BrianCunningham

Or does it?

The turbos can be supplied oil from the engine. The trouble comes when mounting them down low. The oil stays in the turbo and eventually the seals go.

I've read/seen that Callaways Twin-turbos have a separate oil pump built into the belt tensioner. Do they run a completely separate system as well? tank? cooler? If all they do is a separe pump, how does it get the oil out of the sump.

Can the stock pump be used if the return line is above the oil level so the vacuum is broke?

What about using a one-way valve?

Thanks

scorp508

The callaways I think (don't hold me to this) had a seperate smaller oil tank that was bolted to the frame cross member under the frontmost portion of the engine oilpan.

Monty

I don't know first hand, but I have been told on a couple of occasions that Lingenfelter is using a scavenge pump for his TT C5's that uses oil pressure to drive the pump. In my opinion, I'd rather trust something driven by a belt or hydraulically rather than one driven by an electric motor. It seems like it would be more reliable.

Unless stealth is teh deciding factor, I would avoid the low mount/scavenge pump arrangement if at all possible. The less complex the system, with fewer components, the more reliable it will be.


[Modified by Monty, 1:33 PM 12/3/2002]

bill mcdonald

yes.
the oil drains by gravity to the sump tank mounted on the front cross member. it is under the oil pan.

It looks like both turbos drain into it and the belt driven pump pulls the oil out of the sump tank and puts it back into the oil pan.

The only thing I am unsure of is how the sump looks inside, and what fittings on that sump go to what?
In all the pics I have, it appears the oil goes into that sump near the bottom of it. seems to me like the same difference as tryig to drain back into the oil pan. you cant fill something below the full line with gravity.

I dont know if the sump has baffeling, or if it was designed to always run just about dry etc...

bill mcdonald

I am not sure what you are asking here.
If you are asking about using the stock pump to feed oil to the turbo, then yes, that should be fine. You may want to try a high volume pump since callways come with one. turbos dont need a ton of oil going into them. I think it was John Meany who was using either N2O or fuel jets (I forget)in the oil pressure lines to regulate how much oil his turbos get.

The problem with the oil return is not the vacuum, turbo drain oil by gravity.

In the callaway design, the turbos are right near the bottom of the oil pan, to drain that turbo oil back into the engines oil pan would mean the return fittings would be under the oil full line. You cant fill this with gravity, so the turbo oil would never drain, unless you ran about 1/4 quart of oil in your engine. :jester

when you mount the turbos up high, you put the oil pan fittings well above the oil full line in the pan, this way you dont have a problem with the oil draining in to the existing oil level.

Maybe this is close to what you were asking?

BrianCunningham

I didn't realize that the turbos need to completely drained.
I thought it was the pressure from the oil above that caused the problem.

It's not the stealth I after, though that would be nice :jester, so much as the mounting, just use the stock manifolds, granted not an optimal setup, and put them where the cats currently are.

I've thought about a drysump system, I like to road race, but running it on the street could prove a little cumbersome.

mn_vette

You do have room to mount the turbos where the cats are, but you still need custom headers. An electric pump can be used to pump the oil out of the turbo and back into the engine. Many people run electric water pumps and have no problems with them, I'm not sure how this would be any different.

bill mcdonald

I did some reading through all my mags that feature turbo cars and LPE is using a sump tank on his TT C5's as well. it is mounted between the cats on those cars and looks about the size and shape of a coffee can.

I am still looking for info on what or how the pumps are driven.

I was thinking, and a, maybe, stupid idea popped into my head, could a mechanical fuel pump be used as a scaveging pump?

jtjerry

Brian I thinking about TT setup on my vette too.
I found that link where is twin turbo ZR1. In that setup turbos are enough high to gravity work I suppose.
But I am not sure. But that Oil pan is different than in my L98.
Perhaps if mount that small turbos not so low there will be not needed that oil sump pump.
Jerry, Poland

pictures:
http://corvetteactioncenter.com/cgi-...allaway&img=36

bill mcdonald

JtJerry.

The Zr1 is a totally different animal. they dont have the starter mounted low, it is under the intake on the LT5. also the oil filter is mounted on the front. this frees up a bunch of room on it vs the L-98

I dug up a picture of the TT LT5 on my computer, It looks like one turbo drains into the bottom of the oil pan on the passenger side. Looks lik ethe drivers turbo drain is ran up to the front crossmemeber somewhere. No veiw of a scaveging pump. This is the callaway TT ZR1 I am looking at.

Do you have pics of the turbos under the Mallett car?



[Modified by bill mcdonald, 3:54 PM 12/4/2002]

jtjerry

no :(
only engine bay in Mallett ZR1
I can't find undercar pictures "normal" callaway too...
there is a lot of engine bay pictures and no under car :cry
Jerry


[Modified by jtjerry, 9:43 AM 12/5/2002]

Rkreigh

anyone have some nice pics under the TT LPE ZR1 or TT Callaway ZR1 cars??

I'm trying to do a twin turbo ZR1. if I can mount the turbos high enough to gravity drain, that would be nice.

fyi, the holes in the bearing on the turbo limit the oil flow, on my turbo buick, it just uses a 3/8 oil feed line and about a 1/2 drain line, because the oil "foams" circulating around the turbo bearing. you need a pretty big return line to keep the oil from backing up in the turbo. an electric scavenge pump might work if the turbos are down low, and I may even consider a small separate oil cooler and oil supply so I could use a turbo timer to continue to circulate oil after shut down to cool the turbo which is a good idea.

a twin turbo zr1 is a pretty awesome piece, but since no one is building them anymore, alot of custom fabrication is needed. I already have an LPE 368, so lowering the compression isn't too bad, just a piston change away!!!

please let me know of talented fabricators that you think might be interested in this project.

tia for any thoughts.