Turbo Boost question
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Joined: Mar 2002
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From: York, PA
Turbo Boost question ok I'm noticing some things with the boost gauge.
Idle, it's about 20 inHg. This is in park. When I press down on the gas to around 1400rpm it dips imediately down to around 22inHg and slowly comes back up as I press the pedal more.
Question is, on a turbo car, is it true that I wont see any boost unless the car is under load and at WOT?
Also, I'm having problems with the MAP sensor only returning a value of 3 in autotap. I've tried another sensor and it returned 3 as well. Of course this throws code P0107. MAP value doesn't change at all and returns 3 even when the car is off. Do you think that it's not plugged in tightly or perhaps the knock sensor and map plugs are switched? I had the intake off earlier. I guess the only way to find out is to test but I figure I'd ask here first.
Idle, it's about 20 inHg. This is in park. When I press down on the gas to around 1400rpm it dips imediately down to around 22inHg and slowly comes back up as I press the pedal more.
Question is, on a turbo car, is it true that I wont see any boost unless the car is under load and at WOT?
Also, I'm having problems with the MAP sensor only returning a value of 3 in autotap. I've tried another sensor and it returned 3 as well. Of course this throws code P0107. MAP value doesn't change at all and returns 3 even when the car is off. Do you think that it's not plugged in tightly or perhaps the knock sensor and map plugs are switched? I had the intake off earlier. I guess the only way to find out is to test but I figure I'd ask here first.
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From: Jersey boy
Re: Turbo Boost question it all depends on how much exhaust you move. when the car is under load it requires more power to move so you need to burn more air/fuel which = more exhaust. when your at wot your trying to burn as much air/fuel as you can so they should result in boost as well
Re: Turbo Boost question
So basically I shouldn't see any boost on this kit when I'm sitting in park revving, right? wastegate spring is set for 6lbs.
Turbos are load sensitive.... and the QMP kit seems to amplify the turbo's noise a little.... so listen for it as you are cruising and messing with the throttle... the speed doesn't matter... whenever you try to accelerate you should hear the turbo spool up... this is due to the increased load -> more cylinder pressure/heat.
and the vacuum will drop a little upon getting on the gas because your intake track is now more restrictive due to the plumbing, intercooler and turbo... so that's normal.
How is it running overall?
What about Mike's (Bushman)?
I saw you in the burnout contest at MIR... good stuff.. you gotta enter it now with the added hair dryer
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From: York, PA
Re: Turbo Boost question Thanks for the info. I need to get the PCM tweaked. Right now, whenever I try to drive it it just dumps tons of fuel and fouls out the plugs in no time flat.
Here's the things I've done since the morning we finished and I fouled out 3 sets of plugs trying to make it back to the garage.
I've got a boost ref. regulator set for 60ish with no ref, and 50 with ref.
In the PCM I set the MAF table back to stock, set the PE vs RPM back to stock, set the IFR table to 6.8 all the way across.
The fuel setup is in-tank walbro 340 with 3/8" hose going to an 6an to 8an bulkhead to 8an braided line to aeromotive fuel filter to 8an which goes to the pass. side ls1speed 3/8" rail. That goes to a 8an cross over to the other rail which goes out to 6an which then goes to the regulator. The return 6an goes right back to the tank. No Evap, evap codes turned off in PCM. Using Evap hose nipple on driver-side of intake manifold for vac/boost ref for BOV and Regulator.
I raised my idle rpm to 700 as well because if I hit the pedal and let off real quick (goose it) in park the car stalls out. Raising the idle RPM seems to help this some.
What do you think? Is that too much fuel for this car? I figure I could decrease fuel with the PCM but it seems to want to dump fuel no matter what. Also in Autotap it reads 2-3 Inj pulse width for both rails. I would have expected it to read 6.8. At one point it does read 7.x and the AFR goes to 11.9 in autotap (if I recall the car shimmied) rpm were about 5000. This was all in park of course. I'm going to try and drive it around the parking lot and get it under load and on the autotap so you guys can see.
Here's the things I've done since the morning we finished and I fouled out 3 sets of plugs trying to make it back to the garage.
I've got a boost ref. regulator set for 60ish with no ref, and 50 with ref.
In the PCM I set the MAF table back to stock, set the PE vs RPM back to stock, set the IFR table to 6.8 all the way across.
The fuel setup is in-tank walbro 340 with 3/8" hose going to an 6an to 8an bulkhead to 8an braided line to aeromotive fuel filter to 8an which goes to the pass. side ls1speed 3/8" rail. That goes to a 8an cross over to the other rail which goes out to 6an which then goes to the regulator. The return 6an goes right back to the tank. No Evap, evap codes turned off in PCM. Using Evap hose nipple on driver-side of intake manifold for vac/boost ref for BOV and Regulator.
I raised my idle rpm to 700 as well because if I hit the pedal and let off real quick (goose it) in park the car stalls out. Raising the idle RPM seems to help this some.
What do you think? Is that too much fuel for this car? I figure I could decrease fuel with the PCM but it seems to want to dump fuel no matter what. Also in Autotap it reads 2-3 Inj pulse width for both rails. I would have expected it to read 6.8. At one point it does read 7.x and the AFR goes to 11.9 in autotap (if I recall the car shimmied) rpm were about 5000. This was all in park of course. I'm going to try and drive it around the parking lot and get it under load and on the autotap so you guys can see.
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From: Germantown, MD
Re: Turbo Boost question Rob, I'm not a turbo pro by any stretch. But I know I can't build more than a pound at idle. There's has to be load to close the surge and create Manifold pressure. Are BOVs normally open and only close under load like a surge valve?
As for you fouling plugs, I think there is an issue with the incoming air. At idle I could barely feel any air being pushed by the turbo. Now maybe thats normal for a turbo car. I know the D1 pushes a LOT more air at idle. I suspect a leak somewhere or perhaps your wastegate is moving exhaust around your turbo. Not sure. But that would be my guess why you are fouling out your plugs.
Mike
p.s. Jrod, I haven't had a chance to fix my issue cause I just enrolled in school and money has been tight. But soon I'll probably upgrade my lines, fuel filter, and plumb into the tank. That will for sure tell me if it's the line or the pump.
As for you fouling plugs, I think there is an issue with the incoming air. At idle I could barely feel any air being pushed by the turbo. Now maybe thats normal for a turbo car. I know the D1 pushes a LOT more air at idle. I suspect a leak somewhere or perhaps your wastegate is moving exhaust around your turbo. Not sure. But that would be my guess why you are fouling out your plugs.
Mike
p.s. Jrod, I haven't had a chance to fix my issue cause I just enrolled in school and money has been tight. But soon I'll probably upgrade my lines, fuel filter, and plumb into the tank. That will for sure tell me if it's the line or the pump.
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From: York, PA
Re: Turbo Boost question
Rob, I'm not a turbo pro by any stretch. But I know I can't build more than a pound at idle. There's has to be load to close the surge and create Manifold pressure. Are BOVs normally open and only close under load like a surge valve?
As for you fouling plugs, I think there is an issue with the incoming air. At idle I could barely feel any air being pushed by the turbo. Now maybe thats normal for a turbo car. I know the D1 pushes a LOT more air at idle. I suspect a leak somewhere or perhaps your wastegate is moving exhaust around your turbo. Not sure. But that would be my guess why you are fouling out your plugs.
i nearly blew my load when i heard it blow off today. hehehe. I can't tell a percieved difference in torque because I can't hook at all with the nittos on. lol. I scared the **** out of people at the walmart blowing off etc. Definately turning heads. The thing still runs pig rich, in reverse I choke on black smoke, pulled a plug and it looked rich, but not fouled. One thing that is still a problem is the steering clearance. I'm gonna try to shim it up tomorrow. Gotta fix an oil leak on the feed line as well. I'm going to attempt to drive it home tomorrow night after beer-n-mod night!
Also, I multiplied my PE vs RPM by 90 to remove 10% fuel. Not sure how else to remove fuel without increasing the injector pulse width into the 7.x It's at 6.81 right now.
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From: York, PA
Re: Turbo Boost question regarding the MAP sensor I was pushing on it and it feels secure in the back. It's really hard to tell because it's not visible and I can barely get my arm back there but it's in there. I tried unplugging the plug and it still returned a value of 3. 
So now I'm kinda confused. Is it autotap not returning a value or is it the PCM or MAP or bahhhhh.
So now I'm kinda confused. Is it autotap not returning a value or is it the PCM or MAP or bahhhhh. 