250horses Posted December 11, 2004 Share Posted December 11, 2004 Does anybody know the actual BHP of a stock J Spec. I know Toyota quote 280 as per gentlemans agreement MKIV NZ quote 280 Quite a few folk quote 300 Some even say its 320 same as a UK spec On a dyno my J Spec with rear decat and fat v.straight exhaust came up at 335 bhp http://www.mkivsupra.net/vbb/showthread.php?s=&threadid=30144 Link to comment Share on other sites More sharing options...
Matt Harwood Posted December 11, 2004 Share Posted December 11, 2004 More than 280, less than 330. The only way you'll ever know for certain, would be to get a good conditioned JDM Supra, rip out the engine and stick it on an engine dyno. Personally, I believe they'll be around 320 still. Link to comment Share on other sites More sharing options...
Miguel Posted December 11, 2004 Share Posted December 11, 2004 And we know a man Link to comment Share on other sites More sharing options...
LeeT Posted December 12, 2004 Share Posted December 12, 2004 *cough cough* uk spec 326 *cough:D and if thats not spelt right im still pissed:D Link to comment Share on other sites More sharing options...
250horses Posted December 12, 2004 Author Share Posted December 12, 2004 leett, something stuck in your throat mate...... :p Link to comment Share on other sites More sharing options...
Matt Harwood Posted December 12, 2004 Share Posted December 12, 2004 Originally posted by 250horses leett, something stuck in your throat mate...... :p Must be a lump of lard! Deja-vu? Link to comment Share on other sites More sharing options...
dude Posted December 12, 2004 Share Posted December 12, 2004 See a J-Spec owner would only have had the one cough then hed be off !!!! Dude:flame Dev Link to comment Share on other sites More sharing options...
GeordieSteve Posted December 12, 2004 Share Posted December 12, 2004 Mine stock came out at 329bhp but I don't know how reliable the rollers were (although a mate of mine used the same rollers and came out roughly what he expected) Link to comment Share on other sites More sharing options...
Scoboblio Posted December 12, 2004 Share Posted December 12, 2004 Mine made 305bhp at the fly (which was slightly less than I was expecting but everything seems to be working fine), and 336lb of torque (which was a lot more than I was expecting). This was at engine advantages. One thing that suprised me were my horrible transmission losses (about 220-230bhp at the wheels ) I know it's an auto but damn! Link to comment Share on other sites More sharing options...
kghelmet Posted December 12, 2004 Share Posted December 12, 2004 mines standard apart from the exhaust and i`ve still got my cats. Link to comment Share on other sites More sharing options...
Bobbeh Posted December 12, 2004 Share Posted December 12, 2004 kg, is that hub horse power? Cos no way is that wheel hp for a standard car. 250 horses, it says your car is de-cat in your sig, hardly stock there is it! Link to comment Share on other sites More sharing options...
250horses Posted December 12, 2004 Author Share Posted December 12, 2004 OK Bobbeth, I just added the word, "rear", next to the words de-cat in my signature. Link to comment Share on other sites More sharing options...
Tom Posted December 12, 2004 Share Posted December 12, 2004 Originally posted by Scoboblio Mine made 305bhp at the fly (which was slightly less than I was expecting but everything seems to be working fine), and 336lb of torque (which was a lot more than I was expecting). This was at engine advantages. One thing that suprised me were my horrible transmission losses (about 220-230bhp at the wheels ) I know it's an auto but damn! Where in Essex did you get yours dyno'd? I might do another next year. Link to comment Share on other sites More sharing options...
Gordon F Posted December 12, 2004 Share Posted December 12, 2004 Charlie They dont come any more stock than mine and it made 249hp at the wheels when it was dynoed on a r/r. Brian and Angie's old car, which was stock at the time, was within 1hp. You can only measure true flywheel power by taking the motor out and running it on an engine dyno. Link to comment Share on other sites More sharing options...
250horses Posted December 12, 2004 Author Share Posted December 12, 2004 So when mine was put onto a rolling road (just rear wheels), the measure of 335bhp was an estimation of the actual BHP at the wheels reading; with a formula converting the result into BHP at the fly wheel Link to comment Share on other sites More sharing options...
Bobbeh Posted December 12, 2004 Share Posted December 12, 2004 Yeah 335 would be your fly wheel reading, not rear wheels.. if you got that at the rear, you'd have 380bhp ish, which is even more unlikely. Link to comment Share on other sites More sharing options...
250horses Posted December 12, 2004 Author Share Posted December 12, 2004 Originally posted by Bobbeh Yeah 335 would be your fly wheel reading, not rear wheels.. if you got that at the rear, you'd have 380bhp ish, which is even more unlikely. Yes I know its at the fly, my question is how do they calculate that just using rollers on the rear wheels ? As to likeliness, initially I got 294 bhp, then took out the restrictor ring and got 335 bhp at just under 1 bar :D Link to comment Share on other sites More sharing options...
Jake Posted December 12, 2004 Share Posted December 12, 2004 Originally posted by 250horses initially I got 294 bhp, then took out the restrictor ring and got 335 bhp at just under 1 bar With no cats and no restrictor ring it made less than 1 bar? That doesn't sound right. What boost level was the 294 reading at? Originally posted by 250horses at the fly, my question is how do they calculate that just using rollers on the rear wheels ? Seems like a lot of places add 20% to your RWHP figure to guesstimate the flywheel figure. Link to comment Share on other sites More sharing options...
Matt Harwood Posted December 12, 2004 Share Posted December 12, 2004 Originally posted by 250horses So when mine was put onto a rolling road (just rear wheels), the measure of 335bhp was an estimation of the actual BHP at the wheels reading; with a formula converting the result into BHP at the fly wheel Yes. If you had 335 at the wheels, that would be fairly modified, equating to around 370-400 flywheel guestimate. Link to comment Share on other sites More sharing options...
250horses Posted December 12, 2004 Author Share Posted December 12, 2004 still got the front cat in, just the rears gone, with a v straight 3" pipe all the way down. With ring in got .8 bar - gained 40 bhp as soon as ring was removed - it appears ring was not ness on my one cat set up Link to comment Share on other sites More sharing options...
Gordon F Posted December 12, 2004 Share Posted December 12, 2004 Originally posted by 250horses Yes I know its at the fly, my question is how do they calculate that just using rollers on the rear wheels ? As no one seems to have ever dynoed a stock engine, it all comes down to guesstimation. RWHP against Manufacturer claimed power. Figures bandied about were RWHP = FWHP -18% (manual) and RWHP = FWHP - 25% (auto). Nothing ever really proved though. Link to comment Share on other sites More sharing options...
Scoboblio Posted December 12, 2004 Share Posted December 12, 2004 My understanding of dnyo's is that they work out RWHP using the torque figure etc.... then work out flywheel power by calculating how long the rollers stay running for.when they take their foot of the gass.... my thinking is that a nice tight transmission will offer a lot of resistence to the rollers and slow them down quickly, a rubbish transmission will offer very little resistence and they'll keep spinning for ages. Please bear in mind that I just pulled that theory out of my arse Tdraper, my car was dyno'd at Engine Advantages in Witham, on the industrial estate just behind Ford rapid fit (suberb guys btw) p.s., Gordon, my engine was (and is) totally stock when it was dyno'd.... stil had the original 112mph limiter installed, but how accurate the figures are I don't know (somehow made 336lb torque ) Link to comment Share on other sites More sharing options...
GeordieSteve Posted December 12, 2004 Share Posted December 12, 2004 Originally posted by Gordon F As no one seems to have ever dynoed a stock engine... I did... 329bhp at the fly Link to comment Share on other sites More sharing options...
China Man Posted December 13, 2004 Share Posted December 13, 2004 mine done today. Link to comment Share on other sites More sharing options...
kghelmet Posted December 13, 2004 Share Posted December 13, 2004 Originally posted by Bobbeh kg, is that hub horse power? Cos no way is that wheel hp for a standard car. 250 horses, it says your car is de-cat in your sig, hardly stock there is it! yes that is at the wheels,thorn a few weeks ago. Link to comment Share on other sites More sharing options...
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