local Pittsburgh Meet
Oct 22, 2008, 03:14 PM
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It actually has more to do with the size of the wastegate hole where the 2 chambers come together. While making it smooth can help its the hole size that seems to be the culprit. I ported the **** out of my O2 housing making nice smooth transitions and no welds or lips in the way but left the WG hole alone and I still had creep. My boost control system takes it away enough that its not a factor....I look at it as extra help to hold boost up top 
Oct 22, 2008, 03:25 PM
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The only drawback to using a mbc vs an ebc is the fact that a mbc alone cannot account for load increases in the higher gears. I remember mine used to hit like 22 psi peak in 1st and around 25 peak in 5th. An ebc can take care of that.
On my X once available, I'm hoping to just use the ECU to do what Travman is doing. I haven't been into the turbo scene long, but in the past four years I've had three seperate incidents of mbcs failing.
Forge mbc - did not divert any boost signal to the WGA. I never figured out why, but it either bled it all off or the ball was stuck shut not allowing the boost to flow through the mbc to the WGA. There's nothing like pulling onto 376 only to have your car make a horrible sound. I had no idea what it was. Hit WOT again and glanced at the boost gauge as it shot past the 35 max line on the gauge!
Hallman MBC - Had an issue and it had to be replaced. Didn't hold boost at all. Sent Marc Hallman an email and he said send it in. I did and he repaired it and sent it back.
Second Hallman MBC - Same issue, didn't hold boost. Or will hold it initially and then fall to WG pressure. I cleaned it up and lubed the ball. I think that took care of it.
On my X once available, I'm hoping to just use the ECU to do what Travman is doing. I haven't been into the turbo scene long, but in the past four years I've had three seperate incidents of mbcs failing.
Forge mbc - did not divert any boost signal to the WGA. I never figured out why, but it either bled it all off or the ball was stuck shut not allowing the boost to flow through the mbc to the WGA. There's nothing like pulling onto 376 only to have your car make a horrible sound. I had no idea what it was. Hit WOT again and glanced at the boost gauge as it shot past the 35 max line on the gauge!
Hallman MBC - Had an issue and it had to be replaced. Didn't hold boost at all. Sent Marc Hallman an email and he said send it in. I did and he repaired it and sent it back.
Second Hallman MBC - Same issue, didn't hold boost. Or will hold it initially and then fall to WG pressure. I cleaned it up and lubed the ball. I think that took care of it.
On the evo though it doesn't like the MBC. The wastegate design is completely different and they seem to taper too much at higher rpm's. The ecu based boost seems to work the best for my evo. It takes some time to dial in, but so far its been great. I actually got a friends car up and running on the ECU boost control and he likes it over his HKS EBC unit he had...
Oct 22, 2008, 04:26 PM
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thanks for the input guys. I turned the boost down 1/4 turn on the hallman and it seemed to fix it from hitting the fuel cut. it will go to 24psi now, but it will still creep there from 23psi. Nothing to be worried about since the AFR's are okay and i dont think its gonna cause knock. But im still going to port the wastegate hole in the 02 housing asap.
Oct 22, 2008, 09:10 PM
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Oct 23, 2008, 04:02 AM
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depends on the tire. OE yokos from the viii & ix are hockey pucks at around 45 degrees. 
somewhere in between 35 - 45 degrees i would say though. the bfg's i have on my car now seem to be a bit more forgiving than the yokos, but they're still not very compliant once the temp starts dipping in to the 40's.
somewhere in between 35 - 45 degrees i would say though. the bfg's i have on my car now seem to be a bit more forgiving than the yokos, but they're still not very compliant once the temp starts dipping in to the 40's.
Oct 23, 2008, 06:25 AM
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thanks for the input guys. I turned the boost down 1/4 turn on the hallman and it seemed to fix it from hitting the fuel cut. it will go to 24psi now, but it will still creep there from 23psi. Nothing to be worried about since the AFR's are okay and i dont think its gonna cause knock. But im still going to port the wastegate hole in the 02 housing asap.
My mbc would hit 23 fall to 20 and creep to 25 and then fall to 20 by redline in the cold w/ O2 housing - made for a really odd load curve but I just tuned around it and made it work.
Oct 23, 2008, 07:28 AM
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Oct 23, 2008, 07:49 AM
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Oct 23, 2008, 09:04 AM
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we could always go out and get some food during the week. It is getting a little cold, but nothing crazy just yet. I still go out to the subaru meets and there is still a big turnout in cold weather at QSL.
anyone down for Open Kart rentals at beaverun the 26th?!
anyone down for Open Kart rentals at beaverun the 26th?!
Oct 23, 2008, 11:14 AM
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Oct 23, 2008, 11:47 AM
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Dave, yeah I definately noticed the increased stopping distance this morning. My dash said 30 degrees. That's rediculous. Winter tires are going on soon, but I have to make it through the next week. The Advan A13's may be different than the A046's, but they probably have the same properties.
Oct 23, 2008, 12:01 PM
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Dave, yeah I definately noticed the increased stopping distance this morning. My dash said 30 degrees. That's rediculous. Winter tires are going on soon, but I have to make it through the next week. The Advan A13's may be different than the A046's, but they probably have the same properties.
I have all seasons I am going to run for the time being.
Oct 23, 2008, 12:03 PM
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we could always go out and get some food during the week. It is getting a little cold, but nothing crazy just yet. I still go out to the subaru meets and there is still a big turnout in cold weather at QSL.
anyone down for Open Kart rentals at beaverun the 26th?!
anyone down for Open Kart rentals at beaverun the 26th?!