Rod-Tarry

Since this thread is back up mine made 809bhp on DD Rollers about 30 down on the Dyno figure. Im happy with that. Thats within 3.6 % .

Will run it again with the new GTX Turbo & a shot of Nitrous in the new year & this time they will have the latest straps to try & hold it down.

pauljh

iTrader: (1)

Well done Rod,
If my GT35R was ever to fail or wear out i would definatley fit the GTX version, so much more horse power potential.
It will be interesting to see how much you gain.

scoooby slayer

iTrader: (4)

was that 809 wheel or fly calc rod ?

once the sup is sorted i intend on getting it run on a dd, not on my 888s though !

scoooby slayer

iTrader: (4)

mine was run on tdis made 760 last time, the confusion comes when people start adding 17% to the wheel figures, this gives a over inflated flywheel figure, add 9 - 10 % is far more realistic imo, or just stick with the wheel figure.

Rod-Tarry

It was done at a RR road day so calculated fly. The 800+bhp Capri there on the same day made 770bhp & he was not happy most were getting 30ish brake down on what they thought they had , I think the figure was about right.

stevieturbo

The confusion comes when people start quoting dyno figures, of any kind lol.

TimC

iTrader: (1)

If you have time read this.........

http://www.lancerregister.com/showthread.php?t=398130

As far as im concerned dyno figures are a can of worms. How the car/engine performs matters so much more then a figure.

Rod-Tarry

Whys that Steve. Static engine Dyno is the only figures I think are not confusing. Ive compared it on a DD RR & its close enough to suggest it has some merit.

scoooby slayer

iTrader: (4)

i agree non are 100 % accurate nothing can be imo, but dd seem to calculate an accurate fly figure as rods car has proved more than once now compared to engine dyno, hub power is always more than wheel power so less needs to be deducted, take my supra for instance i bought it as 1000 hp car, then got it dynoed and thought it was 900 hp but in reality it is around 840 hp at the flywheel 760 at the hubs.

i want to see a dd dyno with the supra but will have to put my pirellis back on as im 100% confident it will tear the 888s to shreds on a tyre dyno.

stevieturbo

Merit as a tuning tool. The numbers are irrelevant. Maybe if they just gave higher/lower indicators with no numerical content it would be easier lol

The confusion lies because idiots will believe any number they want to believe. Whether it is right or wrong, high or low.

Or in the case of American dyno's, mega high or very high.

Rod-Tarry

Believe me Steve i am no idiot . We dynoed in public with a mags chosed expert in attendance on a rivals engine Dyno where favours were not going to happen . No secret squirel or non showing of Dyno Graphs at MAD .

stevieturbo

I know full well you arent an idiot and the post wasnt directed at you.. But as you also know, there are plenty out there that if someone posts a graph on the internet, then they believe it must be true.

Doesnt matter whether a 2yr old child has drawn the graph, or a drunken heroin addict. Put a graph on an internet forum along with some well written rubbish and there is a wide audience who will believe it's true. Even more so if they are selling something shiny to back it up.

RickyLee53

To the thread.

I find the Dyna packs read about 10% high. This is because;
a, you haven't got the tyres running on the rollers IMO one of the biggest factors.
b' the weight of the wheel.

DD's run a calculation based method, this only applies in shootout 44 mode where the ramp rate is static, obviously if the ramp rate changes you cannot calculate loses from the wheel weights etc.
No methods are 100% accurate, If the dyno has a rundown test at least if you change something like the wheel weights this can be added.

Just something simple like how the car is strapped down or how the RPM is scaled can make a huge difference to the power/torque.

TimC

iTrader: (1)

That bassically everything in the MLR link thread I posted above, in short form. Its been a great thread to read, with a lot of respectable people posting on there, including yourself

RickyLee53

I think the DD is 21% not 24, thats some BS number the MLR made up.
Diff 5% gearbox 6%.
However, I'm sure DD know you cannot loose all that power per extra diff, i'm sure its more down to weight of the drivetrain as well. I.e. prob, shafts, discs, these would play a bigger roll in the acceleration test. When doing a "static" pull you remove the inertia forces, and then just have the actual tyre and gearbox losses which I imagine aren't anywhere near.