• Don't miss out on all the fun! Register on our forums to post and have added features! Membership levels include a FREE membership tier.

What should 2018 M8000 be pulling for RPM

B
Jan 16, 2014
2
0
1
I also went with Cutlers’s adjustable weights and really like them so far. I bought my sled through Cutlers and they installed the kit for me and set it up for 8,000 to 10,000 ft which I think was total of 68 grams. I have since added almost 3 grams due to over taching and I am taching around 8150 now which is what I was shooting for. Was curious what weights you guys ended up at that went with the same kit?
 
N

NWaxys

Well-known member
Feb 28, 2016
467
261
63
36
Eastern WA back country
We demoed two of them and one was 8400 and other 8200. At 7000 feet. 8400 sled was noticeably stronger, 8400 had 280 plus miles. 8200 was at 75, prob still being broke in.
 

Old & slow

Well-known member
Lifetime Membership
Feb 18, 2017
727
393
63
Alberta
We demoed two of them and one was 8400 and other 8200. At 7000 feet. 8400 sled was noticeably stronger, 8400 had 280 plus miles. 8200 was at 75, prob still being broke in.

According to dyno charts at 8400 rpm the engine has lost 5 hp. The peak hp was @ 8100, 7900 to 8200 is a good place to be with this engine. Even at 8250 it was down 2 hp. I wonder if the reason the higher rpm one felt stronger was due to break in? I tried to load the dyno chart but can't for some reason.
 

Allseasons

Well-known member
Premium Member
Feb 2, 2014
238
130
43
Rocky Mtn House AB
According to dyno charts at 8400 rpm the engine has lost 5 hp. The peak hp was @ 8100, 7900 to 8200 is a good place to be with this engine. Even at 8250 it was down 2 hp. I wonder if the reason the higher rpm one felt stronger was due to break in? I tried to load the dyno chart but can't for some reason.

Where is the peak torque line sitting, between 8000-8400??
 
B
Jan 16, 2014
2
0
1
I talked with Scott at HPS quite a bit about this and I know they do a lot of extensive Dyno testing to dial their lightweight mufflers in. He told me to shoot for 8100, he said that's where the peak of the HP curve begins and where it will pull the hardest.
 

fudge313

Well-known member
Lifetime Membership
Sep 6, 2015
528
88
28
Finland
Is anybody else driving at sea level, what max rpm? My stock MC 153 will pull over 8500! Now i have cpc adjustable weights and 74g and still it pulls 8400..
 

fudge313

Well-known member
Lifetime Membership
Sep 6, 2015
528
88
28
Finland
Now there is 77.25g and still it takes 8200rpm.. Close but not close enough.. Have to chance the spring....
 

F_ast

Well-known member
Lifetime Membership
Feb 22, 2008
973
361
63
41
Ontario
I think you need to regear fudge. Probably helix too.

Are you running stock 19/50 gearing?

I ran 2018 high country 153 at sea level (4000km this year) but with stock clutching. Think they are 73gr stock with same helix from the ZR trail sleds. Even with the 19/50 gearing I'd only ever see 8250 max.
 
S
Nov 26, 2007
1,402
968
113
utah
one thing to remember about dynos at low altitude, they don't reflect the air density changes in the pipe at altitude....the pipe builder i've worked with for years is at 5k, we always had peak hp/torque that was a little higher rpm wise than some of the frequently quoted hp figures that came a lower altitudes...we also found that on the mountain we needed to run a little higher rpm for the sled to work best....in real numbers, at 10k-11k, 8150 rpm was about right, even though 5k dyno showed about 8050...suzuki engine...c-tec seems to be very similar so far in experimental side by side hill climbs...:face-icon-small-hap
 

fudge313

Well-known member
Lifetime Membership
Sep 6, 2015
528
88
28
Finland
I think you need to regear fudge. Probably helix too.

Are you running stock 19/50 gearing?

I ran 2018 high country 153 at sea level (4000km this year) but with stock clutching. Think they are 73gr stock with same helix from the ZR trail sleds. Even with the 19/50 gearing I'd only ever see 8250 max.
Maybe...... Yep, stock gearing.. And everything else is stock but weight are cpc... This mountain cats came little bit wrong setups this year but not much... Here in Europe..
 
Premium Features