That brings me back to my original question, how does it know you changed ratios instead of just changing tire size?

 

don't know you will have to ask Mercedes or the computer co that made the computers for Mercedes

all I know is i tried all the old ways ,,the new ways and some ways that i was told would work,,they didn't. there have been some Mercedes guys that used a different rear and tcu out of another Mercedes, and a few say it works and some say it worked for few days then went limp mode.
some say once you get on hard it goes to limp mode.
I just have Rudy, or JS Benz make me a tcu for my car, vin required, and it works. jim

 

If you have a Rudy, then you have it all.

 

I have a Rudy 3 hrs away....lol

 

Well, no more track this year, as the new ring and pinion is exhibiting syptoms of one ready to explode. I took the wife for a spin today to confirm they gear set is angry. I have a spare, but I'm going to drive around on this one until I can get Richmond Gear (or someone else) to build me a gear set from forged 4140 or equivalent (chrome molly, etc.).

What I don't understand is how Daithi2's wife was able to race their 10.9 SRT6 year after year without any R&P problems. I sent him (Harvey) and email regarding this, and he confirmed they never had an issue with the R&P. He wrote "Never had a problem. Several low 1.5X 60's. Could be a lack of lash on the wavetrac install if it's eating gears."

Damn, now I'm really lost.

 

Sorry to hear this Anthony. I hope it holds up for you until your ready for the next change. It needs to be Grip proof, not just bulletproof.

 

I don't think it's a problem of power at this point, but more of setup. I'm only running a 125 shot, which is less power than Harvey ran for two years.

 

Just wondering out loud here... would you think going to the 3.46 in an N/A 6 spd is a worthwhile undertaking?

 

Unless you are drag racing....no... Your top end and cruising speed will suffer greatly. You have the best all around gear in there now with the 3.27.

 

but if you want better,,better mpg then a 307 would be the way to go ,,if i had a limited auto tranny, i would put a 307 in it and push my mph over 30mpg on the highway. it would be like starting off in second gear and that would be the only difference you would notice jim

 

Well, to me every freeway on ramp IS a drag race. Since I never get to make use of the cars upper end, that wouldn't be a big deal, but I can see how cruising and more specifically MPG would suffer. Noticable gains are just so hard to come by with the N/A, I thought this might be something that hadn't been tried yet.
Will be curious to see your results with the setup. Good luck!

 

Where the gearing helps most is from a standstill. All it will do on the on ramp is make the shifts come much sooner. It may speed you up or slow you down depending on your shifting prowess. The hot set up when I was a sprout was a big block and power glide transmission. (2 speed) Remember those Doc?

Les

 

Offtopic....

hehehehe.....
me too....but....no redline?
.....you should be practicing your launches.....;>)

- when coming onto the on-ramp, turn traction control off
- run it back to 1st and almost a complete stop ~1500rpm (without pi$$ing off anyone behind) stop if you can.....
and then just floor it!......tranny will change to 2nd at redline....
0-60 in <5 seconds
have your hand ready to flick the stick up a couple of gears so it's not overreving too long...

so hey - it's a handbuilt amg motor - its designed to spin quite comfortably to redline a few times a week....;>)

 

Billy Bob FAIL! He's got a N/A 6 speed! More fun to drive except in rush hour traffic. I can't floor mine in first, well I can but if I do I don't go forward.

Les

 

wtYour complaint has been echo'd on this forum since its inception. Probably happened the first time somebody pulled up along side a Camary, and had their doors blown off by the Toyota. Or by nearly every other car built that had a lower gear ratio than the Crossfire. (Which includes every other sports car that was considered direct "competition" for the XF.
The only reason the NA, and the SRT's are saddled with such ridiculously high gears is because of Benz's obsession for long high speed crusing on the Autobahn.
To answer your question, yes a 3.46 would be an excellent gear ratio for an NA Crossfire......Automatic. For a 6 spd. it would make the already very low 1st. gear, even lower. Normal everyday driveability would be effected, in most situations you would probably start off in 2nd. But if you're proficient with a manual, and have good biting tires, then you will out accelerate a Crossfire that has a 3.27 gear.
The same is true for any other "lower" gear ratio somebody wants to use.
A stock SRT with DR's and a 3.46 gear will beat a matching SRT with a 3.27 gear.
AN SRT with a 3.73 differential will out run an identical one with a 3.46, and so forth and so on. (as long as traction remains a constant). That's the trick.
But maybe somday, "Wheelie Bars" on 9 and 10 sec. Crossfires will be the norm. Rudy's going to be very busy.

 

Thanks guys. Sorry to take this thread OT, Just something that made me wonder. I am more profecient at speed shifting than the MB trans is...balky,rubbery,stubborn thing that it is. I still prefer rowing the gears myself though. I'm an oldschool pushrod V/8 guy at heart too, and thought maybe this classic driveline upgrade would show dividends here too, (the NA 6spd) keeping gearchanges higher in the powerband. I often find myself grabbing 4th at 80mph or so to pass someone on the highway, and usually wish for more immediate thrust.
Oh, well. Thanks for humoring me, regardless.

 

Mike, maybe just me, but I really don't see why so many go back to the muscle car days and think 4-speed. I ran a modified turbo400 from B&M with a stall converter. I drove over to JEGS, who had not been in business all that long, pick it up installed it the same night. It shifted backwards from regular transmissions, and I installed a Hurst shifter just for this tranny. Quite the set up for it's time. The old big block would turn 7200 rpms. It would bang gears just like dropping a clutch. Many didn't even know it was an automatic. They were 3-speeds in those days, even though 2 was all you needed for the quarter for the most part. All the guys I ran with in those days spent all their time fixing and adjusting linkages, fixing or adjusting clutches, putting band aids on their knuckles...lol... I have had my share of sticks, but autos even in the day, were something they had to deal with.

 

I pulled out the differential last night and everything looks fine. I guess the noise it coming from somewhere else.

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that is good news. what kind of sound is it? a whine, a clunks, grinding? You know you have to be really torqueing over on launch, meaning drive shaft is going to force the rear end to raise the yoke up...if that makes any sense to you. this may sound silly as well, but the power you are putting down, the whole drive line will torque over, engine torqueing to one side putting everything in a twist. But again, these are areas that concern me as we find more ways to come out the hole quickly and with some force. Keep us posted.

 

Check the drive shaft center bearing, mine went bad and it sounded awful under load and at high rpms. Hope you find it.