I have a McXpress 330 kit and am told that it is apprx 280HP @ 17lbs. I guy I talked to said his powderlites was 280 @ 14lbs. I have seen many HP claims at different pounds boost. So if you take two sleds with the same engine work and use two different turbo setups at 17lbs is the horse power different? Or if you take a big and a small turbo and they both make 17lbs is it the same HP?
Whats the truth about BOOST!
- Thread starter h3joe
- Start date
Mcx uses mitsubishi turbos and powderlites uses garrett turbos. The bigger the turbo the more hp you have per pound of boost, but bigger turbos generally take longer to spool up. If you have a 16t mitsu. turbo and he has a gt2860, then yes, the gt2860 makes a little more power at 15lbs than the 16t. Now, if yours has the 19t then they would be pretty close on power per # of boost.
Boost is basically back pressure and if a bigger turbo can move more air with less back pressure it will show less boost on the guage, but will make more power.
Boost is basically back pressure and if a bigger turbo can move more air with less back pressure it will show less boost on the guage, but will make more power.
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its hard to say who is crunching numbers and who is on the dyno. i dont think efficency (hp/#s of boost) stays the same as boost goes up. so crunching numbers wont get an accurate hp rating at differnt boost levels. a dyno chart is the way to go
yeah, thye are all just dyno speculations.. all that matters is how much fun they are to ride.. if your sled is advertised as 100 hp and smokes one advertised as 200.. does that mean your sled still sucks? dont worry to much about the numbers.. go have and enjoy the boost.
M
MTdream
Well-known member
Similar to not a LOT of people can tell the difference in power from 150-155 HP...yet we all think we can....
once you get over 190HP, it is all permagrin, so who really cares? it is more than enough to get you and sled anywhere you want...
My boost is 10PSI, and yet I generally only claim my sled is over 200 HP...which if I followed the claims of 1PSI= 10 HP, then my sled would be mid 200 HP, but who cares after power is not your limiting factor...
once you get over 190HP, it is all permagrin, so who really cares? it is more than enough to get you and sled anywhere you want...
My boost is 10PSI, and yet I generally only claim my sled is over 200 HP...which if I followed the claims of 1PSI= 10 HP, then my sled would be mid 200 HP, but who cares after power is not your limiting factor...
I guess 200~ HP at 10k ft + @ 12#
And really, I could care less what "number" you apply.
It works, and its fun...thats whats more important.
And really, I could care less what "number" you apply.
It works, and its fun...thats whats more important.
The goal is to get as much HP at lower boost with out lossing low end response .
I have an MCX 270 kit. They claim 240 @ 14# and 270 @ 17#. My good friend has the same sled, track, skid with the PL kit. PL claims much much more hp at the same boost levels (280hp @ 14#). However, in the several rides together, we decided that our two sleds were nearly identical on every ride when running equal boost. I know that my sled is dialed in well, and I'm confident that my friend would have his dialed in as good, if not better than me. So I guess 240 Swedish HP = 280 Canadian HP, because his sled does not seem to have 40 more real world hp than mine at equal boost. When he turns his to 20+ pounds, he is definitely faster than my 17 pounds. As far as I'm concerned, hp numbers are all b.s. What happens on the hill is what really matters!
that are two stroke numbers 1psi = 10hp
on 4stroke you have max6hp at 1psi and that on really good fuel.
on 4stroke you have max6hp at 1psi and that on really good fuel.
B
bigbird
Well-known member
based on what?
That's not what I've seen on the hill. An 800 2 stroke does not run with my T-rx1 when we're both at 12lbs...they work good for a light sled, but not like a four stroke. That's just what I've seen though.
Hp #
Joe I was not trying to miss lead you. I was just giving Dave's HP numbers from his website. http://www.powderlites.com/nytro.html
As others have said dyno numbers are very often, miss leading. There are just too many factors.
Joe I was not trying to miss lead you. I was just giving Dave's HP numbers from his website. http://www.powderlites.com/nytro.html
As others have said dyno numbers are very often, miss leading. There are just too many factors.
B
BigFish BC
Well-known member
yes torque is a magical thing
the 2s make a little more hp per # of boost but the 4s make that nasty low down torque.
B
BigFish BC
Well-known member
dyno # are just that # it been proven befor what a sled does on the dyno means nothing on the hill,its a great tuning product or sales pitch but what it does on the hill tells the truth.here one example you take the same sled put it on the dyno make one run at 17lbs it makes 280hp then turn the boost down to 14lbs add some timing through out the pull tweak the fuel a bit now you just made 280 at 14bls on the dyno but does that mean it will work day in day out on the hill maybe maybe not.
Lot of factors determine horsepower. The PL kit is not making good horsepower just because the turbo is bigger. They have a nice header, downpipe, intercooler, fresh air intake, dialed cam timing, the rb3, oh and dont forget the bigger turbo. They breathe really well so the bottom end with the bigger turbo is better than an MCX with the smaller turbo. Based on what I've seen, they do run stronger than an MCX with the same boost.
Originally Posted by YETIms 
that are two stroke numbers 1psi = 10hp
on 4stroke you have max6hp at 1psi and that on really good fuel.
there is not a chance that a 2stroke is making 10 hp... per psi
prove it
that are two stroke numbers 1psi = 10hp
on 4stroke you have max6hp at 1psi and that on really good fuel.
there is not a chance that a 2stroke is making 10 hp... per psi
prove it
M
MTdream
Well-known member
I have no tuning intelligence...most who ride with me agree...so I prefer to trust experts...
All I can tell you, is my Nytro with 10PSI, can and has on several occassions, blown 12 PSI boondocker M8's away...and the guys riding them were VERY good tuners...
Big Iron Shootout also proves the point...pound for pound boost the 4strokes clean house...I agree that it seems to be more about torque than HP, and the torque curves on 4 strokes seem to rule the hills...
Just my experience, and I am NOT an expert, and I am staying at a hotel, but not a Holiday Inn Express..
So according to that with both at 12psi:
Nytro is 135hp stock + 72hp boost = 207hp on pump gas & approx 600lbs
D8 is 154 stock + 120hp boost = 274hp on race gas & approx 550lbs
I went to school in England but we didn't have wierd math like that. Maybe the 4 stroke eats the 2 stroke for breakfast 'cos it has more girth
T
twsandrew
Well-known member
I will say that I own 3 turbos now and have owned 7 total. 3 4 strokes and 4 2 strokes. My TM1k is faster than every 4 stroke I have been around at 0-15lbs (Fairview verified for what that's worth). Above that the 4 strokes win but at anything below boost for boost my M1k seems way more efficient
a motor is a pump
you are comparing a nytro which is a liter plus and an 800
Although the results I have seen are much different you need to compare displacement and boost.
My nytro at 10lbs would get owned by my M1k at 10lbs by a bus legnth and I think it would be close to if not slower than an M8 at 10lbs much less 12lbs. Maybe if those M8s had a intercooler that could be the reason or maybe your nytro is faster at 10lbs than any of the kits I have been around (bd, impulse, pl, alpine)
a motor is a pump
you are comparing a nytro which is a liter plus and an 800
Although the results I have seen are much different you need to compare displacement and boost.
My nytro at 10lbs would get owned by my M1k at 10lbs by a bus legnth and I think it would be close to if not slower than an M8 at 10lbs much less 12lbs. Maybe if those M8s had a intercooler that could be the reason or maybe your nytro is faster at 10lbs than any of the kits I have been around (bd, impulse, pl, alpine)
I think it would be more accurate to compare torque than horsepower
Not sure they even have horsepower in England
Not sure they even have horsepower in England
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