XM ex valve mod

AreWeThereYet

Active VIP Member
Joined
Apr 4, 2009
Messages
12,775
Reaction score
7,554
Location
Grande Prairie
I have decided to forgo the the Thing can for cost reasons and put the money toward other options that could better the sled performance wise.

I hear about the SHR exhaust valve mod and was wondering if anyone on here has done it and how do you like it?

Thanks,
 

BeachSled

Active VIP Member
Joined
Apr 2, 2009
Messages
956
Reaction score
1,238
Location
Sherwood Park
Hey!

I looked at doing the same mod to my sled but decided to go with the complete Rave valve mod from Dean at Mad Motorsports in Leduc. This allows the raves to open freely under Crank case pressure instead of being controlled by the rave valve solenoid. You get alot of performance from this setup.

I'm not going to bash other shops work, but I chose Dean for a reason. At least give him a call and make an informed decision before you spend your money. Ride safe and hope you have a great season!
 
Last edited:

mountainsledmania

Active VIP Member
Joined
Dec 28, 2009
Messages
1,187
Reaction score
1,231
Location
sherwoodpark
Hey!

I looked at doing the same mod to my sled but decided to go with the complete Rave valve mod from Dean at Mad Motorsports in Leduc. This allows the raves to open freely under Crank case pressure instead of being controlled by the rave valve solenoid. You get alot of performance from this setup.

I'm not going to bash other shops work, but I chose Dean for a reason. At least give him a call and make an informed decision before you spend your money. Ride safe and hope you have a great season!

Can you elaborate on what a lot more performance means? i have heard about this mod, and i head the turbos and big bores like it.. but im curious as to what exactly it does? why is it better to run off the crank pressure then let the solenoid do its job?
 

slededjr

Active VIP Member
Joined
Nov 25, 2011
Messages
1,577
Reaction score
1,972
Location
sherwood park
Raves act faster under vacuum. No solenoids to fail or wires to break etc. Will notice a bit more giddy up at partial throttle and faster response with the mod.
 

mountainsledmania

Active VIP Member
Joined
Dec 28, 2009
Messages
1,187
Reaction score
1,231
Location
sherwoodpark
I don't think its that easy. You need to go into the ecm and remove the programming for the solenoid or your dash will be light up like a Christmas tree, and if im not mistaken you also need something to prevent the rave from over extending i believe it can travel outside of the sensors range which would be why dean has the bridge with the springs installed over top. and to top it off if you take the raves out of the monoblock you need to have a calibration done with when they are re installed or the sled will run like a POS.
 

BeachSled

Active VIP Member
Joined
Apr 2, 2009
Messages
956
Reaction score
1,238
Location
Sherwood Park
So here is what I know about the Rave mod. You can clearly see the difference in delay when the raves are controlled by the solenoid vs operating on Crank case vacuum/Pressure. The throttle response is noticable as well as the mid range response. It takes off quicker from a stop in deep snow and completely gets rid of that delay/bog.

The mod included the installation of an aluminum rave valve bridge, the solenoid/hoses being removed, and the computer being programmed.

Does that help any?
 

mountainsledmania

Active VIP Member
Joined
Dec 28, 2009
Messages
1,187
Reaction score
1,231
Location
sherwoodpark
So here is what I know about the Rave mod. You can clearly see the difference in delay when the raves are controlled by the solenoid vs operating on Crank case vacuum/Pressure. The throttle response is noticable as well as the mid range response. It takes off quicker from a stop in deep snow and completely gets rid of that delay/bog.

The mod included the installation of an aluminum rave valve bridge, the solenoid/hoses being removed, and the computer being programmed.

Does that help any?

yea that helps, ive been pondering giving it a try on my naturally aspirated machine to see the improvements and if they were good enough i was also pondering doing it to my turbo machine.
 

treeboy

Active VIP Member
Joined
Nov 14, 2010
Messages
183
Reaction score
112
Location
The Monashee Mountains
Just being curious, I know there is a few ways of doing this. Going to be jealous for three months this winter of people riding, while I'm healing up from foot surgery. Hopefully I can do some mod work when the snow is falling. The couch is going to suck this season. Maybe it's 985 build time....
 

AreWeThereYet

Active VIP Member
Joined
Apr 4, 2009
Messages
12,775
Reaction score
7,554
Location
Grande Prairie
Talked with Dean today and I'm going to do the billet thermostat housing first. Then next year do the rave valve mod as I do not wish to have any warranty issues when its due next spring.
 

kidinloghouse

Active member
Joined
Nov 28, 2011
Messages
92
Reaction score
123
Location
hay river nwt
i did deans bridge last year and it gives a noticable seat of the pants difference. i would recomend this over a pipe or any other bolt on. it removes all hesitation and harshness when the valves do open. as well will get rid of the lean spot mid range from the ecm holding the valves closed for emissions.
 
Top Bottom