cls55

On what gear the dyno operator dyno the car with 7 speed(c63,e63,sls63...),I saw it being done on 4th while the 1:1 ratio is on 5th,but on the 55 KOMP. they do it on 4th because that is the 1:1 ratio.what gives.

cls55

Where are the experts?

SaphGreyC63

Sometimes our experts take time.

We appreciate your patience and hope to be with you shortly.

Thank you for understanding.

-MB Dyno Experts Team

Ezec63

Im not an expert but know it should be done on the 1:1 gear .. So thats 5th gear for the 7 speed trans

cls55

Watch at 3.00m,it's done on 4th.
http://www.youtube.com/watch?feature...v=OmigydVawug#!

mthis

1-1 is in 5th gear but everyone uses 4th for some reason

MBAdon

Do the dyno results vary depending on what gear you are in?

cls55

As far as i know,yes^^

cls55

SuperSprint does it with fifth gear,on 1.00 m start counting:
http://www.supersprint.com/en/doc-s-...80BA_dyno.aspx

cls55

Here is another tuner(HG Motorsports) dyno an SLS on 4th,.49S:

cls55

Any body.

cls55

What is so difficult about my question? Where are the tuner shops?

mthis

What are you still trying to figure out ?
1-1 is in 5th gear !

cls55

I know that, but why most tuners do it on 4th?it shows higher output!

Mort

On baseline dynos (basically stock cars) they use 4th because the car runs into the speed limiter in 5th before it hits red line. The run ends at ~ 6000 rpm so you miss the peak numbers. After a tune it is still done in 4th to get comparable numbers. I have read that the readings may not vary much between using 4th or 5th gears. I think some dyno operators may be timid to run the car flat out in 5th as the speeds reached are quite high.

cls55

As long as it is accepted method and disregarding the 1:1 ratio which is the optimum ratio,how come a car's power was 510 rwhp on 4th stock and after tune its 524 rwhp on 4th on a dyno jet.Am i being clear here.What i'm trying to say is if a car's power from factory was 5xx crank wouldn't it be lower on a dyno by 15-18% ?

Mort

Some dyno operators report in flywheel horse power which they convert from rear wheel HP. I think Europe does this for the most part. Not sure why they do it or what factor they use to do the conversion. In NA most report in RWHP and convert to FHP using a factor of 18% if you wish an estimate of HP at the engine. Otherwise those numbers you have are not correct for RWHP on a stock or tune only C63. You will see 360-370 rwhp on a stock car and 420-440 on a tune only car. You will see higher and lower numbers reported but these numbers are about the mean and not the extreme.

cls55

Thank you Mort,did you watch the video above? stock SLS 563 hp minus 18%=461.66 rwhp,now add headers and tune the end result is 478 rwhp!!.will you please explain it to me.
Thank you

mthis

Stock c63 5th gear run
Don't mind the 391 rw it was a wack as$ powerchip tune


And stock 4th gear

mthis

Mhp tune and filters 5th gear

mthis

I have another sheet in 4th gear that I did about 6minths ago with my mods now 465rw 100rw gains from stock (minus race exhaust not being on)

SLS Qatar

Do it in 4th Gear. 4th gear is close to 1:1. You will also be able to see the power curve until 7000+ RPM. On 5th gear the RPM hits below 7000 rpm. Therefore, do it on 4th

cls55

SLS Qatar
How did you run your car on the dyno?what was the rwhp before and after the SuperSprint?and what was it after the tune?
Thank you

SLS Qatar

On my SLS I dynoed it on 5th gear because 5th gear was closest to 1:1 on the SLS. These were the results that I previously posted:

Stock: 470 rwhp (Even though they usually dyno 480-485, our dyno reads a little lower than normal...)

Supersprint Headers & Xpipe: 507 rwhp (gain of 37rwhp)

Supersprint Headers & Xpipe + Custom Tune: 534 rwhp (gain of 27 rwhp)

cls55

Thank you SLS Qatar,(5th is 1:1),64 rwhp is a great gain from headers & tune over stock.How would you compare it to other super cars?