thetrashcanman Posted March 22, 2014 Share Posted March 22, 2014 Ahh, right...so they can withstand more heat. and more boost Also interested in this thread as I will possibly have a set to rebuild, good luck with this mate Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 22, 2014 Share Posted March 22, 2014 Uk turbos are smaller. Most have steel turbine blades, some are ceramic. IMHO and experience the Jap spec ceramics are infinitely superior. Much faster spool, more reliable, with far less danger of going "smoky" in old age. Given a choice a Jap spec engine would be my choice, by a big margin. Quote Link to comment Share on other sites More sharing options...
Big Supes Posted March 22, 2014 Share Posted March 22, 2014 and more boost Hell yes. QUOTE=Chris Wilson;3843519]Uk turbos are smaller. Most have steel turbine blades, some are ceramic. IMHO and experience the Jap spec ceramics are infinitely superior. Much faster spool, more reliable, with far less danger of going "smoky" in old age. Given a choice a Jap spec engine would be my choice, by a big margin. Interesting that a larger turbo with pretty much the same internals would spool faster. So the jspec turbos are good for 1.3/1.4 bar of boost? My UK's are pretty spot on, but should they ever go (*touches wood), the obvious choice would be jspec replacements? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 22, 2014 Share Posted March 22, 2014 No J-Spec turbos struggle to about 1.2 bar, and seem reasonably reliable at that figure, but they are way outside their efficiency island there. UK spec ones with the common steel internals seem to hold together at 1.3 bar, maybe a drop more, but again are way outside their efficiency zone. It's no good saying you get 1.4 bar if the efficiency is dire and the air temps are going through the roof. the Jap spec ceramics spool a lot faster, and seem to last a lot longer before going smoky. Probably because being lighter the internals put less loading on the bearings. Maybe they are balanced better, that's a comment a turbo rebuilder mentioned about ceramic turbos in general. my experiences lead me away from rebuilt turbos altogether, as they never seem as reliable as a factory new one. J-Spec and UK spec are not directly interchangeable, they have different stud patterns to the manifold. It's just a strong personal preference of mine, I prefer the J-Spec model in every way, engine, less gizmos, likely to have seen far less salt, and likely to have seen less of UK Toyota dealers, who apart from a very few, never seemed to get to grips with the MKIV. Quote Link to comment Share on other sites More sharing options...
thetrashcanman Posted March 22, 2014 Share Posted March 22, 2014 No J-Spec turbos struggle to about 1.2 bar, and seem reasonably reliable at that figure, but they are way outside their efficiency island there. UK spec ones with the common steel internals seem to hold together at 1.3 bar, maybe a drop more, but again are way outside their efficiency zone. It's no good saying you get 1.4 bar if the efficiency is dire and the air temps are going through the roof. the Jap spec ceramics spool a lot faster, and seem to last a lot longer before going smoky. Probably because being lighter the internals put less loading on the bearings. Maybe they are balanced better, that's a comment a turbo rebuilder mentioned about ceramic turbos in general. my experiences lead me away from rebuilt turbos altogether, as they never seem as reliable as a factory new one. J-Spec and UK spec are not directly interchangeable, they have different stud patterns to the manifold. It's just a strong personal preference of mine, I prefer the J-Spec model in every way, engine, less gizmos, likely to have seen far less salt, and likely to have seen less of UK Toyota dealers, who apart from a very few, never seemed to get to grips with the MKIV. Assuming you've driven a J-spec and UK car to compare Chris, do they feel different when you're driving? Surely the earlier spool on the J-specs wouldn't make too much of a difference in sequential mode, as in it wouldn't be that noticeable I would have thought, but I've only driven a couple of TT's all with UK specs or one with UK spec internals And Chris is right the UK's are good to about 1.3/1.4 bar but the extra boost doesn't really do much power wise, just creates a lot more waste heat with no real power gains Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 22, 2014 Share Posted March 22, 2014 I drive the damned things in my sleep The Jap specs definitely spool a lot quicker than the UK spec engines. Not much difference in spool between J-Spec sand J-Spec VVTi, I suspect the VVTi was more to meet emissions than for performance. Not sure what you mean when you say "in sequential mode". They are always in sequential mode unless broken. Quote Link to comment Share on other sites More sharing options...
Suprash Posted March 22, 2014 Author Share Posted March 22, 2014 Haha, I love reading Chris' posts lol, plus his knowledge is untouched. And I thought everyone raved about UK's being better, stronger, being able to hold more boost with better reliability ? What's happening around here lol, it's like when scientist suddenly say eating chocolate is good for you after years of being told it'll make you fat lol Chris can the housings be swapped between uk and jspec to sort the stud pattern issue ? Quote Link to comment Share on other sites More sharing options...
TBDevelopments Posted March 22, 2014 Share Posted March 22, 2014 (edited) i beg to differ that a failed turbo can't damage the engine. i've rebuild a number of 3sgte in my time because of failed ceramic turbochargers. Turbine shatters with a loud bang, driver lifts and it gets sucked back into the engine on exhaust reversion. I can tell you from experience it make a mess and i know this for a fact because of the countless hours digging ceramic out the head prior to rebuild because the ceramic takes the tip off the decking tool when were skimming them afterwards. Tim Edited March 22, 2014 by TBDevelopments (see edit history) Quote Link to comment Share on other sites More sharing options...
inazone Posted March 22, 2014 Share Posted March 22, 2014 Hi Suprash, its funny I am planning to do the same as you, although I will be modifying my turbos to take a GT26 turbine wheel replacing the jap ceramic wheel. I will also be enlarging the waste gates for better flow. I too am a complete novice when it comes to turbos however I am keen to learn by some experimentation. Paul Whiffin is currently doing something very similar making hybrid turbo's. I am surprised that nobody has really bottomed this turbo mystic out for the Supra Twins, as everyone seems to want to go Single all the time. I will be following your efforts closely. Quote Link to comment Share on other sites More sharing options...
mellonman Posted March 23, 2014 Share Posted March 23, 2014 i beg to differ that a failed turbo can't damage the engine. i've rebuild a number of 3sgte in my time because of failed ceramic turbochargers. Turbine shatters with a loud bang, driver lifts and it gets sucked back into the engine on exhaust reversion. I can tell you from experience it make a mess and i know this for a fact because of the countless hours digging ceramic out the head prior to rebuild because the ceramic takes the tip off the decking tool when were skimming them afterwards. Tim You are right they can of corse, but most are saved by the intercooler I would of thought, but I guess its how they fail mine was a total fail with the hole number 2 compressor wheel raming into the housing + a shed load of oil from the turbo, which would of made all the turbo heavy peaces stick in the oil I guess, well I can just count myself lucky then Quote Link to comment Share on other sites More sharing options...
TBDevelopments Posted March 23, 2014 Share Posted March 23, 2014 its the other side of the turbo that typically causes the damage. Its when the exhaust side failure. As you say big parts are caught on the intercooler if the compressor fails, but the compressor isn't ceramic there typically cast alloy or billet (typically) the ceramic turbos are turbine and shaft. its down to ceramic exploding, from inballance, overspeed, high egt few different causes. Loud bang and the driver lifts off and the cam overlap/reversion sucks it all back into the cylinders. This doesn't happy all the time as if you keep your foot in for a few seconds it'll all be blown out the back, or if the turbine snaps off in 1 clean piece of the shaft. Seen this happen before finding a complete turbine while sitting in the backbox tip bung lol. With a tiny amount left on the end of the shaft stopping any shaft movement or leaks. Car just ran like a non turbo without any wierd effects. Tim Quote Link to comment Share on other sites More sharing options...
Suprash Posted March 24, 2014 Author Share Posted March 24, 2014 So lesson here is........always keep your foot in ! Quote Link to comment Share on other sites More sharing options...
markssupra Posted March 24, 2014 Share Posted March 24, 2014 So lesson here is........always keep your foot in ! Quote Link to comment Share on other sites More sharing options...
TBDevelopments Posted March 24, 2014 Share Posted March 24, 2014 yeah works on so many levels. lol Tim Quote Link to comment Share on other sites More sharing options...
Suprash Posted April 27, 2014 Author Share Posted April 27, 2014 So I just thought I would give a quick update here, I have received my turbo rebuild kits all the way from down under Australia Shame they are for the wrong turbos lol, I have CT12b, I need CT20, so we are currently exchanging them, but sending stuff back to Oz and then waiting on the other kits has written off 2 weeks or so But in the meantime, I done this........ And have since completely split the cartridge, oil seperator, thrust bearing, journal bearings etc are all out, I'll post up more pics once my phone is repaired, but its so frustrating not having the correct kit as I could have had these rebuilt/balanced by now Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted April 27, 2014 Share Posted April 27, 2014 Does the shaft need grinding? If so you need oversize bearings. I would be surprised if they don't need grinding. Quote Link to comment Share on other sites More sharing options...
Suprash Posted April 27, 2014 Author Share Posted April 27, 2014 Why would they need grinding ? The shaft play on these was minimal, in fact they where tighter then any other turbo I have ever felt, but they leaked oil badly due to seals. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted April 27, 2014 Share Posted April 27, 2014 Same as a crankshaft might need grinding, wear and surface imperfections on the bearing surfaces of the shaft. It's one of the main reasons why I do not like rebuilt turbos. I prefer full diameter shafts that hopefully are ground on a centreless grinder and have a perfect finish, which the manufacturer is far more likely to achieve than a re-builder. Quote Link to comment Share on other sites More sharing options...
Suprash Posted April 27, 2014 Author Share Posted April 27, 2014 I hate rebuilt turbo too, I've never had a set that have seen past 5-10,000 miles, and when you have to get a pair rebuilt at a cost of £5-700+ is exactly the reason why Im doing what I am. This rebuild will cost me £160 per turbo, so £320 per pair of twins, I dont care if I dont get any better mileage then before, 5-10,000 miles for £160 Vs 5-10,000 miles for £5-700+, Im sure even you can appreciate trying to understand this more yourself I have tolerances to check, I'll check them, if they all play out, bob-on ! Quote Link to comment Share on other sites More sharing options...
Nic Posted April 27, 2014 Share Posted April 27, 2014 i've rebuild a number of 3sgte in my time because of failed ceramic turbochargers. Turbine shatters with a loud bang, driver lifts and it gets sucked back into the engine on exhaust reversion. Tim This happened to my Supra, it wasn't pretty when the engine was opened up! Quote Link to comment Share on other sites More sharing options...
TBDevelopments Posted April 27, 2014 Share Posted April 27, 2014 Thanks nic for bumping this up, i forgot about it. Friday i had a customer drop off a 3sgte with me where the ceramic had exploded on the turbine side only and destroyed the engine. I've had to take pictures as this failure happened at a garage while the car was having a "battery change" or something. so i've had to provide evidence for everything we found. I'll bring the camera back from the workshop tomorrow and post up those pictures just for peoples interest of what has happened when the turbo fails. Tim Quote Link to comment Share on other sites More sharing options...
TBDevelopments Posted April 28, 2014 Share Posted April 28, 2014 heres some pictures for your entertainment. Ceramic turbine failed, and on cam-overlap got sucked back into the engine resulting in one dead engine. Good way to blow 3.5 grand Tim Quote Link to comment Share on other sites More sharing options...
TubbyTwo Posted April 28, 2014 Share Posted April 28, 2014 Ooo crunchy... Quote Link to comment Share on other sites More sharing options...
Suprash Posted April 29, 2014 Author Share Posted April 29, 2014 Holy shit ! And all it's happened whilst doing a simple battery change ? WTF did they do ? I'd be pissed ! Quote Link to comment Share on other sites More sharing options...
TBDevelopments Posted April 29, 2014 Share Posted April 29, 2014 the garage recon'd they just rev'd it up on the ramp, heard and noise and turned it off...... This can only happen on full boost and throttle, so i suspect someone thought it would be a good idea to take it out and see how the car performed without the customers knowledge. But this just my opinion. I'm only here to pick up the pieces lol. But i thought i'd post this as a few people believed it wasn't possible for engine damage to happen when the turbine failed. Tim Quote Link to comment Share on other sites More sharing options...
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