ChrisR Posted October 7, 2002 Share Posted October 7, 2002 Can anyone explain how the UK Spec MKIV TT develops the extra 46 BHP over the J-SPEC. i.e. which components. I have a J-SPEC and was curious. Regards Chris Quote Link to comment Share on other sites More sharing options...
raviahluwalia Posted October 8, 2002 Share Posted October 8, 2002 I asked the same question when I bought my J-spec. It is mainly the larger injectors (550cc on UK spec) and 430cc (i think) on jap. Also, they have different turbos.. Uk has steel and jap ceramic type. But, in terms of performance, the figures are practically the same. Quote Link to comment Share on other sites More sharing options...
paulrenn Posted October 8, 2002 Share Posted October 8, 2002 Hi, Injectors don't provide more power or make the car faster! Rather, they allow the other components to work harder. The main differences are the turbos, and ECU mapping. Quote Link to comment Share on other sites More sharing options...
eyefi Posted October 8, 2002 Share Posted October 8, 2002 its only a peak performance number and probably not really accurate (ie jspec is not 280), dont forget there is the rest of the rev range. cams r also different, the specs of the turbine, impeller and housings on the turbos r different, as well as the material. Quote Link to comment Share on other sites More sharing options...
Doughie Posted October 8, 2002 Share Posted October 8, 2002 In Japan, there is an agreement that manufacturers cannot *claim* more than 280bhp for any of their cars, as sold in Japan. this is the main reason for the 280bhp stated for the J-spec Supra. In reality it will be much closer to the UK-spec. It will actually feel a little quicker (as stock) due to the fact that it is a little more torquey, which is what makes a car "feel" fast. Also most jap-specs are a bit lighter than UK-specs. Quote Link to comment Share on other sites More sharing options...
paulrenn Posted October 8, 2002 Share Posted October 8, 2002 It will probably "feel torquier" than the UK spec, because the turbos are smaller and spin up faster (ceramic blades start to rotate faster than steel ones). On the other hand, UK spec can flow more air, so will have better top end power. IMHO... Quote Link to comment Share on other sites More sharing options...
Simon Posted October 8, 2002 Share Posted October 8, 2002 Has anyone actually put a UK or J-Spec stock car on a dyno and got comparative results? Just interested. Quote Link to comment Share on other sites More sharing options...
Terminator Posted October 8, 2002 Share Posted October 8, 2002 I am sure this has been discused before. There was a test on rollers afew years ago on stock cars, very little in it between the Jap and UK, nothing like the stated 276 - 326 difference. Quote Link to comment Share on other sites More sharing options...
randy Posted October 8, 2002 Share Posted October 8, 2002 If someones has any dyno figures on the jap spec Vs the Uk spec it would be nice to see. Ofcourse both need to be stock. Quote Link to comment Share on other sites More sharing options...
ChrisR Posted October 8, 2002 Author Share Posted October 8, 2002 This sort of leads me on to my next question. I will be very soon going to be getting some mods done by Chris Wilson, Full Decat, FCD, Boost Gauge and shortly after that an after market exhaust system. I have been considering before completing any of this work to get the car on a dyno rig so that for future mods i can see any changes/increases. Can anyone recommend anywhere in Cambridgeshire where i could take the Supra to get this done. Also what information will come from such a test, obviously BHP, is there anything else. Regards Chris Quote Link to comment Share on other sites More sharing options...
Terminator Posted October 8, 2002 Share Posted October 8, 2002 Torque, the most important factor IMO. BHP sells cars, torque wins races. I will find out where the 500+cossie boys do theirs round here. As I am just down the road. Quote Link to comment Share on other sites More sharing options...
Dave R Posted October 8, 2002 Share Posted October 8, 2002 Power engineering in Uxbridge or Jamsport in Northampton they are the closest well established road operators i can think of. Both are mainnly ford specialists but PE have a fair amount of jap car work under their belts now. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted October 9, 2002 Share Posted October 9, 2002 Originally posted by Chris Rimes This sort of leads me on to my next question. I will be very soon going to be getting some mods done by Chris Wilson, Full Decat, FCD, Boost Gauge and shortly after that an after market exhaust system. I have been considering before completing any of this work to get the car on a dyno rig so that for future mods i can see any changes/increases. Can anyone recommend anywhere in Cambridgeshire where i could take the Supra to get this done. Also what information will come from such a test, obviously BHP, is there anything else. Regards Chris Having driven loads of different MKIV's over the years my feeling is the Jap specs feel quicker, and have probably more usable power bands, particularly as an automatic. Unless you really wring their necks the UK specs don't feel as quick as J-Specs, and even then some J-Specs feel quicker than some UK Specs, so there won't be much if anything in it. On some days i feel sure the J-Specs have more power. Find a rolling road that uses a brake type dyno, not an inertia one, which are pretty useless for getting a proper power reading after a few seconds of sustained load, which is what you want. I don't know of any to recommend down there to be honest, unless Brodie Brittain Racing (BBR) have one still. They are near Brackley. Quote Link to comment Share on other sites More sharing options...
randy Posted October 10, 2002 Share Posted October 10, 2002 Thank U Mr Chris Willson! A big thumbs up for the Jap spec!! Actually I too find it hard to believe the UK spec could be faster not that I have dirven a UK spec car, but there is so much torque and power coming out of my jap spec it simply flies spinning wheels on shifts to even third can't imagine the UK being even faster esp at BPU levels. Quote Link to comment Share on other sites More sharing options...
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