Danny @ Enhanced Performance

iTrader: (3)

yes i agree 500+ @ wheels is awesome no matter what (i have 528 at the rear wheels at mo) and yes probably to much for the roads...
as said dave i wasnt digging you or your car as iv always thought the engine was great power...
cheers danny

Spiky

iTrader: (1)

no not at you dude

its a great topic and one i was enjoying, until people are just looking for an argument,

it's ok,

i'll leave this topic now

Chip

iTrader: (3)

Your 528 @ rear wheels is probably very similar engine power to his 491 @ all 4 wheels, if those figures are off equivalent dynos, you expect to lose more power when you have a txb and an extra diff.

So yours is probably just over 600bhp too, like Daves on the lower boost setting, although like I said earlier, different boxes have different losses anyway.

TimC

iTrader: (1)

TBH Danny Simon pissed all over it too, the 3dr got in the way tbh, but it was funny watching the 3door slide onto the grass and sling mud our way, bow and arrows 300 style

dojj

iTrader: (3)

the only way you are EVER going to be able to measure transmissio losses acuratly is to get th eengine plumbed onto the dyno
tehen add a gearbox and emasure the losses through the box
then add a prop and measure again
then add a diff and measure again
then the shafts and measure again
then the hubs and measure again and then the wheels and measure again

this way you are in a controled enviroment where repeatability is easy to achive so the only losses you will find will be through the transmission

but that's not going to happen so the easiest way to measure the power getting to the tarmac is going to be on a dyno whre all the variables have been accounted for

so if you make 50 bhp more than your mate does on one set of rollers, but only make 20 bhp more than your mate on another set, the figures you get will be right for your car on that set of rollers, and then you can argue as to who's "righ" and who;s "wrong" down the pub

or on the internet

Chip

iTrader: (3)

That still wont work as the dyno only has the ability to be reading power directly from a single input, so to feed it power from the wheels, you would need to sit the car on some rollers, or hub dyno packs or similar, at which point its NOT the same dyno anymore, and hence no longer truely comparable, as each stage would need seperately calibrating etc etc

So, going back a couple of pages to where I said it first of all, you cant ever accuratly measure flywheel figures in the car.

turnover

i see what Danny is saying though as on pump fuel at around 2.0 bar of boost,my car made 599 hp on the rolling road and was 450hp@ the wheels which is a big loss and mines rwd,but any how its how a car performs not what the figure is ,just a reference point for when you are making changes to see what gives better response or more power

Chip

iTrader: (3)

Interestingly thats a much bigger transmission loss than Dave's is quoted at, 25% in fact in your case.

As you say though, if you can keep using the same rollers, its a great reference point to know how changes have effected it.

dojj

iTrader: (3)

the sinlge input would be fromn the back of the gearbox or prop in this case chi

you'd just have to fabricate some sort of enclosure to hang it all from

and then you have 2 dyno's to measure the output from either side of the diff, etc, etc

it would be way to difficult and tine consuming to ever be practical realistically, but it would be the only way to measure the losses for a particular set up in my eyes

and if you had several different references over the course of time in which to glean various different bits of info from, youwould have a mroe acruate way to measure the losses

ok, so you still wouldn't be in a car with all the little foibles that being inside a box would create, but you would set a benchmark by wich you could rate everythign else, be it higher or lower

Chip

iTrader: (3)

Manufacturers tend to know what their transmission and instalation in the bay combined is losing fairly accurately, as they are putting the same engine from dyno to rollers quite reguarly, but even with all that data, its still guesswork the moment you go to a different box, or a different power level on the same box, as like I have said its not a direct relationship.

C4llyT

I'd expect it to dip below 20% by a fraction at most.

Why not just take the ATW figure of each, add 10bhp and divide the result by 0.84?

For 500bhp this equates to 595bhp.
Much more accurate than percentages that go off at extremes of power.
Still no definitive number of course but best you can hope for.

C4llyT

523 bhp, but 600 sounds better down the pub granted.

turnover

not pub talk fact,,,does run mid 10s on the quater with a shit 60ft of 1.8 so you tell me if its wrong

Danny @ Enhanced Performance

iTrader: (3)

yes mate thats when i see 602 bhp but at 2.2 bar but at 1.9 bar its 592 so not a lot of difference..iv now got to change the inlet cam for a bit more lift and since then iv got a new turbo manifold 4 inch downpipe and a bigger intercooler so on the engine dyno il get it right then check in car on our rollers and see if the difference represents eachother..
cheers danny

Danny @ Enhanced Performance

iTrader: (3)

im glad you said that because i thought simons was quicker than that..mind you he had a good tussle with jays white 3dr at coombe a while back and although i didnt tussle with him myself his mate said i was 2 secs a lap quicker round brands than him...i was doing brands in 52 secs in the summer but 56s on wets the other week...bring on the new year,i cant wait to get the car out again
cheers danny

J1mbo

iTrader: (1)

hi danny was that on slicks ? do you think you'll get much quicker ?

Danny @ Enhanced Performance

iTrader: (3)

after feeling the car last week on the wets i was dying to get on the slicks but then the clutch started slipping and of course i put the slicks on and that done the clutch completly but back to your questions yes the 52s were on slicks and yes i rekon i can get atleast another second as the car is feeling awesome...
less lag and more tourque has made it handle better to as its tighter through the bends...
cant wait to see what it does on the dyno...
Anyway hows you mate???
cheers danny

J1mbo

iTrader: (1)

thats really getting on with it for round brands mate gotta get down there and see you out in her, dyno will deffo be interesting

im ok thanks bud sounds all is well with you ?? lol

C4llyT

I don't see your point, as it's 450 ATW no matter what the bullshit corrected figure is, so just quote that as that's correct and the engine figure is waaaaaay off.

Or your car has massively more losses than others, in which case if you get to the bottom of the problem you'll have 500 ATW.

Less.

very intresting post for once

turnover

i dont make the dyno,s chap ,and i cant explain why i get 150hp loss,my skyline used to lose simular and thats alot heavier and 4wd but simular power,but as said before if you use the same dyno its a good reference point when developing your engine

C4llyT

If you use and quote the ATW figure, as the fly figure is waaaay off, don't you agree?

Anyway, that's what's contacting the road...

Steven_RW

Guys,

I am not claiming to be a genius, but no one on this post seems to understand how a rolling road works, or why there is a difference in the ATW figure, between different rolling roads, even if they are all being run 'fairly'.

Therefore when another person here posts their engine dyno figure and then r/r figure and we all start debating the % loss, no one on here really understands 'where' all of this bhp is lost. As such, this discussion is pointless.

RW

foreigneRS

i wouldn't agree that nobody on this post understands how a rolling road works, but i would certainly agree that the discusssion is pointless, especially as one side of the 'argument' cannot base his points in proven physics.

as for making a direct comparison for at the wheels figures measured on a dyno to crank figure, it is only possible if you are measuring at the crank at the same time (with a strain gauge or similar torque sensing device, and an acuurate rotational speed measurement, perhaps taken from the ecu's signal)

Fagin

The thread is fine until people start to defend graphs that were done at different venues on different days. A car makes what it makes on the day at that venue.... period. IMO it is pointless (but obviously interesting) comparing in detail, different venues and different days (environments).

If you want to a prove a cars capabilities get it on the black stuff.... but that is another story.

Both of these cars undoubtedly have some real nuts, which is great. Perhaps best to leave it at that.

kouzman

Why do people argue on flywheel numbers? I cant getting!

Who cares? What they should care about is power at the wheels. Thats what you put on your tires...

As said before, if you want to compare them, hit the track!

Ginger Will

Do you have any videos of your car as that sounds pretty quick?