For all of us who like to drag race. Our biggest hurdle to better times is a lower rear gear ratio, stock ones are not meant to drag race. We Need to get a company to make a 3:73 or so for us. I out trap speed guys running 10.00 but there gear gets them there first. WE NEED A GEAR OPTION!!!!! How much would it cost to R&D some gears? Tunes pulleys and all are great but 600hp with a 307 gear nets an 11 second run!

 

Interesting thoughts. I like 0-100 speeds as opposed to top end. Have no desire of cruising at 155mph.
Maybe something will happen.

 

I can't imagine lower gearing since our cars spin too much off the line as it is. You'll need heavy duty slicks to compensate for the extra wheel spin. I would think your track times will be worse without slicks spinning all the way down the track. Besides, when normal driving in city streets, you'll hate the lower gearing since it will attract the peace officers with the sqeeling tires everywhere. I'm saying all this because I owned a Vette and had 370's placed in the rearend and I hated city driving because of it. And of course your gas mileage will plummet. Just my .02 .

 

When I the 4.11's in my 440 challenger I got a minor improvement in the time but took a lot of noise, wear, fuel and heat along with it. I have 3.55,'s and have been looking at going to Carlisle this summer to get 2.81's for the street. That ride has 475 pound feet of torque and the largest BFG's wont hold it now.

At the track I have heard it said that the best gear is no gear, an exaggeration of course. Consistancy is the best for bracket racing and if you are focused on Elapsed time only then more gear is more of a deal.

When I did the phantom grip LSD, I had the rear all apart and it would seem that there may be some factory gear swaps possible. A custom gear would be a tall order as the prototype start up costs would be way costly for the limited audience. Especially that the SLK320 is now old school.

Smaller wheels would seem to be a better option as you can get them in great widths and custom wheel makers dont charge that much. The other plus is that you can swap them back (Stock) for the trip home or town cruzing.

I would suggest that you call Stockton wheels at 1-800-395-9433 to see if they mod wheels for crossfires or IF THEY CAN DIRECT YOU TO SOMEONE THAT DOES.

That would get you bit smaller GEAR in effect, Enjoy Woody

 

Here's a good "old" thread on the subject.
https://www.crossfireforum.org/forum...ht=gear+ratios
I actually purchased my Crossfire with every intention of getting a 3.73:1 gear for it. That was until I found this forum almost 6 months later and discovered it really wasn't possible to simply go to your local Mercedes dealer and just order a ring and pinion.
It's true, You would need a set of good "drag radials" to make use of a new gear at the track, but with the usual "other" mods available, I have no doubts SRT6's would be running in the 11's all the time.
With the right gear, even a NA car might see 13's (but it would probably take something like a 4.56:1 to do it)

 

I don't know too much about independent rear suspensions, I'm more of a solid axle guy with all my Jeepin'. When I put the 37" MT/R's on the ole Rubi, I also did a gear swap that was overkill, but it was meant for the trails, and so I switched to a 5.38:1. That was in a Dana 44 both front and rear. Isn't ours just a center section with CV axles sticking out? Isn't our center shared with other cars, like the motor? Are there no options at all for all the center sections, or is ours special??

 

the easy soluion would be the na xfires 3.27 gear, not exactly what your looking for but a step in the right direction.

 

How much do you think changing to the NA's 3.27 gear would better our 1/4 mile?

 

it should make a noticable drop in et's
we need to get a hold of a na rear diff so we can drop it off to some friends at getrag to beef up the internals and help out our non posi situation

 

I was on www.chryslerpartsdirect.com and was looking to price the parts for the conversion to the NA's 3.27 gearing, but what parts specifically would I need to do this without having to buy the whole assembly?

 

If you do a little research, there are options for rebuilt differentials with various gearing options. They are pricey (as everything with this car) and done in Germany by former / current MB employees. The original post I made back in 2004 regarding BergWerks would ship the differential back to Germany for re-gearing. His shop went under because the amount of people in LA wanting to spend $3,000 to put different gears in MB's was limited.

If you search you'll find it and it will cost you $2,800 to $3,500

 

I know I'm a little slow, but have searched for a while both on this forum and the internet in general and have found nothing for our cars in the way of a gear upgrade thats actually available, do you know of a company ( other than ones that are out of business ) to look to? Thanks in advance. Sometimes " go do a search " doesn't work for us slow folks, we are actually asking for help!

 

i don't pretend to know a lot about doing serious mods to vehicles, so take this for what it is worth: What about swapping out the rearend from a different vehicle with independant rear suspension (vipers, corvette, and cobras) all come to mind. You end up with a rear end capable of supporting high horsepower/torque applications, is limited slip and has lots of gear options.
Spend the money to have the housing tweaked/reconfigured to work in a crossfire, rather than spend cash to build crossfire specific gears and limited slip.

To me it seems making a housing work would be easier than fitting custom gears - maybe I have watched one to many muscle car buildup shows on the weekend.

Just a thought.

Cheers,
KrzyFast

 

You could do this with some serious research, anything is possible with enough money. I have ordered a set of gears for the car ( custom made ) 4-6 weeks delivery time. Stay Tuned!

 

Smaller diameter tires are the only real cost effective way to shorten the gearing up a bit.

 

a used na rear diff would be more cost effective then new rear rims/tires IMO

 

Does anyone know the gear ratios of the SRT6 tranny off the top of their head? Just curious, thanks.

 

From the documentation collection in the sticky thread.

Gear Ratios 1st _________ 3.595 : 1

2nd __________________ 2.186

3rd __________________ 1.405

4th__________________ 1.00

5th_________________ 0.831

Reverse______________3.16, 1.93

Final Drive Ratio________3.07

Overall Top Gear_______2.55

 

Thanks... It would have been nice if that gap between 3rd and 4th was a little smaller, at least for modded SRT-6's.

 

Just for the record I don't think a lower final gear ratio is the answer. The final already has 1st shifting very soon BUT I do think a closer ratio transmition gearing would bring great rewards.
Enjoy the Ride...
Mike