1G Boost Leak?

[holland]

I've recently got my new engine installed and I've put 600 miles on it so far. I've had the boost controller set as low as it would go and my greddy gauge says its at .5 bar ( 7 psi).

I decided to turn the boost up alittle for alittle extra go power. I turned up the boost controller a quarter of the way and the boost went up to about .7 bar ( 10 psi). I thought shoot, I'll turn it up half way then and I got it to go up to .9 bar ( 13 psi).

Here are some of my dsmlink runs, the first one is at .5 bar and the last two are at .9 bar.

For one, whenever I turn my boost controller up more, the boost wont go past .9 bar. I'm guessing I have a boost leak somewhere, or maybe my 2G blowoff valve is worn out? I know the boost est # in dsmlink is usually pretty inacurate, but it seems to be pretty far off from my greddy gauge.

Also, it seems as though I should be making ALOT more horsepower with the boost and mods I'm running....... anyone have any ideas?

 

[alex99gst]

I've recently got my new engine installed and I've put 600 miles on it so far. I've had the boost controller set as low as it would go and my greddy gauge says its at .5 bar ( 7 psi).

I decided to turn the boost up alittle for alittle extra go power. I turned up the boost controller a quarter of the way and the boost went up to about .7 bar ( 10 psi). I thought shoot, I'll turn it up half way then and I got it to go up to .9 bar ( 13 psi).

Here are some of my dsmlink runs, the first one is at .5 bar and the last two are at .9 bar.

For one, whenever I turn my boost controller up more, the boost wont go past .9 bar. I'm guessing I have a boost leak somewhere, or maybe my 2G blowoff valve is worn out? I know the boost est # in dsmlink is usually pretty inacurate, but it seems to be pretty far off from my greddy gauge.

Also, it seems as though I should be making ALOT more horsepower with the boost and mods I'm running....... anyone have any ideas?

I can't view those log files, but the easiest way to know for sure if you have a boost leak is to actually check. Have you done a boost leak test?

 

[holland]

No, I havnt done a boost leak test. Actually I'm not sure how to do one, do you have any suggestions?

Here are the DSMLink files again:

http://www.bobbyholland.com/first_run.dat
http://www.bobbyholland.com/middle_run.dat
http://www.bobbyholland.com/last_run.dat

thanx!

 

[alex99gst]

No, I havnt done a boost leak test. Actually I'm not sure how to do one, do you have any suggestions?

Here are the DSMLink files again:

http://www.bobbyholland.com/first_run.dat
http://www.bobbyholland.com/middle_run.dat
http://www.bobbyholland.com/last_run.dat

thanx!

Sorry about the confusion, I don't personally have dsmlink and so I don't have the software to view the files. Here is a helpful guide on how to make and use a boost leak tester. You can get away with using an air tank and filling the tank up with a bike pump, but I just sucked it up and purchased an air compressor. Some tips that they don't tell you in the vfaq is to use soapy water and spray them on all the connections so that the like is visible and audible, unplug the PCV valve and plug the hole on the intake manifold, and disconnect your MBC so that it won't leak air. This way you can track down just the leaks in you intercooler piping. A good way to check your PCV valve is to leave it connected and open the oil cap and listen for a whistling sound. If you can hear anything, then air is leaking through the PCV valve.

http://www.vfaq.com/mods/ICtester.html

 

[kenamond]

Do your boost leak test on a warmed up motor, or the ring blowby will be pretty bad.

Make a boost leak tester (several designs are out there). If you don't have an air compressor, go buy a portable air tank (I got an 11 gallon one for like $60), and fill it at your local gas station. My 11 gal tank filled to 100psi will last for like 10 boost leak tests or more, so you don't have to run back and forth to the gas station to refill - I don't recommend using a bike pump to fill your tank unless you're hankering for a sweaty workout.

You can seal off your MBC by taking the compressor (inlet) hose off the MBC, folding it in half, then zip-tie it that way so that it is kinked and sealed.

Also, pull your VC breather line off the passenger end of the VC.

Do your first boost leak test and pressurize up to 5psi above what boost you want to run (looks like 20psi would be good for you) and see what happens. If you built the boost leak tester with the gauge on the tester, you can do this yourself, but if you have to use your boost gauge, it'll help to get a friend/spouse/girlfriend to monitor the boost gauge while you pressurize the intake. You don't want to overpressurize!!

Once you've pressurized, check for air leaks out the VC breather nipple on the VC. If it's leaking a lot, it'll either be a bad PCV or low compression. Some is always gonna be leaking out the VC breather due to ring blowby (remember, do this on a warmed-up motor), but if it's a lot, check the PCV first. Unscrew it from the back-passenger side of the VC and repeat the test; it shouldn't leak out the small metal tube sticking out the end of the PCV. If the PCV is leaking, replace it with an OEM part (the Autozone, etc. parts won't work, trust me).

If the PCV is fine, but you're leaking a lot out the VC breather (on a warm motor), do a compression test.

Other common leaks in the intake tract are vac lines, couplers, IC (could have holes), BOV flange, TB gaskets, BISS, TB shaft seals, injector insulators, and maybe IM/head gasket. Big leaks can be found with your ears. Smaller leaks can be found with a spray bottle full of super-soapy water; spray before the test and look for bubbles.

Keep in mind that the 2g BOV might be limiting your boost. Cheapest solution is an evo3 BOV which is bolt-on. 1g BOV requires an adapter, because it connects to the UICP differently. If you're going to upgrade your UICP eventually, I'd recommend a 1g BOV + adapter.

Boost leaks can kill performance. Don't underestimate them.

Good luck!

EDIT: I like these two tester designs: #1 and #2.

 

[holland]

Wow, awesome info guys! I'ma go get one of those boost leak testers and see whatsup! if anyone else has Link and wants to check out my files and give me some hints on tuning, feel free.

 

[alex99gst]

Here is a link to the tuning section of the tech guide. There are plenty of helpful threads in here.

http://www.dsmtuners.com/forums/forumdisplay.php?&f=39

 

[holland]

Thanx for the helpful link! I bookmarked it.

Earlier today I felt what seemed to be a big boost leak. The car would get get to around 5k RPM at 14 psi and it would start sputtering and loosing power. Link said my fuel, timing and knock were all good.

This evening the boost cut out all together, if I'm just cruizin around the car runs fine. As soon as I mash the pedal the boost shoots up to 0 psi and stays there. I'd rev the motor to 5k before shifting and the boost gauge would always say 0.

I can only imagine that my BOV has died and locked at 0 psi because a leak would atleast let the turbo spool up.

Anyone have any ideas??

 

[alex99gst]

Thanx for the helpful link! I bookmarked it.

Earlier today I felt what seemed to be a big boost leak. The car would get get to around 5k RPM at 14 psi and it would start sputtering and loosing power. Link said my fuel, timing and knock were all good.

This evening the boost cut out all together, if I'm just cruizin around the car runs fine. As soon as I mash the pedal the boost shoots up to 0 psi and stays there. I'd rev the motor to 5k before shifting and the boost gauge would always say 0.

I can only imagine that my BOV has died and locked at 0 psi because a leak would atleast let the turbo spool up.

Anyone have any ideas??

Have you done the leak test yet? If not do that right away ASAP and you will figure out where/why its leaking.

 

[holland]

Ok, so this morning I figured since its daylight I'll take everyones advice and check all my hoses and connections for an obvious boost leak.

After popping my hood it became apparent whats happened. The wastegate bracket completly broke in two! Take a look at these pics and let me know whatcha all think!

Does anyone think this caused major damage to my turbo?

 

[zippyshoe]

Ok, so this morning I figured since its daylight I'll take everyones advice and check all my hoses and connections for an obvious boost leak.

After popping my hood it became apparent whats happened. The wastegate bracket completly broke in two! Take a look at these pics and let me know whatcha all think!

Does anyone think this caused major damage to my turbo?

This might explain why you are having trouble building boost - with the broken wastegate actuator bracket, the flapper door of your wastegate might not be held shut completely while you are trying to building boost. I don't see this causing damage to your turbo, it would just severely limit your boost.

EDIT: I see that you mentioned a 2G BOV - If you are using a factory 2G BOV, then this will begin to leak with your boost set much above stock boost level.

 

[holland]

I see that you mentioned a 2G BOV - If you are using a factory 2G BOV, then this will begin to leak with your boost set much above stock boost level.

I've heard the 2g BOV can hold up to 18psi... is this correct?

 

[zippyshoe]

I've heard the 2g BOV can hold up to 18psi... is this correct?

I believe a 2G BOV (stock BOV from a '95 to '99 DSM) would leak like a sieve at 18psi. A 1G BOV (stock BOV from a '90 to '94 DSM) would probably fare much better.

 

[alex99gst]

I believe a 2G BOV (stock BOV from a '95 to '99 DSM) would leak like a sieve at 18psi. A 1G BOV (stock BOV from a '90 to '94 DSM) would probably fare much better.

Just to add to this also, if you pick up a 1g BOV and then the Dejon Powerhouse Leak Stop Kit, the BOV will hold boost even better. You could get all of this for under $100 easy instead of spending $200+ on some expensive name brand BOV. Another plus is that it will perform like stock under 15psi, but any more and it will switch modes and be able to hold even more boost. I personally have the leak stop kit and love it.

http://dsm.dejonpowerhouse.com/

Follow this link if you want to find out more about it and click on "bov and misc tools."

 

[holland]

Sweet, that sounds like a damn good deal. How much boost are you running on your car with that BOV setup?

 

[kenamond]

FYI, if your WGA bracket was broken, your turbo was given the biggest break you can give it other than parking it (well, maybe a bit more of a workout). The WGA is a spring-loaded device that holds the wastegate closed until it is forced open by boost pressure. Since the bracket was broken, there was nothing holding the wastegate shut, so exhaust gas was being allowed to bypass the turbine wheel. So your turbo should be just groovy. Hope you can get a new bracket cheap.

Still do a boost leak test, though.

 

[alex99gst]

Sweet, that sounds like a damn good deal. How much boost are you running on your car with that BOV setup?

Just 20psi right now since I'm almost maxing out the evo injectors, but there is a definite sound differece from when I let off at 5psi and 20psi.

 

[holland]

Just 20psi right now since I'm almost maxing out the evo injectors, but there is a definite sound differece from when I let off at 5psi and 20psi.

Wow 20psi? sweeet, thats all about I'm shooting for... at least on pump gas.



Hey Ken, thanx for the encouraging words about the turbo. I had my friend weld the existing bracket back together. This weekend though my machinist buddy will be making me a nice new reinforced bracket!

 

[alex99gst]

Good deal man. Let us know how it works out.