i often hear stories about rx7 owners that want to shoot their turbo builders... i know one party that sent his new turbos back 3 times because they "SMOKED"

actually, a couple of weeks ago i was ready to call UPS after a summer of smoking up the wisconsin landscape.

i run 2 t04/t3 hybrids. i had started w .09 restrictors and had subsequently downsized to .07 w no improvement.

then i remembered Steve Kan telling me that t3s need .03 or they will smoke. i thought i would give it a try before shooting my good guy turbo builder Kevin Draper. i located a dremel drillset that had a .034 bit and.....

no smoke it has been 400 miles since and my turbos are spooling and smiling.

if you find yourself w a smokin' turbo SIZE does matter so make sure you have the correct restrictor.

BTW, since the area of a circle is radius squared times Pi... my restrictor area is now 27% of what it was at .07.

thanks Steve,

howard coleman

 

Great info Howard

I'll remember this when I hook up my twins

 

Really depends on your engine oil pressure.

I would not usually go smaller then a .05" restrictor.

Hope your turbos are getting a min of 25-30 psi of oil pressure under load or else you will kill those bearing seals.
rotaries are flame throwers and that oil pressure helps keep those puppies cool/lubricated under all that heat and stress.

JD

 

what restrictor would you guys reccomend for a to4r with a -4 feed line and a -10 return line? It's on a cosmo block.

 

now that i have solved the oil smoking out the exhaust problem i do agree that the best restrictor is the largest size that doesn't smoke.

given the fact that rotaries run approx 500 degrees more exhaust temp than piston engines the turbos need all the help that they can get.... certainly not any lube starvation.

i will try sizing the restrictors up until they smoke and post the results.

i did conclude there is alot of difference in jet area when compared to diameter...

.07 is .00385 sq inches
.05 is .00196
.034 is .00091

so a .034 is only 23.6% of the flow of a .07!

a .05 will flow 215% of a .034!

howard coleman

 

http://www.atpturbo.com/Merchant2/me...egory_Code=BCS

This is what I used on a Turbonetics T04B 60-1 .96a/r .70trim etc.

-6an inlet. and 3/4" outlet. (Custom return hose)

Turbo lasted about 4000km if that. This is the second turbo I used. First one had to much play so I returned it but they sent me the wrong one anyhow. (Sent dry only when I wanted wet and dry). Second one has some play.

It did not smoke with either the oil restrictor in or out. I took it out as one of my troubleshooting the lag machine response.

Not sure if it is needed or not. Wondering if this was a reason to why my turbo is shot.

I figure the turbo is done since I'm increasingly getting worse boost response and cannot optain full boost anymore. Turbo binds now when you push the exhaust wheel and try to spin the turbine wheel.

I have been told that some turbo's have built in restrictors.

 

DO NOT DO THE .03 TURBO RESTRICTORS!!!!!!!!!!!!!!!!!!!!!!!!!

i just lost both turbo bearings after 165 miles w the .03 sized restrictors. JD was, in retrospect, right on the money as to them being too small. i will probably go w .05 after they have had a trip to Waco...

howard coleman

 

Howard how is your crank case vent setup? I suspect your oil pan is pressurizing from blowby which will cause the oil to not drain out of the turbos fast enough. That will cause them to smoke as well.

It doesnt cost anything to check for oil pan pressure issues. Just run a vac line from those oil filler neck nipples to the intake just before the turbos. If you cant due to your turbo/intake setup then just vent them to atmosphere for now but beware they will probably make a mess. I've heard of some race cars needing as much as two -8 lines before they had enough vent to keep them from smoking.

If you find that your problem is insufficient crank case vent then check out this thread going on about catch cans, blow by, oil pan issues....
https://www.rx7club.com/single-turbo-rx-7s-23/whats-your-catch-can-376579/


Sorry to hear about your turbo

 

hi steve,

yes i read that lengthy thread a while ago. it was interesting. my turbo discharges are .5
i d. one goes to the front block drain and the other to the rear. i run a 3/8 i d line from near the top of my oil filler tube to a Jegs catchcan that has an air filter on the top and a drain on e

 

ooops i hit the send button, it has been that kind of day....

a drain on the bottom

as to my turbos. they were new abt 500 miles ago and now have lots of sideplay. time for a trip back to waco.

hope to see you at the Rotary Revolution.

howard coleman

 

Howard, when you get your turbos back you might want to try running the catch can to the intake some how so that it will actually pull vacuum on your oil pan instead of just atmosphere pressure.

Well, as much as I'd like to get to RR this year I dont think I'll make it. There is also another event just a couple weeks prior to RR. A bunch of people are getting together and running down Deals Gap. Its going to be kinda like a tour where people go from one city to another picking up people along the way and it ends in Deals Gap where we are spending the day there. These is a sponsor thats going to provide all the food, drinks, T shirts, ect so its not going to cost the group anything but gas money and a hotel room. There is a thread about it in the SE section.

Stephen

 

I went thru turbos like candy, then I realized the same thing- I was pressurizing the frontcover. I put a v8 crankcase filter on my oil filler tube and left the pvc outlet open
to atmosphere and run a -4 straight in and a huge 3/4 inch drain. No more problems
for 2 years now.

 

so if i am running a t2 feed line with no restrictor on my t72 and i havenot noticed any smoking ,does that mean im ok

 

I bet you are ok. The other symptom was a chronic burnt oil smell. This was probably my
pent up oil coaking. The only thing I can't figure out is that I put a 62-1 on with the old
setup[no crankcase vent] and it never smelled or gave any problems for over a year.
I took it off to go larger and the shaft is like new, no play- go figure.

 

I've a question about the smokers. Was the oil coming out the compressor side or the turbine side? Or both?

 

it usually comes out the COmpressor more, but I have seen it come out both.... so it just depends on which seal is weaker. or you are really running high pressure and you blew both...