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Old 01-09-2008, 09:19 PM   #1
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Default Wastegate problems

Ok guys this is my setup:
gt2554
Begi diverted gases downpipe
Begi actuator
DIY EBC set at its lowest DC's on MS (set at 1)
MSPNP

My problem:
Boost keeps raising in 3rd 4th and 5th. It goes beyond my limit (10psi) at 5000rpms and I only want to run 8psi.
The EBC is set at 1, so this is not the problem.
I disconnected the rubber line from the EBC and plumbed directly into actuator and still get overboost. EBC IS NOT THE ISSUE.

Not, the downpipe came with a little beffle gas diverted welded between both of its tubes. But the gt2554 has its own diverted which is part of the housing cast....I called Corky and he said they sent me the wrong DP. So I took it off the car (pain in the ***) and cut that baffle away. I used a carbide tip to smooth everything out. By the way, before I cut this baffle away the wastegate arm could only move about 1/2 inch.
Put everything back in but still, the wastegate only opens 3/4 of its total distance, this is due to the wastegate door touching against the DP top pipe. I dont see how the wastegate could open more than now. Its just impossible with the diverted gases DP.
Its it supposed to open completely?

Now, I unscrewed the actuator arm (its longer) so the gate can open more but I cant unscrew it any more and I still have the problem.

So could it be that the actuator doesnt quite work? On a Begi turbo?
By the way, this kit is not what I expected, they could have done a better job in a lot of minor things and pay more attention to details.
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Old 01-09-2008, 09:37 PM   #2
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can you snap a pic of where it hits?
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Old 01-10-2008, 10:25 AM   #3
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Pressure test the WGA to see if it is leaking. If it is that is the problem, if it isn't... pressure test again and determine the cracking point (point at which it begins to move) and the pressure required to open it fully. When doing this very slowly increase pressure, if you go too quickly you can get inaccurate numbers.

The WGA's stable boost level should be some point between the cracking pressure and the fully open pressure, if the boost pressure you are seeing while driving is above that point then your wastegate can't divert enough exhaust gas to control boost. This can be from the travel being limited (like you suspect) or from the size of the hole in the turbine housing being too small.
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Old 01-10-2008, 10:48 AM   #4
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Quote:
Originally Posted by 90turboMX5 View Post
Ok guys this is my setup:
gt2554
Begi diverted gases downpipe
Begi actuator
DIY EBC set at its lowest DC's on MS (set at 1)
MSPNP

My problem:
Boost keeps raising in 3rd 4th and 5th. It goes beyond my limit (10psi) at 5000rpms and I only want to run 8psi.
The EBC is set at 1, so this is not the problem.
I disconnected the rubber line from the EBC and plumbed directly into actuator and still get overboost. EBC IS NOT THE ISSUE.

Not, the downpipe came with a little beffle gas diverted welded between both of its tubes. But the gt2554 has its own diverted which is part of the housing cast....I called Corky and he said they sent me the wrong DP. So I took it off the car (pain in the ***) and cut that baffle away. I used a carbide tip to smooth everything out. By the way, before I cut this baffle away the wastegate arm could only move about 1/2 inch.
Put everything back in but still, the wastegate only opens 3/4 of its total distance, this is due to the wastegate door touching against the DP top pipe. I dont see how the wastegate could open more than now. Its just impossible with the diverted gases DP.
Its it supposed to open completely?

Now, I unscrewed the actuator arm (its longer) so the gate can open more but I cant unscrew it any more and I still have the problem.

So could it be that the actuator doesnt quite work? On a Begi turbo?
By the way, this kit is not what I expected, they could have done a better job in a lot of minor things and pay more attention to details.
1.6 or 1.8 engine?

Did you buy the turbo from them? I thought the only GT turbine housings with the diverter were the Ni-Resist versions with the different bolt pattern. Anyways...

If by "open completely" you mean 90 degrees, then no, the acutator itself only moves 1/2-3/4 inch of so which means like 30-45 degrees of the flapper (guessing here).

Use a bicycle tire pump to test the actuator and like pat! said pump slowly. If it doesn't have a built in gage you'll have to rig something.
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Old 01-10-2008, 11:58 AM   #5
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Its a 1.6. Ok, I opened the wastegate and safety wired it open and it now only goes to 8-9psi which I think is still too much, the Begi kits are only supposed to get to 5-6psi. Maybe its my 3" exhaust with no cat.
But, I will go to walmart and buy a pump.

Btw, I had my VE table set almost perfect but I did a log and ran it through the analizer and now the car runs like ****. And I'm dumb and didnt save the prior one. Do you guys have any VE tables that would work on a 1.6 running 8psi, 460cc injectors?
Thanks
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Old 01-10-2008, 12:37 PM   #6
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i used to see 6psi wastegate pressure with a 2.25" exhaust. With the same manifold and turbo i cant get in lower than 10psi with my exhaust and headwork.

fwiw, i dont see how you make 9psi with the wastegate wired open.
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Old 01-10-2008, 12:44 PM   #7
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Quote:
Originally Posted by Braineack View Post
fwiw, i dont see how you make 9psi with the wastegate wired open.
x2. Not a Miata, but on an SR20 if you disconnect the actuator arm from the flapper you won't make any boost even without wiring it open... exhaust pressure will keep it open.

C
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Old 01-10-2008, 01:03 PM   #8
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Really would like to see pictures of the turbine housing with the flapper articulated and of the modified DP...
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Old 01-10-2008, 02:17 PM   #9
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Quote:
Originally Posted by Braineack View Post
i used to see 6psi wastegate pressure with a 2.25" exhaust. With the same manifold and turbo i cant get in lower than 10psi with my exhaust and headwork.

fwiw, i dont see how you make 9psi with the wastegate wired open.
I would tend to agree but Paul was making 15ish psi with his GT2560R wastegate wired open before I performed surgery on it.

I'd also like to see pics of the turbine and downpipe.
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Old 01-10-2008, 03:07 PM   #10
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haha, you guys dont believe me. The turbine housing HAS a baffle separating both exhaust and wastegate gases. I would take a pic but I wont have a camera till Sunday.
I put 10psi or air pressure to the actuator with my air tank that I use for Autocross and the arm only moves 1/4". I called Corky and he said that its normal because the exhaust gases make the wastegate open the rest of the distance.
Well, he told me that my setup is good to run 10psi and I raised the boost limit to 175kpa and guess what... I'm hitting 11-12psi still, even with the actuator plumbed directly to the turbine housing. So its not related to the EBC.
I measure the distance the wastegate arm moves by hand and it moves 3/4" that should be enough...
Corky said he's going to measure how much the arm moves on one of his other turbos and he'll call me back.
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Old 01-10-2008, 03:22 PM   #11
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I can make 6psi all day long. Stock head 1.8, 3" catted exhaust, divorced tube DP. Mabye you need to pull the turbo and port the wastegate? The smaller turbos sometimes have issues with being unable to maintain lower boost pressures.

Or get an MS and some injectors and enjoy 12psi.
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Old 01-10-2008, 03:34 PM   #12
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Quote:
Originally Posted by Savington View Post
I can make 6psi all day long. Stock head 1.8, 3" catted exhaust, divorced tube DP. Mabye you need to pull the turbo and port the wastegate? The smaller turbos sometimes have issues with being unable to maintain lower boost pressures.

Or get an MS and some injectors and enjoy 12psi.
I have an MS and 460cc injectors. But I want to fix this problem, not just boost 12psi because I cant figure out whats wrong. And my intercooler is from an fm1 kit so I cant boost that much. I dont want a bigger IC either b/c I autocross.
I'll be pissed if I have to pull the turbo and port the wastegate, I spent all day today trying to fix my problems and cant live my life fixing car's stuff, not that I dont like working on it.
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Old 01-10-2008, 03:39 PM   #13
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put a silencer on the muffler tip that'll work.
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Old 01-10-2008, 04:39 PM   #14
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Quote:
Originally Posted by 90turboMX5 View Post
haha, you guys dont believe me. The turbine housing HAS a baffle separating both exhaust and wastegate gases. I would take a pic but I wont have a camera till Sunday.
No I believe you, I want to see what it looks like for my own personal knowledge.
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Old 01-10-2008, 06:01 PM   #15
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Quote:
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No I believe you, I want to see what it looks like for my own personal knowledge.
Exactly...
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Old 01-11-2008, 09:37 AM   #16
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Probably looks like this new BEGI sourced GT2554R. Thanks to Paul for the pic. This is BudgetRacer's turbo going on tomorrow.

I am 99% sure the 2554 and 2560 share the same turbine. All the 2560's I've dealt with (3) do not have this divider thing. I can only assume the "ni-resist" housings are a little different and this is one of them? I don't know anymore.

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Old 01-11-2008, 09:49 AM   #17
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Quote:
Originally Posted by TurboTim View Post
I can only assume the "ni-resist" housings are a little different and this is one of them? I don't know anymore.

that's how I understand it. the Ni-R ones are off the GTRs and have the divider and some have a different flange.
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Old 01-11-2008, 05:16 PM   #18
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Quote:
Originally Posted by TurboTim View Post
Probably looks like this new BEGI sourced GT2554R. Thanks to Paul for the pic. This is BudgetRacer's turbo going on tomorrow.

I am 99% sure the 2554 and 2560 share the same turbine. All the 2560's I've dealt with (3) do not have this divider thing. I can only assume the "ni-resist" housings are a little different and this is one of them? I don't know anymore.

that's what i have
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Old 01-11-2008, 07:05 PM   #19
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i just got back from grainger with a brand new carbide tip ($25 for a freaking tip). I have an air grinder with a 1/4 chuck. I'll port the turbo casting and smooth out the dowpipe and also port it as much as I can tomorrow and I'll get back to you guys later.
And can somebody please look at my MS settings and tell me why all my WB does is go from 7.4-22.4 all the time. I've been trying to tune it for a long time but can t figure it out. And yes, its set to linear..
Is there someone in Indy or close states that could help. AIM tunning wants $1500 to tune...ouchh
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Old 01-11-2008, 07:19 PM   #20
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what WB is it?
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