Hey guys,

I'm a part of a Formula SAE team that runs a single cylinder turbocharged KTM engine on E85. As per rules, we are required to pull air through a 19mm restrictor pre turbo and because of the intake vacuum are experiencing massive oil leakage into our compressor housing. After about a half hour of run time, the compressor will be submerged almost halfway in oil.

We run an IHI RHB32 that is bone stock. We have tried multiple turbos and each have had the same problem. I can get oil flow rates and pressures if needed, but we rarely ever see more than 15 psi through the engine and have sized an oil restrictor accordingly.

With that said, what can be done to cut our oil leakage? Our intake temps are through the roof and with the rule changes in the upcoming year we need to make sure that we can run our MAF post turbo, so very little, if any, oil passing through the intake is necessary.

Does anybody know of any routes that we could pursue?

 

Have you tried a scavenging pump?

 

Yes, we run a scavenge pump which is functioning correctly. We have the turbo mounted lower than the oil sump so we need it for a return as well as to pull oil from the turbo

 

could try a carbon type seal on the compressor- typically used on draw through carb setups.

another thought is to try making a turbo drain chamber. a small box bolted to the turbo drain with a feed(drain) on the bottom and run a hose from the top to the turbo inlet on the restrictor side to even pressure across the seal and hopefully the scavenge pump can operate at those pressures

 

Ashford - Thanks for the input! After searching Google for IHI carbon seals, I found a couple write ups which took me to this site - http://turbosupply.com/about/ . Are there any other sources which I could go to to try and find a carbon seal for the RHB32?

Also, can you elaborate on how the drain tank would work? How would the pressure be equalized across the seal if there is low pressure on the compressor outlet and higher pressure from the oil supply line? We run fairly low boost (5 to 8 psi), so I'll check if our scavenge is capable of operating at that pressure.

 

So you'r running a mandatory 19mm restrictor on the Turbo's air intake.

Thing is you are running 15psi boost but the 19mm air intake in front of the turbo can not flow enough air to handle 15psi so its sucking oil past the seals to because of the high vacuum created pre compressor side.
As there's basically not enough air the turbo must work very hard to create 15psi which heats up the intake charge to.

You have to bring the boost down to get control over your oil issue.
Bigger or smaller turbo wont change the oiling issue as wont bigger drain. You have so much vacuum pre compressor caused by the air intake restrictor the seals wont cope with that and will pass oil through.