2011 M8 clutching

[ACChad]

Hi, I have a 2011 M8, have been running it since new and have not really had any problems with it. Have been running 63 gram weights (9,000ft+) and a yellow/white stock spring. Have been to Centennial Wy, and Togwotee, and this year we are going to Cooke City Mt.

Usually RPM's max out at 8,300. I bought a BDX back shift assist that i've never got around to install yet and just wondering if it's even worth messing with, I heard they usually take 100 RPM's off.

I also bought another yellow/white stock arctic cat spring just in case this other one would crack, any other springs recommended?

Here's the link to the back shift assist bearing: http://countrycat.com/ccstore/index.php/d-d-racing-arctic-cat-bdx-shift-assist.html

Just doing a little reading on the forum and read some guys think the 63 gram weights are too light with certain springs. Curious any other recommendations out there...

Thanks,

 

[diggerdown]

I run 63.6 grams with a gold spring and a 3/16th spacer on primary. Secondary I have shift assist, 36* helix and orange spring. This is in a 2010 M8 162 with a 2 1/2" CE track. I go 260 or so with gear on. Holds between 8100 and 8200 rpm. I did not care for the harsh engagement of the Y/W with the lighter weights. I think the new green spring would work well.

 

[ACChad]

do you have a part number for the green spring, if i'd decide to use it should i switch anything else out?

 

[diggerdown]

Green spring #0646 252 yellow/white
Rates 2.500" 94 122
2.375 120 138
1.375 300 275
1.250 318 302

You can see a lower rpm engagement and higher finish rate. Speedwerx has a 120/310 that works good too. Y/W works fine it's just that with the lighter weights the engagement gets a little jumpy.

 

[2010Catman]

I run a 2010 all stock except a can the bdx shift assist and team tied titanium primary spring I did notice a small rpm difference with the shift assist but definitely a not hindering hill climb pulls. Another thing that made a difference was new motor mounts the mag side next to the can takes a beating. Noticed a better down shift and smoother up shift.

 

[diggerdown]

Green spring #0646 252 yellow/white
Rates 2.500" 94 122
2.375 120 138
1.375 300 275
1.250 318 302

You can see a lower rpm engagement and higher finish rate. Speedwerx has a 120/310 that works good too. Y/W works fine it's just that with the lighter weights the engagement gets a little jumpy.

I don't know why my post will not print like I typed it but the 122, 138, 275, and 302 were the Y/W rates.

 

[ACChad]

So did you loose some RPM's on some long hillclimb pulls after installing the shift assist?

 

[diggerdown]

Not really but I do think it makes the rpms bounce around a little more. Much better up shift I think but I put mine in the same time I got my secondary rebuilt so it is hard to know which helped it the most.

 

[ACChad]

BDX shift assist

I bought the shift assist last year never got around to putting it in and it's been working great the way it is now, just don't know if I might end up making it worse by installing it?

Anyone else liked using the shift assist bearing in the secondary?