2G Controlling boost

[my1st2genGSX]

so, my gsx has been down just got it back up and running. I've done most of the maintenance: timing belt, water pump, checked spark plugs etc. question is before it went down (due to the crank position sensor) my car wouldn't boost over 13lbs. It appears to have an adjustable internal wastegate...not sure if that is accurate. I do have a turboxs mbc, but I still can't get nothing over 13lbs. I want to make more with what I have already on the car...I haven't checked the injectors yet so I can't tell you what they are, they are black-which with enough reading on here I think they are stock 450s. And also when I'm at wot my afr is reading really rich. So in my mind is think more boost to equal out the afrs. What is your in put by chance? I have been also posting on the Turbo section as well.

 

[pauleyman]

No. That isn't right. Just because you turn the boost up that doesn't lean things out. It will when you can no longer flow more fuel. Approach that point and watch it blow up. All air is measured. Add more air. Ecu squirts fuel for whatever amount of air is measures. That's a layman's explanation basically. If it's more rich than it should be then you need to find out why. Leaks most likely given you state you can't make more than 13psi.

 

[jakk220]

I agree. It sound like you have a big boost leak.

 

[doubleclutch]

First off, I like the color.

Second, what are you tuning with?

Third, you really wont be able to push much more than 15psi without an injector upgrade (need tuning solution) and at least a fuel pump rewire. Ideally you would upgrade the pump with the injectors.

Fourth: if you can't boost over 13psi you either have stuff hooked up wrong or a massive boost leak.

 

[my1st2genGSX]

Thanks.

The PO has a half installed Greddy E manage - Blue. I will be finishing the wiring to get it fully tune-able.

I am looking for some used or decently priced 750cc and will be investing in a Walbro 255lph. I'm wanting to make it a decently reliable weekend driver.

I have the boost source going through the mbc then ending at the waste gate. I have the BOV going directly to the backside of the throttle body (I believe), I will have to look at my pictures again. Since I bought the car I've only put on about 3k in a year. And when I did my first blt it had a leak at the j pipe and one of the fmic clamps, and I fixed those.

 

[doubleclutch]

Not familiar with the greddy bits, but from what I just read about it, get rid of it. It isn't nearly as capable as other similarly priced options and you won't have to ahck your wiring harness to bits. Invest in ECM link where you can do cool stuff like TPS adjustment, SD, Launch control and actually tune things like timing, deadtimes, target AFRs, etc. Not to mention take a logs you can use to tune with.

A diagram of your boost/wastegate lines might help. Another BLT would be good too.

You can use this fuel calculator to get an idea of what size injectors you want. A 255 needs a adjustable FPR and if you don't intend to go to e85 or larger injectors a 190 would do fine and you wouldn't need an AFPR.

 

[my1st2genGSX]

I haven't seen any bad review, just that no body uses it. I have not looked to see if I have a eprom or not yet, haven't had a chance to do anything.

Hopefully this picture shows everything clear enough.

On another post that I am following is the "Turbo" one. I have seen at least to do 750cc and 255lph along with a afpr. I don't have the fund to do what I want to do. So, I just want to have a fun weekend driver or a track night and not look dumb.

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[doubleclutch]

BOV line is right. I cant really see anything to do with the MBC or wastegate lines.

There is nothing wrong with the greddy system, but ECMLink is so much more capable.

What boost are you looking to run? if money is tight, go and get a 190 Walboro skip the afpr and save about 200$. For 750's you will be fine. Make sure to buy the STM rewire kit though ($30).

 

[my1st2genGSX]

That is an older picture before I installed the mbc. But I have a nipple in the j pipe welded in connected to the inlet and then the outlet ran to the waste gate vacuum line.

I would like to use what I have now till I have problems. But I have wanted to go to something simpler, and I don't think the greddy can do launch control.

I want to be in the range of 15-20, nothing too crazy to where I break stuff. 30lbs would be awesome, but I'm pretty sure I cant support that with what I have right now.

 

[doubleclutch]

i have a 190 with a rewire, no afpr and 780cc injectors and i can run 22 lbs no problem.

 

[my1st2genGSX]

that's what I would like to get to..

 

[my1st2genGSX]

I know its not the best picture, there is one of my mbc.

 

[doubleclutch]

MBC looks right. Is your waste gate stuck open?

 

[boostdawd]

Your mbc is not hooked up right. The line coming off the j pipe needs to go to the bottom. The side port will go to the wastegate.

 

[doubleclutch]

Your mbc is not hooked up right. The line coming off the j pipe needs to go to the bottom. The side port will go to the wastegate.

I love that drawing. Good call on the backwards MBC.

 

[boostdawd]

Yea courtesy of Google . Serves it's purpose though

 

[my1st2genGSX]

The instructions are wrong then...I will double check....thanks for the input.

 

[Vegas Smith]

Hmm, starting to think my hallman is wrong too....I could never get my EBC to work so I switched to a hallman I had sitting around and I can't get that damn thing to work either. Maybe Hallman has the wrong directions....

 

[boostdawd]

Pressure from the bottom pushes on the ball and spring. Once it pushes far enough the ball will pass by the side port where pressure will then travel to the wastegate.

 

[my1st2genGSX]

I will be trying this on my next day off and installing a smaller serpentine belt....

 

[Vegas Smith]

WTH, checked my boost controller and it is setup properly, yet it's only getting 10psi. Always something.....

 

[Bleakley]

WTH, checked my boost controller and it is setup properly, yet it's only getting 10psi. Always something.....

There's only so many things that will cause a low boost condition.
But man have I just about had them all and I'm only 24. Lol.
Boost leak tester is an essential tool once you're boosted. From an eBay pressure fogger to a home depot boost leak tester, get something. If you go with the latter, you'll need a spray bottle with soap and water.
Leaking couplers is very common, as is blown gaskets. I've had throttle body gaskets go AND a blown J-pipe gasket. Also check the intake manifold gaskets.

A boost leak tester will not show this but double check your head-manifold gasket AND your turbo-manifold gasket. I haven't yet seen a common problem with a head-manifold gasket, but with all the heat it IS possible for nuts to loosen. Just double check that they are torqued to spec.

The number one identifier of a blown exhaust gasket is the build up of carbon / soot around the area or on a part across from the side that's blown. A blown turbo to manifold gasket can easily be identified in this manner. Again, double check the bolts are properly torqued.

I ALWAYS BENCH TEST MY WASTEGATE! Hook up your air compressor and see at what psi that SOB starts opening and at what psi it is wide open at... Come up with an average and jot it down. Once it's back on the car, expect a couple psi lower than what your bench test was at because exhaust gasses will be pushing on it AS WELL as boost pressure.
Once it IS back on the car, establish your baseline by hooking the wastegate DIRECTLY to the boost source. Do NOT hook up your boost controller yet. Again, see what your baseline wastegate psi is.
I always say for best performance do NOT go higher than 1.5 times wastegate pressure. If you're looking to control boost higher than 1.5 times what your wastegate holds by itself, time to upgrade the spring. Start the process over..

After establishing your baseline NOW you can start adding on the boost controllers.
Personally, I go out around the block with the boost source disconnected completely. I keep an eye on the wideband and boost gauge and make a couple pulls to ensure I can get some serious boost. This is just kind of an extra step to help validate everything done up to this point.

Anyways, back to hooking up the boost controller. Now you should be able to hook up your boost controller and dial it in accordingly. If you have an issue, double / triple check the lines themselves for pin holes, cracks, etc. Replace as necessary. At this point you should have no problems dialing in your boost. Double check the plumbing is correct. If you can't build boost higher than your wastegate spring pressure, then maybe the boost controller is at fault OR you plumbed it incorrectly.
In either case BENCH TEST THAT SUCKER TOO!! If it's a MBC hook an air compressor up to it. If it's an EBC test the solenoid with 12v power...

EDIT: If you think your turbo is at fault (don't have experience in this area, but I HAVE researched this) disconnect your j-pipe, cut up a piece of steel and bolt that to the turbo outlet WITH your gasket. BLT and see what the result is. You should be able to build some SERIOUS pressure with ZERO leakage... If you have a coupler that clamps the the outlet, find an end cap to clamp in the coupler...

 

[my1st2genGSX]

Here is the instructions that came with it.

 

[Bleakley]

Here is the instructions that came with it.

Now that I almost fully understand how this thing works:

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You do have it hooked up correctly.

 

[Vegas Smith]

Here is the instructions that came with it.

Oh wow, thanks man. I just realized that I do have an XS controller and their design is different. Interesting.