yoeddynz Posted May 11, 2012 Share Posted May 11, 2012 I just read in a read about turbo installations that most turbos only require very little oil pressure. Like about 10psi? Some turbo feed lines have a restrictor built in to keep the pressure in check. I am wondering about this. my setup is draw through and if my turbo is seeing too high oil pressure then when my throttle is shut then this will only assist in oil wanting to get sucked past the seals by the vacuum? Quote Link to comment Share on other sites More sharing options...
Hemi Posted May 11, 2012 Share Posted May 11, 2012 yup they literally only need a constant stream of oil mang . too much WILL get past the seals id be happy with 6-10psi Quote Link to comment Share on other sites More sharing options...
My name is Russell Posted May 11, 2012 Share Posted May 11, 2012 Get a one from this joker! http://www.ebay.com.au/itm/Turbo-Oil-Fe ... 852wt_1185 Good quality and can do you any custom combo you require. Fitted 1.5mm restrict-or each end after my pressure blew a seal and seems to have resolved it. Escorts allot quicker not sunning on oil too Oh and the stuff he sends is 'kinugawa' which is apparently quite good. Even gave me a spare fitting. Quote Link to comment Share on other sites More sharing options...
yoeddynz Posted May 11, 2012 Author Share Posted May 11, 2012 cool- i'll look at my feed line tomorrow and check that it doesnt already have a restrictor in it. My car does use oil- 1 litre over the 1800 km trip just done so not that bad. Also some leaks from the sump etc and I lose some from open breather too. I did increase the oil pressure by modifying the regs when i rebuilt the engine so if my turbo seals are tired it must be best not it over feed it eh? Quote Link to comment Share on other sites More sharing options...
Shandangles Posted May 11, 2012 Share Posted May 11, 2012 prob wrong but i have always thought restrictors slowed the flow of the oil but the pressure stayed the same. i dont see how making the hole smaller reduces pressure, if anything it increases it. Think of putting your finger over the end of a hose, more pressure but way less flow. Quote Link to comment Share on other sites More sharing options...
Yowzer Posted May 11, 2012 Share Posted May 11, 2012 More pressure on the restricted side. We are talking about pressure after the restriction. Which in your hose scenario would be zero. Quote Link to comment Share on other sites More sharing options...
lou Posted May 11, 2012 Share Posted May 11, 2012 Na you're thinking about it wrong. You are thinking about the flow not the pressure. Someone else need to elaborate cause I'm shit at explaining this. Quote Link to comment Share on other sites More sharing options...
Yowzer Posted May 11, 2012 Share Posted May 11, 2012 Increased pressure will increase the flow through a restriction. However decreasing the restriction will decrease pressure but increase flow through it. If you are electronicly minded, it is the same as a resistor. The turbo itself is a restriction to the oil. The bearings have a very fine clearance, and the oil pump slams out 50odd psi depending on many things. Fed direct, there would be 50psi of oil at the turbo bearings (assuming they are not fucked / leaking). A restriction in the line to the turbo limits the amount of oil that can get past. As such, the turbo will be getting less oil pumped through it, but also at less pressure. As the turbo does not need 50psi and a shittonne of flow this is all G. More or less. Quote Link to comment Share on other sites More sharing options...
yoeddynz Posted May 11, 2012 Author Share Posted May 11, 2012 ^ i get it. So any ideas on what sort of max and min pressure most modern turbos need? I suppose i could be really anal and put a pressure gauge in line after the restrictor to check. Quote Link to comment Share on other sites More sharing options...
yoeddynz Posted May 11, 2012 Author Share Posted May 11, 2012 Ok found this. My turbo is a older type with journal bearings. Looks like my pressure might be fine for it. Read here... http://www.turbobygarrett.com/turbobygarrett/faq Quote Link to comment Share on other sites More sharing options...
Hemi Posted May 12, 2012 Share Posted May 12, 2012 what yowzer siad . if you mash too much in there to the point were the return cant cope is just bails out the turbine seal . which is very much like a piston ring and as such does not cope with constant positive pressure very well . trust me i know had a truck with its breath blocked and the turbo was the weakest link . that = entire road covered in white smoke Quote Link to comment Share on other sites More sharing options...
yoeddynz Posted May 12, 2012 Author Share Posted May 12, 2012 I think my turbo has the old style carbon seal which is much better suited to draw through turbos. The car doesn't seem to blow any blue smoke but I just wasn't sure if I may have been over feeding it. I think I will still make a little tee that I can screw a pressure gauge into. Quote Link to comment Share on other sites More sharing options...
Llama Posted May 13, 2012 Share Posted May 13, 2012 Ok found this. My turbo is a older type with journal bearings. Looks like my pressure might be fine for it. Read here...http://www.turbobygarrett.com/turbobygarrett/faq Yup, that site seems correct with everything I've heard too. Quote Link to comment Share on other sites More sharing options...
yoeddynz Posted May 13, 2012 Author Share Posted May 13, 2012 Yep and my turbo is a garrett ai research. Not sure what else my model was used on. But quite old. Quote Link to comment Share on other sites More sharing options...
drftnmaz Posted May 14, 2012 Share Posted May 14, 2012 normal restrictors are 2mm for journal bearings and 1mm for ball bearing, it is often drilled into part of one of the banjo's(or bolts) or built into the oil inlet of the turbo Quote Link to comment Share on other sites More sharing options...
yoeddynz Posted May 14, 2012 Author Share Posted May 14, 2012 I'll have a look and see if any restrictors. Cheers Quote Link to comment Share on other sites More sharing options...
l1ttle_d3vil Posted May 15, 2012 Share Posted May 15, 2012 Just had mine oil lines off lastnight, and its got a 2mm hole for my journal bearing turbo. Steve Murch explained it all to me in really simple terms, now I can't remember any of it... something like it doesn't need any massive pressure at all, just a constant oil supply for the bearing to float on and it wasn't the pressure which kills the seals but the volume going passed them... probably way off there though... Short answer was just put a restrictor on. First turbo I put on shat itself with oil coming out anywhere it could, second turbo I fitted a restrictor and its been fine since. I've got a brass fitting which goes directly into the turbo core, which the oil line connects to. Filled the centre of the brass fitting with braising, then drilled the hole through it... simple as Quote Link to comment Share on other sites More sharing options...
drftnmaz Posted May 16, 2012 Share Posted May 16, 2012 yea journal bearing turbos just need a constant trickle to give the bearings a film to run on, and BB turbos only need a constant drip to keep them lubed in race cars where you have high oil pressure you would normally fit a restrictor at the feed from the block and then a gauge in the line to check it doesn't go really high with sustained high rev's, then check on the dyno, and fit a smaller or multiple restrictors reducing the flow and altering the pressure i killed a hks t28 turbo on one of my early engines, i went from a factory t28 BB to a hks BB, thinking the restrictor would be in the line (and seeing the 2mm one in the banjo) i thought it would be sweet, 700k's later dead turbo, only to find out when nissan got garrett to produce the t28 they requested the restrictor be fitted on the inlet of the turbo, however hks did not stipulate this and requires external 1mm restrictor, im still sour about that turbo!! damn you HKS! Quote Link to comment Share on other sites More sharing options...
cletus Posted May 16, 2012 Share Posted May 16, 2012 http://www.compturbo.com/spotlights/oil_less no oil feed needed on these Quote Link to comment Share on other sites More sharing options...
yoeddynz Posted May 16, 2012 Author Share Posted May 16, 2012 Hmmmmmm. I wonder if other turbo companies will head this way? I must check my feed line ASAP (not now..it's cold outside and sitting in front of fire place is nicer than being under bonnet) My car uses more oil when town driving ie start stop, waiting at intersections. It's not blowing blue smoke but if the pressure is to high then it is most likely getting a little past the seals at idle. Plus if so then that may be one reason, on top of the over rich idle setting, that my wideband sees rich mixture? Would extra oil getting burned raise the reading? Quote Link to comment Share on other sites More sharing options...
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