and drilled a little hole and went for another spin... My boost gauge got to 14 PSI for about a second before I removed some right foot. I tweaked it a little and now I have a fairly steady 8.5-9 PSI by 3000rpm and all the way to REDLINE. :bigtu: :cool:

And it comes on like a train, not trickling on like it used to. I'm still on the stock exhaust cat-back, so when that goes in the bin and my 2.5" system goes in I'll be a very happy camper. :yippee:

Thanks again Braineack and to the forum!

Who else has a DIY MBC?

t25miata 05-03-2007 03:08 AM

BTW - t25g from 180sx, emanage blue, olderguy's autotune, 305cc supras, RX7 AFM, ebay FMIC, 1.8 flywheel and clutch.

fatty 05-03-2007 04:08 AM

maaate. schwweeeeet. that sounz fooly sikk.

t25miata 05-03-2007 07:58 AM

Mayte. Itsh onli 2.5"... It haz 2 b tr33 1nch 2 b fooli s!k. :gay: :bigtu:

I've just got the ok from SWMBO to get a all ali radiator too! :D

Braineack 05-03-2007 08:37 AM

yeah I need to add the "hole" to my instructions...good job. Glad you were at least able to put it to some use. I've been rocking to same one since I built one for my 626 Turbo a few years back.

t25miata 05-03-2007 08:41 AM

It kinda sucks though... I built at a friends workshop with stuff he had lying around, so it was free. (W00t! Saved $30 by not getting it on ebay)

Then I got a parking fine while I was in his shop. The fecking fine was $50. :vash:

spoom 05-03-2007 10:53 AM

I'm assuming this is a ball and spring type controller? You can add the bleeder hole in the line leading back to the wastegate instead of making a hole in the MBC body itself (if memory serves me correctly, I didn't drive that car today) by adding a plastic connecter joint with a small bleeder in it (I used a hot needle to make the hole in the plastic.) A leak check on my DSM revealed I was losing boost through the bleeder hole on the MBC all the time. I JB welded the bleeder hole and moved it down the line - problem solved.

Braineack 05-03-2007 10:58 AM

if you put it here on the outlet it shouldn't leak:

http://www.geocities.com/chmwatson/F.../mbc-close.jpg

samnavy 05-03-2007 11:04 AM

I've got the VooDoo eBay special, and it's awesome. I still have about a 2psi drop in the higher gears... but that's OK. An extra 2psi in the midrange makes for great torque, and then a slight dropoff up high makes for less knock threshold. I don't mind it so much.

I drilled out the hole a little bigger than it came with... plus I expirimented with swapping the balls to both sides. One of my balls is bigger than the other. I wondered why? I would have thought that both the balls inside would be the same. It seemed to make no different which was on what side of the spring.

Does anybody know?

Braineack 05-03-2007 11:19 AM

I think the ball on the threaded side was just the help keep the spring planted. No chance it can catch on the threads of the adjuster or get crooked inside....something like that.

Put the larger one on the bottom to help seal it closed.

spoom 05-03-2007 02:47 PM


Originally Posted by Braineack (Post 109001)
if you put it here on the outlet it shouldn't leak:

http://www.geocities.com/chmwatson/F.../mbc-close.jpg

I was/am using a Joe P. boost controller. I'm assuming that it was probably drilled improperly. I'm just offering another location for the bleed hole for those who don't want to drill into the MBC body. Having driven the car with the bleed hole removed entirely, I can tell you that having the bleed hole on the ball/spring controller is a necessity and increases boost response between gears tremendously.

PaKMaN 05-03-2007 04:47 PM


Originally Posted by t25miata (Post 108967)
It kinda sucks though... I built at a friends workshop with stuff he had lying around, so it was free. (W00t! Saved $30 by not getting it on ebay)

Then I got a parking fine while I was in his shop. The fecking fine was $50. :vash:

:rofl: Owned!


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