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T2 MSW
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Steve, looking at your sig you know your car is 568bhp at the flywheel yes? go put it on a hub dyno and see what it makes if you dont belive me.

 

My car is not 1200bhp, at a decent guess id say its just over a real 1000.

Yeah - the figures in my sig are Ryan's reverse calculations from those measured at the wheels, to give an indication of the power at the flywheel (because those are the pub tak numbers - and in fact Mike is doing it right by stating the non-fudged figures, those that actually get to the road).

 

Obviously the real measured numbers for my car (i.e. at the wheels when on a dyno) will be less than those stated in my sig (IIRC about 18% losses are standard for the calculations for a manual Supra?) - but you were suggesting to Mike that the 'real' flywheel figure will be less than the (actual) figure measured at the hubs?

 

677 rwhp is good going, what rolling road was that on Mike?

Ahh hub bhp, about 650 at the flywheel then ;)

 

Hub bhp/torque are measured, flywheel figures are guessed! :)

 

Your engine output surely hasn't been measured at the flywheel? It's been measured at the wheels and guesstimated back to the flywheel, just like everyone else's. :)

Edited by SteveR (see edit history)
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Yeah it'll be less at the wheels (about 18% losses are standard for the calculations for a manual Supra IIRC?) - but you were suggesting to Mike that the 'real' flywheel figure will be less than the (actual) figure measured at the hubs?

 

 

 

 

Hub bhp/torque are measured, flywheel figures are guessed! :)

 

 

I know how it all works Steve and ive been on many dynos, there is no confusion if you keep to the facts, if you go on a hub dyno just quote the RHHP, dont try and convert it to anything as its just a guess.

 

IMO hub dynos over read like mad, put it this way, at low boost my car made 902 flywheel bhp at SRR, same boost a couple of days later it made 975rhhp on Dans Hub dyno.

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I know how it all works Steve and ive been on many dynos, there is no confusion if you keep to the facts, if you go on a hub dyno just quote the RHHP, dont try and convert it to anything as its just a guess.

I know you know how it works, which is why I'm confused (I did edit a previous post to say that; no offence was meant or implied by my questioning, I wanted to understand hat you knew and I genuinely didn't understand). However...

 

IMO hub dynos over read like mad, put it this way, at low boost my car made 902 flywheel bhp at SRR, same boost a couple of days later it made 975rhhp on Dans Hub dyno.

This sheds light on it - from your experience either that hub dyno must have somehow over-read, or SRR at-the-wheels dyno and reverse calculations to get the fly caused an underestimate, or a combination of both.

 

I trust SRR above all else, but can't figure out how a hub would read more than SRR's figure. That's just weird :blink:)

 

I see why you don't necessarily trust hub figures now - I'd never heard of hub number being higher than flywheel numbers before because that's impossible. I thought hub numbers should always be trusted almost implicitly as there wasn't meant to be any reverse calculations going on. :(

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Corr you love an edit Steve.

yeah I know - but I didn't remove anything, just cleared up what I meant (and tried not to come across as knowing more, I don't!) :)

 

I was keen to understand more so posted quickly but then had to go went back to clarify after I read it back a few times. :(

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Your on rob, get yourself booked up for Cadwell and we can see what that GTR of yours can do :)

 

Threads fine cheers mate. Ive finished playing with the car now. I'm happy with the engine. Need to run a better power feed for the fuel pump from the battery to the relay. Sort a power steering leak and then I'm just going to enjoy it.

Edited by T2 MSW (see edit history)
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Your on rob, get yourself booked up for Cadwell and we can see what that GTR of yours can do :)

 

Threads fine cheers mate. Ive finished playing with the car now. I'm happy with the engine. Need to run a better power feed for the fuel pump from the battery to the relay. Sort a power steering leak and then I'm just going to enjoy it.

 

I'm sure despite now being stage 4 it'll still be sluggish compared to yours ;) :D I'll have to get it booked :cool:

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I know how it all works Steve and ive been on many dynos, there is no confusion if you keep to the facts, if you go on a hub dyno just quote the RHHP, dont try and convert it to anything as its just a guess.

 

IMO hub dynos over read like mad, put it this way, at low boost my car made 902 flywheel bhp at SRR, same boost a couple of days later it made 975rhhp on Dans Hub dyno.

 

That 902bhp at SRR was with alot of wheel spin tho mate!!

 

From what i have found the Hub Horse power on a Hub is the same as a fly figure on a Dyno dynamics.

 

But then the Hub figures are pretty much spot on with Dyno Jet figures.

 

End of the day the only dyno that i can properly calibrate these big HP car is on a Hub dyno so just compare figures between each other and go with that.

 

Ryan

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Dont get me wrong, i love hub dynos, great tool for mapping, i just take the readings with a pinch of salt now, check this online calculator i found.

 

http://mkiv.supras.org.nz/dyno.htm

 

My 1132 at the hubs on a dynapack = 943 rwhp on a dyno dynamics rolling road, thats a huge difference and looking on the net im not the only one who thinks hub dynos massively overread.

 

I think you are spot on though mate, i hear what you say about wheel spin, I too think hub bhp is about the same as flywheel.

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Been to WIM today and to say I'm disappointed with the service is an understatement! I booked this session over 4 weeks a go and had numerous emails back and forth confirming the date and to be there for 10 and no later.

 

Car was ready to be put on the ramp before 10. Then get told I'm not booked in and I'll have to move it - WTF! They put a drift car on which I was told would be really quick as they were just adjusting something, 2 hours later I'm still waiting.

 

I just hope the settings we have put on make up for the customer service. Gone midway towards a race setup now so we will see what it's like later this week when I get some tax on it.

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Been to WIM today and to say I'm disappointed with the service is an understatement! I booked this session over 4 weeks a go and had numerous emails back and forth confirming the date and to be there for 10 and no later.

 

Car was ready to be put on the ramp before 10. Then get told I'm not booked in and I'll have to move it - WTF! They put a drift car on which I was told would be really quick as they were just adjusting something, 2 hours later I'm still waiting.

 

I just hope the settings we have put on make up for the customer service. Gone midway towards a race setup now so we will see what it's like later this week when I get some tax on it.

 

Does not sound to good , not to sure why so many travel all over to go there just need to find a local place that has a hunter machine in fact I found a place that had the latest one local Toyota but refused to do it because of being a import! but they did put me in touch with a company just down the road that had one got it all sorted it had all the models of supra on the machine he asked if I wanted a custom setup though for track . Have you got the print out before and after be intresting to see

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Been to WIM today and to say I'm disappointed with the service is an understatement! I booked this session over 4 weeks a go and had numerous emails back and forth confirming the date and to be there for 10 and no later.

 

Car was ready to be put on the ramp before 10. Then get told I'm not booked in and I'll have to move it - WTF! They put a drift car on which I was told would be really quick as they were just adjusting something, 2 hours later I'm still waiting.

 

I just hope the settings we have put on make up for the customer service. Gone midway towards a race setup now so we will see what it's like later this week when I get some tax on it.

 

I would have booked with http://www.centergravity.co.uk/ much closer and heard good things about them.

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Will bear that in mind for next time Ibrar. I really wanted the car corner weighted before it was aligned. I've seen it done at WIM on a demo day but it appears all that's just for show as they don't actually offer it as a service. They just hire the kit for the demo days!

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Will bear that in mind for next time Ibrar. I really wanted the car corner weighted before it was aligned. I've seen it done at WIM on a demo day but it appears all that's just for show as they don't actually offer it as a service. They just hire the kit for the demo days!

 

Centre Gravity do the lot mate, but Chris (owner) isn't cheap. Expect to be there all day, he's a perfectionist. :) There are a few write-ups on here, mine included.

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Will bear that in mind for next time Ibrar. I really wanted the car corner weighted before it was aligned. I've seen it done at WIM on a demo day but it appears all that's just for show as they don't actually offer it as a service. They just hire the kit for the demo days!

 

I'd take it to Chris Wilson :)

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