Schantin

iTrader: (6)

Started work on this today after experiencing some oil issues on a recent trip to Alabama. The purpose is to correct a common problem with STS systems "leaking" oil past the turbine oil rings and into the intake tract and exhaust pipe. Oil in the exhaust pipe creates smoking and/ or oil smell when driving. Oil in the intake eventually coats the intake pipes with a light coat of oil vapor. On a car with a MAF tune the oil coats the MAF sensor and leads to erroneous airflow readings. The result.....greatly decreased power. This is probably the biggest downside of the system and one that many people seem not to understand. Thus, people (me included) get pissed off and call the STS a #$%^ POS. In reality, it's a design flaw that can be corrected for more reliable, no-oil-in-the-intake operation

STS has a whole pamphlet on oil control issues and a host of excuses for them. In many cases, the STS supplied return pump itself is not capable of returning oil from the turbine as fast as the engine driven oil pump is feeding it. This results in oil buildup in the turbine which then seeps past the turbine oil rings and into the intake/exhaust.

I have been working on a 3-part fix for this problem. These tips/directions are for helpful information. I'm not liable if your car explodes after doing some or all of these mods Total cost for this fix (all three parts) is approx $225. Not cheap, but better than cleaning the intake piping every couple months

Part 1: Remove the resistor:

This is easy. If you have the stock resistor (the gold one that gets stupid hot), remove it and reconnect the wiring on either side. The purpose of the resistor is to run the return pump at a reduced speed for "noise control". This in turn means less than maximum oil return rom the pump until the boost pressure switch tells the pump to bypass the resistor through the little black relays and put the pump into high-speed mode. Since the pump can barely keep up w/ oil etun in high speed mode.....low speed adds to the problem. After removing the resistor you'll hear the pump cycle at a much faster rate when the ignition switch is turned to the "run" position, but it is not any louder.

Part 2: Install a restrictor fitting:

This was not as easy as I origonally intended. STS uses a -3AN line to feed the turbine from the engine just above the oil filter. STS also went the cheap route and used common pipe fittings instead of traditional automotive AN fittings. The difference is that AN fittings have ends that are angled at 45 degrees, while pipe fittings have ends angled at 37 degrees (Thanks to Mike at Va Speed for helping me with this bit of info). So, below is a "how to" on using a traditional nitrous jet ( the restrictor) adapted to work with the BS that STS provides.

Below is the stock oil feed to the STS GT67 turbo. It connects to the oil check velve which in turn is threaded into the turbine itself.


You'll need an adapter that looks like this. I got this one from Home Depot.


This is what the adapter looks like when it is disassembled.


You'll also need a nitrous jet. I started with a .082, but also purchased a .062 and a .046. Testing in the near futire will determine the best one to use. Will update when I figure this out


Here's the basic assembly of the restrictor (nitrous jet) in the supplied housing assembly. The crush sleeve in the adapter (the piece the nitrous jet is sitting in) needs to be machined to make up for the thickness of the nitrous jet itself. This was done on a bench grinder.


Bench grinder to grind crush sleeve


Crush sleeve after grinding.


Assembly after machining the crush sleeve.


Teflon tape on STS check valve inlet.


Nitrous restrictor and housing assembled on turbo.


Part 3: Install a higher-volume ("Better") oil return pump.

I puchased a Mocal pump. The Mocal unit appears very similiar to the STS pump in dimensions and the mounting plate to attach to the car appears identical as well. The inlet/outlet threads also look the same. Hoping that the pressure buzzer and fittings will just transfer from the STS to the Mocal w/out issues. The Mocal pump differs in that the wires come from the side of the pump and can thus be soldered, vs the crappy spade connectors on top of the STS pump that like to work themselves loose (and cause oil issues). The Mocal pump is also supposed to be able to return oil pumped in at a rate of 55PSI. Honestly the pump alone might be enough to solve the issue, but I believe in over-engineering, thus the restrictor too

I have not installed the pump yet and will post pics of the assembly when I do....(next day or 2). I also have to pressure test the restrictor and ensure there are no leaks and that the 37 degree hat on top of the nitrous restrictor didn't shift when installing the oil feed line (it cold block the oil flow if it shifts too much). So........will post more info as I go.

Hopefully this will prove of some help to other STS peeps out there.

OUTLAWZ RACING

iTrader: (9)

Wow thats hot! The mocal pump it self should fix your issue. I cant for the life of me figure how your still gettin oil in the exhaust. I did notice the I have two differnt check valves. There is one that has a little bigger outlet size on it I orderd off of trt . The one from sts that I had was smaller and that one leak oil. I honestly think you should try the pump with out the restricter first. That mocal is a mean pump it vibrates my car! I dident hook up my buzzer warning I have a led light that lights up when it is on.

Project Dc2

iTrader: (4)

easier to just buy a restrictor


14$

Schantin

iTrader: (6)

Update on progress:

I pressure tested the restrictor setup I "created". It worked, more or less. The 37 degree hat fitting on top of the nitous restrictor was origonally cocked off a few degrees when I installed the restrictor and it caused a leak of approx 1 drop per minute at 55PSI oil pressure. Not really diggin that. Once I re-aligned everything it didn't leak. No oil blowby either. I like the piece shown below, as this would be leak free and easier to install......who makes it and where to get it, those are my Q's

Noted what you said about the Mocal pump....got me wondering. So, I removed the restrictor setup (for now, as I know it stops the oil blowby) and will try the Mocal pump alone to see if it can handle duties on an unrestricted oil feed. Was busy with a sick infant today, so not much progress made.

Like the idea of replacing the warning buzzer w/ an LED light for operation too. Nice idea

Anyhow, will post progress as I continue my experimentation on this topic.

MonochromeSS

iTrader: (1)

Got any pics of the Mocal pump installed yet? I may be going down this road myself.

OUTLAWZ RACING

iTrader: (9)

I will ask lethal if they could post some pics. They have my ride now.

Schantin

iTrader: (6)

Not yet. Family member health problems have delayed progress for the past couple days. Will have The pump installed/pics/instructions by Thursday. Also got one of those restrictors posted by PorjectDc2. Will post that info too if I feel a restrictor is needed w/ the Mocal pump His one-piece restrictor is definetly easier to deal with than my 4-piece design.

The 1st thing I noted is the inlet/outlet flow direction on the Mocal is reversed from the STS pump. Will require a little rearrangement to make the return lines look good and keep the pump vetically mounted.

mcx

i use the Mocal pump for my set up...you can easily disassembly it to pivot the in/out to the position you prefer....i believe it was four screws.

HydroStream6

iTrader: (16)

I've had the Mocal pump and restrictor setup just like this going for about a year now. I still get a very slight amount of oil every once in a while, nothing like it used to be though.

One thing worth mentioning is my Mocal pump needed a rebuild after only about 4k miles... $50 kit, I figured it should have lasted longer than that.

Schantin

iTrader: (6)

Got a little work done tonight. Removed the STS pump. Tomorrow will install the Mocal. Noted a couple things:

1. Removing the oil lines from the STS pump was a biotch. Had to cut the oil return lines, as they were really stuck to the pump fittings. Plenty extra line though

2. Will have to redrill 2x holes to reinstall the Mocal. The mount plate is bigger and the bolt spacing for the top/bottom bolts is about 1/4 longer. The sheet metal screws that STS provides to mount the origonal pump to the body will be inadequate for the Mocal. Will use bolts to secure. The nuts will attach under the rear driver seat. Should be better overall.

3. The fittings from the STS pump screw into the Mocal pump w/out probs. The STS pump is superior in one way....the fittings are brass. The input screws for the Mocal pump are plastic. That' about where the advantage of the STS pump ends.

4. Size.....well, the Mocal pump might be a tad bigger







As you can see the Mocal pump is a monster compared to the STS pump. This should provide for better oil scavenging

Will update more tomorrow/Thursday when I get the pump actually in the car.

John_D.

iTrader: (2)

That's the design of the Insta-Grip hose. No clamps needed, but you have to cut them off. Their site suggests making two diagonal crossing cuts in an x-shape when it's time to take off the hose. That way you don't have to cut all the way through the hose to the brass.

CamaroSS19

iTrader: (24)

Nice right up its going to be helpful in my build . Hey could you PM me the link to where you got you pump from thanks

DLong

iTrader: (1)

Great info. Off the subject but do you have problems with oil in the intake? I have a Corvette with the sts kit and when I let out of the gas after I've been in boost I get some oil smoke. I am actually looking at a vacuum pump. I am just curious. I am going to pull the pipes and see if my problem is similar to yours or something else.

Schantin

iTrader: (6)

PM sent.

Oil will seep into the intake pipes and exhaust when the turbine housing gets too much oil in it. I don't get oil smoke from the engine intake though. I've never had enough oil in the intake pipes to make it past the FMIC and into the engine. If you don't have oil in the intake piping, it sounds like your PCV valve is getting oil soaked under boost. A vented catch can would solve the latter prob if this is the case.

DLong

iTrader: (1)

I checked my pipes on the intake and exhaust side and they are clean. It looks like your are right about the pcv. The inside of the intake manifold is soaked. Thanks for the reply.

Project Dc2

iTrader: (4)

hope that restrictor works out well for ya !! it works out good for us !!

smoke20

iTrader: (2)

schantin - hey man im really watching this thread, i dont have oil in the exhaust problem or on decel but i do get a llittle oil in the intake piping. not much just about 1/8 cup when i take it off and clean it. can you pm me the part # and where you purchased the restrictor. thanks David

Schantin

iTrader: (6)

Mocal pump installed. Restrictor as pictured in thread by Project Dc2 installed too

Impressions/install:

1. The Mocal pump is a heavy SOB when holding it up to measure the mount holes under the car I used 1 of the existing STS pump mount holes to hold the pump, and then drilled 3 new ones. The Mocal pump mounting bracket is bigger than the STS (about 1/4" wider and 1/2" longer), so the mount holes do not line up between the 2 pumps. Mocal does not supply hardware to install. They supply 4x rubber isolation grommets. The fat side of the grommet goes between the pump mount and the car frame (did one backwards to find that out ) You need to use a bolt with a washer. The washer squishes the front of the grommet and hold the pump in place. I used lock-bolts to secure my pump. I accessed the nuts by removing the driver side rear seat and then reached under the carpet with the seat removed. It's a 2-person job, but easy enough. Here's a pic of the pump installed:



After bolting it to the car (which was the real PITA), I connected the black STS pump wire to the + (red) Mocal wire and the yellow STS harness wire to the black - (black) Mocal wire. I soldered the connections and sealed w/ liquid electrical tape to form a weatherproof seal. I also did NOT clock the pump, but rather hooked up the STS return inlet/outlet lines in reverse (the Mcal pump is 180 degrees off from the STS pump). I had no clearance or fitment issues doing business this way. I also E-mailed the guys that make the pump (ThinkAutomotive) about a break-in procedure. There is none. Hook it up and go.

Impressions..... the Mocal pump is mean. Period. No need for a buzzer. Priming you can feel the pump vibrate the entire car and it lets out a nasty low brrrrp sound when doing it. I can hear the pump over the engine when part-throttle cruising, but it's not obnoxious. It's a deep tone. Checked the oil cap return. This pump is no joke. It shoots the oil back to the engine.

Restrictor (shown in Project Dc2 Post). Got the restrictor. Appears to be red anodized aluminum like an AN fitting. It has to be installed between the 90 degree coupler and the check valve (or after the check valve). Heres a pic of the fitting installed:



The fitting is a .065 restrictor and it threaded into the STS check valve w/out issues.

Final impressions: After perfoming oll these mods I rn the car for 30minutes continuous and did not get a single drop from the turbine intake or exhaust. I am leaving for the Hot Rod Power Tour tomorrow and will check again after that 3K mile road trip. That will be the "real test". So far all is well.

P.S. If you see this car on the side of the Hot Rod Power Tour broke down.... give a peep a lending hand




Will have the final verdict in a week Hope tis has been helpful to my STS peeps

spaz1

iTrader: (9)

Where do you get the restrictors? pumps from? I am sure if you mount the pump off the rear suspension or something more isolated it wouldn't be as loud.
Thanks

OUTLAWZ RACING

iTrader: (9)

Told u that pump is mean! Now i just got to find out why some fail after 5 k and 2 years Im guessing heat and abuse but I will see. Great thread for us remote mounts