This is the KING of all mods. Changed my differential to 3.7. OMG Bring it on including all
the V8's

 

Pretty bold statement. I take it you like the new gears.

AMX tried lower gears in his V8 beast and his ET's were pretty much the same on the 2 or so runs where the car didn't go into limp mode.

I'd guess on the street the 0-60MPH would suffer as a result of tire spin from the lower gears, unless you're driving around with R rubber.

Do you have a performance meter?

 

How was it done???!!!!(TCU fix)

 

I know about the TCU software but where did you find the gears are you using?

 

Who does the TCU programming besides EC?

 

I'm guessing you're limited to 150mph....
at 6200rpm and on 19/255/35's

Gear Ratios..Tran ratio..overall ratio....speed...........stock
1st Gear........3.59.........13.3..........35 mph.........42 mph
2nd Gear.......2.19...........8.1..........57 mph........69 mph
3rd Gear........1.41..........5.2...........89 mph......107 mph
4th Gear........1.00..........3.7.........126 mph.......151 mph
5th Gear........0.83..........3.1.........151 mph.......182 mph
Reverse........3.15.........11.7..........40 mph.........48 mph
Diff Ratio......3.7


'Tis interesting - more info on the gear please....where and how much?

 

Speedriven did it along with a performance trans software upgrade. Oh, and as far as EC doing TCU tubes and gear changes, ask AMX1397 how theirs worked out for him.

 

Pics/other proof or it didn't happen.

 

Haha! Awesome. Thanks for the info.

 

ML320 has 3.7:1 axle, I thought about swapping one in.

 

I have completed all the mods everyone else has enjoyed but the 3.7 diff. takes it
to a higher level. Speedriven did the coding or recoding and that has been flawless.
It is expensive however. Finding the 3.7 differential is a different matter. My research
indicates it was only offered in 1995. I have purchased two and that took 5 months.
One was NOS and the other with 100 grand. There are a few mods that are necessary.
PM me if you can find a 3.7 and I will be glad to walk you through it.

 

I can't believe somebody finally did this and got it to work, and only 6 SRT drivers respond? I've been preaching for the last eight years all the XF needs is a better gear to wake it up.
I installed a 3.73 gear into my X and without making any other changes it cut my 1/4 mile ET's by 1/2 a secound.
That means some modded SRTs will soon be ripping off 10. sec runs, and we should get to break into the 13's on all NA cars with just a few mods, just using all motor, This should revolutionize the crossfires performance.
There should be dancing in the streets for news like this,

 

I can't believe you've had 3.73 gearing in your XF for years, but never thought to share that with the rest of us.

 

He's talking about a different X... an AMX.

 

That's making a lot more sense.

 

Oops, My Bad, sorry about that, I meant my AMX. (A car that has the same weight, H.P. wheelbase, and frontal area as the NA Crossfire).

When I purchased my Crossfire brand new 8 years ago, I had every intention of installing a 3.73 gear in it, because I thought all I had to do was go down to my friendly Mercedes dealership and order a ring and pinion. I soon found out it wasn't that easy. The company in Germany that sold aftermarket gears stop selling them, and besides they were insanely expensive.
After doing some research I found out there was one year Mercedes SL that used a 3.91 gear, and I believe some Diesel wagons did too, but that was several years ago so don't ask me for details because I 've forgot.
Then somebody here on the forum told me the SL's differential housing was bigger than the one the SLK used so it wouldn't fit.
Finally, after reading the problems Jim had when he tried running 3.23's in his SRT, I put everything on the back burner.
With the news that Doubleloader installed a 3.7 gear in his SRT, it just blew me away. I thought WOW this is the best news I've heard since NeedsWings CAI.
Check out specifications of nearly any other sports car that competes with a Crossfire, and every single one has a gear ratio that's more conducive to acceleration than Top End. Since most of us don't have much chance of running the Autobahn on a daily basis, I would think winning stop light Grand Prix's would be more useful here in the good old U.S.of A.
The only problem I can think of when using a 3.73 gear in a Crossfire, is that it just won't work that well with a 6 speed. 1st. gear would be practically a "creeper" gear with anything more than a 3.54, maybe even a 3.42.
Automatic's should respond amazingly well though, and thanks to the Crossfire's tire size, I don't think a Wavetrac posi would be necessary on anything except an SRT.
Of course fuel mileage will go down on the highway, but may even go up slightly in the city.
FYI, I live in Ohio, and I've driven as far South as Miami, as far North as Toronto, to the East Coast several times, and as far West as St. Louis in my AMX with a 3 speed automatic (that doesn't have overdrive) and I was able to stay with most traffic running around 65 mph. at 3000 rpms, using a 3.73 gear. A Crossfire could cruise at 70 and 75 with no problem.
I hope this turns out to be a viable modifcation for many here. I can't wait to start hearing about 10 sec. SRT's.

 

HMMMMMMMMMMMMMMMMMMMM !!!!!! srew the trubo , this look like hell of alot fun , would like to know more about 0-60 numbers

 

OK Rudy. This is next project once I figure the dashdaq out. Hopefully you can do some local research. I will definitely come to Chi-town.

 

Intriguing...

 

hmmm......
more info? A little teaser....
Where should we be looking?
Brands/Makes/Models/Year....