No one can diag my turbo issue,please help!!!
11-13-2007, 07:03 PM
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No one can diag my turbo issue,please help!!! Okay here i am again. One month later,alot of money later and still the same problem. Im running the old qmp log single turbo setup. With a 5lb spring everything is great. I put the 14lb spring in and as soon as it hits 10lbs it instantly drops to 0 and strats pulling vacum at wot.
I had it on they dyno for all testing. We took the IC out of loop for a run just to test and it held 14lbs like a champ. So i paid alot of money for a nice big fmic. Get it on the dyno and same exact thing.
Im a technician and have done an insane amount of testing. Ive rulled out the bov and waste gate by rebuilding them and actually putting my hands about the bov on the dyno. Ive felt to see if the wastegate valve is opening also, its not. Ive pressure tested the entire system many times. It does not leak at all. Ive tried a million different tuning ideas, nothing.
You go wot it hits 10lbs really fast and feel insanly fast, then instantly drops to 0psi and starts to pull vacum.
Plese help, i have no more ideas.
Alex
I had it on they dyno for all testing. We took the IC out of loop for a run just to test and it held 14lbs like a champ. So i paid alot of money for a nice big fmic. Get it on the dyno and same exact thing.
Im a technician and have done an insane amount of testing. Ive rulled out the bov and waste gate by rebuilding them and actually putting my hands about the bov on the dyno. Ive felt to see if the wastegate valve is opening also, its not. Ive pressure tested the entire system many times. It does not leak at all. Ive tried a million different tuning ideas, nothing.
You go wot it hits 10lbs really fast and feel insanly fast, then instantly drops to 0psi and starts to pull vacum.
Plese help, i have no more ideas.
Alex
11-13-2007, 07:43 PM
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the exhuast is not block,im running a cutout and its flowing fine. I held a rod in the top of the wastegate on the dyno so i could feel if the valve was opening and it wasnt. I had my hand over the bov on the dyno and it did not open when the problem happened.
Yes all i did was bypass the ic and it worked perfect for 3 dyno pulls,just really hot air.
Yes all i did was bypass the ic and it worked perfect for 3 dyno pulls,just really hot air.
11-13-2007, 07:49 PM
#7
sounds like you need to replace the intercooler or at least cut it open and see where the rag is stuck inside it.
qmp kits tend to drop boost reguardless when you turn them up.
move the wastegate to the cross over and dump it to atmosphere. that is the best you can do.
qmp kits tend to drop boost reguardless when you turn them up.
move the wastegate to the cross over and dump it to atmosphere. that is the best you can do.
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11-13-2007, 07:54 PM
#8
Are you running an air filter??? If so this was happening to a customer of ours with a S88. The filter would collapse under boost and boost would instantly dissappear.
11-13-2007, 08:00 PM
#9
If you bypassed the intercooler and it worked,then you have your answere!The intercooler probably has a crack n it. When it build's boost and get's to a certain point then the crack in the intercooler open's up and bleed's off your pressurized air!
Do a pressure check on your intercooler and see!
Do a pressure check on your intercooler and see!
11-14-2007, 07:17 AM
#12
if there was a boost leak, the engine should reach 0psi and never pull a vacuum at full throttle, as once in full throttle the engine should read 0psi regardless and hopefully on a boosted engine more then 0psi, something funky is happening, like Dr. turbo said about the filter, have you checked that?
11-14-2007, 08:24 AM
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The intercooler is brand new now. Everything has been tested to 40psi and no leaks. Ive ran it with no air filter with the same results. This seems impossible,but it happens everytime like someone is fliping a switch.
11-14-2007, 08:26 AM
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what would moving the wastegate do? Is 14lbs to much to ask from this kit.
If im on the highway in 4th at 70mph,i give it 1/4 throttle it builds 14lbs and i can hold it there all day if i dont go past 1/4. Once i give it more gas it instantly drops. So its building the boost no problem. It just dissapears.
If im on the highway in 4th at 70mph,i give it 1/4 throttle it builds 14lbs and i can hold it there all day if i dont go past 1/4. Once i give it more gas it instantly drops. So its building the boost no problem. It just dissapears.
11-14-2007, 10:02 AM
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11-14-2007, 11:57 AM
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where are you taking your reference for the WG? From the intake or turbo? If its from the turbo and you have a crappy intercooler it will have a pressure drop. Also I'd measure the backpressure, if its really bad it can force the gate open.
11-14-2007, 12:11 PM
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Its referanced off the turbo. Ive even tried taking the referance off all togeter just as a test to see if it would go to max boost. It does the exact same thing.
How can i mease the backpressure?
How can i mease the backpressure?