kponti

I agree with your theory. Torque limitations are nothing new on MBs, and given the same hardware, torque limits are adjusted from model to model to achieve whatever the end goal is for MB.

We reduced or eliminated them on the E55 and a car or two have run 9s without blowing anything up (yet)

Mike450

Tourqe limits are generally employed in lower gears due to the tourqe multiplication of those gears.

So while the trans can handle max engine torque in gears 3-7, doesn't necessarily mean the trans is built to handle that limit in gears 1-3.

gaspam

exactly... many people dont realize the torque multiplication in first gear is about ~2560 ft-lbs on stock vehicle and 1687 ft-lbs in second

kponti

That is true, torque multiplication will cause spikes well above what the trans is rated for. That being said, do you think the trans in the Audi/Porsche setups are rated for 2500-3000ft-lbs? They do make 750 to 800 ft-lbs at the flywheel (tuned) and weigh about the same or more than the E63. Launch a whole whole lot harder and have an even more aggressive 1st gear (increased torque multiplier)

gaspam

do you think audi/porsche doesnt have torque limiting software programmed in their ecu/tcu as well? they do, just like everyone else... moot point

audi/porsche also has a way better awd transmission that was designed for performance from the start... mercedes awd system was designed for their non-performance family cars and recently adapted for amg use

efiftyfizzle

Clutches are very sensitive to torque and this is a premiere reason as to why Audi used an automatic transmission in the RS7 as opposed to the dual clutch transmission they use in the S4, S5, S7, etc.

Porsche seems to have the best of both worlds - a dual clutch transmission that has smooth shifts when it needs to and very aggressive/harsh shifts in a sports mode. Mercedes should take notes.

kponti

Who cares whether they do or not? They are in the mid to low 10s and we barely break high 10s. So yes moot point, they also have high torque multipliers just like AMG does and still manage to run their cars at mid to low 10s tuned of course

gaspam

there are M157's at 10.03(sl63) @141 and 10.12 (e63s) @139, so whats your point?

fastest RS7 is 10.15 @ 135 mph with custom turbos/custom tuning in russia (and is now making ~942 AWHP on dynocomp), next fastest is 10.35 @135

i would personally want a car that traps 141 mph but i guess you think 135 is better

i have raced tuned RS7's on the highway and they are nothing special ... my car and buddies tuned M5 were both faster than a tuned APR RS7 on the highway.

efiftyfizzle

Good points... I think the cars to chase after are the F10 M5s... 9.90 @ 140mph.

kponti

I think we have deviated from the topic, my point is those torque spikes due to mutiplications are part of the whole table that determines whatever a manufacturer decides to limit their trans ratings on and does not mean much when looking at say the torque limits on say the RS7 vs E63.

I was stating that torque limits have been present in most Merc well before the 4wd M157 and have always hindered max acceleration more so than in other manufacturers. Removing (or reducing it) on the E55 did not immediately result in blown rear ends and trans. It is of my opinion due to the way MB has used limiters in the past that traction was one of the main factors in determining where to set the limits and not just preserving the life of the trans or diffs.

Those cars you refered to have had a lot of these limiters removed and have not blown the trans or diffs (yet). Furthering my point

gaspam

i agree on this 100%... they could certainly let 200 ft-lbs more torque come thru in the lower gears and not grenade our trannys instantly... just 99% of amg drivers (doctors, cpa's, attorneys ) would complain about "how impossible these amg's are to drive" ... the other 1% (you, me, few others) would get street legal drag radials, wider tires, etc

Mike450

The hurdle to overcome is tuning the TCM. While the W210 guys have been able to raise TQ limits via tuning for years, they just recently developed complete tuning control of the TCM. Like 6 months ago recent.

Having complete control over things like vb pressure, converter lock up and shift points is essential once you start putting big power down. Its what keeps big power transmission from tearing up, even the "built" ones. That lack of that control, until now, is why even the built Nag1's have been fairly unreliable past ~800wtq or so. That may change now, to be seen though.

With that said, I d guess the M157 has some time to go before you see that kind of control on a stock TCM.

TX E55

LOVE the front grill! Is that an easy mod? I will search the forum. Nice work.

kponti

Word on the dealer street states tuning for our TCU is not that much different than the W211 (which is already cracked and tuned). However it requires plugging into both the ecu and tcu simultaneously to make it happen. Usually done via OBD and some plug under the car.
The problem now I think is the inability to tune the stock ECU via OBD. So how do you access the needed files on both ECUs when you cannot access much via OBD right now?? Also what specialized instrument do you need to be able to simultaneously plug into OBD and TCU?

All things that could come later, hopefully before my kids leave the house and I trade for an RS7 with APR stage 2 lol. Hey Gaspam, 130-133mph traps are more than even Renntech is doing now

gaspam

not sure where you get your info, but renntech has trapped 130.8 on stock turbos and PP-performance has trapped 132.15 on stock turbos for M157.... Audi RS7 on stock turbos is trapping same (129-133)

renntech has also trapped 136-137 full interior on upgraded turbos that you can buy and bolt-on, APR RS7 only trapped 135 on upgraded turbos and it was a one-off setup that you cant buy, with race seats and no rear interior, with 65 awhp more (765awhp RS7 vs renntech M157 700whp) i dont see your point?

renntech is not the fastest btw as PP-performance has trapped M157 even higher at 139-142 depending on which on of their cars and GAD m157 has trapped 143 on wet/ cold tarmac

here is that fastest in the world Audi RS7 +900awhp (oleg's car) vs vasily's e63s car when it was still renntech tuned/turbos (about 900awhp) before he sent it over to GAD for his current much faster configuration (1115 awhp)


seems the M157 is still faster than the fastest RS7

johnnyblaze

The CLK63 Black Series was the first time I've seen this done with the "blip-mod" added to the TCU via reprogramming OBD and TCU. The 08 models was before they added in the rev-matching downshift (which is the best thing ever in the C63 period ) for the m156.

From what I know about OBD programming is a hash is written at the start of the ECU then again at the end of the file to match the original hash (usually including VIN). The car does a CRC check on the file and if it checks out it "runs" the file. The problem is, Bosch, no one knows the hash "code" to rewrite the file.

TL;DR

C63 Bosch ME 9.7 Control OBD-II yes!

E63 M157 Bosch MED17 Control OBD-II no

Note: this is just a small amount of knowledge after speaking with several tuners.

efiftyfizzle

So what makes the new Bosch different than the old Bosch? are the new ones more secure?

JoeNobody

I tried a tuned TCU in my lightly modded E55, and less than a year later my transmission was chewing itself to pieces (big chunks of metal in trans fluid, even though was just changed). Eventually got a used transmission and learned my lesson.

Zod

Am not sure why some are complaining. I wouldn't want more in first and 2nd if it effects the trans life/ traction.

Most of you had modded 55k and well... 1rst and 2nd were semi useless unless you had fresh sticky rubber and wider wheels. Not sure why you would want to unleash more trq. I have not gone full power in 1rst in my 55k, since 2006...

Day to day is where most of us use the cars and frankly MB controling how traction works was the first thing i noticed when driving on a race course in yas marine with the new biturbo cars. Frankly I was amazed as to how this stock 520+ whp car (equal in power to a stage 5+ 55k) was not just spinning in its place. The yellow triangle was far more manageable as well and less intrusive.

''They made the car more powerful, while also far more manageable''

The GTS even takes this further, that car was an absolute joy to drive hard down low and was planted, giving you the feeling that you were in complete control, while also allowing you to have fun, without constant interference.

Now making more power uptop, that should be where most of us want it...but I can not remember the last time I hit 150mph, since it pretty impossible with traffic & cameras


As for how to tune the TCU, you have to take it out of the trans and send it along with the ECU

kponti

If I wanted an all-out race car I will certainly not be buying a 43 - 4500 pound 4 door sedan for that. What I meant was simply buy a tune and load it up either by bench flash or OBD don't matter, get to the track and pull a 129 to 133 trap speed with mid 10-second times. This is something the RS7 can do this is something that E63 cannot do renntech AMS whatever none can do that with any frequency currently.
Now we start upgrading turbos blah blah blah blah blah well sure the E63 should have better potential it is 1.5 liter larger than the 4.0 in the Audis, but if that's what I want to do I certainly won't be doing it to a 4500 pound sedan.
Let's not forget that 129 to 133 traps on the RS7 is with stock downpipes, the 130 traps on the E63 by renntech was a one-off on aftermarket no cats downpipe. PP performance cars ran at a track that is dubious at best. All kinds of world records have magically been set at that track.
I can understand why the Audis do not have better aftermarket turbo support, it's hard to justify larger turbos when you're going that fast with just a tune to begin with.

kponti

I have been wondering why your above statement stood out to me. I remembered why now. Yes one off, yes crappy track conditions, car is still being setup, preliminary runs is what you are quoting as the ultimate larger turbos can do on that platform(RS7)??
Correction: Crappy tires not track, car goes sideways at launch on a 4wd; reworked stock turbo; first time at the track with that setup
http://www.audizine.com/forum/showth...des?p=11586148
In that case we could look at the video of a member here, Weistec W.3 turbos vs the Renntech tune/downpipe car and make an assumption that larger turbos despite higher dyno and trap speeds will still be slower than a tune only car on a half mile run (how much faster do you want to race???)

Larger Renntech turbos vs tune only

gaspam

trust me, i am an audi fanboy (see my sig), and still active on the audi forums and have had many audis and still have my B5 S4 stage 3+, so im not hating on audi (honestly if they made the RS6 in north america, i would of gotten it), but you are dreaming if you think you are going to run 129-133s with just a tune driving up to the track on regular fuel.... all the 129+ runs are on race fuel 109 tune file.... the timeslip below is pretty much the guy with fastest rs7 on stock turbos... timeslip is 132mph on ms109... but when you see his trap on 93oct, best he has hit is 127mph (something many tune only M157s have done)... go look him up on audizine

racefuel on the RS7 adds 50-60 awhp, so on 93 oct you RS7 is going to be a lot slower

http://dragtimes.com/Audi-RS-7-Timeslip-28334.html

here are his 93oct pulls from audizine:

See below runs on APR 93 octane map with all the data from the timeslips and DA

# Date rt 60ft 330ft 1/8 mile trap km 1000 1/4 mile trap km weight weight kg Comments DA
22 9/23/2015 -0.56 1.974 4.915 7.367 100.02 160.93 9.497 11.300 125.13 201.33 4710 2141 APR stage 1, pumpgas map, 5450 miles on odometer, no spare tire 413
23 9/23/2015 0.562 1.731 4.651 7.094 100.48 161.67 9.212 11.008 125.49 201.91 4710 2141 APR stage 1, pumpgas map, 5450 miles on odometer, no spare tire 413
24 9/23/2015 0.541 1.734 4.645 7.078 100.95 162.43 9.186 10.975 126.14 202.96 4710 2141 APR stage 1, pumpgas map, 5450 miles on odometer, no spare tire 413

See below my last three runs on APR tune 93 map and aftermarket intake

# Date rt 60ft 330ft 1/8 mile trap km 1000 1/4 mile trap km weight weight kg Comments DA
45 3/13/2016 0.416 1.710 4.601 7.018 101.51 163.33 9.109 10.877 127.76 205.57 4690 2132 APR Stage 1, Shell V-Power 93 octane, no spare tire 263
46 3/13/2016 0.392 1.727 4.638 7.062 101.22 162.86 9.159 10.932 127.40 204.99 4690 2132 APR Stage 1, Shell V-Power 93 octane, no spare tire 263
47 3/13/2016 0.323 1.746 4.625 7.031 101.85 163.88 9.116 10.882 127.82 205.66 4690 2132 APR Stage 1, Shell V-Power 93 octane, no spare tire 263

so when you pull up to a M157 in your new tuned RS7 on the highway and try to run, you are going to be disappointed... sure you can roll down your window and tell the M157 to pull over and wait for you to pull a can of VP ms109 out of your trunk and switch from 93oct file to race gas file and then let the ecu adapt to the new fuel, butttttttttt i am pretty sure the M157 isnt going to wait for all that to do another highway pull

then you're going to have to either run race fuel all the time if you want to achieve the performance on the street you are quoting, or you are going to have to upgrade your turbos, which isnt really available on the rs7 platform (except one-off custom basis)..... which means if you ever want to compete with a upgraded turbo M5/M157 you're going to be disappointed, and even against a tune only M5/M157 you are going to be even at best on the street tune 93 oct

you're acting like you are going to have some amazing machine that no one can touch if you sell your e63 and buy a tuned RS7... go for it, you will be sad when you cant pull on a tuned M5/E63 on the street on regular gas

with all the cost of selling your e63, buying rs7 and buying tune, you could just buy upgraded turbo kit from ams/renntech and be way faster for way less money..... but if RS7 is your dream car and you hate e63 looks and design then i could see RS7 being worth it (main thing that kept me from getting the RS7 is lack of future turbo kits and the panamera-like ugly rear end)

gaspam

lol that was from 2013 when renntech was still testing out their stage 1 turbo kit (the smaller one that dynos 660whp).... since then they have come out with stage 2 (710 whp) not to mention changed the ecu/tcu software... there;s a lot on that on the boost site, you might want to look it up... the old renntech kit was basically the same as the W3 kit which has upgraded inlet wheel but nothing on the exhaust side (can you say plugged up ) ... renntech realized that didnt work much so they came out with stage 2 (weistec realized the same and coming out with W4- eventually)..... so basically the video posted is tuned vs tuned M157 as stage 1 turbo upgrade is worthless (maybe worth a few mph's in a 1/2 mile event at best)

kponti

Lol I am DEFINITELY NOT looking to switch to Audi anytime soon. But in a few years down the line, I might when presented with choosing between another E63 or something else is what I was insinuating.

However most 128+mph Renntech runs have also been with racegas

http://www.dragtimes.com/Audi--RS-7-Drag-Racing.html

kponti

Right! Exactly right! Just like the APR car now

EDIT: Renntech is tuning the TCU?? Any info on that??? With a tuned TCU, I might just switch to a 4wd E63 with tune (don't get me all worked up and deflate gaspam!!!)