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Low and Fluctuating Boost Problem

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Old 01-29-2010, 11:52 AM
  #76  
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Originally Posted by Kane
Hey now, some people paid with their life to live that motto...I hope you are not making fun of Cpt English.
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absolutely not - I totally agree with that sentiment .
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Old 01-29-2010, 12:03 PM
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I wish we could mount a small webcam under Ngo's car while on a dyno run to see what the wategate is doing.
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Old 01-29-2010, 12:09 PM
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Originally Posted by Jedi54
I wish we could mount a small webcam under Ngo's car while on a dyno run to see what the wategate is doing.
I can do that.
Though, there are other way to do it that are just as effective.
If time permits, I'll do some diagnostic on his car at Steve's.
The easiest and best way is to hook up a gauge and a Mighty-Vac and just look at it first.
If the full-open pressure is correct, then it is the diaphragm sizing ratio.
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Old 01-29-2010, 12:46 PM
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Originally Posted by MazdaManiac
I can do that.

If the full-open pressure is correct, then it is the diaphragm sizing ratio.
there is not a lot of room down there to fit a big *** diaphragm .....
Last edited by Brettus; 01-29-2010 at 12:52 PM.
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Old 01-29-2010, 01:57 PM
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Originally Posted by Brettus
there is not a lot of room down there to fit a big *** diaphragm .....
I do it. Its all in the bracket fab.
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Old 01-29-2010, 06:11 PM
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I was able to get under there to snap some pictures of the actuator.







I will try to test the actuator's cracking and fully open pressure right now. I do believe it opens fully at 10 psi but doesn't hurt to check.
Attached Thumbnails Low and Fluctuating Boost Problem-img_0414-medium-.jpg   Low and Fluctuating Boost Problem-img_0418-medium-.jpg   Low and Fluctuating Boost Problem-img_0422-medium-.jpg  
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Old 01-29-2010, 06:37 PM
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I am going to bet a dollar that the diaphragm is too small.

That thing is even smaller than the greddy.
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Old 01-29-2010, 06:41 PM
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yeah it does look a lot smaller than my greddy diaphragm
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Old 01-29-2010, 06:43 PM
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That is the problem with piston stuff on a rotary.... we flow over 150% more exhaust for the same power output.

So if you are aiming for 300 WHP, you need like a 500WHP waste-gate.
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Old 01-29-2010, 06:45 PM
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Good news is that the actuator seems to have a good amount of room where it is located
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Old 01-29-2010, 06:48 PM
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hmm... anyone know the diameter of the greddy diaphragm?
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Old 01-29-2010, 06:49 PM
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Better idea would be to ask Jeff what size he has on his.....
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Old 01-29-2010, 06:53 PM
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Originally Posted by dannobre
Better idea would be to ask Jeff what size he has on his.....
Big.... mine is 2mm off the frame rail.
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Old 01-29-2010, 06:54 PM
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/\ good point
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Old 01-29-2010, 06:58 PM
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This is actually a case of " bigger is better"
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Old 01-29-2010, 07:21 PM
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lol!

I measured the diameter of the actuator and it is 48 mm (1.9").
I'm going to have gregs check his spare greddy actuator tonight. Will ask Jeff the size he uses too.

For kicks, I tested the actuator. 6-7 psi cracking, ~10 psi fully open.

I'm crossing my fingers!
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Old 01-29-2010, 09:54 PM
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just measured the greddy wastegate and its 1.6"
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Old 01-29-2010, 10:07 PM
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sold the 8... :(
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huh...wtf...
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Old 01-29-2010, 10:12 PM
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/\ yeah - I just measured mine as well and ...................










wait ,wrong thread !
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Old 01-29-2010, 10:19 PM
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Originally Posted by Brettus
/\ yeah - I just measured mine as well and ...................










wait ,wrong thread !
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Old 01-29-2010, 10:36 PM
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I guess mine is bigger than yours.

looks like I will be testing my wastegate a little more...haha
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Old 01-29-2010, 10:48 PM
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be careful man you prolly shouldn't go over about 8psi at 7500 with that turbo without meth.
Last edited by Brettus; 01-30-2010 at 06:53 PM.
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Old 01-31-2010, 03:31 PM
  #98  
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any more news ?
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Old 01-31-2010, 06:48 PM
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i believe he is going to try to attempt and force the wastegate flapper close and see what the result is
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Old 01-31-2010, 08:00 PM
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not fully closed i hope
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