MetricMuscle

Thread revival! Sorta.

Has anyone considered using a power steering pump to provide the turbo with oil pressure and scavenge? I am in the process of depowering the rack in my '96 Miata and it occurred to me the output pressure might be just right?
-It has to pull vacuum on the return side as well.
-The pump is small and already on the car.
-The pump pulley is actually also the tensioner for that belt so removing it altogether would be a pain.
-Inline oil cooler on the way back from the turbo to pump.

I need to confer with Darth Rohmer as to my scheme.

busa4

power steering pump runs 1000 psi or more. not a good supply for a turbo that needs 40psi or less.

MetricMuscle

I believe that is what it can make for a short period of time if dead headed, no place to pump to. The more I think about it, the pump will probably not make any pressure until there is a restriction, a load so to speak. Using a return style fuel pressure regulator should work to maintain whatever pressure you want.

sparky91381

i rear mounted a gtk-1000 on an 02 trans am - engine built for boost made some really sick power (1218rwhp@28.2psi) but was bad in water - cracked turbine housings - later front mounted the same car and made less power(had to add timing and fuel) much hotter iat temps car would detonate but had no boost lag

sparky91381

also rear mount is much more expensive than front mount because of all the extra piping and the scavenge pump on the oil system - but is much cooler on the intake air temp

rohmer

sparky..... not much more expensive.. a good oil pump is the same cost as a cheap manifold. and the rest of the piping is usually straight.. fewer elbows and couplers...
an excellent stainless gasbacked/purged tig welded equal length divided manifold costs more than some turbochargers....

how did you crack a turbine housing?

i ran mine for over a year through crappy weather.... not a single issue with the turbo.... even went throught some deep puddles in an already low car and never had any cracking issues....

MetricMuscle

Thanks for the info Sparky. Might you have any pictures?

I don't see why the scavenge pump has to be so expensive or hi-flo capable. The trickle of oil coming out of a turbo with the correct restriction jet, for me a .060 or 1.5mm hole at ~35psi, should be easy work for a small electric fuel pump sized pump. I have two candidates should I go that way, a Holley Red fuel pump for carburetors, high volume, low pressure, around 7psi max.

...and/or a motorcycle turbo scavenge pump. I can't find a picture of the one I got via eBay but it is small. I'd be more worried that a larger pump would introduce air into the system or have other issues due to too little oil flow. I may actually wire the pump in series with a fan so both run slower and constantly.
Sparky or Rohmer, did either of you ever measure how much oil flowed thru your turbos? What size restriction jet did you use or did you have to?

I am currently excited about the possibility of using my power steering pump to provide oil pressure and scavenge to the turbo. The power steering rack will soon be de-powered, a popular mod on Miatas, as the PS makes the steering twitchy on the highway and is reasonable at parking lot speeds. Not only can the PS pump system provide plenty of pressure and flow, it also provides suction on the return side for a vacuum scavenge. This will allow for a separate oil supply system from the engine using OE parts that are already on the car and not known to have much failure.

sparky91381

I have lots of pics on my home PC n will post later - I was out and abouts one night doing some serious street racing and I bottomed out that is how housing cracked - the reason I said rear mount was more expensive - I work in an exhaust shop and used my factory manifolds with a crossover for the front mount setup - pipe I get comes in 10' sticks at cost. The pump I used for the rear mount was like $400. Is a sts pump.

sparky91381

Wish I would have thought of an external fuel pump for scavenge - hot oil doesn't hurt the pump? I always thought a fuel pump was cooled by the fuel going through it.

MetricMuscle

A fuel pump is not designed to pump oil but with the Holley, everything is metal except for a flat gasket piece made of rubber or Buna or Urethane of some sort. I figure if it will withstand fuel it should withstand oil but if it won't then just cut a replacement one out of Buna or Silicon.

If the pump is placed a few feet ahead of the turbo and the oil run thru a cooler or piping I don't think the heat will be an issue. The motor on the Holley is external and should not have to work very hard, I'd think it would be fine.