how much difference does a head make at altitude?

[mikes99ss]

I rode out west this year with a BONE stock 09 summit x 800 146" and it ran okay but i was wondering how much difference a head set up like this would help http://www.startinglineproducts.com/catalog.cfm?pageID=detail&catalogID=4&catID=28&productID=1180
I rode at togwotee this year which i think is around 9000'. They claim a peak horsepower difference of only 2.5 but is that at sea level of at altitude.

 

[sledhead_24_7]

some are claiming more hp than others. some are 5-7, some are 8-11 it is hard to say.
But what I can say is that with a head at 9,000 or 10,000 ft your sled sill start better. Also generally runs better, how much better is a ?? largely dependent on clutching, belt alignment etc.

Then couple a head with a single pipe or piston kit or boyseen reeds or some other type of small mod you will generally see better results.

 

[portaboy]

you would notice it

If you changed the head on that thing i know you would notice it
Just make sure you put the right domes in it for the elevation you ride in
If you do that it will start and run better.
Another thing you can do is change your pilot jets to 22.5 that seems to give them a little more gas at the bottom end just a suggestion

 

[mikes99ss]

Is there anything simple that i can do to wake this sled up at elevation? My clutching was stock with the clickers on 6. I was pulling 8300 on the tach but i don't know if that means the clutching was good just because i hit my target RPM's. Is there a magic clutch set-up? ........thanks!!!!

 

[bigrig73]

i did a rkt head, crank shop pipe / y pipe, delta reeds, and a dynamo joe clutch kit. i love it, it is very snappy and best of all it holds rpms. back shift is incredible. i can not be happier with the performance of my sled. it works in every place i've rode this year ( revy, fernie, cranbrook, forrester, bugga boos, and radium ). try it, you'll like it.

 

[Sako7STW]

What about shaving the stock head? Thats what I am having done along with can and clutching.

 

[h3joe]

head

I put on a engine tech 3000-6000 ft head and it will pull 1.2 grams more weight in my team setup. I ride 10000ft but I wanted a head that I could ride any where. Talk to Art a Engine tech and tell him Joe from Montana said to call. Also I put on his thermo housing. Expensive but now the temp sensor does not retard the timing.