Can not boost past 20psi - GT35r

[->PrOjEcTGS<-]

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!



http://www.perrinperformance.com/shared/PERRIN/documents/instructions/universal/asmint700.pdf

Ummm... This is TiAL's installation image:

You must be logged in to view this image or video.

This shows the Boost controller going to the top port and a boost source going to the side port. I used the other image to oversimplify it.

 

[dsm-onster]

Besides, is there a spring that will let you boost past 20 psi withOUT an mbc???? He had terrible boost leaks before he fixed them. And now:

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?

'Come on' sheldon , it makes sense that he can't get any more boost than 20 psi because he is running the blue TiAL spring.

 

[->PrOjEcTGS<-]

Besides, is there a spring that will let you boost past 20 psi withOUT an mbc???? He had terrible boost leaks before he fixed them. And now:

This makes complete sense if you were to follow OLDMAN's post in this thread: http://www.dsmtuners.com/forums/newreply.php?do=newreply&p=151169306

Trust me Paul #1, I have done alot of research on this and I have a brand new TIAL 44 from Extreme PSI sitting right in front of me with instructions to use only the side port and VTA the top port with MBC, on the top of the instruction sheet there is a *NOTE* For electronic boost controller installation, use the manufacture's instruction.

Let's break it down into different situations for better understanding.

1. With both ports open, much like leave the fitting on an internal wastegate fitting open, the wastegate is suppose to hold approximately 2x the spring pressure (its ability to hold back exhaust pressure). Example, 14psi spring = 28ish psi of intake pressure.

2. No boost controllers but both top and bottom connected to straight intake pressure, the result is the same as #1, 28psi.

3. No boost controller but with side port connected to intake pressure signal and top port VTA, much like running no MBC with an internal wastegate, the wastegate will hold exact the spring pressure. Example 14psi spring = 14 psi of intake pressure.

4. EBC or bleeder MBC, side port sees intake pressure (which will result in #3), the outlet of EBC or bleeder connects to the top port, for every psi the top port sees, there is one PSI increase in intake pressure. Note, a bleeder MBC will work in reverse in adjustment as in an internal gate environment, the more pressure you bleed off, the less the top port sees, the lower the boost level.

5. Ball/spring MBC, top port VTA and outlet of MBC connects to the side port. No pressure will be sent to the side port until the spring pressure in the MBC is overcomed, just like an internal setup. The reaon a ball/spring MBC doesn't work with the top port is because you have no control over exactly how much pressure to send, either you get nothing or you get everything, unlike an EBC or bleeder MBC. Let's put it in examples of running a ball and spring mbc using the TIAL instruction, assuming the wastegate spring pressure is 14psi.

A. MBC all the way out (no pressure on the ball), top and bottom port sees the same pressure, you get #2, 28psi.

B. MBC all the way in (max pressure on the ball), nothing gets sent to the top port, you get #3, 14psi.

So far so good but the problem is contolling boost pressure in between.

C. MBC set to anything between 0-14psi, as soon as the ball gives, the top port will immediately see the same pressure as the side port, you'll always get #2, 28psi.

D. MBC set to anything 14psi+, the top port will never see anything at all because the side port will open the wastegate before the ball is overcome, you'll always get #3, 14psi.

Hope my explanation isn't too confusing.

Lastly, to get away with using a smaller wastegate spring while trying to run higher pressure, you leave the side port open, 28psi, then for every psi you add to the top port, you get 2psi more in intake pressure.

If he's testing this off the car and he gives the side port pressure, it's going to open at spring pressure. Then if you put a restriction in the pressure line it's going to open at a higher pressure of course since there is less pressure getting to the wastegate. What he's not accounting for in the bench test is the pressure from the exhaust gasses against the wastegate.

So in your situation I would try and use just to top port and see if you can get higher boost that way by putting more pressure on the diaphram.

 

[sheldon]

Your not reading the diagram your just looking at the lines

The top port can either be "vented to the atmosphere" or have "air added for adjustable boost control" (ie from a solenoid that pushes the gates valve closed to spool the turbo faster, the advantage an ebc has over a mbc)

The side port is the "air supply" that opens the gate at the spring rate.....

 

[->PrOjEcTGS<-]

Your not reading the diagram your just looking at the lines

The top port can either be "vented to the atmosphere" or have "air added for adjustable boost control" (ie from a solenoid that pushes the gates valve closed to spool the turbo faster, the advantage an ebc has over a mbc)

The side port is the "air supply" that opens the gate at the spring rate.....

Sorry my initial assessment of the situation and connection image was wrong for his situation. I am still curious which port he has everything connected to. Originally he had the small red (6.8psi) spring and that should only technically net him 14psi. The large blue (14.5psi) spring should get him closer to 28-29psi with the line removed. Therefore if he's not getting enough he should try to only put pressure on the top port to see if he can raise it. Doing so will also help his spoolup.

 

[gsxrtalon]

Sorry my initial assessment of the situation and connection image was wrong for his situation. I am still curious which port he has everything connected to. Originally he had the small red (6.8psi) spring and that should only technically net him 14psi. The large blue (14.5psi) spring should get him closer to 28-29psi with the line removed. Therefore if he's not getting enough he should try to only put pressure on the top port to see if he can raise it. Doing so will also help his spoolup.

Ok so amongst all the conversations about how I have the wastegate hooked up, here goes.
The member I bought the turbo/WG/Dowpipe setup off of ran 25psi all day on the setup before I put the Big Blue spring in.

Here is how I have the MBC/WG hooked up

1) Hallman Pro MBC bottom port vac line ran to the BOV source line

2) Hallman Pro MBC side port vac line ran to the side port on the Tial 38mm Wastegate.

3) Top port on the Tial 38mm is VTA( previous owner said leave it vented, I have airfittings if needed)

When reading Oldman's post.......Im a correct in assuming my "ball and spring" MBC isnt the best choice for my setup then?
And I guess I should run my MBC side port vac line to the top of the Wastegate?

 

[->PrOjEcTGS<-]

Have you tried to run the wastegate without the vac line with the new large blue spring in it? I know you did it before with the old red spring.

Try to run it without the MBC and strait intake pressure to the side port you should get roughly 14.5psi.

Then disconnect the intake pressure all together and you should get roughly 28-29psi.

If you don't get 28-29psi I would try to put some pressure to just the top port regulating it with the MBC. It shouldn't matter if it's your ball and spring type or not with that setup. You will only need a bleeder type if you run the side port as well.

Note: when on the top port your MBC will work in the reverse that it does on the bottom port. Unscrewing it will put more pressure on the diaphram which will increase boost screwing it in will limit the amount of pressure to the diaphram and will decrease your boost pressure.

I would also try to run a dedicated line from the intake to your wastegate. Do not tee off of the BOV line. I know some people have not had problems with this but since you are diagnosing a problem with the mechanics of your wastegate system it only makes sense that you eliminate every possible problem.

 

[gsxrtalon]

I have tried doing pulls and adjusting boost with the new spring in and still the same 20psi

I have tried running the boost line directly to the side port and doing a pull.......same thing 20psi.

Then ran the both WG port open and still........same thing(yes I plugged the boost source line)

I am still confused as to why Im only getting 8psi while BLTing after the TB but 20+psi from the turbo to TB

 

[->PrOjEcTGS<-]

I have tried doing pulls and adjusting boost with the new spring in and still the same 20psi

I have tried running the boost line directly to the side port and doing a pull.......same thing 20psi.

Then ran the both WG port open and still........same thing(yes I plugged the boost source line)

I am still confused as to why Im only getting 8psi while BLTing after the TB but 20+psi from the turbo to TB

Try putting it to the top port and see if you get more than 20.

You probably still have a boost leak somewhere though if you are getting odd numbers with the BLT.

 

[gsxrtalon]

I just put my downpipe back on and mounted my wastegate back up. Tomorrow I will do another boost leak test and see if I can't find the mysterious leak.
Can I leave the airfitting on the side of my wastegate VTA while I try using the top port?

 

[->PrOjEcTGS<-]

I just put my downpipe back on and mounted my wastegate back up. Tomorrow I will do another boost leak test and see if I can't find the mysterious leak.
Can I leave the airfitting on the side of my wastegate VTA while I try using the top port?

Yea leave it VTA. If you have it hooked to vac/boost then it will yield less boost. It will make it like Oldman's #4 and at the max will get you double the spring pressure.

 

[keltalon]

Do you have a picture of your engine bay

 

[gsxrtalon]

Do you have a picture of your engine bay

there are some in this thread. I am going to do a good BLT today and try a couple different configurations.

http://www.dsmtuners.com/forums/newbie-forum/291836-new-setup-gt35r-3.html

 

[DSM90AWD]

The intake manifold is the least reliable place to tap for a W/G needing ~4' of vaccume line and being post all bost leaks.

Do yourself a favor and pick up a 1/8"NPT barbed threaded air fitting at any Automotive store and install it at the compressor outlet as your new boost source for the MBC.

On the MBC, make sure that your MBC has a small steady leak btw the MBC and Wastegate. Ball-Spring WGs need this to purge the pressure in the line to the WG, else the WG would never shut once the MBC valve opened.

Lastly, make sure that all the exhaust connections Head>Manifiod>Turbo/Wastegate are solid and no leaks.


FYI, I have a GT35R and Tial44 and have no issues with boost (my headgasket did though )

 

[gsxrtalon]

ok I just went out and tried hooking the mbc to the top port on the wastegate and with the mbc turned all the was both ways I still got 20psi.

I also re-ran the boost source line from the I'M to the wastegate with the only T in the line being for my gm3.3bar....I will get a fitting on my comp cover soon.

I'm about to give up

 

[Rob10_99]

Whats the AR on your 35r?
any updates on the problem?

Are you still trying to balls out this turbo without a tune or any A/F readings? I wouldn't run anything more than 10psi without an A/F reading.

 

[keltalon]

Post a log I see that you have dsmlink v2.

 

[gsxrtalon]

I have posted tons of logs on dsmlink forums.....everything looks great but just can't go past 20psi

 

[gsxrtalon]

I'm starting to think I have some internal problems with my rings or something. I'm just confused about it because the car runs good but does seem to be making th power I would think it would even at 20psi. I know that's not the turbos effiency range but it does feel like it pulls hard at all. Plus now that I think about it the last comp test I did I think it varied from 115-135 across the board.

 

[DSM90AWD]

I'm starting to think I have some internal problems with my rings or something....the last comp test I did I think it varied from 115-135 across the board.

Um, yea that's pretty low for a 2G. May also want to check for bent valves / cam timing is good.

I assume you've checked the turbo itself for damaged fins, freeplay and that it spins freely?

 

[gsxrtalon]

Um, yea that's pretty low for a 2G. May also want to check for bent valves / cam timing is good.

I assume you've checked the turbo itself for damaged fins, freeplay and that it spins freely?

When I did the comp test I was a little worried about the results but the car runs/drives good. Yes the turbo is good, spins freely with no damaged fins and since its ball bearing has the little play(not much)ball bearing turbo's do.

Im going to check my exhaust and see if my cat is plugged or something.........as well

 

[Rob10_99]

Yeah that sounds like whats causing it, low compression as well as no free flow exhaust.

 

[gsxrtalon]

Jackpot!

I unhooked my vband downpipe from my exhaust and did a pull and my dsmlink log noted boost jumped to 27psi according to my gm 3.3bar map and holy s&%T the boost hit hard/loud and fast so I had to let off it before boost shot even higher.

I would haveto say something in my exhaust is plugged so Ill look at that now and go from there

Thanks to everyone for the advice and ideas!

 

[dsm-onster]

Bad catalytic converter.

 

[talon187]

catalytic converter whats that? got to love the apexi full exhaust