280rwkw, Stock Turbos Stock Boost

[R31Nismoid]

Maybe our Gibson Mechanic of 15 years can give us an idea of how unrealistic dyno readings are attained

[neil_se]

How does the inlet temperature get lower than the air temperature?

[GTR1993]

it cant, but i have seen it before, the sensor is suposed to be put infront of the filter to get the air the motor is sucking in but sometimes it sits on something cooler (still a bit baffeled how you would get something cooler then ambient in the engine bay). To get the most accurate results i have found to just hand the sensor up on the dyno, at IT and AT are always the same, if the motor sucks some hotter air it will make slightly less power with out compensation, but same car should do the same each time.

Also on the note of ramp rate, i have tryed shoot out mode and non shoot out mode, 100 to 150 ramp rate and all has been with in a few kw, never tryed 200 though.

My gtr in RWD mode made 240 rwkw at 14 psi, steel wheeled std turbos (unknown if they are slightly bigger or just std) tomei cams and tomei cam gears, cat back exhaust, power fc.

Edited June 21, 2006 by GTR1993

[The Mafia]

280rwkw..

My R33 GTS-T made 400awkw, with a SR20 turbo at 6psi of boost, running on 5 cylinders.

[khunjeng]

No, The blue line represents torque.

R31Nismoid - If you read my post I never said the car was completely stock. I agree with you, 280rwkw is not possible out of a COMPLETELY stock car.

lol - I want ur car, close to 900mn of torque....

dyno results should be used to determine if your mods have given u a gain...and by how much. However if ur dyno reads 300kw when it should be 180 then thats a bit pointless also...cos by that logic...I wack on a new cam gear and it says i get a 50kw gain LOL we all need one of those..

Edited June 21, 2006 by khunjeng

[predator]

^ er.. you do know how to divide by the final drive figure to work out the real torque figure from the graph? http://www.skylinesaustralia.com/forums/in...opic=116669&hl=

this thread is funny already..

[Mr. Keets]

89 GTR

Stock turbos (Ceramic)

PFC

3inch from the turbo

Adjustable cam gears

EBC

Tuned by Ant Scali

336rwhp / 250rwkw

[GTRsean]

Two different power runs on the same graph.

Green lines, power 282kw and 452Nm of torque, (18 PSI??????)

Blue lines, roughly 210kw and 350Nm of torque.(stock boost??)

Just my thought on the graph.

[paulr33]

even if it is legit, what are you going to do when you have to rebuild when one of the ceramic wheels let's go ?

[GTRsean]

'even if it is legit, what are you going to do when you have to rebuild when one of the ceramic wheels let's go ?'

ouch!!!!

That would be not good for skyrine, grasshopper.

[rb26s13]

a dyno is simply a tuning tool.. you cannot compared dyno to dyno as no 2 dynos anywere around the place are goin to give the exact same power reading for the same car regardless

and as for 280kw out of stock turbo's on stock boost i f**king doubt it... unless your 'stock' turbos are r34 n1's.. even then i'd doubt they'd be sitting on stock boost..

and also in regards to you being a mechanic.. or who you've worked for it doesnt really mean shit.. as there is always someone out there who knows more than you do.. regardless of wat its about

[khunjeng]

^ er.. you do know how to divide by the final drive figure to work out the real torque figure from the graph? http://www.skylinesaustralia.com/forums/in...opic=116669&hl=

this thread is funny already..

so what would that be from the 1st graph shown?

[PranK]

What a load of shit...

Even my fish know that any dyno can be made to give a 'desired' result. Dyno settings can be changed as well as the amount of power that a dyno is given (A performance shop in Hornsby, NSW used to share the same power box as the carpenter upstairs... lets just say that when the bloke upstairs was on his bandsaw, the performance shop's clients weren't impressed with their figures...)

My GTR made 250-something at the rears with stock turbo's, 1.1 bar, cam gears, fuel pressure reg and full exhaust (actually, stock dumps).

I dont give a crap about how many years experience you have, if you don't know the physics of dyno's and how to calibrate them correctly, then readings will be off. Thats not to say that you are bad at tuning, cause thats a different kettle of fish.

C

[brenr33]

Maybe our Gibson Mechanic of 15 years can give us an idea of how unrealistic dyno readings are attained

altering b.p is the most common

[rb26s13]

also i'd like to note.. at a dyno comp up in cairns(ignham car show actualy) recently a skyline picked up 65hp at the rear wheels with having its bonnet up compared to having it down.. and shoot out mode rules state that you must run your bonnet down n latched

Edited June 21, 2006 by rb26s13

[Cubes]

mechanic for 25 years 15 of them with gibson motorsport and so yeh i might know more ya toss

Shootout81 what a load of crap.. Have it run it in the correct shootout mode as 'SHOOT81' reads around 20-30rwkw higher than SHOOT6.

That pulls the power level back down to being close to reasonable.

This was shown at a recent dyno day when all cars were being run in SHOOT6F mode, a ls1 jumped on and made no where near as much power as it did on Donnan's dyno, Shaun then dropped it in to SHOOT81 and it instantly made another 30rwkw or so.

[Jolinator]

hahahaha

[mad082]

i should've been run in shoot6f.

also IT can be lower than AT. remember that the air is passing the IT sensor fast, so it cools it down. remember that the sensor is surounded by cold metal (as well as hot) but the air is usually coming from the cold side. and it creates a vacuum which also lowers the temp.

[Roy]

No, The blue line represents torque.

But i dont get it, there are two pairs of lines. Is one pre exhaust etc, one post?

mechanic for 25 years 15 of them with gibson motorsport and so yeh i might know more ya toss

Cool, can i ask which 15 years were you at Gibson? ie which era? I need a bit of info on a few of the cars that were built in the Grp A days

[Cubes]

Yes my bad.. I missed the F.

I did a quick google and found this interesting post over at the ford forums

Scenario; We take a turbocharged six cylinder vehicle and place it on an unnamed dyno (this info comes later), a dyno whereby the software makes it impossible for the operator to in any way fudge the figures, with the only variation being temperature correction (via an inbuilt weather station that automatically corrects in relation to the ambient), which is of course to SAE standards, and once again can’t be played with.

1. Said Test Vehicle produces 282.1 rear wheel kilowatts @ 14 psi boost.

2. Said vehicle is then driven approximately 300 metres to another workshop where it is placed on a current model Dyno Dynamics chassis dynamometer equipped with the latest Dyno Dynamics Shootout Mode software. Software designed, we’re told, to ensure an absolute level playing field between every Dyno Dynamics dyno in the country (when fitted with the Shootout Mode software).

3. Once said vehicle is strapped onto the dyno and the software is set to the ‘Shoot6’ Mode (for six cylinder powered cars), a power run is performed for a relatively consistent result of 288.5kW @ 14 psi.

4. Said vehicle is now run with the ‘Shoot8’ Mode (designed for V8 powered cars), with the power run resulting in 304.9kw @ 13 psi.

5. Said vehicle is finally run on ‘Shoot81’ Mode (designed for turbocharged/supercharged or nitrous facilitated V8 powered cars) with the power run resulting in 317.8kw @ 12.5 psi.

Okay, so we have the very same car producing more power with each run but with a lower boost output. Interesting huh! The bottom line is that the bigger the engine (4 versus 6 versus 8 versus forced induction 8), the faster the ramp rate, hence the potential for a turbo to achieve maximum boost is lessened. In other words, the run is so fast it’s hard for the turbo to come on boost.

So the question is this: Why should a V8 benefit from a faster ramp rate (hence vastly improved power output)? Could it be that the more the power, the more potential there is with a Dyno Dynamics dyno for the car to spin the tyres if a ‘real’ ramp rate was allowed?

Another thing to consider with these fast ramp rates is that they are far from ‘real world’. A ramp rate that sees an engine achieve maximum power and rpm in say five seconds is simply ridiculous. A concern here is that the slow ramp rate allows a tuner to go with greater boost, greater ignition advance et cetera because during a five second run this may not be a problem. In the real world it is.

The bottom line is that using the same car on the same dyno, and run after run it produced almost an additional 40 rear wheel kilowatts by simply changing the Shootout Mode.

Which is similiar to what we experienced at the dyno day some time ago.