Can not boost past 20psi - GT35r

[gsxrtalon]

Paul hows it goin? Hows the car running?

Well I thought since it being the first WG Ive dealt with, I thought it was a big red but come to find out and compare with my new big blue spring I just got I found that it was the small red so that makes more sense now that with the WG unhooked I could only get 20psi.
However, I did a BLT today and found that my BISS was leaking bad, my compressor housing was leaking bad(I had copper hi-temp RTV on it but when FP put a new wheel on it they didnt do it), and my d@#m Forge bov is leaking AGAIN so I found a thread on here to fix the Bov leak and Ill fix those and wire in my 3.3bar and put the big blue spring in and see what happens.

Paul........looking at that big blue spring and knowing how hard the small red was to get in there, how the H#LL am I going to get the big blue in there? I would like to keep the WG on the car and do it but not sure that'll happen. Im sure I can get it in there but any easy way? Thanks

 

[T9S1i]

take it off and use a rag and a vice

So how many psi is spring pressure for the small red?

 

[99gst_racer]

Paul hows it goin? Hows the car running?

Well I thought since it being the first WG Ive dealt with, I thought it was a big red but come to find out and compare with my new big blue spring I just got I found that it was the small red so that makes more sense now that with the WG unhooked I could only get 20psi.
However, I did a BLT today and found that my BISS was leaking bad, my compressor housing was leaking bad(I had copper hi-temp RTV on it but when FP put a new wheel on it they didnt do it), and my d@#m Forge bov is leaking AGAIN so I found a thread on here to fix the Bov leak and Ill fix those and wire in my 3.3bar and put the big blue spring in and see what happens.

Paul........looking at that big blue spring and knowing how hard the small red was to get in there, how the H#LL am I going to get the big blue in there? I would like to keep the WG on the car and do it but not sure that'll happen. Im sure I can get it in there but any easy way? Thanks

I'm good, but the car's down. I think I spun a bearing, but haven't built up the ambition to pull the pan and investigate.

Yeah, being that you have the small red spring, I'm almost sure that's why you're limited on boost. I'm genuinely surprised that you were even able to get 20 psi out of it.

You'll probably have to remove the gate from the car to swap springs. Maybe, if you can find a friend, you can hold the top down while he threads the screws in. It wouldn't be easy, though. I used the rag and vice method like T9S1i mentioned.

So are you saying if he disconnect the boost from the wastegate that the actual exhaust pressure would push the wastegate open?

Yup. With a small-rate spring, it would eventually push it open even without a pressure source hooked up.

 

[keltalon]

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Yup. With a small-rate spring, it would eventually push it open even without a pressure source hooked up.

 

[dsm-onster]

My ebay wastegate with the stock ebay spring does this. It runs 20 psi or so maximum no matter what.

Since then I've run this setup with 2 MBCs since I had 2 lying around:

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Works great to 30 psi. Start with MBC number 2 and adjust boost to 15 or so psi. Will act like a wastegate with a larger spring (spool speed is slower like running off wastegate pressure). Then add in MBC number 1. This will be like adding a mbc to an intgernal gate turbo. Boost will ramp up fast to the threshold then the gate will open. Expect a little spike like any other MBC setup. But this has held to 30 psi with my holset.

 

[keltalon]

Any udates?

 

[gsxrtalon]

Update:

I put the big blue spring in my WG and fixed my leaky BISS with a new Steel one and new o-ring and I fixed another boost leak at my Forge. I installed my GM 3.3bar as well while doing this. I am finishing up fixed a boost leak from the compressor housing and then Ill get it back on the road and get another log and see where I got with all this. I hope to do this by this weekend. Ill keep updated

 

[dsm-onster]

Update:

I put the big blue spring in my WG and fixed my leaky BISS with a new Steel one and new o-ring and I fixed another boost leak at my Forge. I installed my GM 3.3bar as well while doing this. I am finishing up fixed a boost leak from the compressor housing and then Ill get it back on the road and get another log and see where I got with all this. I hope to do this by this weekend. Ill keep updated

Did you have a leak at the coupler for the outlet? or a leak where the compressor housing mates to the backplate ???

 

[gsxrtalon]

There was a leak that I previously had where the comp housing mates with the back plate. This was a leak I had before and fixed it then had to send the turbo to FP to get a new wheel put on it and when
they took the comp housing off they didn't seal it back up so I did it. Just waiting on my laptop now.

 

[keltalon]

There was a leak that I previously had where the comp housing mates with the back plate. This was a leak I had before and fixed it then had to send the turbo to FP to get a new wheel put on it and when
they took the comp housing off they didn't seal it back up so I did it. Just waiting on my laptop now.

Please keep us posted! Thanks.

 

[gsxrtalon]

Ok so after fixing my leaks I still can't boost past 20psi. I BLT`ed the IC pipes up to the TB and they held 20 + psi and I tried to check the intake manifold for leaks but it was hard alone but I didn't see anything so I'm thinking it has something to do with my tial 38mm WG. I have the WG sourced to the line from the intake manifold t`d to the bov as well. Obviously there is something wrong post TB which is causing me to not reach more than 20psi.

 

[keltalon]

Ok so after fixing my leaks I still can't boost past 20psi. I BLT`ed the IC pipes up to the TB and they held 20 + psi and I tried to check the intake manifold for leaks but it was hard alone but I didn't see anything so I'm thinking it has something to do with my tial 38mm WG. I have the WG sourced to the line from the intake manifold t`d to the bov as well. Obviously there is something wrong post TB which is causing me to not reach more than 20psi.

It seems that you have the same problem that i have.. This is why i am so interested in what could be your problem. I have a brand new borg warner s259 and cant boost past 20psi either. I have checked for boost leaks and found none. I have replaced my Bov with a brand new one from forgedl. The only thing we have in common is the 38mm tial which i also think might be my problem. Plesease keep us posted!

 

[gsxrtalon]

I am going to try to get the WG off and check it out. Unfortunately I wish I had access to another WG to check but I don't so I guess we will see.

 

[92awddsm]

Remove the wg and make sure the sealing ring is installed in the bottom of the valve. If it is missing, it will cause slow spool and low boost pressures. At what rpm do you see 20 psi?

 

[gsxrtalon]

I just took the WG and downpipe off the car. I honestly don't know what I'm supposed to be looking for so a little help would be great. I tried to push thw WG open while off the car and it wouldn't open or it was very very hard to push open. I finally got it to open be hitting down on it with the butt end of a hammer(not sure I should of done that but it was very hard to open) It does look like there is a ring of some kind on it I think thought.

 

[gsxrtalon]

I just took the wg off and I'm pretty sure the ring is on it. It looks like there is some kind of ring but I don't know what the ring looks like installed on a wg so. The wg was really hard to open....I had to use the butt of a hammer to hit it open. If the ring is in there I am at a lose for what my problem is

 

[keltalon]

Remove the wg and make sure the sealing ring is installed in the bottom of the valve. If it is missing, it will cause slow spool and low boost pressures. At what rpm do you see 20 psi?

Well these are my symptoms to a tee. very slow spool and low boost.

 

[92awddsm]

Well these are my symptoms to a tee. very slow spool and low boost.

Tial 38mm wg and sealing ring

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Sealing ring installed

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[gsxrtalon]

Is there anyway to test my WG? I'm thinking while the WG is off I'm going to hook it up and do a boost leak test with the mbc hooked up as well. Ill just face the WG towards me and use my boost controller to see when it opens or if its even working. Will this work?

 

[xlMcMlx DsM]

I had the same problem on my talon after the winter. The car would not boost past 10psi for it's own life. Zero boost leaks, everything was working as it should. The MBC wasn't turned in far enough, but I thought it was . Take it out and clean it,too, to make sure the spring is compressing properly and not getting caught. Quick and easy thing to check.

 

[gsxrtalon]

Ok Ill take the MBC out and clean it and check.........but even when the MBC isnt installed and I run just on WG pressure I still cant get past 20psi. I should be able to get more boost than 20psi out of my WG since I have the big blue tial spring in it, right?

 

[gsxrtalon]

I tested the wastegate and with the Hallman MBC hooked up to it with 20+psi the wastegate wouldnt open.

Without the MBC and the boost source directly to the wastegate it started to open at 17-18psi.

So Im thinking now my wastegate is fine and my MBC is junk. But here is what is confusing me.
I ran the boost source on the car directly to the wastegate and did a pull and I still could only get 20psi???? Does this make sense to anyone?

 

[dsm-onster]

Yes, this makes sense. I.E., the 16g internal gate when running a line directly to the wastegate actuator port, only allows 10-12 psi. However, with an MBC, I've been able to get 22psi or so to redline.

Your default wastegate pressure is 18psi. Based on my above described results, wouldn't you think an properly functioning MBC would be able to almost double that boost? or at least give you 30psi to redline?

 

[->PrOjEcTGS<-]

I think the one thing that hasn't been asked is:

Are you hooking the wastegate up correctly to a boost source? This could be the very problem you are having.

It should be like this:

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This is how it works:

The top one will add pressure to the diaphram holding your wastegate shut. Thus, increasing your boost pressure. Without this the wastegate will just blow open at/around spring pressure.

The side one will assist in opening the wastegate. Therefore once boost has reached spring pressure and then surpasses the additional pressure from the top feed it will start to open the wastegate.

So, if you are only feeding the side port with your MBC line then you are only either assisting it open or not giving it any pressure in which the WG is just opening at spring pressure.

 

[sheldon]

Come on guys....

if you cant bring in more than 20lbs with the vac line off the gate...then the problem lies in the gate! (since you did boost leak tests and exhaust leak tests)!

the top port of the external gate is for an electronic boost controller!

hook your mbc up to the side port only...leave the top port alone!



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