Rippers

Any good? or does it depend on the operator?
having my Monte on a one for a power run on sat

Any predictions? made 439bhp on the SCS dyno and has been run in and live mapped now by Ahmed

Would be happy with 400plus

Charlie Chalk

iTrader: (1)

I've mentioned to Chris Todd about sorting out an RR day soon....


He has this set-up. I dont mind doing the chasing, Im gonna go see him Friday to see if he wants to actually do it as it was just a brief mention when I last see him!


Up for it?

Richie.

iTrader: (5)

Surely you mean Dyno Dynamics

bassboy

which one u getting it done at Paul?

bassboy

Rippers

Yeah i do rich

Rippers

Radders yes mate

Bassboy my mates mate works at a Jap tuning firm called Perfect Touch which is local to me, based in Hoddesdon, Herts

Richie.

iTrader: (5)

Very good rolling roads Paul If used in standard shoot out mode you should be able to get virtually the same results on any other set of Dyno Dynamics rollers.

Made by same company as Autronic

I reckon yours will make 430 bhp as long as the ambient temp is ok

Mine made 397 and i built it myself Although MSD did the mapping

Rippers

Finger crossed then

Richie.

iTrader: (5)

Yeah but that was with my turbo on it

Andy_R

iTrader: (3)

300@wheels

foreigneRS

yes

yes

same as any other rolling road

Christian and Beccy

iTrader: (14)

I depends on the operator and whether they chose to use the correct method to run the car. Standard Shootout mode must be carried out in 3rd gear and with the tyres at 50psi (though the tyre pressure isn't as important as the gear used).

Personally, I wouldn't use the engine dyno figure as the benchmark as engine dyno's aren't the be-all-and-end-all of measuring power. In theory, yes, but in practise, not so.

foreigneRS

here we go again. an engine dyno is the best thing for measuring engine power - that's what they were designed and built for believe it or not

a chassis dyno is the best thing for measuring power 'at the wheels' (barring tyre deformation on small rollers, strap down forces etc)

but you can only compare the 2 results if the conditions are exactly the same that includes things like having the same induction and exhaust systems, same barometric pressure, ambient temperatures, coolant circuit and temperature etc.

and most important of all on a forced induction engine is the same level of intercooling. and that is the thing that is usually the most different between an engine dyno (with perhaps a water cooled charge cooler keeping a constant temperature), a chassis dyno (with an electric blower) and the real world driving conditions on the road (airflow from forward movement of the vehicle).

if you were a proper mechanical engineer, you would understand these things

edit: not meant as having a go at you christian, as you are right about the practice bit just meant as general information

RichardPON

Why tyres at 50psi?

If you don't run tyres at 50 psi on the road, what relevance will it have?

foreigneRS

i guess that's to minimise the effect of tyre deformation on the rolling losses so that they have a standard to compare between all of the DD shoot out results.

as that is nothing like what happens on the road, who cares?

PT

I had mine rolloing roaded on a dyno dynamics rollers at SCC Performance, Rob swears by it

rapidcossie

if it made 430 on the dyno then it will make 100 bhp less in the car at the wheels.

gingeRS

think you may be wrong there christian as that is the sole purpose they are designed for, i should know as thats what i do for a living

If you are referring to how they perform in 'real life' then that has too many parameters to even think about. but if its the most accurate power figure you want for an Engine then it has to be an engine dyno

Rippers

...and remember SCS engine dyno is TUV approved

Kev.H

my 2 penneth Ive run on a DD rolling road @ SCC I made 267bhp, I then ran at Track & Road http://www.tracknroad.com/ it runs within 1.5% of HT's Proper SF901 Superflow Engine Dyno http://www.dynoit.co.uk/ and I made 285bhp Both roads are regarded as accurate and are calibrated on each run..... Rob runs in 4th with tyres enflated and its a twin roller jobby where as T&Rs is a single roller device and they run in 5th but according to Clint Gaskin this is fine as its all based around the ability of you car to accellerate the known mass of the drum. At T&R they run the car up so the roller was exactly spinning at 60mph then press a button, which callibrates something I also ran at EA with no boost controller or manifold and made 295

as a joe public non techy I have no clue how much real power I have and am not bothering running on a RR anymore

DD




T&R




EA

GARETH T

good rolling roads

cossie4i+

iTrader: (15)

Mine was 20bhp less on a DD Rolling Road compaired to EAs.

Steve.

Christian and Beccy

iTrader: (14)

I agree that THEORETICALLY an Engine Dyno is the best way to measure power at the ENGINE. However, that's not to say that there are as many innaccurate engine dyno's as there are chassis dyno's. It is no different. I shall not be specific, but why do the results have to be gospel just because they were measured on an engine dyno? It may not have been properly calibrated to 10 years. Infact it is so much easier to 'fudge' the figures on an engine dyno, by altering any one of the many cell parameters that are controllable by the operator.

At least on a chassis dyno the car runs in its 'road trim', with all the ancillaries that it runs on the road. Not a dyno-specific exhaust, cooling system and so-on.

As said above, the 50psi thing is what DD have discovered to be the best pressure for consistency. Similarly, their system was designed to use 3rd gear, so we don't question it. Those who use 4th gear on a DD Dyno might aswell have not paid Dyno Dynamics prices and just gone for something cheaper as by altering the suggested methods, you are simply providing an inaccurate figure.

On the tests we have done, the car usually produces the expected figure in 3rd gear and, believe it or not, a lower figure in 4th!!

RichardPON

Why 3rd gear though, when 4th is usually 1:1?

Christian and Beccy

iTrader: (14)

I'm not in a position to explain the technicalities of that one, but as a Dyno that is used a trusted throughout the world, I don't tend to question it. I must make the effort to learn though and when I do, I will let you know!!

I agree about the logic of 1:1, but DD say 3rd, so we use 3rd.

Garage19

I would say it is not 3rd specifically that they are after but a given road speed due to friction/heat build up at higher road speed which may not be present so much on coast down.

A rally car may top out at 60 in 3rd where as a big engined road car may be doing over a ton so to just say 3rd is pointless.

Because i was told so is not really an answer i would want my RR operator to give. I would want them to know WHY.

Billabong

You should question it imo, for all the hype regarding DD rollers, you really should know exactly why you do certain things. That isn't a pop at you btw, and putting 50 psi into the tyres is hardly running in road trim.....

And yes, I do believe you when you say 4th gear would give a lower reading (gearbox = torque multiplier)

GaryEvo

dd say that 3rd is normal gear used as peak power should be made between 60-85mph as this is the most accurate window

tyres are run at 50psi to give consistent readings for dyno days and prevent tyre damage while mapping

SteveB

iTrader: (3)

Who told you that????

rapidcossie

How do you run big horsepower rear wheel drive cars?

There is no way my car would grip being run in 3rd on a DD rolling road.

Mine wheels spins in 4th on AVA's and were are testing power at 150 mph at the top of 4th gear.

Mark Shead

The only thing Autronic make for them is the AFR meter and its badged Dyno Dynamics.

Mark

SteveB

iTrader: (3)

I've seen 800bhp (Supra) on DD's rollers with NO spinning and no people sitting in the boot wasting their time compressing the suspension

GaryEvo

personally ive got skyline's gts's running around 450bhp at wheels though rear wheels and they are run in 3rd

my evo makes 480bhp at wheels run in 3rd

plus christians is run in 3rd too!!

but world wide there are loads of cars that are run with no spin!!

rapidcossie

A 800 brake supra isnt a 550 bhp cossie with 235 tyres.

GaryEvo

euan,im game to try it if you want to come have a run

rapidcossie

I would defo take you up on that Gary if you were not so far away

SteveB

iTrader: (3)

Your question was..... "How do you run big horespower RWD cars"

To which I answered with the RWD Supra

rapidcossie

Sorry Steve my questions should have been "how do you run high power RWD cars with thin tyres and crap suspension?"

RichardPON

If I remember, for that sort of car - i.e loads of power, and shit suspension, don't DD have some sort of lever bar setup?

If Mike still used the board, he'd be able to answer all these questions....

SteveB

iTrader: (3)

Lol gotta agree there

I've seen a few big bhp RWD cars run and none have had any probs, even this week saw a 440bhp 3dr run at SCC with no probs. The DD rollers have a trick system to hold down big power cars