Begi-s boost creep issues - Page 3 - Miata Turbo Forum - Boost cars, acquire cats.

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Old 02-26-2008, 11:31 PM   #41
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you wouldn'd agree that free-er flowing exhaust allows the car to build more boost?

it allows the exhaust gases to exit more quickly out of both the wastegate AND the exhaust housing. but since they are not equally restrictive the whole path of less resistance comes into play. air will flow more through the turbo than through the wastegate since the wastegate passage is more restrictive therefor building more boost

the unrestricted exhaust further exaggerates the difference in how restrictive the waste gate and exhaust outlet are.
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Old 02-27-2008, 12:15 AM   #42
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That does not make sense at all. A free flowing exhaust system should let the exhaust gases exit more quickly = less boost creep.
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Old 02-27-2008, 01:11 AM   #43
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That makes perfect sense. A free flowing exhaust system should let the exhaust gases exit more quickly = more boost creep.
fixed it for you
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Old 02-27-2008, 04:50 PM   #44
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Porting the wastegate is not something we recommend you do at home. Not only does the casting get drilled out, Corky said there is a small hole drilled elsewhere.

We are more than happy to port a wastegate for anyone (regardless of who it was purchased from) at no charge. Just send us your turbo and we can send it back within a day or two. A pain to do, yes, but safer in the long run.
Stephanie
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Old 02-27-2008, 04:59 PM   #45
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^ any turbo?
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Old 02-27-2008, 05:02 PM   #46
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Garrett, with an internal wastegate.
Stepahnie
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Old 02-27-2008, 05:44 PM   #47
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hmm......with an offer like that, i'll have to keep an eye on any signs of boost creep with my new begi-s 2554.
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Old 02-28-2008, 01:16 AM   #48
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Wow. that's an awesome offer buy BEGi. another reason I am placing my order for the S tomorrow through Shore Motorsports.
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Old 02-28-2008, 02:00 AM   #49
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i need money to order my kit from them...... makes me not happy
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Old 02-28-2008, 09:15 AM   #50
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Quote:
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Wow. that's an awesome offer buy BEGi. another reason I am placing my order for the S tomorrow through Shore Motorsports.
Yeah. BEGI for the win!
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Old 02-28-2008, 09:29 AM   #51
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Had boost creep initially - ended up shortening the dp just a bit (1") and it went away :-) This is on a high flow 2.5" cat back.
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Old 02-28-2008, 10:42 PM   #52
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order has been placed. eta 2 weeks due to turbo shortage or backlog(because of porting?)
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Old 02-28-2008, 10:45 PM   #53
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Quote:
Originally Posted by Stephanie Turner View Post
Porting the wastegate is not something we recommend you do at home. Not only does the casting get drilled out, Corky said there is a small hole drilled elsewhere.

We are more than happy to port a wastegate for anyone (regardless of who it was purchased from) at no charge. Just send us your turbo and we can send it back within a day or two. A pain to do, yes, but safer in the long run.
Stephanie

At what cost? my T3 doesn't see less than 13psi at redline with your manifold and DP and Jason's 3" catback. I planned on doing it myself with a die-grinder, but i cant refuse this offer... I still need your water-bypass kit, so i might as well get it sent back with my order.
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Old 02-29-2008, 03:01 PM   #54
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At what cost?
Shipping cost only.
Stephanie
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Old 02-29-2008, 03:45 PM   #55
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Shipping cost only.
Stephanie
Amazing service!
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Old 02-29-2008, 06:50 PM   #56
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I was constantly under the impression it was making the wastegate opening bigger.
This does work but then there is a chance that when you do actually want to turn up the boost the flapper will blow open. This has been proven time and again with larger flappers on MHI turbos. But we're talking about 15+ psi and over 300hp so I'm not sure what bearing this has in this application.
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Old 02-29-2008, 09:58 PM   #57
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Good point. As most of you probably know, force is surface area times pressure, and area goes up with the square of the radius. Doubling the diameter for example means quadrupling the area. I'm not saying of course that anyone would double the size of the wastegate, just using that for illustration. But the point is a small change in the wastegate diameter has a potentially strong effect on the force required to hold the valve closed, thus probably requiring a stronger spring in the wastegate actuator to compensate.

OK that is enough technobabble for a Friday night. Time for a beer.
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Old 03-01-2008, 01:43 PM   #58
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Synasthetic,

You're on a turbo website. Guys building, installing, modifying there own stuff. Of course there are going to be issues. Take a Greddy kit and push it to 18psi and stuff will break.

The BEGI S system is basically brand new. BEGI saw the boost creep problem and are now taking steps to correct it - porting the WG.

There are hundreds of guys running FM, BEGI, custom and DIY kits for a long time without significant issues. There are lots of guys here that have great running systems with little or no issues. The thing with DIYers is lots of the problems wouldn't be significant if we weren't always looking for ways to get more power, more efficiency and push closer to the limits of the engine. You take a small 4 banger and double or triple the horsepower there are going to be occasional problems. Lots of people also can't pay for dyno time for proper tuning.

Check out the websites, if there are any, on the engine swaps. I'm sure everything isn't all rosy there either.

Enough trying to convince the Newb not to give up on turbos. Just ban him.
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Old 03-01-2008, 02:13 PM   #59
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i had a swapped civic once, it sucked... never ran the same, always had stupid little issues
have a boosted miata now, and it runs like stock, only faster...

turbo - my replacement for displacement
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Old 03-01-2008, 02:28 PM   #60
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No boost creep here at 8psi!
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