Another option for Cen diff runners

[xtremsavage]

While looking for replacement parts and prices for my cen diffs, I stumbled upon an upgrade for the pinion in the cen diffs. The stock pinion is a 9t and the part number is MX037. When I searched the website the stock pinion and the upgrade both showed up. The upgraded pinion is an 11t and the part number is MXS37. Here's a link to the upgraded pinion.

http://www.cenracingdirect.com/index.asp?PageAction=VIEWPROD&ProdID=1288

I was talking to Bankrupter the other day about switching over to the 11t pinion and he thinks (not 100% sure) that it will get you back closer to the stock Savage diff gear ratio. He told me he was gonna try and figure out the ratio numbers and all that and I told him to just take his time. Then, Freddy PM'ed me the other day with a link to RCuniverse.com with a post from Doesgo (Bruce, former owner of SMF) about how to do all the calculating from CB/SG down to pinion/ring gear, including trans gears. I'm gonna try and figure it all out using his calculating method and post up later. Here's the link that freddy gave me. Post #6.

http://www.rcuniverse.com/forum/m_6358979/anchors_6358979/mpage_1/key_/anchor/tm.htm#6358979

Anybody who want to chime in on this is more than welcome.

P.S. the stock cen ring gear is a 26t. For those who want to try and figure it out on their own also.

 

[Derty Werk]

Looks like they also have an upgraded 38t ring gear part#MXS38. Ill bet that you have to use the 11t pinion with the 38t rg

 

[Blazer X]

If you go to the 11t from the original 9t you will be raising the gear ratio even higher.

 

[Larsenracing]

The size of the teeth look much different don't they.

the 11t and the 38t would put you back closer to stock. The stock Savage 13t & 43T is .302:1 where the CEN 11T & 38T combination would be .289:1 ratio on the diffs which is rather close to the stock ratio but would give better low end. However your CB/SG combo could overcome this.

FYI: The stock CEN diff ratio is .346:1.

So long as I am figuring correctly?

 

[Blazer X]

Original GST gear combo is 26/9 = 2.88

 

[frddyj]

so, my question here is:

do you feel the change in gear-ratio is worth $40 to change the 9t pinions to

11t pinions or would you yield similar results changing your cb/sg combom to

make it 'not worth' this upgrade?

 

[Blazer X]

If you change to the 11t you will be raising the final gear ratio higher again thus more top end over the already higher cen ratio. You will be putting alot of strain on the engine clutch by adding work applied to the engine clutch...not good. It's like trying to take off in 3rd gear in a normal car. If you want more top end change your cb/spur combo, its much cheaper.