p3te Posted June 20, 2009 Share Posted June 20, 2009 just got back from motoscope having my car on the dyno, it’s a uk spec tt auto bpu according to my boost controller I peaked at 1.28 bar but according to the printout it says I hit 20psi :o and hit 455bhp at the engine, so do I take this as a trigger happy dyno or is there something to worry about these figures? Or accurate? I was under understanding that these are supposed to be accurate dynos, all be it harder to dyno autos? What do you guys think? http://img20.imageshack.us/img20/3650/img016o.th.jpg http://img20.imageshack.us/img20/3530/img015u.th.jpg Quote Link to comment Share on other sites More sharing options...
jevansio Posted June 20, 2009 Share Posted June 20, 2009 455 sounds a bit ott to me too, I'd suspect the drivetrain loss factor they're using is a bit generous. If you look at the RWHP figure 340, and apply an accepted drivetrain loss (15%) you get 400bhp at the flywheel (a lot more acceptable figure for a UK spec BPU). PS I know they find it hard getting accurate readings from autos Quote Link to comment Share on other sites More sharing options...
imi Posted June 20, 2009 Share Posted June 20, 2009 455 sounds a bit ott to me too, I'd suspect the drivetrain loss factor they're using is a bit generous. If you look at the RWHP figure 340, and apply an accepted drivetrain loss (15%) you get 400bhp at the flywheel (a lot more acceptable figure for a UK spec BPU). its an Auto so the drivetrain loss factor will be higher than 15%... I would expect it to be in the region of 20-25% Quote Link to comment Share on other sites More sharing options...
jevansio Posted June 20, 2009 Share Posted June 20, 2009 Ah right Imi, if you go with 20% thats 420, they're obviously using 25%. I wouldn't be too concerned with the fwhp and use the rwhp to make comparisons. I personally don't care what any dyno states my hp level to be, I know they all bullshit, and I normally state mine at 500+. I care more about how the car drives & performs in real world scenarios (30-130, top speed etc) Quote Link to comment Share on other sites More sharing options...
p3te Posted June 20, 2009 Author Share Posted June 20, 2009 what do you think of my afr? after 3500rpm is it running lean? Quote Link to comment Share on other sites More sharing options...
jevansio Posted June 20, 2009 Share Posted June 20, 2009 No, it's rich as, looks like it's dropping under 10 at some points & the graph can't show it Quote Link to comment Share on other sites More sharing options...
p3te Posted June 20, 2009 Author Share Posted June 20, 2009 ah so the lower the number the richer it is? Quote Link to comment Share on other sites More sharing options...
jevansio Posted June 20, 2009 Share Posted June 20, 2009 Yip Quote Link to comment Share on other sites More sharing options...
p3te Posted June 20, 2009 Author Share Posted June 20, 2009 what do think about it saying i hit 20psi and my boost controller saying 1.28bar? Quote Link to comment Share on other sites More sharing options...
jevansio Posted June 20, 2009 Share Posted June 20, 2009 what do think about it saying i hit 20psi and my boost controller saying 1.28bar? 1.28bar = 19PSI. A one PSI difference between 2 boost measuring devices is to be expected. On my car my AEM sensor (for the ECU) & defi sensor (for the boost gauge) have that sort of difference. It'll be a calibrartion error in one (or both) of the devices. They won't be 100% accurate. Quote Link to comment Share on other sites More sharing options...
p3te Posted June 20, 2009 Author Share Posted June 20, 2009 so is 1.28bar 19psi ive just tried to do a conversion online and it says its 1.378949bar :s or have i messed it up lol Quote Link to comment Share on other sites More sharing options...
jevansio Posted June 20, 2009 Share Posted June 20, 2009 Iirc 1 bar = 14.7 psi Quote Link to comment Share on other sites More sharing options...
imi Posted June 20, 2009 Share Posted June 20, 2009 Ah right Imi, if you go with 20% thats 420, they're obviously using 25%. I wouldn't be too concerned with the fwhp and use the rwhp to make comparisons. I personally don't care what any dyno states my hp level to be, I know they all bull$#@!, and I normally state mine at 500+. I care more about how the car drives & performs in real world scenarios (30-130, top speed etc) couldnt agree more. I use the SAME dyno just to keep track of the effectiveness / performance impact of the mods that I have done on the car over the years. Quote Link to comment Share on other sites More sharing options...
p3te Posted June 20, 2009 Author Share Posted June 20, 2009 ah right so im worrying for nothin then on the whole fairly accurate just a bit ott on the engine hp Quote Link to comment Share on other sites More sharing options...
jevansio Posted June 20, 2009 Share Posted June 20, 2009 ah right so im worrying for nothin then on the whole fairly accurate just a bit ott on the engine hp I would say that sums up things nicely Use the 455bhp when you're in the pub, it's what everyone else does Quote Link to comment Share on other sites More sharing options...
p3te Posted June 20, 2009 Author Share Posted June 20, 2009 haha exactly dont forget the .2 on the end , well im happy with that thanks for the info:thumbs: Quote Link to comment Share on other sites More sharing options...
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