oil/water feeds on turbo

[mike86ze]

hey guys
having a delemor where i've gone through two turbos and not wanting to wreck my new t25.
when i first put them on they've gone from fine to quite smokey in not to much time at all, say a month.

there seems to be a lot of oil going through
- how much is enough?
- maybe not good enough oil? 15or20w50 i think

the water coolings set up off the heater pipes
should i have it T-off from the after the pump up bypass around the thermostat so it gets more flow and a little colder water?

one rb20det turbo one s4 rx7

any ideas would be greatly appreciated

cheers
Michael

[GT4 20]

Use a fully synthetic oil such as Mobil 1 or Castrol RS for example. Water feed on my Rover which uses a T25 comes from the cold side of the radiator and 'drains' to the bottom hose. This way, after shut down, water is syphoned upwards to help with cooling.

When you fit a new turbo, what start up process do you go through. You MUST disconnect the HT lead and crank the motor over until full oil pressure is reached. The new turbo will not have any oil to lubricate the bearings and by starting the motor up straight away, the turbine will spool up due to the exhaust gasses and will run for several vital seconds until the olil pressure is high enough to ensure proper lubrication. Failure to follow this proceedure often ends up in irreversible bearing / seal damage.

Also, shut down is equally important. Don't switch straight off after a hard run. The oil will overheat in the housing and as a result, carbon deposits will build up which restrict oil flow. Much the same with with coronary arteries of smokers etc.
HTH
Gary

[Ae92typeX]

Probably not this, but is it a custom 4age'd turbo?- if so where are you running your oil drain to? Ive heard afew guys on here say if its to low then it does not drain properly and you get a pressure build up in the turbo, potentially blowing seals. Linked to this also is making sure the crankcase is breathing/venting properly.

[Lloyd]

While on the subject, how much oil pressure is too much for a turbo? Mine smokes a bit after a thrashing and wondering if the oil pressure is a bit high. Turbo is a bit worn out and need replacing eventually, but once I get a new one I dont really wanna be blowing seals and things

[Bazda]

i wouldnt run fully synthetic oil in your 4agte, when i ran it, my oil pressure got real low once the oil was hot and oil temps went right up!.
Also people told me that fully synthetic can shorten the life of your turbo cos its so thin. And I also have a earls oil cooler mouunted in the front.
i just run a 15/40w mineral oil in mine and it seems to be working well.

[atmosports]

Are you running any sort of restrictor in the oil feed line??? Most factory turbo setups have some form of restriction in the oil feed going to the turbo. Usually it's just a small hole for the oil to flow through. If you haven't got one & the turbo starts smoking quite quickly, even if the seals etc have been replaced or when idling for long periods then this would be your cause, too much oil. As above make sure the drain is high enough in the sump & baffled to stop oil from being forced back up it when accelerating/braking/cornering etc.

[mike86ze]

thanks for the info
yea, the last one just started after a long period of idle in traffic jam but now comes after only short periods.
but it makes a kinda faint high pitch whine when crusing on the highway which made me wonder if there wasnt enough oil getting there?
or is this ok for a sleeve bearing?
ran a 2mm restrictor on the rb20 one but just used the line that came with the rx7 so ill check on that.

it is a custom 4agte but the sump drain is pretty high.
how would you put a baffle in?

ill re-arange the water lines to. cheers for the info Gary.

Michael

[matt dunn]

Use a fully synthetic oil such as Mobil 1 or Castrol RS for example.
Gary

i wouldnt run fully synthetic oil in your 4agte, when i ran it, my oil pressure got real low once the oil was hot and oil temps went right up!.
Also people told me that fully synthetic can shorten the life of your turbo cos its so thin.

Yes Castrol RS and synthetics etc are no good for turbo's.
We had both turbo's on our corolla overhauled and on shit itself first event.
Sent it back to the turbo man and he had one look at it and said " your running synthetic oil arn't you" That was the cause of our turbo failures.
Changed to non synthetic and solved our turbo problems.

[GT4 20]

Yes Castrol RS and synthetics etc are no good for turbo's.

Where do you get that from?
I've had turbo cars for years now and always run them on a fully synthetic oil and yet to have a turbo failure. Admittedly, I found Mobil 1 too thin for the Rover, so swapped to RS and have had no issues with it whatsoever.
Gary

[Bazda]

Yes Castrol RS and synthetics etc are no good for turbo's.

Where do you get that from?
I've had turbo cars for years now and always run them on a fully synthetic oil and yet to have a turbo failure. Admittedly, I found Mobil 1 too thin for the Rover, so swapped to RS and have had no issues with it whatsoever.
Gary

he gets that from over 10 years of circuit racing experience. When the car is pushed to its limit fully synthetic oil isnt good.
As my old man has been racing cars turbo and n/a for over 20 years now he has never ran a synthetic oil!! people who do run bearings and all sorts.

maybe u dont drive your car hard enough. Maybe u should go put some oil temp gauges and pressure gauges on your car and see whats going on

[GT4 20]

Oh well, guess that I'm some little teenager who has no experience with cars or racing so I'm obviously talking cr@p I'll get my coat.....
Gary

[Bazda]

hey man no ones calling you a little teenager who doesnt know crap, you might know lots for all we know. But from experiences 4ages dont like fully synthetic oil, and turbos blow up when they are being used all the time.

[atmosports]

I'll agree with Bazda here, my old man has probably got similar experience to his, i.e 40 odd years of Motorsport work, mostly engine builds etc. To this day we still run a mineral oil, usually a straight 50w in the vast majority of our motor's, the exceptions being those that we are screwing every last HP out of & we see back after every two meetings for a full rebuild or the odd Honda VTEC. All our WRX/EVO motor's we run mineral, my own turbo road cars I run mineral. Don't ask me why but syntethic just doesn't seem to have the same cushioning effect as mineral does & I've yet to see a synthetic that is as tacky/sticky as the mineral oil we run.

As for a baffle, same as any sump baffle really, you need to make up a plate baffle that minimises the chanc of any sump oil going back up the turbo drain, yet still allows the oil from the drin out, basically you'll need a plate to cover theopening around the top & sides but let the oil flow out the bottom from the turbo drain. I ain't got anything to take a pic of to show you, but Bazda might have one or a sump etc he could show you.

[Bazda]

i dont have any baffles on mine, i get no smoke at all, never seen a puff in it's one year being turbo.
my drain is at the top of the sump right below the oil filter.

[vvega]

you just put the exit above the sump baffel

as with sinthetics its the oil thinning that causes the issues
synthetica gerally get way to thin under heavy load and require a oil cooler to keep the oil temp within spec

as a rule of thumb i use for a 15-50 for nz conditions
this is what the the handbook sugests for our range of operating temperatures
as for restrictor a i.5mm hole is plenty for a bushed turbo if its a gt ball bearing they recomend a .9mm restrictor

hope this helps

v

[Wildcard]

Some pretty broad sweeping statements being made here!
Can someone provide evidence thats not circumstantial regarding the superiority of mineral to synthetic oils for stressed turbo applications? Its an interesting area and a bit of back reading would be good.

A quick search indicates there are a number of high performance manufacturers such as Porsche / Aston Martin and AMG who recommend Mobil 1, no doubt there are others representing the other brands.

Also FWIW I believe synthetic oils have only been on the market for about 30 years from the first release by Mobil / Amsoil so compared to mineral there is still going to be less experience out there.

[Lloyd]

The stupidly expensive Shell oil (fully synthetic) states that its recommended/approved for the likes of BMW, Porsche etc etc and of course the Helix ads on TV "If its good enough for Ferrari...."

[GT4 20]

Echoing Ben's comments. It's a pretty wild statement saying....

Yes Castrol RS and synthetics etc are no good for turbo's.

I have no experience with the 4AGE motor, so fully synthetic oil may well not suit this particular engine, but to say that it isn't suitable for all turbos is a bit of a silly thing to say IMHO.

There are many reasons why an engine may fail to be 'lubricated' effectively by an oil. Temperature is obviously the main factor and while I may not have over 10 years circuit racing experience, I have owned a few turbo cars and raced them. My current build will still run on Castrol RS fully synthetic but will have a front mounted oil cooler controlled by a waxstat thermostat. This will ensure that the oil isn't overcooled on touring stages and isn't overcooked on the specials - especially as a sump guard will effectively prohibit airflow over the sump which acts as a cooler in itself. Waxstat will operate at 80 degs C, the approximate optimum temp you want oil to be at.

And Castrol RS is what I put into the GT4 and will continuse to do so until someone shows me some hard evidence that it isn't a good thing to do

So before you make comments like....

maybe u dont drive your car hard enough. Maybe u should go put some oil temp gauges and pressure gauges on your car and see whats going on

don't assume that someone doesn't have any experience. If you're going to make a claim, back it up by evidence. Just saying "My Dad says it's cr@p" doesn't prove anything
Gary

[Bazda]

well u do know your stuff you obviously do a few targas or something so u have experince under your belt, i guess why change unless u have seen the proven results.
maybe because some turbos are ball bearing and some arent, that could be why u can use synthetic on some.....thats just a guess i dont really know.

[matt dunn]

Not trying to cause an arguement or anything here.

All I can say is the guy who does our race car turbo's and does turbo reco's as a full time job told us not to run synthetic's

Is there a synthetic on the market that has "turbo tested" written on the bottle like GTX protec??

Matt