PeterUbers

A friend of mine and I have been having a discussion:
(Amg63-)


in both these videos against 2 different awd e63 they both lost.

it seems from time slips that tune for tune both the e63awd and e63rwd are trapping about the same at 126-129 mph for both, so in general WHY do roll racing show much of a difference?



also

https://mbworld.org/forums/w212-amg/...s-video-2.html

where the AWD e63 lost to a stock SLS63

And here the rwd e63 keeps up with sls63 BS that also has tune and long tube headers



the difference in rolling speeds are immense and just don't make sense even with an extra 5% power loss for AWD it stil looks like too much of a difference

Amg63-

one more thing that came to mind, is that the 4matic system we have is a fixed torque split of 33 front and 67 rear.

So maybe also ask them if this system is possibly hurting it from a roll start?

ferrari AWD changes it on the fly and at MOST only
puts 20% of power up to the front.

So so maybe this fixed torque split is what's hurting the car the most uptop, maybe amg should update to a better AWD?

or maybe I'm wrong and this torque split helps it better from a roll, I really not sure but I guess it would be good to ask so we can get all the factors in to narrow it down to the final reason.

shardul

iTrader: (1)

Seems like the AWD system is robbing the power

Georgee6086

Can't wait to see where this thread goes.

gaspam

i guess the RWD is hurting the BMS tuned F10 M5 shop car? It puts out same WHP as E.French's RWD E63 yet still gets destroyed by the heavier E63.... E.French's vids are much like Gustav's vids from GTboard... his car never loses

gaspam

somehow he also manages to beat a RWD Mclaren 650s which weighs about 1500 lbs less with the same HP (these cars run 10.3 1/4 @137 so faster than the fastest tuned e63 by a lot).... so either he has a turbo kit that he's not telling anyone or something else is up as the numbers/results dont compute

Amg63-

maybe your right and he has upgraded turbos and is not telling us.

putting this point aside do you think that from a roll with everything being equal, same tune on both cars that the AWD e63 can keep up with the RWD e63 despite the RWD e63 losing less power through the drivetrain as speeds increase?

also, this AWD system Mercedes uses with the 33/67 permanent torque split, wouldn't all that power to the front also hurt the rolling speed? That's a lot of wasted power seeing that at those speeds the front grip is not needed like it is from a stop or a low speed 1st gear rolling start.

Amg63-

im pretty sure the f10 m5 is heavier than the RWD e63

someone correct me if I'm wrong

TMC M5

I don't know about the AWD system being a huge detriment. The E63S with 4matic seems to dyno higher on every dyno than the pre-'14 RWD models with performance package. Those wheel horsepower figures are post parasitic losses, so the AWD doesn't seem to be hindering the E63S and/or AMG has seriously underrated the power compared to the old performance package. Either way, we may have a small sampling size and comparing tuned to tuned is less than ideal. I would compare stock-to-stock for more definitive results.

Amg63-

in stock form its most likely that amg just gave the AWD a more aggressive tune to compensate for the extra drivetrain loss of the 4matic.

Tune for tune between AWD and RWD would be the better question because this way both are pretty much pushing it to the same level. I just wonder how much difference there is in the real world once both have the same software.

Amg63-

In case anyone is interested in the thread where the owner of the RWD posted his vids here it is


https://mbworld.org/forums/w212-amg/532074-2013-e63-1-3-mile-roll-event.html

he also was asked in the thread if the upgraded turbo e63 was running ok and he said it was running fine but he also said there's some sort of torque limitation on AWD e63 that tuners need to work around.

Anyone have any idea what he meant by this?

PeterUbers

read this ... has some great info

https://mbworld.org/forums/w212-amg/...ver-stock.html

otakki

Correct!

garrettg

Rotating mass which is fixed is factored into work/torque output which can vary with rpm. Meaning the penalty for extra rotating mass compared to a rwd is more at lower torque levels then at higher torque levels. Assuming all E63's make the same torque after tunes then unless traction is actually needed its just wasted mass and lowers torque/work that can be applied to the wheel. At some staggering high torque levels the extra mass may not make a noticeable difference or always be needed to get torque fully applied to the ground but that is a Bugatti situation.

Amg63-

What about comparing trap speeds of the average tuned only e63 RWD vs tuned only e63 AWD?

if they are both the same then shouldn't they be about equal from a roll when both are tune only vs tune only?

unless the RWD e63 on average is trapping higher than an equally modded AWD e63...so that is the queestion here.

gaspam

http://dragtimes.com/Mercedes-Benz--...ag-Racing.html

Amg63-

very very interesting thread.

But this TCU torque limitation being discussed seems to be in reference to all e63s, including the RWD models.

What at am I curious to know is if it's true or not true that for whatever reason it may be, the 2014+AWD e63s respond better and make more power with ECU tunes compared to the power output of 12-13 RWD e63 with the same tunes on them.

If so, that extra power should be able to compensate the extra drivetrain losses of the AWD models which should allow them to trap just as high and keep up with tuned RWD from a roll despite the additional power losses and weight associated with AWD 4matic system of 33/67 trq split that MB chose to go with on these cars.

Pumpkinate

It would be good to get a comparison/race of two S models of the same year, one RWD and one AWD. The trouble is they are sold in different countries.

Zod

This has been done and a vid was posted a while back, will have to search, might ave even been onthe main page

Geno51

I am number 10 on that list STOCK

PeterUbers

not the same year but same engine and specs apparently

gaspam

this video obviously proves rwd is faster than awd in every circumstance ever :P

Georgee6086

It looks as if they both start from a dead stop, I don't think that is a roll race

gaspam

after seeing this , can someone explain to me why RC cars are so much faster than 1000whp cars? should i sell my car and get a RC car instead? or is it just because the RC car is a ferrari model?

PeterUbers

hp:weight ratio my friend! Ive seen those rc vids and they crack me up