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Coops
03-02-2008, 11:18
First time i've had the turbo rr'd

12psi it ran, so 3 below what the limit of the chips map is, only ran that as was having issues with the cluth still randomly slipping sometimes at 15psi with the boost controller fitted, so decided to 'play it safe'

It put out 190bhp at the wheels, so back calculated for around 20% transmission loss thats 230bhp near as damn it. corrected it was 185 atw, so 222bhp atf all @5950rpm

got 170lb/ft of torque aswell at the wheels, so around 204lb/ft at the fly @5100rpm

Coops
03-02-2008, 11:27
http://i14.photobucket.com/albums/a330/coopahstar/Turbo/P1010001.jpg

Mr.AdamB
03-02-2008, 11:36
nice, wats going on with ure clutch then diddnt u replace it with a decent 1?

Wobba
03-02-2008, 11:54
Nice one Coops! That torque looks nice and flat too.

I wionder what it will do on nutter boost then! Have to find out when you sort your clutch.

I think my little tungsten is faster though :P

Coops
03-02-2008, 12:14
clutch is being a bitch, sometimes still slips, and did alot on the way down to the rr when i had it set at 15psi, so i thought best to drop it to 12psi where i never had a problem so i could at leat get a figure on the rr. to be investigated

Jamie.
03-02-2008, 12:23
I thought it would have more torque than that.

stan
03-02-2008, 12:53
First time i've had the turbo rr'd

12psi it ran, so 3 below what the limit of the chips map is, only ran that as was having issues with the cluth still randomly slipping sometimes at 15psi with the boost controller fitted, so decided to 'play it safe'

It put out 190bhp at the wheels, so back calculated for around 20% transmission loss thats 230bhp near as damn it. corrected it was 185 atw, so 222bhp atf all @5950rpm

got 170lb/ft of torque aswell at the wheels, so around 204lb/ft at the fly @5100rpm

How are you calculating torque at the fly mate?

MicKPM
03-02-2008, 13:17
I heard Nick had a dyno day on yesterday... me and Marshall were gonna pop up for a look and I wish I had now just to see your car Coops.

You happy with those figures?

Mick

lewis_willy2
03-02-2008, 13:18
i thought it got 217 when it was low boost?

hope the clutch aint too big a prob :?

Coops
03-02-2008, 15:20
217 low boost, loose bhp for comp ratio change, gain it by upping boost, but as said i only upped it 3psi from before so 230bhp instead of 250bhp

craig mate, it was nick hill who did the rr mate, so his figures, believe its same road as ur gettin. he just goes on around 20% loss

jamie, erm, well tbh its plenty enough for only 12psi :lol:

lewis, yeah am a bit nervous as the guys on rtoc have told me that that clutch is rated to 200lbft of torque max and am makin more than that so that could be the issue, i need to chatter with neil about it

Coops
03-02-2008, 15:23
I heard Nick had a dyno day on yesterday... me and Marshall were gonna pop up for a look and I wish I had now just to see your car Coops.

You happy with those figures?

Mick

yes mate i am, as said the chip i have is for 15psi and the engine can handle that also, was a shame i couldnt run it at max boost to see what its capable of under the current map, but the figures are close to what i epxected anyway at 12psi

also nick only actually took it to 6500rpm (limiter is 7500rpm)then backed off, he wasn't keen on maxing his dyno as its good to 220atw supposedly but he doesnt often get close to that, which i fully understand and accepted beforehand.

will have it done again soon i think, go for full boost for the map and bollox to the clutch :lol:

Jamie.
03-02-2008, 16:21
I dont really know much about the mechanics of tuning cars but from what I have seen generally the torque on most turbos isnt too far from the actual bhp which is why i was suprised it was at the level it is.

I mean yeah its still going to be very quick like,

MicKPM
03-02-2008, 16:22
Yeah get in before the summer though cos we usually run an RSC dyno day at Nick's in the summer and we always cook the damn thing or break the cooling pump.

What clutch are you running BTW?

stan
03-02-2008, 17:48
Coops:

Torque isnt subject to losses..only power is. The torque measured will be flywheel torque. Since its only influenced by gear ratio, the dyno calculates overall transmission ratio by comparing the to speeds and finding the ratio of them. This is the factor used to get back to fly torque.

Aye its the same roller set I have...thats about it. The absorber, data-logging hardware and dyno software are all latest versions. The absorber i have will hold 800lb.ft torque and 900bhp 8)

Coops
03-02-2008, 18:49
that cant be right tho craig mate, if it is then all that work i've done has basically got me **** all? and its definaly pulling significantly better than before :?

jay s
03-02-2008, 19:25
torque would seem ok to me, mine made 143bhp atw and 124lb/ft on the same rollers and thats with my mods cams,remap,manifold. yours is almost 50lb/ft more which is shit loads and thats on low boost u say :D

Coops
03-02-2008, 19:27
but 170 is wank mate for a turbo that made 172 on 3 less psi and high compression low boost engine? :?

jay s
03-02-2008, 19:39
and what rollers did they do that on, bb's rollers?

stan
03-02-2008, 20:14
Ok..im going to check on whether torque is affected by transmission losses. Im 99% certain it isnt, and only power is due to it being the RATE of work done, as opposed to actual work....but like i say i'll confirm or disproove this.

HOWEVER..if you think about it from another angle:

a gearbox is simply a torque multiplier. All it does is use internal ratios to increase torque from an engine to make it usable at the wheels (hence why low ratios accelerate quicker..and why your more likely to wheelspin in first than in 5th).
so say your 4th gear ratio is 1:1.2, and your final drive ratio is 3.5:1, the overall transmission ratio is 4.2:1 (3.5x1.2).
This mans the torque developed by the flywheel is multiplied by 4.2 to obtain torque at the wheels......

.....i.e if yours was making 170lb.ft at the wheels, it would be making 170/4.2=40.5lbft at the fly! which obviously isnt right!

(just so you know, the software measures WHEEL rpm, AND ENGINE rpm...from this it calculates and overall ratio, to calculate back to flywheel torque from what is ACTUALLY measured by the load cell)

Coops
03-02-2008, 20:36
i think your right mate, which means am now less than happy, okay bb probably bullshit the result to give more torque but still if the nana's rr are correct and true a f7r on standard inlet and compression makes more torque than mine, so my engine is a waste of nuts and bolts basically

think i'll go to another rr for a comparison, and to allow a full run at full boost and to the limiter

to be continued.................

stan
03-02-2008, 20:58
mate...dont condem your engine on the basis of a rolling road run at one place.

for the record I personally think THE FIGURES QUOTED are low for torque.

with a turbocharged engine, you would typically expect the torque to be 10-20-30 units more than power. So if yours is say 220bhp, personally I would expect to see maybe 240lbft peak torque. this is the usual trend.

but like i say, get another r/r test before you make any full judgements.

Coops
03-02-2008, 21:07
been talking to my neighbour and he says that all rr measure wheel torque and use that to calculate all other figures, and at like 5252rpm the torque figure is always nigh on identical to the bhp figure for all cars under all conditions. as such for this to work the figures for bhp and torque have to be quoted from the same point of reference, i.e. wheels or fly

my original rr printout from bb had torque and bhp of 170 at 5252 rpm both qouted to the fly as the peak torque of 172 and peak bhp of 217bhp were on the same graph for those figures

the hill power one the figures are the same again for bhp and torque at 5252rpm but this time at the wheel figures, with peak torque of 170 and peak bhp of 190 shown on the same graph lines

so if the bhp at the wheels is upped for transmission losses of around 20% then in order for torque to match bhp at the critical point of 5252rpm again then the same percentage increase for transmission lost must also be added to the torque figures

this is what his take is on it anyway

jay s
03-02-2008, 21:19
bb will have a corrected torque figure, not sure if its ment to but thats how they do it. had mine rr at bb 2 years ago, in the same 2 weeks i also had it rr at hillpower ( first time it was running lean hence the shite torque, bb fig looked more impresive but i knew it was running shite so couldnt be right)
http://i10.photobucket.com/albums/a117/jay16v-/DSCF1196.jpg
http://i10.photobucket.com/albums/a117/jay16v-/DSCF1296Large.jpg

Coops
03-02-2008, 21:29
on those two graphs jay mate, see how at 5252rpm or there abouts the torque and bhp figures are comparable to within a few units?thats for the corrected line of bhp on hill power btw, as i think the torque is automatically corrected also, thats what i'm on about, the torque figure at hill power isnt shite, its just not atf, am sure of it

i will speak to nick tomos

jay s
03-02-2008, 21:37
im 99% sure nicks torque figue is at the wheel :D

summeh
04-02-2008, 01:17
Coops mate when I was talking to Nick about my somewhat impressive results :wink: He stated the way he calculates is to add 20% to BOTH BHP and Torque figures to give ATF results.

So mine:

150bhp ATW became 180bhp ATF
129lb/ft ATW became 154.8lb/ft ATF

I'm planning on going back with my nitrous bottle filled up at some point, so if you fancy going at the same time that'd be cool.

stan
04-02-2008, 09:29
as stated....torque at the wheels is in the order of 4 times the ammount at the fly. So even discounting the losses issue, if its 170lb.ft at the wheels, then it would be 4 timess LESS at the fly.....so like 35lb.ft!! which just isnt realistic.


coops i know what your saying about 5252rpm. if u look at jays graph, its the CORRECTED power which crosses here. The measured, or observed power...i..e what is actually measured (from actual torque), crosses at 4750.

stan
04-02-2008, 20:13
right thinking about this over a sandwich today....its logical torque is subject to transmission losses (the reason i was thinking otherwise is because torque is fxdistance, it doesnt have a vector component...but f=ma, a is the vector component).

However,
the torque figure shown on the graph is torque at the flywheel. The dyno measures torque at the wheels...this is the raw data. Since its at the wheels, it has "experienced" the transmission and any losses induced by it. The dyno measures roller speed AND engine speed. ZFrom this it obtains an overall drive ratio between the rollers and the engine. This ratio is applied to the wheel torque to get flywheel torque. As said, since the calc is using wheel torque which is inlcusive of losses, the flywheel torque is also inclusive of losses.

MAXIBOY
04-02-2008, 20:32
plus just adding 20% seems wrong as when we used to run minis etc the transmission loses would very quite a lot between vehicles if i remember correctly from 18 to 36 % depending on the quaility/type of box used..

Coops
04-02-2008, 21:05
spoke to nick, his dyno prints raw power and torque at the wheels only. both figures have to be upped to the fly craig mate.

stan
04-02-2008, 21:42
the realtionship between torque at the input shaft (flywheel) of a transmission, and the output shaft (wheels), is determined by the internal gear ratios. a gearbox is a torque mulitplier. this is is explained earlier. and can be confirmed by any basic textbook...even google.

IF thats torque at the wheels, what gear was it in??? as it will be a higher figure if it was in a lower gear, or a lower figure if it was in a higher gear.....think about it....a car wont wheelspin in 5th cos the torque at the wheels is less...it will in first cos the torque is more.
so based on that...if I wanted to up the graph figures, i;d just run in a lower gear....
unfortunately its doesnt work like that................

jay s
04-02-2008, 22:08
afaik mate nick does the clios in 4th gear ( think this confirmed by the speedo reading on the graph, mine say 91.56mph @ 6.5k which would seem about right or i could be wrong lol )

stan
04-02-2008, 22:20
your missing the point :P what i mean is, if what coops was saying was right and that figure was a wheel figure, then it would alter dramtically depending on the gear you were in.

but due to the software it doesnt....the sofware will produce near-as-damn it the same figure no matter whjat gear your in, because as I explained above, the software (its made by the same manufacturer as mine...Land&Sea) uses the overall drive ratio to obtain a flywheel figure.

(i say near as damn it because the lower the gear you ar in, the less losses experienced).

Coops
04-02-2008, 23:30
well all am going on is what nick said, hes been using this system for years and quoting bhp and torque figures for people for the same amount of time, so how come this question has only just cropped up? he added 20% to both my figures for me, with no prompting, as he did for everyone else and am guessing for everyone whose ever had a car on his rollers, so either he's lying or something fishy is going on :?

i understand what your on about stan i think, but i dont think thats how it applies to a rr, all rr work off measured torque only, then use the equation with 5252rpm as a constant to find out bhp from that, so if the bhp figure qouted is at the wheels and worked out from the toque figure, then the torque figure must be at the wheels. and it follows logically that if this bhp figure can be said to be at the wheels then any additions for transmission loss added must be added to torque also in order to hold true to the original equation used to calculate the bhp figure from measured wheel torque. otherwise it simply doesnt add up

Coops
04-02-2008, 23:41
heres a quote from emerald:

'The simple formula for calculating bhp is based on 33,000ft lbs of work being done in one minute. This amount of work is regarded as one horsepower. The formula is: HP = Torque x rpm 5252 From this you can see that when the rpm is at 5252 the HP and the torque are the same. If the power and torque lines do not cross here on the graph then someone is telling you porkies! We use the term "Brake" horsepower because the engine torque is measured on a device called an Engine Brake, or dynamometer as it is more correctly known. Dynos measure torque at a given rpm and then we calculate the bhp from there. With an engine bolted to a dynamometer we take the torque reading directly from the flywheel and without any form of gearbox.'

apply this to my graph

at 5950rpm my car produced 163lb/ft of torque and 184.6 bhp at the wheels (both corrected figures)

check this on that formula,

torque x rpm / 5252 = hp

163 x 5950 / 5252 = exactly 184.6 bhp

so add 20% transmission loss to the bhp figure to give 221.6bhp at the fly and shove that back into the equation

hp / rpm x 5252 = torque

221.6 / 5950 x 5252 = 195.6 lb/ft

which is the same as 20% ontop of the original 163 lb/ft measured at the wheels!

stan
04-02-2008, 23:50
lol

your just plugging numbers back into an equation, and transposing them at a later position...of course your going to get the figures you've quoted!!!



do you agree that a gearbox increases torque at the wheels???

jay s
04-02-2008, 23:52
why is the figure bothering you so much fella, power at the wheel is so much more relevent as its the power you will be putting down on the road fullstop no losses etc. 170lb/ft atw is a hell of alot and im pretty sure bb's low boost Does'nt produce anything like that.

Coops
05-02-2008, 00:08
lol

your just plugging numbers back into an equation, and transposing them at a later position...of course your going to get the figures you've quoted!!!



do you agree that a gearbox increases torque at the wheels???

you missing what am saying mate, if you add 20% to take the bhp figure to flywheel figure, then the equation to remain true must increase the torque figure also, otherwise the sums the pc does to work out bhp from torque are meaningless between atf and atw. how can you slap transmission losses on one figure and not another if they are directly related by a constant is what i want to know?

jay its just this loss of torque from the past years worth of work on the car thats niggling at me mate, i refuse to believe its putting out less torque on high boost, okay bb may of tweeked their graph a bit but still, as stan says you'd expect a **** of a lot more torque from a turbo, and if mine isnt producing that why not? and also why would nick not know how his rr works? he added transmission losses to both corrected atw figures for me, why do that as common practice since 2001 when he got the rr if its not correct?

jay s
05-02-2008, 00:25
a few graphs from when i went to a rr day at bb, these are from there turbo conversions, first is high boost, 2nd mega high boost :D :shock:
http://i10.photobucket.com/albums/a117/jay16v-/DSCF1284.jpg
http://i10.photobucket.com/albums/a117/jay16v-/DSCF1283.jpg

both make lower torque than bhp, so cant see why yours should be much different..
1st: 274bhp atf, 232lb/ft atf

2nd: 378bhp atf, 325lb/ft

oh and my 2pence worth is yes i reckon transmisson is subject to losses as torque is what the engine produces then is output to the gearbox ( power will be lost driving the gears then driveshafts etc untill it hits the wheel )

Coops
05-02-2008, 00:39
am so confused :lol:

basically a disgruntled that after 8 months hard work and god knows how much ball ache i've got less torque than a n/a willy lump on standard inlet and internals, not that my friends is pants :cry: **** it am turning the boost up till summit explodes thats all there is to it.

been reading loads of articles and they all use this universal equation but it all applies to bhp and torque of an ENGINE, none of them mention associated issues with cars and transmission losses to the wheels from the fly. but all say that bhp and torque at and engines flywheel are identical at 5252rpm, always, full stop, no arguments

so what i dont get is that is true so therefore if my cars torque figure is at the flywheel, then its producing 184 bhp at the fly aswell, so thats 184 BEFORE transmission losses.

richy
05-02-2008, 00:55
why you getting so worried about figures coops?

you know it goes much better and should be more reliable, so relax and smoke some scoobys or the likes!! :lol:

stan
05-02-2008, 08:58
mate its not a case of low torque....as i said in my third/4th quote (after questioning myself!) losses are applied to torque. so you adding 20% isnt the issue...

my point is, the figure on the graph isnt a wheel figure!

i think theres confusion becasue to get from wheel POWER to fly power, you add 20%. for this instance you are adding 20% to a torque figure, so maybe you are just assuming its wheel torqe also. In actual fact it isnt...its actually an insignificant figure,,,,imagine it as "flywheel torque but obtained from a loss free transmission"..so to make it something relevant we have to make it "flywheel torque with transmission losses removed" that makes sense!

Allan
05-02-2008, 14:31
http://www.pumaracing.co.uk/POWER3.htm

One of the first things they say

First, let's look at how a chassis dyno works. The car is driven onto a rig so that the driving tyres are resting between two steel rollers. The torque is measured at different speeds in exactly the same way as an engine dyno works except that it is torque at the rollers rather than torque at the flywheel.

summeh
05-02-2008, 16:14
don't let maxiboy see that link :evil:

J o n
05-02-2008, 16:46
well, whichever figures are correct it's making some very good power Coops and the torque seems about right for a 1.8 turbo F7P. Would worry either way, I doubt much on the road gets past you mate

stan
05-02-2008, 19:17
http://www.pumaracing.co.uk/POWER3.htm

One of the first things they say

First, let's look at how a chassis dyno works. The car is driven onto a rig so that the driving tyres are resting between two steel rollers. The torque is measured at different speeds in exactly the same way as an engine dyno works except that it is torque at the rollers rather than torque at the flywheel.

yes thats not disputed.

Coops
05-02-2008, 22:10
meh bugger it, either way its pretty nippy :lol:

i just like to diagnose things all and understand how they work and this one has still got me thinkin/confused and will do i guess for some time :oops:

i do get what stans on about, loss free transmission etc, but according to nick and also paul at rs tuning now aswell the printed torque figure can be adjusted depending on the rr in question and the software and they both agree and think that it can be measured at the wheels and displayed so against wheel power in bhp and that both can be adjusted for transmission losses back to the fly. so theres a very definate divide in opinion between these two guys and craigs take on it. and as i cant get my head round it am confused as to who is right :lol:

Crossers
06-02-2008, 10:56
Your max boost should be 1.1bar, so 16.2psi not 15. just crank it up :P

Paul

Coops
06-02-2008, 19:16
15.5 psi mate is max for that chip according to henk at fastchips and andy at bbpt

Laine_16v
08-02-2008, 11:29
Dont worry about it coops lol its only a figure, if u boot it and it puts a smile on your face who cares, jsut think you could be in my boots with 131ATW :roll:

titcharoony
08-02-2008, 11:31
detonation=boom=cry

Ahmed Bayjoo
08-02-2008, 12:22
nuthing wrong with yours laine, just needs a good remap (and a heatshield :) )