Boost myth that drives me crazy!

[happylilcuss]

I am always reading threads where people talk about hp loss and how a NA sled will lose more HP than a boosted sled because "There is less air at altitude". This just is not true. It is a medical fact that at any altitude the air contains the same ammount of 02 roughly 19%-20%. The difference is how much atmospheric pressure there us within that air. Even though at the summit of everest there is the same ammount of o2 it feels as if there is 66% less o2 than at sea level.
It can best be exampled by thinking of a box. If that box at sea level holds an amount of o2 well say 100 for easy math. Than at the summit of everest it will still hold 19-20% of 02 only at a value of 66. So as it seems there is less o2 there is still the same percentage its just lots harder to get because you have to move more volume to get the same result as you get at sealevel. Clear as mud??

[/QUOTE] According to Dr. Eric Weiss, when trekkers first started to going to Everest, one out of every 50 died. Nowadays, thanks to awareness of the consequences of high altitude, that figure is one in 10,000 to 50,000. The medical syndromes encountered at altitude all come down to the body's response to the decline of oxygen pressure.

Atmospheric pressure is a gauge of how many oxygen molecules are available per given volume, say a breath. While there is the same percentage of oxygen in the air up high, lower atmospheric pressure at higher altitudes means fewer oxygen molecules are available with each breath. [/QUOTE]

 

[JoHNI_T]

huuuh, just booost it, then there are no worries on power loss....

 

[DaveB]

http://snowest.com/forum/showthread.php?t=101480

If it was this thread that set you off....I believe most replys say the same thing you did....

 

[Interceptor]

I thought you meant the myth that turbos are bulletproof and never break down - I saw more turbo four strokes on the hook last year than XP's

 

[mb1]

because "There is less air at altitude". This just is not true. It is a medical fact that at any altitude the air contains the same ammount of 02 roughly 19%-20%. The difference is how much atmospheric pressure there us within that air. Even though at the summit of everest there is the same ammount of o2 it feels as if there is 66% less o2 than at sea level.
It can best be exampled by thinking of a box. If that box at sea level holds an amount of o2 well say 100 for easy math. Than at the summit of everest it will still hold 19-20% of 02 only at a value of 66. So as it seems there is less o2 there is still the same percentage its just lots harder to get because you have to move more volume to get the same result as you get at sealevel. Clear as mud??

[/QUOTE]


uhhhhh..... so since a sled moves "x" amount volume of air, ( cylinder volume times efficiency or whatever ) then at altitude your sled will be getting "less air" than at sea level, right? I don't think anyone means theres less % O2 in the air, they say there's just less air, which there is. Per volume there is less mass of air, thus less power available. On boost you can move far more air, like you said, and get the power to stay up. I think those running boost can run higher boost at altitude cause the air is "thinner" and will not cause a burndown due to the lower mass of O2 in the air.

?But I found a 66 of the Captain's finest about an hour ago so I might be wrong.

Oh and Sally I LMAO cause I just finished "reading" your other thread and I was thinking of math and science when I saw your post here. nice.

 

[happylilcuss]

Dave, Nope I didnt get set off!! MB I agree 100%. I agree those that have boost understand the concept. I just feel that there are so many people that are reading about all of the people on here with turbos and they make wrong assumptions.

I also think that for the most part the people that keep posting the "should I boost" Or "What if I Turbo" threads have no business riding a turbo. I mean really if you have to ask "should I" then really... should you? I dont remember seeing thread after thread asking "should I big bore". When you got to the point you needed more you just did it!! By that time you had been around enough to make an informed decision on which route to go.

It seems like more and more there are people with no where near the back country skills or riding ability getting turbo sleds. It is my opinion that this is why you see so many 1 and 2 year old turbos for sale. Its just my opinion..
Not here to point fingers or bash anyone.. Just making an observation.

 

[grizzly]

I agree with the idea that some people buy turbos that shouldn't. It's just a case of more dollars than sense.

 

[DValentine]

boost

A supercharger, belt or gear driven off the engine, will run at the same speed at a given engine rpm at sea level or at 10,000 feet. So even though it produces boost those boost numbers will fall off at higher elevation. The advantage with an exhaust driven turbine is that it isn't restricted to a ratio of engine rpm. It spins faster as it goes up in elevation, as the atmosphere gets thinner.

 

[Bagger]

I also think that for the most part the people that keep posting the "should I boost" Or "What if I Turbo" threads have no business riding a turbo. I mean really if you have to ask "should I" then really... should you? I dont remember seeing thread after thread asking "should I big bore". When you got to the point you needed more you just did it!! By that time you had been around enough to make an informed decision on which route to go.

It seems like more and more there are people with no where near the back country skills or riding ability getting turbo sleds. It is my opinion that this is why you see so many 1 and 2 year old turbos for sale. Its just my opinion..
Not here to point fingers or bash anyone.. Just making an observation.

So does this apply to questions about track mods as well? Maybe it's just thier way of talking thru a decision, or, ironicly enough reading this, maybe they just felt like talking and didn't really have anything to say?!?

Bagger

 

[mb1]

Dave, Nope I didnt get set off!! MB I agree 100%. I agree those that have boost understand the concept. I just feel that there are so many people that are reading about all of the people on here with turbos and they make wrong assumptions.

I also think that for the most part the people that keep posting the "should I boost" Or "What if I Turbo" threads have no business riding a turbo. I mean really if you have to ask "should I" then really... should you? I dont remember seeing thread after thread asking "should I big bore". When you got to the point you needed more you just did it!! By that time you had been around enough to make an informed decision on which route to go.

It seems like more and more there are people with no where near the back country skills or riding ability getting turbo sleds. It is my opinion that this is why you see so many 1 and 2 year old turbos for sale. Its just my opinion..
Not here to point fingers or bash anyone.. Just making an observation.

Thanks.

I think people, especially right now, are itching to talk about sledding stuff and will throw out qiestions cause it's fun to talk about them.

Personally, I could never ride the pants off of any sled, but if I can somehow convince my wife to let me get a TNytro next year, I'll do it. I figure, I have a 3 bedroom house, I use only 1. I have a truck capable of towing 15k#, I run empty. I have a gym membership I use once per month. Why shouldn't I get a Tsled? I'm not going to run around saying I'm the baddest thing on the hill, far from it. But I know it's fun to light up the tires in my truck, and it'd sure as he77 be fun to have boost. I doubt if many people on this site need a sled at all, so what's the diff if a guy has one with big HP? Good for him I say.

 

[happylilcuss]

Mb Again I agree with you!! However obviously you have some expierence and fit into the category of not needing to ask the question. You have paid your dues and found that you would be well to have a Tnytro.. The only reason I brought up the second part of this is because I have ran into WAY to many people in the back country that got in over their heads and needed help out because they didnt realize what "they" were capable of. Stock sleds are more than most people can handle. We on snowest are the small vocal minority of sled owners/ riders!!

I know that the majority of people on this site are exempt. But in reality there are a ton of lurkers and a ton of newbs that read this website and all of the sudden they need the sled burandt or story are riding because it seems everyone has one. Well in reality only a very small amount of people are able to handle these sleds. Again why I think there are so many new turbos in the swap for sale.

I dont feel that a track decision or a handlebar decision is anywhere near the same. You cant ride off the back side of a Mtn because of the bars you choose.

Anyway, I dont want to start an argument. Just felt like venting tonight. I just hope everyone is safe this year and everyone watches out for signs of avy's. I dont wanna ever have to help another avy vic again!! And I promise neither do you.
Be safe this year and pray for snow!

 

[sled_guy]

It's no different with turbos than it was in the late 90s when the OEMs started turning out super capable mountain sleds. Heck, in '98 I saw more people in the back country of Utah on 700RMKs that didn't have a clue about riding there. The sled was way more capable than they were. Add boost, same deal.

However, those people learned, not too many got killed, and they got better. If we waited around until we knew what we were doing we wouldn't ever do anything.

sled_guy

 

[sled-fiend]

It seems like more and more there are people with no where near the back country skills or riding ability getting turbo sleds. It is my opinion that this is why you see so many 1 and 2 year old turbos for sale. Its just my opinion..
Not here to point fingers or bash anyone.. Just making an observation.

I don't know about that. Seems like most people that sell their boosted sleds end up buying another boosted one or building a better one. Lots of 1 or 2 year old sleds boosted or not for sale every year. Different strokes for different folks.

 

[jlebrun_05]

I didnt mean to get anything started up on here, I just honestly started a thread because me and my roommates are bored at college and were fighting whether or not you lost horsepower with a turbo 4 stroke. none of us have one, but you gotta argue about something right?

 

[happylilcuss]

I was not tryin to get anything started either. like I said was just venting a little. Obviously I am way off base so I will take a big ol bite off the humble pie!! Ride safe guys and girls!! Stay safe!

 

[revpilot]

So what are you saying lil cuss, that turbos don't lose power with altitude? The only way a boosted sled wouldn't lose power with altitude is if it was set up to maintain a certain amount of manifold pressure. Most that I know of push x pounds of boost on top of whatever the air density is, therefore at sea level you'll make your sleds rated hp+10#'s of boost and at 10k you'll make rated hp-30% plus 10#'s of boost.

 

[todd460c]

Well now I feel kind of stupid. I'm one of those guy's that asked if I should turbo or not. But I guess I was asking if I should do it to my year and model of sled. I thought this site was all about asking qustion's. I did'nt know that there was some that you could not ask. And the people that replyed really helped me out and I met a local guy and became friends with him. So I guess it worked out for me.

 

[ryan7]

Just stirring

If you have a volume of air at sea level at 10# and the same volume of air at 10000' at 10#, what is the difference in O2 content? I thought the density of air decreased as you reach elevation due to pressure therefore the quantity of O2 decreases. If you pressure this high altitude air back up to 10#, isn't it going to have the same O2 content. Like said previously, the composition of air does not change with elevation. It will be harder to reach 10# at elevation but if this is achievable, won't results be the same??

One more, if boost is measured relative to sea level elevation on your boost gauge and not at elevation, when you reach elevation, you will see a vaccuum on your gauge. Now, you will have to turn up the boost knob to get back to sea level boost numbers.

 

[revpilot]

If you have a volume of air at sea level at 10# and the same volume of air at 10000' at 10#, what is the difference in O2 content? I thought the density of air decreased as you reach elevation due to pressure therefore the quantity of O2 decreases. If you pressure this high altitude air back up to 10#, isn't it going to have the same O2 content. Like said previously, the composition of air does not change with elevation. It will be harder to reach 10# at elevation but if this is achievable, won't results be the same??

One more, if boost is measured relative to sea level elevation on your boost gauge and not at elevation, when you reach elevation, you will see a vaccuum on your gauge. Now, you will have to turn up the boost knob to get back to sea level boost numbers.

Air density decreases with elevation and your boost guage will stay constant because it's regulated at the popoff valve. (within the perameters of your system) You're not pressuring back up to 10#'s you're adding or( BOOSTing)10 #'s to your otherwise NA system.

 

[Original Tetonice]

Your stock sled will lose approx 3% of its HP per every 1000 feet it climbs. The same sled with a turbo installed will lose approx 1.5 HP per every 1000' it climbs. Air is Air and the Air has the same effect on both sleds.

Where the differance is is in the the RPM ....A turbo is exhaust driven and as long as your turning the RPM the exhaust output that spins the fan inside the turbo remains stable at all elevations creating consistant boost......But than theres the Air again which is always unstable.

OT