Also the R35 has been proven to have just about 10% friction loss.
No it hasn't and please don't show me that effort where they measured drivetrain drag on rundown. If you want to use that effort then please press the ends of your fingers on to rough sand paper and drag them back and forth slowly. Then do the same fast and see if you record the same skin loss.
This 650hp may well actually be a 5hp lawn-mover engine that's been slotted into a crashed R35 that's been welded to a G35 but 650hp is possible with stock turbos.
thistle said:
Best ET is listed there, not best trap which was 128mph in 10.9, and since we're splitting hairs the one in the video didn't actually break 130mph either did it, although some similar ones have, many don't.
0.05mph? Seriously? You should know that it takes a lot of power to make 2mph on trap for a similar time. What was the 128mph ET?
thistle said:
On stock actuators and injectors, with stock ECU boost control and considering how long we've had the cars in the UK that is respectable, have you done better on an R35?
Never said I could. You started this whole affair by incorrectly stating that 650hp flywheel couldn't be achieved on stock turbos, which is still incorrect despite your efforts to diversify the argument. Didn't Amuse bloody measure 550+whp with stock turbos anyway. What am I even arguing about here? Is Amuse's dyno faulty too?
thistle said:
I believe your source overestimates the size of the injectors. The injectors are wide open at 11.5:1 AFR on external wideband. And that is with appropriate ignition timing. I was after all the one who disassembled the stock ECU knock control so I should know how to get the best timing out of them when most tuners haven't even started logging it yet and most are oblivious to how much timing their ECUs are pulling out.
Well it looks like BoostLogic's GTR is in defiance of your 600hp (510whp) calculation and Amuse's GTR is too.
thistle said:
Yes I do believe the stock car is 478 BHP.
Well I'm afraid that's mathematically impossible. The fact a 1740kg car makes a quarter in
[email protected]+ with less than 600hp is a miracle atributable to the gearbox. Making that time with 478hp would require divine intervention. By that logic every stage 1 skyline GTR would be in the high 11s. Nissan achieved a lot through science but stopped short of outright magic. Funny how pretty much none of the 10% magic men dispute that their quoted torque output is total bollocks.
thistle said:
I tend not to use dynos to tune since I have found that best acceleration on turbo engines often does not tally with the tune that gives the best dyno figures. Dynos are simulators, and usually poor ones at that. The airflow, loading, cooling, tyre deformation are all unrealistic.
Yes. I'm not a tuner and even I know that. They also don't do well at measuring performance when not on WOT. They're a place to start before going on to the road.
thistle said:
The fact that a standard car on one dyno can run higher power than a well tuned car on another that accelerates faster proves it to me.
Well of course it will. That's like saying that your quarter mile will be slower if you run it up a 1:3 gradient. But dynos of the same make should give approximately the same results under the same ambient operating condition if they're in the same state of repair and configuration. But yes it's best to use them to measure performance differences between mods. However, given that they don't necessarily measure true acceleration potential maybe you should test your cars with 40-95 and 60-125 runs in 3rd and 4th on a local bypass.
thistle said:
If you have timing box equipment it is susceptible to question, just like dynos. Quarter mile times with proper certification tend to be better accepted, but I agree rolling acceleration is more important.
If you don't configure it correctly it becomes more open to question but then couldn't you also question track times since under NHRA rules a track can vary by up to 12ft in altitude between start and finish. A slight uphill to give better traction at the start, with maybe 15ft of downhill for the last 350yards.:flame: Then you've got windspeed and altitude and temperature and humidity.:flame: So in the end a track time is also full of shit unless you measure on the same track on the same day but even then the temperature or altitude could unreasonably advantage or disadvantage a turbocharged car against an NA car, especially a turbocharged car with a small engine, or with poor cooling.:flame::flame::flame:
thistle said:
The day I took my Subaru to a dyno, had 80 BHP less than a similar weight car and then pulled six car lengths on him on an airfield afterwards, repeated with swapped drivers, was the day I stopped taking too much notice of dynos.
Well you tend to use more than 1rpm of a car's powerband - that could also have had a bearing.
thistle said:
The car was tuned for maximum safe acceleration, did not knock in road or track use, but did on the dyno.
Usually the otherway round from what I've heard, especially with the sort of boost spikes and early spool you can get from uphill acceleration in a high gear.
thistle said:
GTRs are difficult to properly dyno test, and the engine bay is crowded and hot. The transmission can cause all sorts of limp modes. Consistency can be difficult.
I'll take your word for it.
thistle said:
So I've got little ambition to resolve cross Atlantic dyno differences. Those that know, know. Occasionally I point it out and get drawn into debate. I'm probably too keen to waste my time shooting down dyno figures that don't square with what I call reality. But we all know big numbers sell, and that is the real reason they are used.
Well you really should because I'm tired of these discrepancies and they're always going to be here until someone takes a car over there, or vice-versa, and takes some measurements.
Here's another one, check the signature. 551whp up from 420whp:
http://www.nagtroc.org/forums/index.php?s=&showtopic=30401&view=findpost&p=423377