MBC Install a success another problem

[dale187]

Well the TurboXS MBC works great! holds pressure and raises boost as i turn knob.. Well i kept pumping boost up and noticing there wasnt a difference in power. I got all the way up to 16, went to make a 2nd gear pull and my knocksum gauge which is my stock boost gauge and each division on the gauge counts as 7counts. I got 7 counts of knock on the 2nd gear pull. But i also noticed no difference in power. Whats going on here anyone know? After that of course i didnt make any more pulls i took the car home. My set up is in my profile for mods. Any suggestions?

Also car was not bogging or anygthing felt just like it did at 9psi....

 

[92awddsm]

Well, if it is knocking, it is pulling timing. That alone will offset any power you made with increasing boost. Have you done a boost leak test yet?

 

[dale187]

I wouldnt feel any power at all? And no i have not done a boost leak test yet.

So knock has to do with timing? If the timing was out wouldnt the car idle, run weird?

 

[marq95gst]

If you are getting that much knock, turn the BC knob down a bit. Do a boost leak test. If you are running a stock throttle body chances are one of your leaks is there. Check all of your couplers too. What is your vacuum reading at idle?

 

[dale187]

20in. But for some reason my needle is sticking sometimes so it reads like 15-16 but if i press the gas to unstick it it will come back down to 20... I will try the boost leak test but i honestly dont understand how it could not show power going to the car. I turned the boost controller all the way down so that it's at stock 9psi now. Explain this boost leak and knock how they can relate and mess up performance that bad.

 

[knochgoon24]

Bascially, the boost leak is leaking out air that has already been metered by the MAF. The car injects the appropriate amount of fuel for that amount of air. Since some of that air has leaked out, you now run rich. You can have a rich knock.

Also, boost leaks make the turbo work harder to provide that extra air, to hold a constant boost even though air is leaking out. That extra work heats up the air and you can get knock that way too.
Think of it like trying to inflate a balloon with pin holes all through it. You might eventually get it inflated, but it's going to take a lot more work.

Now, when your ECU sees this knock, it pulls timing to prevent damage to the motor, a type of "safe-mode" if you will. The ECU will continue to pull timing until the knock is under control. Pulled timing robs you of power, and power you would get from turning up the boost.

 

[dale187]

Holy crap you should be a teacher.. So first thing is boost leak test? Where do i go from there

 

[Dert]

how come everybody seems to have 9 psi as stock? I havnt done anything to my 97 gst except greddy type rs bov, and apexi cold air intake and aftermarket gauges. My boost was constantly at 12psi until I did the bcs resrictor mod which then put it up to 15psi. Did I get one of the only 97 gs-t's that puts out more than 9psi?...and ya..start with boost leak test

 

[dale187]

I might just leave it the way it is until i get my front mount which i should have in the next week.. The setup for the IC piping right now is garbage anyways.

 

[92awddsm]

I might just leave it the way it is until i get my front mount which i should have in the next week.. The setup for the IC piping right now is garbage anyways.

Spend the next week reading and learning about your car. You should have known these things long before you ever started modding or turning up the boost.

 

[dale187]

I'm going to look up different stuff. I understand alot of the stuff i just dont understand how alot of people can turn their boost up on cars that are worse than mine and see a performance difference. I understand boost leaks and stuff like that just.. I dont know. But thanks for the help if anyone has any other ideas please post.. I'm going to perform a boost leak test for the heck of it.

 

[92awddsm]

I'm going to look up different stuff. I understand alot of the stuff i just dont understand how alot of people can turn their boost up on cars that are worse than mine and see a performance difference. I understand boost leaks and stuff like that just.. I dont know. But thanks for the help if anyone has any other ideas please post.. I'm going to perform a boost leak test for the heck of it.

What is the maintenance history on the car? Replaced plugs, wires, fuel filter, etc lately?

 

[knochgoon24]

What is the maintenance history on the car? Replaced plugs, wires, fuel filter, etc lately?

I had bad plugs that caused a stumbling feeling. They are definately something to check, especially as you turn the boost up. I installed some plugs in August, gapped to .028". By this February, they had spread to .042" and were causing problems.

You really need to do a boost leak test to see what's leaking. If it's your throttle body seals (shaft seals, BISS O-ring, gaskets) or injector seals then a new FMIC and piping won't fix any of your problems.

Build and use a boost leak tester now. It will still be the same size that you need even after the FMIC, since it attaches to the the compressor inlet.

 

[dale187]

Ok, yea im going to do a boost leak test. Can someone link me to where i can see what i need to make one and what to check for for leaks. Also i did routine tune up not too long ago. But i am still running BPR6ES at .028 gap.. Should i be running a different plug and gap setting with higher boost?

 

[dale187]

I found out how to make boost leak tester any suggestions on plugs and gaps?

 

[92awddsm]

I found out how to make boost leak tester any suggestions on plugs and gaps?

BPR6es gapped @ .028 for boost under 17-18psi. If you run over 18psi normally, bpr7es gapped@ .028

 

[dale187]

I appreciate the advice. I'm having a hard time finding a radiatior hose end with a 2.5 inch diameter to run the boost leak test so for the time being i got my boost set at lowest point

 

[joey17]

i just made a boost leak tester it can be a little less then 2 1/2 inch ID mine was. it was pretty snug but worked and i have a stock talon tsi with knn filter and im at 14 psi so no ## not the only one but i did to the same mod you did.

 

[debbie]

2.5" 64mm Silicone Hose turbo TD06 intercooler focus T3:eBay Motors (item 280343866178 end time May-16-09 19:33:39 PDT)

 

[boostin3030]

I would suggest buying a boost guage. I wouldnt trust that stock POS in the cluster.

 

[boostin3030]

Boostpro.net has the best boost leak testers I have seen. They are inexpensive too.

 

[92awddsm]

I appreciate the advice. I'm having a hard time finding a radiatior hose end with a 2.5 inch diameter to run the boost leak test so for the time being i got my boost set at lowest point

Go to home depot/Lowes/almost any hardware store and get a cheap fernco coupler. They can be had in an assortment of sizes and are readily avaiable. They dont work good for ic pipe couplers but they work just fine for boost leak testers.