Bottom mount turbo scavenge pump setup?

**tptrsn** · 08-06-2016, 11:43 PM

Off topic, but I am so confused if a bottom mount should really need a scavenge pump or not if the proper restrictor is used... A check valve in the feed line seems like a pretty good idea on a bottom mount now that someone mentioned it. But then with a decent gravity drain, why would it really be needed?

**rajicase** · 08-07-2016, 01:03 AM

Originally Posted by tptrsn

Off topic, but I am so confused if a bottom mount should really need a scavenge pump or not if the proper restrictor is used... A check valve in the feed line seems like a pretty good idea on a bottom mount now that someone mentioned it. But then with a decent gravity drain, why would it really be needed?

It really depends. Some bottom mounts position the turbo lower than others. Bottom line, without a pump, the oil is draining 100% via gravity. So you can have the proper feed size, restrictor, etc.. but if the turbo drain isn't higher than the oil pan, youll need a pump.

A check valve would really be most beneficial if your set up required a scavenge pump. If your turbo can adequately gravity drain, it shouldn't need a check valve. But when you turn your car off, pump goes off too...

**FromSVTtoM3** · 08-13-2016, 12:54 PM

So I am now running a -3an feed line per Comp, instead of -4an. I took it out to a track day last weekend plus drove to and from the track. With 80 minutes on track time and 5-6 hours total commute time I used about 3/4th-1 qt of oil, which didn't seem too bad. I was still getting some smoking on startup after sitting awhile and occasionally on track on deceleration.

**twirknolove** · 08-13-2016, 07:41 PM

The lines on your catchcan are plumbed backwards. Your valve cover has to be plumbed to the TOP of the can and exit from the SIDE of the can.
Also, where is your exit on the can plumbed to? Disconnect it for now and let it go to atmosphere to see if you stop getting smoke on Decel.

**FromSVTtoM3** · 08-15-2016, 05:59 AM

Originally Posted by twirknolove

The lines on your catchcan are plumbed backwards. Your valve cover has to be plumbed to the TOP of the can and exit from the SIDE of the can.
Also, where is your exit on the can plumbed to? Disconnect it for now and let it go to atmosphere to see if you stop getting smoke on Decel.

I will double check for sure when I get home, but I believe the exit on the can is being routed to the intake piping after the filter before the turbo. If that's the case, do I just need to swap the orientation of the lines?

**twirknolove** · 08-17-2016, 08:25 PM

Originally Posted by FromSVTtoM3

I will double check for sure when I get home, but I believe the exit on the can is being routed to the intake piping after the filter before the turbo. If that's the case, do I just need to swap the orientation of the lines?

Yes!
Plumb the line coming out the valve cover to the top port of your can.
Plumb the can's side outlet to your turbo's intake elbow pre-turbo the way you have it.
Check out the picture of the can i showed you and the orientation of the velocity. I think if you google your can, you'll see people setting it the same way as well.

My advice is to just plumb the side outlet of the can to atmosphere *for now* and see if you still get smoke on decel throttle blips.
I used to have my M20 turbo this way and I would blow a lot of smoke out the exhaust on decel. The oil vapors being introduced to the cylinders through the intake was also lowering my fuel's octane rating if that makes sense.. As soon as I took the line off the intake elbow and vented it to atmosphere, my car ran really rich on WOT and fuel tables had to be adjust (I was able to make more power because of this as well). Your catch can must filter better than mine though.
Try it out.

**FromSVTtoM3** · 03-30-2017, 05:58 AM

Update:
I decided to purchase a Turbowerx exa pump scavenge pump. The car is at the shop now having it and several others things installed. Are there any suggestions on mounting location and setup? The shop doesn't believe a collector tank is necessary, but they suggested running a timer so the pump continues to run for a brief period after the engine has been shut off.

**NOTORIOUS VR** · 03-30-2017, 09:06 AM

Originally Posted by FromSVTtoM3

Update:
I decided to purchase a Turbowerx exa pump scavenge pump. The car is at the shop now having it and several others things installed. Are there any suggestions on mounting location and setup? The shop doesn't believe a collector tank is necessary, but they suggested running a timer so the pump continues to run for a brief period after the engine has been shut off.

IMO tanks always seem to work best... It's simple and proven to work.

Just remember to correctly vent your system or else it doesn't matter what you do it will never work right.

**FromSVTtoM3** · 03-30-2017, 10:01 AM

Originally Posted by NOTORIOUS VR

IMO tanks always seem to work best... It's simple and proven to work.

Just remember to correctly vent your system or else it doesn't matter what you do it will never work right.

Wouldn't the catch can help the system to vent adequately and relieve crank case pressure?

**rajicase** · 03-30-2017, 10:07 AM

Run a tank. Some people have smoking issues without one. I run a small tank and a single 12an breather off the valve cover as the only vent in my system and it works great. No smoke from my 366sxe which sits really low and has a 4an unrestricted feed going to it.

I don't think a timer is necessary. I have my pump wired to turn on with the key on the on position, I usually try and let it run for 10 seconds or so after shut off. But sometimes I don't let it run at all after shut off and never notice any smoke on the next start up..

**FromSVTtoM3** · 03-30-2017, 11:01 AM

Originally Posted by rajicase

Run a tank. Some people have smoking issues without one. I run a small tank and a single 12an breather off the valve cover as the only vent in my system and it works great. No smoke from my 366sxe which sits really low and has a 4an unrestricted feed going to it.

I don't think a timer is necessary. I have my pump wired to turn on with the key on the on position, I usually try and let it run for 10 seconds or so after shut off. But sometimes I don't let it run at all after shut off and never notice any smoke on the next start up..

I must have incorrectly read some of your posts earlier. I thought you ran a pump, but no collector tank or check valves. Where did you get your collector tank? Where did you mount the pump and collector tank?

- - - Updated - - -

It seems like I have read a number of different solutions for different people. Scavenge pumps with a check valve on the pump return line. Pumps with a check valve on the return line AND a check valve on the turbo oil feed off the filter housing. Venting without collector tanks and venting with. I feel like my head is spinning with all these options...

**rajicase** · 03-30-2017, 11:12 AM

Originally Posted by FromSVTtoM3

I must have incorrectly read some of your posts earlier. I thought you ran a pump, but no collector tank or check valves. Where did you get your collector tank? Where did you mount the pump and collector tank?

- - - Updated - - -

It seems like I have read a number of different solutions for different people. Scavenge pumps with a check valve on the pump return line. Pumps with a check valve on the return line AND a check valve on the turbo oil feed off the filter housing. Venting without collector tanks and venting with. I feel like my head is spinning with all these options...

I have always ran a scavenge pump and collector tank off the turbo. I do not run any check valve or breathers except a breather off the valve cover. Never had any smoking issues.

I got the tank from someone here on the forums, it's just a small aluminum tig welded tank with an 8an fitting on it.

I mounted the pump to my x brace

ForumRunner_20170330_101241.jpg

**rajicase** · 03-30-2017, 11:16 AM

This is the tank

ForumRunner_20170330_101615.jpg

**FromSVTtoM3** · 04-21-2017, 06:05 PM

So I got the scavenge pump on. It still smokes some on startup, but not as much. However, it is smoking more frequently during normal using. It is blowing a lot more smoke than previously when it's in boost.

**whoshaunq** · 04-22-2017, 02:21 AM

Install psi cracking check valve on feed line, problem solved for smoke on start up. As for smoke when lettin off the gas after a pull aka in between shifts, needs vent in return or small collection tank

**pbonsalb** · 04-22-2017, 09:36 AM

You might need collector tank or vent line on drain or restrictor or check valve in feed. Or route lines better to gravity into scavenge. Or use timer on scavenge. Or you may have crankcase vent issue.

A few possibilities. Hard to guess which without seeing it and knowing all the details.

**FromSVTtoM3** · 04-22-2017, 10:14 AM

Yea I know it can be difficult to diagnose all the possibilities over the internet. I appreciate what feedback you all have been able to provide. The scavenge pump is mounted up top to the left of the engine, same height as the catch can but closer to the firewall. The thing that has me concerned is the heavy smoke in full throttle as it gets into boost. I'm wondering if the seals are compromised as the vehicle sat all winter with the possiblity of oil collecting/sitting in the housing. The shop mentioned it looked pretty wet around the center housing.

I'm starting to debate if the source of all these issues is the Comp turbo. I know those and Precision are considered less robust/reliable than a Garret/Borg Warner. If I were to change I would probably consider a GT35r.

**boostd4** · 04-22-2017, 10:17 AM

Originally Posted by whoshaunq

Install psi cracking check valve on feed line, problem solved for smoke on start up.

Can you explain the theory behind this? I must be having a brain fart... If the check valve keeps oil from getting to the turbo except under boost, can't that ruin the turbo? The shaft in the turbo is spinning whenever exhaust gasses are going though it (all the time).... ?

**rajicase** · 04-22-2017, 10:44 AM

Originally Posted by boostd4

Can you explain the theory behind this? I must be having a brain fart... If the check valve keeps oil from getting to the turbo except under boost, can't that ruin the turbo? The shaft in the turbo is spinning whenever exhaust gasses are going though it (all the time).... ?

It would allow oil to go to it whenever the engine was running (oil pressure). The only time it wouldn't allow oil to the turbo is when the car is off. I don't think this should be needed and I'd be hesitant to put anything in line with my oil feed, but that's the idea any way.

**vollosso** · 04-22-2017, 11:23 AM

I didnt read through it all but try parking on a hill or lowering your oil level. If that fixes the smoking then you know what the problem is.

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**vollosso** · 04-22-2017, 11:26 AM

Also i have a baller scavenge pump system if you decide you need one. Ill include all the fittings, the bracket, hoses and whatever else i have.

Weldon pump..

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**pbonsalb** · 04-22-2017, 11:31 AM

Up high is bad place first pump for bottom mount turbo. Put it where RAJ has his. Return to pan or obd2 dipstick stem with 5/16 hole through main tube just after it enters pan. Keep it simple. Down hill to pump, short lines.

Originally Posted by FromSVTtoM3

Yea I know it can be difficult to diagnose all the possibilities over the internet. I appreciate what feedback you all have been able to provide. The scavenge pump is mounted up top to the left of the engine, same height as the catch can but closer to the firewall. The thing that has me concerned is the heavy smoke in full throttle as it gets into boost. I'm wondering if the seals are compromised as the vehicle sat all winter with the possiblity of oil collecting/sitting in the housing. The shop mentioned it looked pretty wet around the center housing.

I'm starting to debate if the source of all these issues is the Comp turbo. I know those and Precision are considered less robust/reliable than a Garret/Borg Warner. If I were to change I would probably consider a GT35r.

**FromSVTtoM3** · 04-22-2017, 12:16 PM

Originally Posted by pbonsalb

Up high is bad place first pump for bottom mount turbo. Put it where RAJ has his. Return to pan or obd2 dipstick stem with 5/16 hole through main tube just after it enters pan. Keep it simple. Down hill to pump, short lines.

Out of curiosity what is the issue with having the scavenge pump (turbowerx exa pump)up higher than the turbo? Shouldn't it have the ability to flow enough for the setup? Would that height alone be enough to cause heavy smoking during WOT acceleration?

**pbonsalb** · 04-22-2017, 12:25 PM

When you shut down all the oil in the line flows down into the turbo drain. You could add a check valve but that is a restriction for the drain to overcome. It's up to you what to do. When I ran one, I bought what was proven to work and installed it with parts proven to work in a way proven to work and never had an issue in over 5 years.

**FromSVTtoM3** · 04-22-2017, 12:58 PM

Originally Posted by pbonsalb

When you shut down all the oil in the line flows down into the turbo drain. You could add a check valve but that is a restriction for the drain to overcome. It's up to you what to do. When I ran one, I bought what was proven to work and installed it with parts proven to work in a way proven to work and never had an issue in over 5 years.

FYI I don't want my questions to come off as ignoring your advice, which I very much appreciate. Just trying to understand the logic behind the different location/setups. I'll most likely get the car back to the shop to have the pump relocated to the x brace. The shop's main concern was if something were to accidentally come into contact with the pump in a low placement while commuting/racing and have a catastrophic failure due to related oil pressure loss.