My APR Supercharger has arrived!

[S4Player]

Sure is mate. As previously said aslong as your happy that's all that matters. See you soon buddy

[mutantfatcat]

Catch you Saturday bud.

[RSKiwi]

Am I happy? ............................ you better believe it!

You folks can go argue all day................I really couldn't give a rats ass..............especially when I'm driving my 'charged 4

Well said mate

+ about a million.

[S4Player]

Just for comparison I went out in the soaking wet and managed 4.0-60 9.9-100 and 4.6 60-100 best results, so the apr kit must be doing something around the 580ish marker well done lee good purchase

[sonny]

Car and APR S/C looked very very nice in the flesh today at ADI.

[mutantfatcat]

Car and APR S/C looked very very nice in the flesh today at ADI.

Yeah, was good to see you again Sonny. I didn't get to watch much track action but I could definately hear when you were out there.

[mutantfatcat]

Just for comparison I went out in the soaking wet and managed 4.0-60 9.9-100 and 4.6 60-100 best results, so the apr kit must be doing something around the 580ish marker well done lee good purchase

Danny, just looking back at James's message when he sent me the picture, the above numbers were 2 up with full tank of fuel with 1 foot roll out NOT activated.

[S4Player]

Nice one Lee I couldn't get any lower than the stated times for the life of me. Pissing down with a half tank was my scenario

[mutantfatcat]

Driver only, full tank of fuel.

[RS4POWER]

^ Nice results!

Enjoy your new car

[JCviggen]

Hey AwesomeHAssan,
you know I got a lot of love for you guys there at Awesome, but losses calculated by your dyno are 9.05% which just isn't correct.

A while back, I was having lunch with Roland Mayer and Peter Link from MTM. We got into a discussion about quattro drive train losses. I was told at the time to expect 25% loss approx.....the more power you put in, the more the loss.........unfortunately.

Just came across this and would like to pick up on "dyno losses" which are always good for a lot of back and forth arguing.

Losses do not increase as you add more power. Well not counting the odd horsepower here or there. The losses in the actual gears of the transmission are small, otherwise they would start melting pretty quickly with the sort of cooling they have available. Most of the real loss that you see is inertial (accelerating the weight of the wheels) and frictional. Taking into account that each dyno has a different resistance depending on load you will see different loss numbers anyway. Tire pressure, tire temperature etc make much more difference for loss numbers than adding more horsepower.
And the gear you dyno in of course. The actual tire speed makes a huge difference, so you see less "loss" in 3rd gear than 5th where tire speeds are high.

Whether you have a 400hp or 500hp car if you make peak power at the same rpm and dyno in the same gear, you will see about the same amount of loss (100-120hp depending on tires). So it might be 25% stock but as you add power the percentage inevitably drops to 20 or lower. That's still different from what you see on the actual road because load dynos usually have double rollers. 2 contact patches means more resistance (not quite double but a lot more than a single contact patch as in real world driving) so on the road you're not quite losing as much as you see on a dyno.

What you see with turbo cars is that they start making a LOT more at the wheels when you give them a stage 1 map. That's partly due to actual increased BHP, secondly due to the peak power occurring typically at lower rpm than stock. Lower rpm, lower tire speed = less loss.

Example from my own car, before MRC remap it did 396ps at the wheels for 522bhp (precats removed + wagner ics) at 5900rpm. After remap it did 441 at the wheels for 546bhp 5250rpm. That's +45 at the wheels although maximum engine power only went up by 24bhp. That was caused by peak power being a mere 650rpm earlier - 25 km/h tire speed difference. So you can see that tire drag starts increasing enormously at high speeds. If you would calculate drivetrain losses from my 2 dyno results you would end up with 24% stock and 19% mapped. But you can't apply those to any other car because you can get completely different results.

On a proper dyno you can dyno in 3rd, 4th or 5th gear and you should get pretty much the same BHP figure each time. But wheel power and losses will differ greatly between each one.

Last point: great result! Those are very nice values for a family saloon. My volvo track car did a 7.8 62-124mph run once (~430bhp front wheel drive) but would get nowhere near your 0-60. I always loved the B7's, perhaps my next DD should be a SC'd 4 rather than a big heavy C6 RS.

What kind of oil temps do you see after "playing" ? I imagine it would be a great tracktool as well but I wonder what the SC does to oil temps on a circuit if you don't add an aftermarket big oil cooler.

[PetrolDave]

Just came across this and would like to pick up on "dyno losses" which are always good for a lot of back and forth arguing.

Oh g*d not again!

Am I the only person on here sick to death of us continually going round and round in circles on the dyno issue?

The simple fact is that the B7 does NOT dyno well as (amonst many other factors)it is so sensitive to intake temperature which makes it alter the timing dramatically which alone makes dyno readings (unless you have a HUGE fan) worthless.

Add to that the many other - well documented on here for anyone that can be bothered to search and read - factors and the simple conclusion is this - dyno readings on the B7 are no use whatsoever to indicate absolute values, BUT they can be useful for comparion between cars (on the SAME dyno) and for before/after comparisons (on the SAME dyno).

[JCviggen]

Only wanted to point out that more power = more loss is wrong.

NA cars are always more compromised on a dyno than turbo cars, lack of moving air and all that. Doesn't change the physics behind drivetrain losses.

[PetrolDave]

Only wanted to point out that more power = more loss is wrong.

Mentioning dynos on here is tantamount to declaring World War 3 - don't do it unless you like seeing lots of blood spilt

[JCviggen]

Only wanted to point out that more power = more loss is wrong.

Mentioning dynos on here is tantamount to declaring World War 3 - don't do it unless you like seeing lots of blood spilt

Okay even without a dyno it's still true just you wouldn't know it