diverter valves
#1
diverter valves
My car boosts up to 1.0 bar and as the rpm rise the boost drops off towards .9 or .8. Sometime the car doesn't get to 1.0. I am trying to figure out if this maybe due to the Bosch diverter valves which were changed back in 03. They are now going on 7 years. Also when I start the car from cold, I hear a "skill saw" type sound which seems to go away after a little while. Is that the famous "honking sound" which means a tear in the diaphragm? I realize swapping diverter valves maybe the solution to this boost bleeding, but I also like to diagnostic things properly instead of merely throwing parts at the car and see what works or not. Car is a 2001 with a RUF kit on. Thanks.
#2
What do you mean by "RUF kit" ? - Engine or Body upgrades? - and what other mods are you running? A quality set of billet DV's should accompany any ECU tune, you'll keep replacing the plastic/rubber Bosch units if you stick with them.
#4
Yes Ruf engine kit. Exhaust turbos and ecu sent back to Germany. Ruf intake manifold, and bigger diameter hoses from the intake manifold tot he compressor side of the turbos. Will aftermarket diverter valves keep the boost steady at 1 bar, or is it something that needs to be handled via the wastegates? I am trying to figure out how to hold the boost level steady all the way to red line, instead of it tapering off. On my previous car, Evo 9, this was accomplished by "using a calibrated boost hose assembly which allowed the tuner to modify the wastegate ecu maps. " And I am not sure that the diverter valves are the culprit in my case. I have been wrong before though. Excellent on the skill saw noise. I'll leave that one alone. Thanks.
#6
If your car never maintained 1 bar up to redline, that is probably because the tune has backed off the boost at higher rpm. If the fueling hasn't been upgraded, you may be running out of fuel, and increasing the boost is just going to push more air through and make the car run lean. That can lead to detonation problems.
I'd suggest hooking up a Durametric and doing a few runs at WOT from 2000 rpm to redline to see what your engine is doing.
Jon
#7
I have done the boost leaks checks from both the maf side and the compressor side of the turbos. In both instances I found boost leaks. One was the F hose which had a slit and both junctions at the intercoolers needed cleaning and proper fitting. Could not find a leak at the DVs. The leaks are now gone. Since I have owned the car, I have never seen it do anything but occasionally hit 1.0 Bar and then taper down towards .9 or .8 bar. This is what leads me to believe that may be the way the tune is set up. I did test drive a car while I was shopping which held boost at 1.2 steady to red line. What I am really trying to do is to make sure, the car is operating as it was intended by Ruf when tuned back in 2002. I started logging in recently. I am looking at rpm, intake air temperature Ignition angle, actual throttle value, boost pressure of sensor and set point boost pressure. I should be looking for a trend that shows if the boost actually goes down as the rpm rise. Is that right? Thanks.
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#9
I don't know what Ruf did to the turbos back at the workshop in Germany. I am going to try and figure out how to test the wastegates and see at which psi they trigger to open. Ruf may also have changed the compressor wheel on the turbos? We are talking 2001/2002 technology. Things have progressed quiet a bit since. AMS billet wheels on K16s etc... I pulled the id #s on the turbo, passenger side.
996 123 013 75
EF 504 1332 88052
5316 990 6726
Is this a stock KKK ID for a 2001 turbo?
996 123 013 75
EF 504 1332 88052
5316 990 6726
Is this a stock KKK ID for a 2001 turbo?
#13
Is there a standardized procedure for checking proper boost pattern and level? By this, I mean, is there a specific gear I should be doing the WOT runs? At what RPM should I be seeing X amount of boost? Haven't had my Turbo for long and would like to test and see if it is boosting normally.
#15
I have done the boost leaks checks from both the maf side and the compressor side of the turbos. In both instances I found boost leaks. One was the F hose which had a slit and both junctions at the intercoolers needed cleaning and proper fitting. Could not find a leak at the DVs.
The leaks are now gone. Since I have owned the car, I have never seen it do anything but occasionally hit 1.0 Bar and then taper down towards .9 or .8 bar. This is what leads me to believe that may be the way the tune is set up. I did test drive a car while I was shopping which held boost at 1.2 steady to red line. What I am really trying to do is to make sure, the car is operating as it was intended by Ruf when tuned back in 2002. I started logging in recently. I am looking at rpm, intake air temperature Ignition angle, actual throttle value, boost pressure of sensor and set point boost pressure. I should be looking for a trend that shows if the boost actually goes down as the rpm rise. Is that right? Thanks.
I prefer to datalog in 4th gear, since you don't get as much data in 3rd gear, especially if you collect a lot of different quantities. Top speed is higher though, so you have to have someplace to do it.
Jon