Dingy

So at 31psi @ 6800 @ nobles its about 410 @ wheels compared to TOTD at 27psi is 380 @ wheels...

Not that much difference really...if the car would have made the boost @ TOTD

Dingy

Going on that it looks like the ACT was to high and knocking off the power.

So maybe the simple factor is the cooling @ nobles is much better than TOTD.

Its always very cold in the Room at Nobles, and it wasn't cold at all in TOTD.

My car @ nobles with 26psi @ 6800 made 394 @ the wheels...

Mike Rainbird

iTrader: (3)

Steve,
Were you not able to sit in the car like at AVA and monitor the ACTs?

Dingy

Nope.

Lloyd

center diff was set to 50/50,gt 30 7.3 comp,ran 30psi at 7 k limit,when set up it should run 37 psi boost spike,at 8k +.i expect the power to be 530 to 540.the limit of the turbo.i didnt see the afr,but chris said it was ok,and its normally 12.to 12.5 on the incar monitor

foreigneRS

the actual room temperature doesn't make as much difference as the airflow across the intercooler

Dingy

Exactly what Karl said - somert bout pressures in side and outside the engine bay...

Straight over my head - clearly the nobles setup suits my brick shaped shit box better than the DD one LOL....

GaryEvo

maybe i should come to nobles next time then?

Dingy

Did you reach your peak power RPM then gary ?

Mike Rainbird

iTrader: (3)

So you also lost some boost cpmpared to what it normally runs on the road?

Lloyd

i didnt lose it mike,just limited it for safety reasons.

foreigneRS

that's probably because we're both proper engineers

it's quite simple really - air can only flow from a place of high pressure to a place of low pressure. the same as heat energy can only go from a hot place to a cold one, and the same as water can only flow downhill

take the weather. if you have an area of constant pressure around you, you will have a still day. if there is a high pressure area to the north and a low pressure area to the south, you will have a wind coming from the north.

apply this to a car, and to get air to flow through the intercooler you need to have a higher pressure area in front of the intercooler than in the engine bay behind it. a little fan several feet away from the front of the car will probably not achieve that high pressure area in the same way that driving along the road at 70 mph (honest officer ) will the airflow will just tend to take the path of least resistance around, over or under the car.

Dingy

Thats what he said mate

Would make sense really....

JonnyBravo

lloyd, 12 - 12.5 AFR ?

Surely thats a bit lean

foreigneRS

if intercooling is not good, overall the engine is not performing as well as it could (the volumetric efficiency is not as high, as colder charge air is more dense) so there is not as much exhaust gas energy to drive the turbine of the turbo. that may mean that the turbo cannot spin fast enough to make the boost that is normally seen on the road

that's probably not the whole story though

Fiecos Dan

Hi Steve.

its best to check Boost's, AFR, ACT's, RPM's off your car gauges whilst run up on the dyno,
as then if it changes, you know its the value's not the accurancy of gauges.
Did you record your runs on your Defi's?

i always watch my cars gauges when on RR's, as i know what they all read on the road, and what i set it up too.


Also your find if the RR is not set up to your car correctly, it will read RPM incorrect, and then in turn the read out.

Steven_RW

Holy cow - lots to read

R/R's don't u love em!

Someone should bring along an m5 as a benchmark to all days.

RW

AlexF

it couldbe with mine...

the IC is small and relies on ducted air. Couple that with the fact superchargers are veru efficient might be 20bhp....

Alex

AndyRST

I did say at the time that i reckoned yours was down to that tiny intercooler and the posistion its mounted ontop of the engine and the fact a RR fan probably cant get the air into it like it can on the road.

Look at these RS500 front mounted ones tho, these intercoolers cool massivly because of sheer size.

AlexF

Did you

bud-weis

But, as i had explained to me the other day...the air on a RR doesn't actually flow through it as it would on the road....it tends to go around it.

mk1 chris

Dingy, why dont you come back down, we will strap it down and i will show you how to run it yourself on our dyno, we can check rpm, run in whatever gear you like put the fan right up to the intercooler and you can put the boost where you so wish, check your act's and coolant temps, make sure the heated rear window is not on, blah blah blah.

you seem to be pointing the finger at me/our dyno for the lack of power your car made, i still believe you had an accurate result, no other person who attended the day seemed unhappy with the figures to the extent that you are.

anyway, offer is there fella.

mk1 chris

oh, just on a quick note, did anyone stand in front of our fan sat?

Alan s1

That sounds like a VERY FAIR offer nice one Chris would stop all the moaning imo

RSescorts

Dingy,

PM'd you?

Ken.

dojj

iTrader: (3)

one of your guys did chris

and then one of your other guys turned it off as he was having his shirt blown over his head and couldn't see what he was doing

there are a lot of good points being made here and, me not knowing as much as some of the rest of you do about this sort of thing, have learnt a fair bit

as for the problem with dingy's car not making the power, reading it all it seems that the reason is due to it not making as much boost, and now it seems that the reasons are becoming clearer

Dingy

I have not once said i am unhappy.
I am not pointing a finger.

I am asking questions mate nothing more, if you don't like the direct questions then i will leave it at that.

And your saying nobles is innaccurate - they read the board to mate.

Dingy

Sorry mate but am not moaning, i am interested in why it can change in the following ways..

Less power
Less Torque
Less Boost
Peak power reached lower

All points to the ACT - as this is not known its then its hard to determine the problems but explains it.

Mike Rainbird

iTrader: (3)

Dingly,
Regarding the peak power, this would depend on how they picked up the rev signal from your car. Either Chris's will clarify .

foreigneRS

i wasn't even there on saturday sadly, so haven't seen your fan but i have seen similar. and to be honest, they don't really compare with ours that is 'only' capable of 70mph over the front of a vehicle and is driven by a 200kW motor











sorry if christian gets fan jealousy again

Dingy

Whats the point of having an inaccurate graph then.....kinda defeats the purpose of the rollers if the graph isn't actually the RPM used.

yrkesman

Would be interesting to see your boost/afr plot from the run that you did at TOTD.

Alan s1

Nick whot do i need to do to get the speed up on my FM12 420 @ work

Alan s1

Ok so you may not but others have been imo and this would be the best way to solve/prove the problem no
Iver way your car was one of my favorts on the day iven my littlen pointed it to me

RichardPON

Looking at those pics that Nick posted made me think...

Has anyone in the aftermarket tuning field ever done the simple test of seeing what the air speed equates to out of one of these fans at full chat....

Nick says what he has pictures accurately recreates 70mph conditions, so what sort of speed does a portable fan on most rolling road use?

Does it help to have extraction at the rear as well to help keep the temps down?

AlexF

Extraction at the rear is vital IMO....

as Nick said earlier, air flows from high pressure to low pressure.

Blowing into a closed box will not be as good as blowing through one, if you catch my drift!

Alex

Mike Rainbird

iTrader: (3)

The AVA set up has underfloor extraction and even when it was running on it's temporary low power set up when I first went, you could lean forward into the air flow and it would support you .

They did also mention the air exchange capabilities, but I can't remember the exact figures, but basically, it could change the ENTIRE air in the dyno cell every several seconds

Alan s1

Alex you should leave coments like that in the Mens Room not in GD

mk1 chris

Cool, a Rolling road shootout day at your place would be great!, when can we do it

in all seriousness, a fan the size of that would take up our whole unit, I still believe for a 10 sec power pull our fan and extraction is perfectly adequate, charge temps when using that fan when i'm mapping rarely exceed 30 odd degrees C when we have checked them, we recently did some back to back intercooler testing with performance ford and the results were published in either this or last months mags, have a read!

Dingy- , i was not dissing Nobles dyno whatsoever, but they cant prove their dyno reads 100 % correctly and neither can I, what if the figures they give are shown "too high" on some cars?, as i said before, people always want to believe the higher figure.

"ESTIMATED" FLYWHEEL POWER is all a chassis dyno can give, and we estimated yours at 450 bhp .

AlexF

Chris, can you imagine the electricity bill