What boost levels do you run?

Wheel House Motorsports · Jul 30, 2010

Well, with my converting to propane this year, the 1 ton powered DOO is gonna get a hair more boost... now im just curious what is a good level to crank it to.. and just curious on other folks opinions on whats a nice level..

I do feel like as much as I can is a good level, which with a headshimed motor on propane is like 18-20#, but I think the excess power will start to eat my homemade motor mounts and other parts as well.. always the weakest link!! Last year I ran 10# but with a poorly setup system, bad clutching, and a way overtightned track that made the power like 7-8#... it was pretty damn fun and fast, it ate anything NA without a problem, but who wants to go fast when you can go faster eh? probably will end up at 14-16 this year.

I run a LOT of boondocking, so I feel like there can be to much.

and basically, im bored as crap, its the summer. and want something to chat about.

sledfvr · Jul 30, 2010

14-17#'s is max usable climbing horsepower. I usually run 15#'s. The people that claim they run over 20#'s of boost are in and out of throttle so much that it only averages about 15#'s. You can climb anything you want as long as the front stays down on 15#'s of boost. Just my .02. Edit...This is on a properly setup sled with 12.0afr's, good clutching, and good all around tuning.

Wheel House Motorsports · Jul 30, 2010

sledfvr said:
14-17#'s is max usable climbing horsepower. I usually run 15#'s. The people that claim they run over 20#'s of boost are in and out of throttle so much that it only averages about 15#'s. You can climb anything you want as long as the front stays down on 15#'s of boost. Just my .02. Edit...This is on a properly setup sled with 12.0afr's, good clutching, and good all around tuning.

good to hear... thats kinda what I was thinking. If just racing in lower angle uphills, Higher boost might be rideable, but I know mine creaped to 14+ a time or two.. and it was NUTS.. it haules arse. and mine running crappy power on low boost was crazy fast in any sort of setup snow. Heck, with the stock DOO skid, im not sure how its gonna do at those levels, turn it up till its unrideable then back it down a hair??

My main goal for the year is getting the power to the track as last year I had some bad clutching/alignment issues from bent motor mounts. and my drivers were wore out, so the track was as tight as physically possible(bent adjuster bolts.)

Motleyone · Jul 31, 2010

Boost level is a combination of many different things. Snow depth, snow condition, hill length, hill or shoot width etc. I think the key is to not limit yourself because you ARE gonna want more power. This is why I don't understand why people go with a stage 1 kit or a stage 2 kit etc. Get the extra fuel pump and surge tank, get the larger injectors etc to begin with. Sure it might cost you one or two thousand more but you can set your boost where you want it. If you want evidence that 17-18lbs is needed look no further than the linked youtube video.http://www.youtube.com/watch?v=pQkCFjUN7QU&feature=related Travis pulled the steepest line out of the McLarens Mile on 17-18lbs. I don't think he would have pulled that at 15lbs, maybe but i doubt it. Check out his front end, it is barely moving. Stop the video at 28-29 seconds to see just how steep it is. That wall he climbed up was literally a 60-65 degree incline. Our buddy was scared to death to walk down it to get Frenchie unstuck the weekend before. So my point is set your system up to what you are gonna wanna climb not to what you can climb now. Start off at 13-15 pounds and move it up to 17-18 lbs. Anything over 18 lbs has much more potential to damage the motor so I would not go that high. The included pic is of our friend standing on that face.

sledfvr said:
14-17#'s is max usable climbing horsepower. I usually run 15#'s. The people that claim they run over 20#'s of boost are in and out of throttle so much that it only averages about 15#'s. You can climb anything you want as long as the front stays down on 15#'s of boost. Just my .02. Edit...This is on a properly setup sled with 12.0afr's, good clutching, and good all around tuning.

sledfvr · Jul 31, 2010

I agree with you Motley. I do run mine at 17-18lbs, but it only is needed for 2-3 climbs per year. He only had that thing pinned for about 3 seconds in that vid though. On 15lbs the front might have stayed down a little more and he would have had a little more momentum for the last climb. I am just saying that for 99% of the riding 15lbs is all that is needed.

EZmoney · Jul 31, 2010

With deep deep snow i may run 18 psi. But for the most part with my sled i run 14 or 15 psi. Not saying my sled is some freakish power monster but it is hard to ride and and stay with your line at the higher boost levels, you just get going way to fast if you just hold it pinned.So your on and off the gas and thats where your suspension is loading and unloading and thats where you wheelie out and crash! I believe if you can hold it down rather than be on and off the throttle you will go higher and be in control resulting in a better pull.Each sled may make more or less power at the same boost levels and suspension choice and and track length will make a difference. So we will hear some different opinions.

zebiraross · Jul 31, 2010

I run 17 most of the time. When I race or it's really deep it's up to 20. There are certainly some chutes I have a hard time climbimg in deep snow at 17 and that's when I turn it up. I wouldn't run more then 16 or so if I didn't have a suspension to keep the front end down regardless of snow condiitons. "Useable" power or boost has everything to do with suspension, not some arbitrary boost number.

Remmy · Jul 31, 2010

Some really good info in this thread. I voted 17-19 lbs. but recently upgraded to a 2871 and found that 15 lbs. was just "killing it" so I haven't gone over with the new turbo. I've had loads of fun at 18 -19 lbs. and have pushed my setup to 20+ lbs but the power is hardly rideable in anything technical.

IMO your chassis/skid end up being the limiting factor.

Smooth power delivery is crucial. When you see Irmen make some of his epic pulls in the Boost movies he's so smooth in and out of the throttle you never even hear a blowoff valve.

Can't wait to ride again...:face-icon-small-coo

Wheel House Motorsports · Jul 31, 2010

Good reading guys.. I definately appreciate the info.

I am a firm beleiver in the slightly less boost, but being able to stay WOT all the time is a lot more rideable then huge power just on/off the throttle all the time. I will admit im not a HUGE hillclimber, I like my steep and deep hills, but I prefer shorter and super steep, so more techincal keeping the sled from flipping stuff, maybe some trees in the top to dance with. This is also nice, so if you wreck, you dont cartwheel all the way down the mountain!!

as far as skid and track, Methinks thats gonna be my limiting factor, althought I am upgrading tracks its not that much, gonna be running a 162x16x2ish paddles, it was a 2.25 or a 2.5 cut down (not sure, im getting it for free) this should be a decent amount of track for the sled, but im only running the stock DOO skid, and I like to have it setup to boondock nicely, which isnt necasarily the best for big steep stuff. I am working on building some little coupling blocks for it to help keep it from being out of control...

I also know my turbo system being a homebrew setup is nearly as efficient as the big name systems, BUT, my setup this year with the midmount header and 16g turbo should spool like a SOB at those levels, it already came on real quick with my crap header I built last time, so this one should be a lot nice for on/off power delivery. also tuning propane is pretty simple and should be less finickey on angles the the gas carb setup. either way. thanks all for the input. My wastegate starts at 10#.. so i guess just get a boost controller and start having fun!!

Now I guess its time to start looking at better clutching!!
My fuel system will be able to handle whatever I want to throw at it.. got good drivetrain drievers, big enought turbo. I can turn it up beyond IMO I would be able to ride. I kinda forgot to mention Im a little smaller then most gents I see on t-yami's... Im 150# in street clothes, that definately makes a big difference in what it takes ot push me around.

Wheel House Motorsports · Aug 2, 2010

thanks for the input guys.. methinks I have a good idea of what levels to be clutching to.

turboless terry · Aug 2, 2010

I ran my nytro at 15 pounds, most of the time. Much more then that, in the trees would be a handful. I had one chute that i wished it was at 18. It took me an hour and a half to get unstuck from that one. 15 is also pretty maintenance free on the four strokes.

xtrememotorworks · Aug 4, 2010

I think rider abilty and chassis set up is key. We run our iqr/nytro @ 25lbs a lot. I'm a big fan of throttle control and having the power there when needed. You can always let off the throttle,but can dial the boost knob in the middle of a chute

Wheel House Motorsports · Aug 4, 2010

haha.. 25 is a LOT!!! BUT, for the riding I do, going WOT for more then say 10 seconds is a rarity, and having run my sled in harder snow, I do find a reasonable boost level that you can stay WOT more is a lot easier to ride.. and as far as boost controllers. I am gonna hook mine right to the top of the bars.. I had a tuning knob there for my previous turbo setup, and I would dial and adjust when climbing plenty, definately looks funny when wheeling up a hill and adjusting things on the sled one handed.

Wheel House Motorsports · Aug 9, 2010

Well.. after mulling long and hard over it.. I will just set the thing at 10(minimum)# to start and get the tuning on propane figured out, make sure my new stuff works right, then as I get the kinks of my new setup worked out, I will probably bump it up to 14/15#, But I find myself riding a LOT of different conditions, and mostly tighter trees... I ride with a nytro on 14/15# and also had a mcx 270 horse nytro come by one day.. IMO, the 270 setup was WAY more then I would ever need.. I just dont play on the same hills, its not my gig.. also, I think the stock suspension is gonna be about at the end of its abilites come 15#

thanks for all the votes guys.

Thunderguy BOOSTED · Aug 13, 2010

Do u have a thread of where your moding it all????? i wanna see it!!

twsandrew · Aug 17, 2010

I think its worth mentioning that rider size/weight is a factor here. Franklin can run 15lbs all day long but he weighs about the same as my left leg so 18 is about right for me ;-)

Wheel House Motorsports · Aug 18, 2010

VERY good point.. i find myself being one of the smaller people that sled, let alone ride a t-yami.. After watching boost 4 and paying attention to how mig most of the fellas on there are... not many sub 200's.

I weight 150 in street clothes after a good meal. Im not weak by any means(for my size) but the sled is just a LOT bigger/more powerful then I am. I used to greatly notice the benefits on almost identical sleds highmarking with my buddies. I could always outmark if the sleds were the same.. 50# or more weight difference does matter. The issue for me is, big boost is fun, but when the sled wants to rear up and go, It cant tell im even on it, and takes of doing whatever it plans on, Just so much power for a smaller rider.

HANDSOME · Aug 20, 2010

I voted 14 -16 but I have rode a lot at 10 - 12 as well and 17 - 19 enough to know that its too much for my style of riding. Well set up at 12 lbs is all I need but if she holds together at 16 on av gas that is what I ride at and that is FUN power.

Tarzannr1 · Aug 25, 2010

I run on E-85 Ethanol mixture and runs 1,3bar

RACINSTATION · Aug 31, 2010

Engine configuration also plays a part. Rods and low compression pistons will accomodate more boost than stock compression will. Also the quality or octane level of the fuel plays a role.

What boost levels do you run?

What boost do you run?

0-10

11-13

14-16

17-19

20+?

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