Can-Am DS-450 Forum :: DS450HQ.com banner
1 - 20 of 29 Posts

·
Registered
Joined
·
84 Posts
13.1 will help a little but if your gonna run race gas and want bottom end you should have gone a touch higher. I think they offer a 13.6ish and that would have been better. You will probably pick up about .5whp across the board with the piston you got. What other mods have you done? If you milled your head a touch you could get up around 14.1 and that would probably work much better at picking up good bottom end. 13.1 is just not enough to notice.
 

·
Registered
Joined
·
83 Posts
Discussion Starter · #4 ·
13:1 is the highest i could find through my dealer. I put a 12.5-1 in my yfz450 and i noticed a fairly big difference in low end power. I got the motor together tonight and i am hoping to get on it tommorow
 

·
Registered
Joined
·
477 Posts
i would never go through a dealer to find performance parts, go to rotax.net or rossiereng.com to order a high compression piston. I'm sure if you wanted higher compression you could call and ask...
 

·
Registered
Joined
·
83 Posts
Discussion Starter · #6 ·
i would never go through a dealer to find performance parts, go to rotax.net or rossiereng.com to order a high compression piston. I'm sure if you wanted higher compression you could call and ask...

Yea I ordered it through the dealer because it was about 80 bucks cheaper then the rossier piston. I am almost wondering if it was a mistake because this thing runs like a dog!! It revs fine and doesnt sound abnormal but it just has no power.
 

·
Registered
Joined
·
459 Posts
What other mods do you have? Did you get it dynoed tuned?
 

·
Registered
Joined
·
84 Posts
I told you, you wouldnt notice anything. 13.1 pistons are a waste of money. If you are gonna have to run race gas might as well go higher. Then actually feel a difference. 4 strokes love high compression.
 

·
Registered
Joined
·
477 Posts
now that i thought about it stock compression is 11.8 or 11.9:1, 1 point isnt that much of a jump. need like 15:1 or 14.5:1 to really feel a gain
 

·
Registered
Joined
·
83 Posts
Discussion Starter · #10 ·
i havent had it dyno-tuned. I think thats gonna be the next step. I didnt want to run higher then 13-1. I know my yfz runs awesome with 13-1 in it. I have a friend who ran 13.5-1 in his and he liked it better with stock in it. They tend to rev better with lower compression. Hopefully i can get this tuned in.

I have the motoworks pipe, airbox lid removed, 13-1 piston, pink wire cut and stage 1 ECU. Does anyone have any recommendations as far as an efi controller goes?
 

·
Registered
Joined
·
459 Posts
I would get a Power commmander 3 or 5.
 

·
Registered
Joined
·
128 Posts
at 2500 ft elevation will 13.6 to one run on pump gas 92 octain or will it need more octain! i also run at 4500 ft. thanks
 

·
Registered
Joined
·
290 Posts
What you are running up against here is two things: Compression equals added resistance. Another thing is, race fuel burns rich. Rich will give you a lazy feel, and coupled with the added resistance of the high compression piston you are probably making less power overall than stock. You will have to get a fuel programmer or reflash your ecu and at least do an exhaust cam swap to pick up the gains the piston will give you. Add a good head port and a full exhaust,with a sniffer tune on the dyno and hold on.
 

·
Registered
Joined
·
128 Posts
right now i have a k&n, fmf programer, and a woods pipe. i was told the higher in elavation the higher in compression i could go ?? can you feel the defference on 12.5 over stock. what do you have? thanks
 

·
Registered
Joined
·
4,819 Posts
2500 isn't really that high up. My house is at 2000ft and the stock piston works fine.
 

·
Registered
Joined
·
128 Posts
so what are you thinking on compression are should i stay stock! is there any engine troubles when going with higher compression. thanks
 

·
Registered
Joined
·
4,819 Posts
Id stay stock but that's just me....I'm happy with almost 50hp lol...12.5 would be fine....anything higher and ur running race gas and I can't justify that expense lol
 

·
Retired Moderator
Joined
·
3,417 Posts
i can when i get vp 110 for 35 bucks lol

opps did i just let the cat out of the bag lol

ya im getting a 13:1 piston
 

·
Registered
Joined
·
811 Posts
On Rossier website hes doing E-85 conversions for the ds so you can run a race piston on $2.85 a gal gas.
 
1 - 20 of 29 Posts
Top