330BHP Rebuilt Engine Smoking on Overrun

[ibizacupra]

Can anybody confirm that this restrictor is defo required on ALL makes of turbos with ball/roller bearings, or is it just garrett family/ garrett hybrid? i'm now fiting an IHI vf searies turbo which is ball bearing but done a serch and not found much on anybody having any problems with IHI?

IHI oil intake port is already reduced bore.

 

[cupra_matt]

every turbo kit i have ever fitted have included restrictors, All have been garrett turbos mind.

1.8T oil pressure is over 45 PSI, iam sure of it.

 

[Andy Cotton]

HTC - I wouldn't say it was hi vacuum. If I rev to 6K with 1Bar of boost and let go of the throttle I get no smoke - I would class that as hi vacuum.

I basically get it with no throttle when the revs go from about 2500 to 1500 and then if you blip the throttle at tickover it will smoke until it's cleared itself. It gets worse if you go downhill with no throttle and the revs are sustained around the 2500 mark.

Bill - this is why early on in the chat (see above) I did mention that I thought that it already had one as mine looks exactly like your photo above.

Anyway - I put an inline oil pressure gauge inline with the turbo oil feed pipe and was getting around 30PSI at tickover (with cold engine) and when I gently reved it to 3000rpm the oil P went to around 50 PSI. I spoke to Turbo Dynamics about this and they said that you will need one if the oil P is > 45PSI.

I've replaced the oil and filter and TD sent me a back to back with a built in oil restrictor which screws straight into the turbo housing. If I compare the two different adaptors the one I have been running with has about a 2.5-3mm hols and the TD one has a 1mm hole.

It's a bit dark at the mo but I will try it out in the light - see if she's stopped smoking.

Anybody know if I have damaged the turbo ?

I spoke to the company who re fibed the head and they said that they have never had a problem with the valve guide oil seals and the Karl Schmidt oil pump is the same as OE so it souldn't give any more oil P.

As for the IHI - ask Bernard Scouse as he always uses the VF34 IHI but I don't think that he uses an oil restrictor.

Andy

 

[ibizacupra]

I spoke with Owen Developments yesterday as they rebuilt my new one with their uprated bearings in it. The bearing cartridge is held in with an insert which itself has a small 1mm hole in it, which is the restrictor they say, so no additional restrictor is req'd.

such conflicting inputs.

 

[minimivic]

I spoke with Owen Developments yesterday as they rebuilt my new one with their uprated bearings in it. The bearing cartridge is held in with an insert which itself has a small 1mm hole in it, which is the restrictor they say, so no additional restrictor is req'd.

such conflicting inputs.

This is doing my head in.....aahhhhhhhhhhhhhh i think i'll flip a coin on this one probably more reliable. It is interesting that the garrett website says use a restrictor so I may just do that anyway.

 

[cupra_matt]

On a garrett, definately use one, this i know to be fact.

 

[ibizacupra]

This is doing my head in.....aahhhhhhhhhhhhhh i think i'll flip a coin on this one probably more reliable. It is interesting that the garrett website says use a restrictor so I may just do that anyway.

I know what you mean.. read all the same stuff even on garretts site.
looking at my cartridge it does have a very small inlet size tho

 

[Andy Cotton]

Read this and make your own mind up - I'm putting one in .

Ball-bearing turbochargers can benefit from the addition of an oil restrictor, as most engines deliver more pressure than a ball bearing turbo requires. The benefit is seen in improved boost response due to less windage of oil in the bearing. In addition, lower oil flow further reduces the risk of oil leakage compared to journal-bearing turbochargers. Oil pressure entering a ball-bearing turbocharger needs to be between 40 psi and 45 psi at the maximum engine operating speed. For many common passenger vehicle engines, this generally translates into a restrictor with a minimum of 0.040" diameter orifice upstream of the oil inlet on the turbocharger center section. Again, it is imperative that the restrictor be sized according to the oil pressure characteristics of the engine to which the turbo is attached. Always verify that the appropriate oil pressure is reaching the turbo.

The use of an oil restrictor can (but not always) help ensure that you have the proper oil flow/pressure entering the turbocharger, as well as extract the maximum performance.

 

[Fl@pper]

so not too little and not too much i guess - i can see the theory windage wise though

we use scraper plate off the crank webbing on the dragster but thats mainly to ensure the oil doesnt go short anywhere

 

[ibizacupra]

the internal one is ~1mm said Owens, which is the same diameter as the 0.040" on garrett's site.......... to similarly sized reducers next to each other wont effect flow much different to one.. but they quote pressure reducing, which is flow related from the bore.

adding one seems the wiser choice.

 

[Andy Cotton]

MMMmmmmmm - Bill that is even more confusing.

If there is already a 1mm restrictor built in (mine looks bigger than that although I have not measured it) then why are Garett giving the above advise on their site ?

On one hand they are saying if your oil P is > 45PSI then you need one, and on the other hand they are putting one in anyway. I must admit the one in your phot looks bigger (looks the same size as mine).

So in theory then (according to Owen) adding that restrictor to my Turbo will make no difference as it has one built in.

 

[Andy Cotton]

Chaps,

See below



Photo1 is my new back to back with 1mm restrictor
Photo 2 is my old back to back which has been in the car for the last 15K
Photo 3 is the so called built in restrictor (within the turbo) and I recon is just over 3mm dia.

Any comments ?

 

[ibizacupra]

MMMmmmmmm - Bill that is even more confusing.

If there is already a 1mm restrictor built in (mine looks bigger than that although I have not measured it) then why are Garett giving the above advise on their site ?

On one hand they are saying if your oil P is > 45PSI then you need one, and on the other hand they are putting one in anyway. I must admit the one in your phot looks bigger (looks the same size as mine).

So in theory then (according to Owen) adding that restrictor to my Turbo will make no difference as it has one built in.

mine does'nt have a hole down the middle like yours looks to have. There's a small hole (the 1mm one) out to the side. The insert looks like yours, but I cant see if the middle of your insert for its bore.

Arnold from Pagparts has confirmed I need one, but since he sold me the original unit I've had Owens put in their motorsport bearings in there. Maybe they used different fittings on reassembly.

how much was your reducer fitting Andy?

 

[Andy Cotton]

Turbo Dynamics - £9.95 + £2 delivery + VAT

About £15 delivered.

 

[ibizacupra]

thanks Andy

 

[Willie]

The one in picture 3 seems to have a ball in it which I would assume it a shuttle or one way valve, was there a spring behind it?

 

[cupra_matt]

If you run a GT28RS you need number 1 from the photo's. Even the GTRS elims need one.

 

[Andy Cotton]

Just thought I'd let you know (to end this thread) - I have fitted the back to back as in photo 1 above and been for a 20 mile drive and .............

NO SMOKE !! I don't believe it myself. Hovever I have changed the oil for normal mineral oil (just while I finish the running in) and it's a grade thicker when it's hot - I think I'll go to the Motul stuff after.

Bill - How much for 5L ?

Andy

 

[max_torque]

When you are at high load, then you have high turbo rotational speed, and at high speed the oil is simply centrifuged off the shaft and bearing pack into the void of the oil return chambers within the CHRA. So i suspect that is the reason that it did not smoke at high load/rpm, but only at low load/rpm's, where the turbo is spinning slowly enough for the oil to remain attached to the shaft and then be sucked through the compressor oil seal???

 

[ibizacupra]

Just thought I'd let you know (to end this thread) - I have fitted the back to back as in photo 1 above and been for a 20 mile drive and .............

NO SMOKE !! I don't believe it myself. Hovever I have changed the oil for normal mineral oil (just while I finish the running in) and it's a grade thicker when it's hot - I think I'll go to the Motul stuff after.

Bill - How much for 5L ?

Andy

its in 2ltr tins. V300 15W50 Motul Competition like I run badgerwagen on.
£17.84+vat /2ltr

Glad it looks like its sorted.
restrictor it is then.