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Old 08-06-2011, 05:44 AM   #1
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Default IWG not giving me desired boost

The wastegate that came with my turbo was rated at around 7 psi.
However, the wastegate will open nowhere near that. It was opening around 21 psi. No matter how much I adjusted it, I brought it down to a minimum of 13 psi.
This is the turbo I have,
http://cgi.ebay.com/ebaymotors/T25-T...d=253266173196

So, I was wondering, does angling the wastegate slightly cause the wastegate to open at a much higher PSI then what it is rated. Here is how my wastegate was originally mounted.


Then I switched to another wastegate and brought it down to lowest 11 psi but I only want to run around 8 psi. But this wastegate is too big and I can't move it anymore to angle it better.


Do you suggest I try to buy the same wastegate that originally came with the turbo because maybe I bent the old one? Or what should I do?

Also, does having a 3" exhaust make any difference?
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Old 08-06-2011, 09:56 PM   #2
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anyone?
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Old 08-06-2011, 09:59 PM   #3
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It looks like in both pictures the rod is crooked going into the canister. That part needs to be a's straight as possible for it to function. Also, if that is the begi sgdp it has been known to boost creep slightly
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Old 08-06-2011, 11:46 PM   #4
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Yeah, that should be straight as possible. Cocking it may be causing the spring to have more pressure on it, thus making it open at higher PSI. You can test it...take a regulator with a gauge and a barbed fitting on the exit end of the regulator. Obviously have an air compressor supplying air on the inlet side of the regulator. Connect a rubber hose from the exit side of the regulator to the actuator. Start at zero psi and increase the pressure of the regulator until the actuator rod moves and opens the wastegate. Now you will know roughly how many psi's it takes for your wastegate to open.
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Old 08-07-2011, 05:35 AM   #5
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Would having a 3" exhaust change anything though? I can't think of any physics behind it that will cause it to change but I remember reading somewhere that it does.
Thanks guys for the help. I will go find a way to make it straight.

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Old 08-07-2011, 06:16 AM   #6
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Quote:
Originally Posted by x8mrxjohn8x View Post
Would having a 3" exhaust change anything though? I can't think of any physics behind it that will cause it to change but I remember reading somewhere that it does.
Thanks guys for the help. I will go find a way to make it straight.
Probably, I noticed an extra 1.5psi after replacing my stock exhaust with a 2.5" system.

I'm, in the same boat because my wastegate actuator is supposedly set for 8-9psi but I'm seeing 12-13.5psi.
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Old 08-07-2011, 03:12 PM   #7
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-That WG rod is crooked as ****.
-Yes, a bigger exhaust makes a huge difference.
This is typical boost creep, port your turbine housing. Make sure the flapper doesn't hit the downpipe as it opens. If none of that works, you're going to have to make the exhaust/turbine less efficient. The best solution is an external wastegate but thats expensive.

I have a thread on the front page of this subsection talking about my issues with boost creep. May wanna do a search as well.
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Old 08-07-2011, 04:17 PM   #8
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Thank Abe,
does anyone know if say I wanted to run at 7psi, do I want the cracking pressure to be at 7psi or the opened pressure at 7psi?
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Old 08-07-2011, 05:53 PM   #9
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Quote:
Originally Posted by x8mrxjohn8x View Post
Thank Abe,
does anyone know if say I wanted to run at 7psi, do I want the cracking pressure to be at 7psi or the opened pressure at 7psi?
Cracking. My wastegate is for 7 psi and with a hand pump it barely starts to crack open at 7 psi. With the car actually running there is pressure pushing the flapper door open.
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Old 08-07-2011, 06:26 PM   #10
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crooked wastegate is not the issue.
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Old 08-07-2011, 06:40 PM   #11
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crooked wastegate is not the issue.
What do you think the issue is?
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Old 08-07-2011, 09:06 PM   #12
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Cracking. My wastegate is for 7 psi and with a hand pump it barely starts to crack open at 7 psi. With the car actually running there is pressure pushing the flapper door open.
But aren't you having the problem of not being able to run at a lower PSI (around 8 PSI, even though your wastegate cracks around that PSI)? So, if I got a lower rated PSI wastegate (cracks at 3 PSI, opened around 7 PSI), wouldn't it end up being slightly higher.

For example, your wastegate is rated at 7-8 PSI, and actually runs at 10+ PSI,
so maybe a 3-4 PSI will actually run at 7-8PSI. lol
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Old 08-07-2011, 09:13 PM   #13
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Your turbo and exhaust are still too efficient so you'd creep anyway.
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Old 08-08-2011, 12:37 AM   #14
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Where is the signal line connected to?

Also make a new mount with some metal and a bench vice.
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Old 08-08-2011, 01:26 AM   #15
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It is connected to a nipple after the throttle. I will be making a new mount if Brain confirms that the problem doesn't actually lies in the wastegate.
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Old 08-08-2011, 01:42 AM   #16
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Quote:
Originally Posted by x8mrxjohn8x View Post
It is connected to a nipple after the throttle. I will be making a new mount if Brain confirms that the problem doesn't actually lies in the wastegate.
Err the signal that opens the wastegate. Where is that connected to?
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Old 08-08-2011, 01:48 AM   #17
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I think it is due to your new exhaust and I reckon porting a channel toward/into the wastegate hole will fix it.
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Old 08-08-2011, 01:51 AM   #18
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It needs to be connected to a source BEFORE throttle body. That is most the biggest issue. Also, crooked wastegate could definitely have negative effects on performance. Borg Warner says a max of 2 degrees from straight is allowable, although that is another brand
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Old 08-08-2011, 09:29 AM   #19
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Quote:
Originally Posted by x8mrxjohn8x View Post
What do you think the issue is?
I dunno sounds like your wastegate is rated too high.



I've run worse than this:




It probably doesn't help you any, but it appears you could easily bend your bracket to point the can inward.
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Old 08-09-2011, 07:05 PM   #20
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Quote:
Originally Posted by wittyworks View Post
It needs to be connected to a source BEFORE throttle body. That is most the biggest issue.
i dont see how this would be a problem... ive ran them both ways without issue... the upside to connecting the wastegate to manifold pressure instead of pre throttle body pressure is so you can compensate for a crappy low flowing intercooler that creates a pressure drop. making the wg open at a specified manifold pressure and not the higher pressure seen on the turbo side of a poor flowing ic.

just my $.02
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