Pro's/Con's of single pipe vs. twins?

[powdercrew]

When I bought my M8, there was one for sale next to it with twins. I bought the stock set-up. But I've been wondering ever since, other than the modest horsepower gain... what are the differences to going with twins? Figure there must be, or they'd all have 'em... right? Im gonna install a full SLP set-up and just looking for feedback from different places. I ride 7,000-10,000+ and ride hard. Large mountain climbs, jumps, drops, some tree boondocking... and we like to travel. Idaho, Utah, Wyoming and the Sierras mainly.

 

[leadfoot33]

i believe singles are more tuneable and not as sensitive to altitude changes and temp changes, and from what i recall the twin pipes make the sled more "peaky" runs better at high rpm and takes away from low end where a single usually increases low to mid and mildy up top.
anytime i asked about this kind of question dealers told me that singles are a better option. not as finicky.
Hope this helps some

 

[imdoo'n]

have a set on a 700 summit, all i can say is they make power, have never had any tuning problems once set up. as in love them. beats alot of newer and bigger sleds.

 

[plio7]

have a set on a 700 summit, all i can say is they make power, have never had any tuning problems once set up. as in love them. beats alot of newer and bigger sleds.

How ever not so great in water

 

[Summiteer]

I've read that the twin pipes are better for the lake racer, singles better for the mountains. Of course that was back when everything was carbed not EFI.

 

[imdoo'n]

How ever not so great in water

View attachment 132924

and you thought we couldn't 4x4 with sleds. hehe.

i will say that i will not miss any more snow days out there again.

 

[Nytroman]

Ran lots of twin pipes back in the day and worst thing was heat. Way more pipe so closer to everything. They may be designed better now but not yrs backM melted belly pans, hood side panels and cracking rub spotsM also seem to resignate some more vib which seems to cause earlier wear on clutching. More gratitude in making impressive lines by talent imo

 

[powdercrew]

Thanks for the input... its kinda along the lines of what I've always been told. Am just wondering with technology where it is today... would twins be an "upgrade" on an efi mountain sled (specifically M8)? I had a '99 700 RMK with a 151", had twins and ran HARD! Didnt really notice ant lack of lowend. At the same time, I ran single pipe on my '03 900 cat...and didnt find myself "looking" for more topend. Im thinking about going twins on the M8 and just cant seem to find any "factual" knowledge that it would be a "mistake" in doing so. I do know that it would require a "reflash". That twin M8 that was sitting next to mine (in Utah) is the only twin setup I've ever been personally aware of here in the inter-mountain west. What was he onto? Or was he?...

 

[honda450]

I dont think he was necessarily onto anything. I beleive that most guys are scared of making a good running machine in a hour pig. Tuning instead of riding. I my self have dealt more with 700 yamaha triples and man can they make power and huge throttle response WHEN THEY ARE SET RIGHT. If not set right pistons and jugs all the time. I am currently throwing the idea around for my 2010 m8 but i think i will end up on a nice slp single and boondocker box and playing with my clutches. I know i wont make as much power as a twin pipe sled but i want to be able to pull the rope and ride all day all week.

 

[0neoldfart]

Benefits of twin pipes: More hp.
Downsides of twins: SLIGHTLY more difficult to tune, added weight, reduced engine life in most cases (higher operating RPM), and heat (melting underhood components in some cases).
EGT's and an air density guage are essential in setting up a set of twins - they are not for everyone. Newer EFI systems are less finicky to tune with the advancements in fuel controllers IMHO.

 

[powdercrew]

I guess thats the real question... how much "tuneing" is there with an EFI system? I know you need to re-flash the computer (the one I looked at didnt have a fuel controller on it), weight-to-horsepower gain seems acceptable, can get around the heat issue, I actually have an EGT ready to install, RPM can be dealt with on clutching ?... or are my theories incorrect? I appreciate all the feedback! Oneoldfart... do you feel the issues listed would be specific to an EFI M8? Pipes=re-flash, re-clutch (need to look into fuel controller more)

 

[0neoldfart]

I guess thats the real question... how much "tuneing" is there with an EFI system? I know you need to re-flash the computer (the one I looked at didnt have a fuel controller on it), weight-to-horsepower gain seems acceptable, can get around the heat issue, I actually have an EGT ready to install, RPM can be dealt with on clutching ?... or are my theories incorrect? I appreciate all the feedback! Oneoldfart... do you feel the issues listed would be specific to an EFI M8? Pipes=re-flash, re-clutch (need to look into fuel controller more)

Powdercrew, clutching changes will be mandatory, and I suspect you will require a fuel controller of some sort. Some guys jack the fuel pressure , but it's a poor substitue for a good fuel map. (perhaps that what was done to the one you were looking at)... Only two places I know that make twins for the m8: Jaws and CPC. Which one's better? Same pipe - jaws makes them for CPC. I would recommend checking your fuel pressure, and give Eric Kay @ Racin Station (driggs falls, idaho) a call - he spends more time making maps for different combinations then anyone on the planet. (He'd probably sell you a whole kit that would work well, and he really knows his cats. Baseline maps I've used from vendors were always too generic, never had one as crisp as a Racin Station map. As far as clutching, there are 30 different ways to achieve your operating RPM, and about 28 of them are not that efficient. I ran lots of twins in years past, but I stayed with a single pipe for the M8 & M1000 we had. I understand Brent Linderman at Arctic Edge has had good sucess with the M8 too, but being that you are in the U.S., may as well shop locally...hope this helps, PM me if any questions.

 

[macronut]

and you thought we couldn't 4x4 with sleds. hehe.

i will say that i will not miss any more snow days out there again.

Where was this?

 

[imdoo'n]

sorry loose lips sink ships.

 

[Team Pigeon]

'HEAT' as the fellas mentioned is more specifically 'underhood heat'- and with twins, there's lots of it. So you're gonna need some good venting as Arctic Cat has ceased production on stock M series hoods.... hint hint.
Egt's are a good idea. Air fuel gauge is a good idea.
There's no 'reflash' for your computer. You buy an aftermarket fuel control box and make the changes yourself. Trial and error. Some shops have got guidelines to go with. D&D has got loads of maps on their website for boondocker numbers. Gives you a starting point.