Jezz Posted August 11, 2005 Share Posted August 11, 2005 Jake, second post on branners says he got the pics the wrong way round. Darker coloured (smaller) blades are ceramic. Quote Link to comment Share on other sites More sharing options...
Jake Posted August 11, 2005 Share Posted August 11, 2005 Jake, second post on branners says he got the pics the wrong way round. Darker coloured (smaller) blades are ceramic. No it doesn't! (Unless I'm going blind ) Branners' second post in that thread (3rd post of the thread) clearly says edited to position the pictures better, basically the white turbo is the j-spec ceramic. Quote Link to comment Share on other sites More sharing options...
Clarkey Posted August 11, 2005 Share Posted August 11, 2005 and mine's fast enough! for now.. I think I'm going to have to race someone who has a BPU J-Spec. They'll be plenty to choose from at Bovington! Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted August 11, 2005 Share Posted August 11, 2005 Correct about manifolds, just had a look. Cant say i've ever driven a uk car. Is there really that much difference?? Yes, a huge amount. J-spec turbos for normal road use, are far superior, IMO. Quote Link to comment Share on other sites More sharing options...
Jezz Posted August 11, 2005 Share Posted August 11, 2005 No it doesn't! (Unless I'm going blind ) Branners' second post in that thread (3rd post of the thread) clearly says Ok, thats probably the hardest to understand thread ever!! Can we just stick to 'j spec turbs are made of cheese'?? I'd rather take the word of someone that can single handedly fit a vvti engine! I was always lead to believe it was the uk turbs that had bigger wheels. Now i'm going to sit in the corner and cry. Quote Link to comment Share on other sites More sharing options...
Homer Posted August 11, 2005 Share Posted August 11, 2005 And whats spool up rpm? I'm not totally sure what you mean. Spool time does depend on gear. When booting it in from no throttle in 1st it makes 1.0 bar at about 4.6-5k rpm. In 2nd it makes 1.0 by about 4.5k rpm. The real difference I find is when booting it from a rolling start. At 4k rpm and above in 3rd to 6th gear it goes from cruising at 0 bar to 1.0 bar in a fraction of a second. There's really no noticeable lag at all. I've driven quite a few UK and Jap cars on stock turbo's and in whatever state of tune the equivalent Jap one *feels* quicker. It might not appear to be when looking at the power figures but the fast spool really makes the Jap cars feel faster. Quote Link to comment Share on other sites More sharing options...
Jezz Posted August 11, 2005 Share Posted August 11, 2005 Probably not much in it then. My j spec comes on to boost on first turbo at around 2.5 then 4k rpm for second turbo. Its a bit down on boost for a de-cat car though. Tops at around 1.0 bar. Still on stock smic though, and its battered! Quote Link to comment Share on other sites More sharing options...
Nic Posted August 11, 2005 Share Posted August 11, 2005 What a very confusing thread, with lots of mis-information. Suggest it is pruned to show the correct info for future reference. Quote Link to comment Share on other sites More sharing options...
Jspec Germany Posted August 12, 2005 Share Posted August 12, 2005 Whoa, pruning of threads now? What are we, elitest botanists? Let's not remove peoples' comments unless we're putting this in the FAQ section. I think it's good that people have opinions and express them. There's a lot of good knowledge and experience on this forum. I could sum up this discussion with one statement. Jspecs are quicker, but export models are faster (assuming bone stock config with all equal perrishables and same driver). Personally, I prefer the raw uncivilized manner of my Jspec, but then again I'm bias having brought if from Japan myself. I do envy the bigger brakes (upgrade in progress), bigger injectors, and various coolers, but you can have the creamy leather, rhino tusks, hood scoop, and extra weight. Is there really a mini-bar in the backseat? Quote Link to comment Share on other sites More sharing options...
Nic Posted August 12, 2005 Share Posted August 12, 2005 Whoa, pruning of threads now? What are we, elitest botanists? Let's not remove peoples' comments unless we're putting this in the FAQ section. I think it's good that people have opinions and express them. There's a lot of good knowledge and experience on this forum. I could sum up this discussion with one statement. Jspecs are quicker, but export models are faster (assuming bone stock config with all equal perrishables and same driver). Personally, I prefer the raw uncivilized manner of my Jspec, but then again I'm bias having brought if from Japan myself. I do envy the bigger brakes (upgrade in progress), bigger injectors, and various coolers, but you can have the creamy leather, rhino tusks, hood scoop, and extra weight. Is there really a mini-bar in the backseat? I woudn't normally suggest it, but there are a lot of conflicting facts here and facts that are not actually facts IYKWIM. I don't think we should leave mis-information on tech threads that *could* be reffered to or found in a search later. This is a Tech section, so the info should be accurate IMO. Quote Link to comment Share on other sites More sharing options...
JohnA Posted August 12, 2005 Share Posted August 12, 2005 Speaking of difference in power delivery (JSpec vs UKSpec): When I first bought my UKSpec it felt flat as a plank. In fact, I was convinced that the second turbo (at least) wasn't working (no boost gauge, car was dead stock). That was also the impression of another experienced member of this board, who also drove the car. I didn't mind because I bought it very cheap, so I got a spare set of refurbished turbos to swap them. As soon as I fitted a boost gauge, I realised that the turbos were working perfectly (11psi held throughout the range), it was just the flat delivery that fooled me. My first turbo bike I had 20years ago, so I'm not exactly a newbie either The UKSpec is a different animal. Quote Link to comment Share on other sites More sharing options...
Jspec Germany Posted August 12, 2005 Share Posted August 12, 2005 I woudn't normally suggest it, but there are a lot of conflicting facts here and facts that are not actually facts IYKWIM. I don't think we should leave mis-information on tech threads that *could* be reffered to or found in a search later. This is a Tech section, so the info should be accurate IMO. All valid points, I agree. Quote Link to comment Share on other sites More sharing options...
chilli Posted August 12, 2005 Share Posted August 12, 2005 I'd really like to experience a UK spec car and it's power delivery - anyone live local lol? All I can say is that the j-spec turbo spool up is almost instantaneous and often on the road (as opposed to a straight line / dyno test) this counts for a lot, possibly it's worth quite a few bhp but that would be almost impossible to quantify of course as it depends on the circumstances so much... Comparing to my old Lancia Delta Integrale, well at the time I was used to it so didn't think about it much, now after experiencing the j-spec turbos on the supra I realize it was extremely laggy indeed! Whatever I do to tune the car up, one of my priorities now will be to minimise lag where possible! I suppose to quickly summarise what was originally asked: are they bigger? J-Spec act as smaller, less laggy units. Uk spec offer slightly higher limits in terms of max boost, at the price of more lag. are they stronger? UK spec are stronger (handle higher boost), J-specs have a 1.2 bar abs max limit. Quote Link to comment Share on other sites More sharing options...
Clarkey Posted August 12, 2005 Share Posted August 12, 2005 are they stronger? UK spec are stronger (handle higher boost), J-specs have a 1.2 bar abs max limit. Beyond that boost pressure UK/J-Spec .. the turbos are nolonger within their efficiency range and all that is being generated is hot air. Quote Link to comment Share on other sites More sharing options...
chilli Posted August 12, 2005 Share Posted August 12, 2005 Beyond that boost pressure UK/J-Spec .. the turbos are nolonger within their efficiency range and all that is being generated is hot air. Are you saying that beyond 1.2 bar neither type of turbo is working efficiently? I guess that would make sense since they are not a million miles apart in terms of design. So at 1.2 bar then you have the choice of potentially more reliability but more lag with the uk spec verses less lag but possibly earlier failure with the j-spec. Quote Link to comment Share on other sites More sharing options...
Branners Posted August 12, 2005 Share Posted August 12, 2005 okay, for clarity I have gone back and edited the posts on that thread. Hope its clearer now. The j-spec turbo internals are bigger than the UK ones, they were able to do this because the ceramic weighs nothing compared to the steel and so they could go much larger. I think the UK spec is much better suited to true twin conversion than it is to sequential operation, and the j-spec suits the sequential operation very well indeed. I really need to find a friendly importer some time and run the cars back to back to really see. Ideally I would have 2 cars, a single turbo beast for that kick in the back feeling and a j-spec auto with BPU+ for days when you dont want any lag at all. JB Quote Link to comment Share on other sites More sharing options...
Ewen Posted August 12, 2005 Share Posted August 12, 2005 am I right in believing JDM and UK TTs have different gearing and that the max torque is available at slightly lower revs on a JDM car ? Quote Link to comment Share on other sites More sharing options...
Ian C Posted August 12, 2005 Share Posted August 12, 2005 a j-spec auto with BPU+ for days when you dont want any lag at all. JB Apart from not getting full boost until 4000+rpm no matter what gear you are in -Ian Quote Link to comment Share on other sites More sharing options...
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