My turbo conversion has been Dyno'd @ THOR

[CosmosblueMR2]

where does it says he's a different ecu? (that would make more sense)

he deosn;t have a diff ECU - just mapped using a piggy back and an AVCR i think...

here:

I think the main contributing factor that's been missed here is the F-CON, which given the 10.6 AFR (and it still det'd - purple plot, hence the reduced boost), would suggest the ignition advance being chucked in there is huge. I don't know if this was as bought from Japan or mapped here in blighty, but it may explain how this uber power figure may have came about (and the sub zero air temp super chilled by our massive cooling fans).
Nod.

[jimGTS]

where does it says he's a different ecu? (that would make more sense)

he deosn;t have a diff ECU - just mapped using a piggy back and an AVCR i think...

here:

I think the main contributing factor that's been missed here is the F-CON, which given the 10.6 AFR (and it still det'd - purple plot, hence the reduced boost), would suggest the ignition advance being chucked in there is huge. I don't know if this was as bought from Japan or mapped here in blighty, but it may explain how this uber power figure may have came about (and the sub zero air temp super chilled by our massive cooling fans).
Nod.

ah, ok! missed that bit.....so the avcr is mighty handy then......

[V8Killer]

At a guess maybe 280WHP. Which is probably around 330FHP, which i'd say is the limit on the CT20B / Optimax combo!

These are similar figures, which both me and Dino got about 2/3 years ago, albeit at slightly more PSI. I remember mine being mapped on a soaking hot day! Made for a lovely drive home with the T-Bars off

Good results.

just that i just saw someone on another thread who has 300 at the hubs, but 235-240 at the wheels......
i would have thought julians car would be the same spec as franks and bry's....both 240whp ish...and i think they were running 1.1bar...
just confused how someone with relatively mild mods could have 40whp more running less boost........

Yup...it did cross my mind...something just didn't quite add up. I'd just put it down to the weather \ freak car and gave the benefit of the doubt!

Thinking about it again, 300 at the hubs at 1 bar is quite freak! But then losing 60HP between hubs and tyres is also freak!

I was running 325BHP/310LB-FT (280WHP/265RWTQ) on probably one of the most accurate dynos in the country and it made for a seriously quick car. When i had it dynoed on another dyno a couple of weeks later it made 304RWHP and 301RWTQ, but saying that i've never actually thought much of those figures, because all the numbers were relatively high that day!

Think we need to get Doctor Dino here...

I've sent him a link!

[Goto10]

I thought RWHP=Hub figures...? Are there further losses through the wheels/tyres then..?

[jimGTS]

I thought RWHP=Hub figures...? Are there further losses through the wheels/tyres then..?

hubs is direct bolt onto the studs, whereas wheels is obviously with the wheels on, and takes into account the power on the road itself....if you think about it the wheels figures takes into account the grip on the tyres on the rollers that is actually touching and contacting the road....hense there would be more lose from wheel than from hubs......
i think im quite close in my attempted explanation, lol.....

[aaronjb]

i think im quite close in my attempted explanation, lol.....

Friction accounts for part of the loss between wheels & road, so there's a loss there that you don't have with the hub attachment.

You're also spinning up a greater rotating mass when you have the wheels on (especially with heavy wheels) - same difference there as fitting a lighter flywheel etc.

Elastic losses etc, though those should 'reappear' at some point after the wheel has started moving when the rubber unsprings (you can get the same effect with carbon & aluminium driveshafts & propshafts IIRC, with the shaft twisting and then unloading stored energy later).

Hmm.. that's about it I think Someone with a bigger brain than me will correct me in a minute if I'm wrong, I'm sure

[jimGTS]

Friction accounts for part of the loss between wheels & road,

thats the word i was looking for....

[V8Killer]

I vaguely remember Dino once saying that the largest frictional loss from FW to the power on the road is most likey the actual tyre. I maybe wrong though! He may have said something completely different! Don't take it as gospel

[raptor95GTS]

cover the tyres in oil and therefore no friction to lose power through, oh no wait a mo.

[aaronjb]

thats the word i was looking for....

I re-read your post after I posted mine, and you were pretty much spot on really - just didn't mention rotational mass (of the wheel & tyre - which can be quite heavy really) and/or elastic damping - though that one will be so tiny it's not worth thinking about really.

But aye - you lose a little power every time one rotating part transmits energy to another rotating or fixed part via contact (rather than physical attachment), and that lost power (energy) comes out as noise and/or heat - so you lose power between every cog & bearing in the gearbox, driveshaft bearings, tyre-to-road interface etc (but not flywheel to crank as they're physically attached to each other).

I'll stop wittering now

[Goto10]

Hmm.. that's about it I think Someone with a bigger brain than me will correct me in a minute if I'm wrong, I'm sure

Roger Peanut-Head is coming? To this thread? When!?
I didn't realise the losses from hubs to wheels were that significant - I thought whatever the hub figure is would be quotable as RWHP as it would be as near as dammit. Learn something new everyday and all that
Anyone know what sort of percentage drop from hub to wheel 'footprint'?

[aaronjb]

Roger Peanut-Head is coming? To this thread? When!?

Cheeky git

I'm sure I've read someone quote an estimated wheel-road loss.. can't remember who it was or how much it was though, Dino maybe?

Short memory (yea yea, shut it you )

[juliankv73]

where does it says he's a different ecu? (that would make more sense)

he deosn;t have a diff ECU - just mapped using a piggy back and an AVCR i think...

here:

I think the main contributing factor that's been missed here is the F-CON, which given the 10.6 AFR (and it still det'd - purple plot, hence the reduced boost), would suggest the ignition advance being chucked in there is huge. I don't know if this was as bought from Japan or mapped here in blighty, but it may explain how this uber power figure may have came about (and the sub zero air temp super chilled by our massive cooling fans).
Nod.

ah, ok! missed that bit.....so the avcr is mighty handy then......

SO is the F-CONV when mapped properly, so I was told! But as Nod told me, there aren't many places that can do it well in Blighty and I was advised that my next mod will have to be a a new ecu when I want more power

At the end of the day, I am just pleased I am getting the sort of power all that Frank, Bry etc were getting on the Essex RR day. I was kinda disappointed that day as I had blown all that dosh on my car and it rewarded me by performing like thoroughbred race horse draggin its legs when coming last at the Grand National!

I was gutted! But now a few more probs have been fixed and the car is throwing out some decent power wheich now I can really feel, so I have a smile on my face regardless of the RWHP! If there is a loss at the rear wheels, theres probably a big loss when I drive it lol, coz I still havent managed to adapt my driving style from NA to tubby!

Cheers for all the positive comments, i'm very happy with the figures which confirm that at the end of the day it is definitely faster than my NA !!

Cheers all

[luthor1]

20-25% flywheel HP is lost by the time you get to the wheels where there is no prop shaft, eg MR and FF cars. Scoobies for example run 285bhp at fly (say), and 180bhp at wheels. Go figure!

Also, only 25% of the energy produced by the explosion gets to the flywheel in the first place. Rest goes to noise and heat. (Quoted from my Mr David Vizard learning years).

TVR quote power figures measured at the flywheel with no ancillaries on the engine, no waterpump, alternator, air con, etc etc. That's why their figures are "misleading". For TVR you must ignore the power and refer to the weight, 0-60, 1/4mile and top speeds to realise how mental they are. the power is not all the story.