Lean condition after boost run, but normal after reset.

[CPR_MCOCHRAN]

I was curious if any of you guys ever had a issue similar to mine. I'm still getting the kinks out of my turbo install and i thought i would post this one because its got me scratching my head. The dyno tuner left me pretty rich to be on the safe side. Normally at idle it running between 10.0 and 11, then under throttle and boost it runs at about 12.5 to 13. Everything was going good until i made a interstate run and hit the boost a couple times. During the runs it was fine running the normal 12.5 to 13, then after letting it decelarate and getting off on a exit ramp, I down shifted and came to a stop. I watched it start leaning out as i was coming to a stop and it went all the way up to 16 when i got stopped and it was wanting to cut off. Giving it a little throttle it would bounce around 14 until i was coming to a stop. I switched off the ignition, turned it back on and it was back to the normal rich 10 to 11 again. It ran fine again until the next interstate run to see if i could reproduce the issue and it did it right on queue. A quick reset of the ignition and it was back to rich side and ran fine all the way home. I have no clues on this one. I do have s2000 36lb injectors on it, which i know is over kill for the velocity stage 1, but i figured that would keep it rich if nothing else. Fuel pressure at idle is only about 20 lbs, but as soon as you touch the throttle it jumps to 40 and then pegs it at 120 under boost. Any ideas?

 

[turbobusa2000]

Stop driving that bike bro. Your gonna fry the motor. You should be running 11.5-12.0 at any rpm above 4.5k. Your running pretty lean and it won't be long before it goes boom boom if you don't do something about it.

 

[atticdog]

that sounds backwards you want 13 at idle and in the 11's underboost

 

[CPR_MCOCHRAN]

Yeah, thats what i was thinking. One reason i put that o2 wideband on it. Sounds like maybe i need a better fuel map?

 

[turbobusa2000]

Yeah, thats what i was thinking. One reason i put that o2 wideband on it. Sounds like maybe i need a better fuel map?

Who tuned this bike? Your, fuel pressure is WAY to high under boost also. Thats high enough to lock the injectors if I'm not mistaken. Not good. Get it to a tuner who knows how to tune a turbo bike or you will be paying for it.

Trust me you don't want this.

 

[CPR_MCOCHRAN]

Lee over at Lee's Performance. He came pretty highly recommended and runs trubo's on his land speed bike and they were doing other turbo stuff while i was there. He had it on the dyno about 4 hours changing maps, changing fuel pressures, timming, etc. Nothing we changed really made much difference during the session. Makes me lean toward those injectors are just too big for my build. I'm wondering if i should just put the stock injectors back in and take it back for another session. The dual boost setup never really changed anything either. We got it to load two maps, but never was able to see much of difference on the boost gauge. Is there any other tuners you would reccomend in the NC area?

 

[turbobusa2000]

I've heard of Lee and I'm sure he is far more experience than you and I. I would call him and tell him that your running 12.5-13, see if he can help you out.

Are you peaking at a gauge while your running or looking at datalogging after you run? M

 

[CPR_MCOCHRAN]

just peaking as i'm going, it seems to bounce around quite a bit. I have a autometer 3378 in one of the 3 gauge brackets mounted to the triple tree. it draws my attention when it goes from green to yellow or red. i've only seen the red when it was under 4k which makes me feel a little better. I just feel something isn't setup right. I've heard to many folks say they can run at two different boost pressures and fuel maps successfully. I have a PCIII, hub, MPS switch to switch between maps off a toggle, the toggle also supplies the 12 V to the humphreys selonoid which is in line with the manual boost controller, then to waste gate. From all the diagrams i've seen i have that part installed right and we verified the maps change succesfully, i'm just not sure that selonid is doing its job.

 

[CPR_MCOCHRAN]

Here's a pic of the selonoid.

 

[CPR_MCOCHRAN]

and then the manual one...

 

[turbobusa2000]

Yeah, thats the down side to the stage one systems. That system has an internal gate correct? If it does, I would ditch the boost controller, those gates aren't capable that additional exhaust flow. Heck they usually boost creep at the factory spring ratings. Maybe thats part of the problem.

 

[CPR_MCOCHRAN]

PCIII, hub and mps switch.

 

[CPR_MCOCHRAN]

Yeah, thats what Lee said. Unless i run a external gate the boost controller is no good to me. It was part of the used kit i bought. I guess thats what i get for getting a used kit.

 

[POWERHOUSE]

Matt:

Your injectors are fine. Your FMU is not fine. First of all, you should be idling at 13.2 . . . steady-state and cruise areas should also be around that and certainly no higher than 13.5. When you are on boost, the your A/F should be between 11.5-11.8. Your fuel system is not set up right. Lee has a great reputation for normally aspirated and built motors, but obviously did not set your bike up right.

One of the first things you need is a recalibration kit for your FMU. A recalibration kit will modify your fuel pressure regulator from a 5:1 down to a 3:1. This will keep your fuel pressure while on boost to around 80 pounds, and will prevent your pressure from spiking early. When it comes to FMUs, it is all about "rate of gain" and the highest pressure you are seeing while on boost.

Again, your 36 pound injectors are fine . . . we have gone as high as 65 pound injectors with modified FMUs with no issues at all. Get your fuel system straightened out, and get that thing mapped by someone who knows how to map street turbos!

 

[POWERHOUSE]

Oh yeah - you can run a boost controller on an internally-gated turbo, we do it all the time . . .

 

[jdsbusa]

Is the 20lbs of pressure at idle normal for larger injectors? 43 is normal for oem injectors but 20 sounds low.

 

[GPW]

Lee knows what he is doing, if he can't figure it out, its got be mechanical.

 

[CPR_MCOCHRAN]

Yeah, i think Frank is probably on to something with the FMU. My only concern is why it would be rich at 0% TP and then go lean at 0% TP after a boost run and immediatedly go back after rich after just a quick reset. Makes me wonder if something in the PCIII or ECU is doing that part of it.

 

[POWERHOUSE]

Lee knows what he is doing, if he can't figure it out, its got be mechanical.

If that is the way that the bike rolled out of the shop, I disagree. Lee knows what he is doing with GSXR1000s, thats for sure! But somebody dropped the ball on this one - it is not mechanical.

Those injectors should be idling with 30 pounds of fuel pressure, not 20!

 

[boosted 2]

Try Rodney Williford in Rougemont NC. This cat knows turbos.