Upgrading the 722.3 trans - Page 3 - PeachParts Mercedes-Benz Forum

RBYCC · #31 12-31-2007, 03:08 PM

Quote:

Originally Posted by Motor Head

More specifically, I have a partial Mosselman kit with all the important parts like the manifolds, turbos, and some of the piping. I do not have the electronics so to Split Second will solve that problem. I realize I'll have to fab some custom pieces with injector bungs but that is not a problem. I'll give Mark a call to find out which unit will work for my application.

Sounds like you have a great start with all the major hard parts.
I used the Split Second AIC1-A2L which is for the two additional injectors.

The key to power and not burning holes in your pistons is to get the AFR around 12.5:1 under boost.

Keep me posted, anything I can help you with feel free to ask !

Happy New year

Ed A.

Motor Head · #32 12-31-2007, 08:13 PM

You know the thought occurred to me last night that your fuel maps would probably be of great value to me since I will be running the identical setup and the same level of boost. Is there any way you can do a data dump from the Split Second or perhaps convert you computer map file to a pdf. Even better would be to email a copy of your fuel map file since I will be using the R4 software to program my unit as well.

Do you run a AFR meter in your car? What gauges are you using to monitor the health of the turbo related systems?

Thanks again for all your help and a happy new year to you too.

Kurt S.

Motor Head · #33 01-03-2008, 11:22 AM

Well I just got back from a road trip over the new year. The car got 25.1 MPG on the highway including a climb from sea level over a 4000 foot pass and down again. That's about 3 mpg better than I got prior to replacing the diff 3.46 gear with the 2.88 gear. Going up hills I just grab 3rd gear and the car is as happy as it can be with the stock engine. Now I am ready for the turbo's as soon as I get the tranny rebuilt.

Motor Head · #34 01-07-2008, 06:19 PM

RBYCC,

Are ya still out there?

Motor Head

Hit Man X · #35 01-07-2008, 06:23 PM

Quote:

Originally Posted by Motor Head

Well I just got back from a road trip over the new year. The car got 25.1 MPG on the highway including a climb from sea level over a 4000 foot pass and down again. That's about 3 mpg better than I got prior to replacing the diff 3.46 gear with the 2.88 gear. Going up hills I just grab 3rd gear and the car is as happy as it can be with the stock engine. Now I am ready for the turbo's as soon as I get the tranny rebuilt.

AH! Someone else had this idea and acted upon it.

I think I sent you a PM, but if not... how do you feel acceleration is starting in first with the 2.88:1? What about a 70mph cruise down the road?

RBYCC · #36 01-09-2008, 08:58 AM

Quote:

Originally Posted by Motor Head

RBYCC,

Are ya still out there?

Motor Head

I think I'm here ????

Having major lower back problems, but improving !!!

Should be visiting more .

Ed A

Motor Head · #37 01-21-2008, 04:50 PM

Hit Man X,

Actually, my wife (it's really her car you know) thinks it accelerates better with the 2.88 gear and I agree but let me qualify my statement. It accelerates better at part throttle and the reason I believe this is true is because we are in the converter a lot more with the lower gear and reaping the benefits of torque multiplication. However, when we reach freeway speeds we are safely above the converter stall speed so I don't worry about overheating the transmission.

Acceleration from say 70 mph seems about the same and 3rd gear is definitely more useful during a downshift.

Full throttle acceleration is slightly penalized but since we don't drag race the 300 SEL it's not to much of an imposition

I got what I was looking for in this swap with the improved fuel economy and the engine is much more relaxed at freeway speeds.

Motor Head · #38 01-21-2008, 04:58 PM

Quote:

Originally Posted by RBYCC

I think I'm here ????

Having major lower back problems, but improving !!!

Should be visiting more .

Ed A

Ed,

Sorry to hear about your back but glad you are... back

Hit Man X · #39 01-21-2008, 05:29 PM

Quote:

Originally Posted by Motor Head

Hit Man X,

Actually, my wife (it's really her car you know) thinks it accelerates better with the 2.88 gear and I agree but let me qualify my statement. It accelerates better at part throttle and the reason I believe this is true is because we are in the converter a lot more with the lower gear and reaping the benefits of torque multiplication. However, when we reach freeway speeds we are safely above the converter stall speed so I don't worry about overheating the transmission.

Acceleration from say 70 mph seems about the same and 3rd gear is definitely more useful during a downshift.

Full throttle acceleration is slightly penalized but since we don't drag race the 300 SEL it's not to much of an imposition

I got what I was looking for in this swap with the improved fuel economy and the engine is much more relaxed at freeway speeds.

Makes total sense and just the reply I was looking for. I'd gladly give up some acceleration for smoother part throttle driving along with lower revs in each gear. The 300 is a cruiser, not a stop light bandit.

Do you still have it coming off a dead stop in 2nd gear?

70mph cruise RPM? 2800-2900?

Motor Head · #40 01-21-2008, 05:54 PM

I still have it starting in 2nd gear but have a first gear start valve body ready to go in when I do the rebuild.

To my recollection you are about right on the rpm @ 70 mph. It works out to about a 600 rpm drop over the old 3.46 gear.

Hit Man X · #41 01-21-2008, 05:59 PM

Excellent.

Did you mod the VB to start in first yourself or send it out?

Sorry for all the questions..

ALSO - I have the factory PDF for the 722.3 if it can help you. PM me with your email and I'll zip it over. Please be certain it'll accept a large file.

altz · #42 01-23-2008, 11:40 AM

Any pictures of the modifyed valve body?

Motor Head · #43 01-24-2008, 10:44 PM

Hit Man,

I had the valve body done by Mario Aristides at Independent Transmissions in Miami. He is a small business but a recognized Mercedes trans expert. In fact, I understand that he designed the shift kit you can order from superior transmission on the internet.

You can reach him @ (786)597-7738

Superior Transmission Shift Kit:

http://www.superior-transmission.com/products/shift_correction/722A_g.htm

But to answer your questions above, the answer is yes and yes

First I installed a kit supplied by Mario into my own valve body. It was a combination of a shift improvement kit and a first gear start. It wasn't to tough to do but I have some experience with valve bodies.

The shifting was greatly improved but I could never get the car to start in first.

After a number of discussions with Mario we determined that my valve body fell into a roughly six month production run that is not compatible with the normal first gear start mods. As a result I just had him build, test, and ship me a valve body and seperator plate which I have not yet installed. The valve body is fully assembled so there isn't much to see.

A word of caution: be prepared to wait if you comission the valve body mods. It took about six months for him to turn my stuff around but I was in no hurry.

Let me know if I can answer any other questions.

Motor Head