Help needed with Turbo Set up
09-21-2009, 05:34 PM
#1
Registered
Thread Starter
Help needed with Turbo Set up
A local recently decided to go with a turbo set up. He purchased a brand new Greddy Turbo Kit and immediately upgraded it with the BNR upgrade. He upgraded his primaries to 650cc and used the 390's and and replaced two secondaries with them. He also upgraded his coils with BHR coils and I'm not too sure what brand fuel pump he upgraded to. He had all of this installed at a very reputable shop in Houston, and drove to Dallas for Steve Kan to tune with the Accessport. During the tuning session his car was doing fine until suddenly it just began to run super rich. Regardless what Steve Kan did, and the car also could not hold boost past 6.5k rpm. Does anybody know what could possibly be going wrong?
I did tell him to upgrade his intake, where as I know a straight 3.5 inch piping enables the maf sensor to receive better readings, but I'm sure this isn't the reason why the turbo isn't holding boost past 6.5k rpm.He has a Racing beat dual resonated midpipe with a stock exhaust system. I don't think the stock exhaust can possibly choke the turbo, since I ran the stock exhaust system for a good month and it held boost past 7k rpm. Steve Kan mentioned there could be a malfunction in the AVI where it's not opening. We altered the duty cycle up to 60% and it did not do anything different.
This local is fairly young, and I've seen him save up for two years straight to one day become turbocharged. He really knows almost nothing about his car, and I don't want to see him blow this motor. I've never upgraded my injectors, coils, or fuel pump so I was seeing if anybody with experience can give me some input. Thanks a lot!
I did tell him to upgrade his intake, where as I know a straight 3.5 inch piping enables the maf sensor to receive better readings, but I'm sure this isn't the reason why the turbo isn't holding boost past 6.5k rpm.He has a Racing beat dual resonated midpipe with a stock exhaust system. I don't think the stock exhaust can possibly choke the turbo, since I ran the stock exhaust system for a good month and it held boost past 7k rpm. Steve Kan mentioned there could be a malfunction in the AVI where it's not opening. We altered the duty cycle up to 60% and it did not do anything different.
This local is fairly young, and I've seen him save up for two years straight to one day become turbocharged. He really knows almost nothing about his car, and I don't want to see him blow this motor. I've never upgraded my injectors, coils, or fuel pump so I was seeing if anybody with experience can give me some input. Thanks a lot!
09-21-2009, 05:56 PM
#2
possible boost leak, you need to pressure test
http://www.fighters-garage.com/rx7.html
get the one for single turbos, scroll near the very bottom. you may have to buy a coupler to fit to the Greddy turbo, I forgot what size inlet it has
http://www.fighters-garage.com/rx7.html
get the one for single turbos, scroll near the very bottom. you may have to buy a coupler to fit to the Greddy turbo, I forgot what size inlet it has
Last edited by arghx7; 09-21-2009 at 06:02 PM.
09-21-2009, 06:00 PM
#3
Registered
Thread Starter
When his turbo kit was installed I went with him to the car shop to double check all his couplers before he drove to dallas. Is there any other possibility other than boost leak? I will manually check his car again, and get a pressure check as soon as possible. More inputs would be helpful.
09-21-2009, 06:03 PM
#5
you'd be amazed how much stuff you can miss without a pressure tester. there's simply too many places to leak for the naked eye to catch with the car assembled
you can also make your tester. you need a coupler with two clamps, a PVC cap, a 1/4" NPT tap, and either a tire valve or male air compressor fitting that will thread into 1/4 NPT
you can also make your tester. you need a coupler with two clamps, a PVC cap, a 1/4" NPT tap, and either a tire valve or male air compressor fitting that will thread into 1/4 NPT
Last edited by arghx7; 09-21-2009 at 06:04 PM. Reason: DIY tester
09-21-2009, 06:10 PM
#6
Registered
Thread Starter
He did mention that one of his intercooler piping was blown of during the tuning session. Let me question him again and see what he says. Thanks a lot of rthe inputs so far you guys are great!
09-21-2009, 06:12 PM
#7
also check out these threads:
http://www.rx7club.com/showthread.php?t=863559 "how to build pressure tester"
http://www.rx7club.com/showthread.php?t=863949 "using boost leak tester on a rotary"
http://www.rx7club.com/showthread.php?t=863559 "how to build pressure tester"
http://www.rx7club.com/showthread.php?t=863949 "using boost leak tester on a rotary"
... keep in mind that this isn't the kind of pressure test where you fill the system up with air and see if it will actually hold pressure for a given period of time. The charge piping and associated plumbing is not a sealed system. Air is going to escape out the exhaust ports, but that's ok. You are testing to locate where air may be escaping out (vacuum leak or boost leak). You are not testing to hold pressure...To directly pinpoint leaks, get an empty spray bottle of Windex or something similar. Fill it up with water and a pretty small amount of soap. Spray the soapy water in areas that you suspect have air escaping...
Also, don't pay much attention to the pressure gauge on the regulator--it doesn't matter how much pressure is coming out really. It matters how much air the boost gauge in the car reads, or the gauge on the tester. At about 15psi on the car's boost gauge you will begin to reach the limits of the worm clamps on the tester. At that point, you may hear a violent popping sound and the tester will fly out due to insufficient clamping force. Don't be alarmed by this. Heck, it's kind of a good thing in a way. Sometimes the boost leaks are so big that you can't even get pressure to hold high enough to blow the tester out.
Also, don't pay much attention to the pressure gauge on the regulator--it doesn't matter how much pressure is coming out really. It matters how much air the boost gauge in the car reads, or the gauge on the tester. At about 15psi on the car's boost gauge you will begin to reach the limits of the worm clamps on the tester. At that point, you may hear a violent popping sound and the tester will fly out due to insufficient clamping force. Don't be alarmed by this. Heck, it's kind of a good thing in a way. Sometimes the boost leaks are so big that you can't even get pressure to hold high enough to blow the tester out.
09-21-2009, 06:21 PM
#8
He should have put the 650cc s in the P2 position and the 390cc in the P1 position.
Also the reason for no boost past 6500 is probably the same afliction that everybody else with a clipped turbine seems to be having . Wastegate is not holding .
He needs to mod to the actuator wastegate arm to get more boost above 6500
Also the reason for no boost past 6500 is probably the same afliction that everybody else with a clipped turbine seems to be having . Wastegate is not holding .
He needs to mod to the actuator wastegate arm to get more boost above 6500
09-21-2009, 09:23 PM
#9
also check out these threads:
http://www.rx7club.com/showthread.php?t=863559 "how to build pressure tester"
http://www.rx7club.com/showthread.php?t=863949 "using boost leak tester on a rotary"
http://www.rx7club.com/showthread.php?t=863559 "how to build pressure tester"
http://www.rx7club.com/showthread.php?t=863949 "using boost leak tester on a rotary"
In the absence of a compressor I found that a vacuum cleaner set on 'blow' will do the job nicely as well . Just take off the air cleaner shove the hose in the intake , wrap a rag around it to seal it off and go crazy with the soapy spray .
09-21-2009, 10:28 PM
#10
Registered
Thread Starter
I remember i read upon the wastegate actuator a few months ago.. Ever since I unbolted my own turbo kit I haven't been keeping up with the rx8 and all boost matters related to it... Has it been proven that the actuator is releasing too early? I think first thing first I will have to do is do the boost pressure test.. will keep you guys updated.. thanks a lot guys
Thread
Thread Starter
Forum
Replies
Last Post
Solidtrance
Series I Wheels, Tires, Brakes & Suspension
22
09-04-2015 12:47 PM
