Lots of posts and threads on this forum of big bore, nitrous or powerful two stroke 500 bikes. Great bikes with lots of power!
Sometimes, turbos comes up as a solution to big power snowbikes.
I can see some people having skeptisism in turbocharging snowbikes. Lag, reliability and cost looks to be the things that many people think is the downside in turbocharging.
There seem to be not much real knowledge or discussion in turbocharging snowbikes. Maybe there are too few turbokit manufacturers or too few boosted snowbikers out there that can share the opinions, reliability issues and performance?
So far, we've seen only two production turbo kit manufacturers, Boondockers and KMS. Different solutions, price point and marketing. We all hope seeing more manufacturers get in to the market.
Have seen many second hand Boondoker kits for sale. Maybe this is an indication that many users aren't satisfied with the performance, tuning or reliability?
KMS offers a BD upgrade kit that more or less replaces everything but the turbocharger in order to get it to work properly. It tells me that BD haven't made the proper R&D to get it to work....
First of all, don't consider my nickname on this forum as I'm an expert in turbocharging. I picked this as I live in sweden and like turbo engines
I've designed and built a homebrew rear mount turbokit on my KTM500 snowbike. Maybe you've seen my build thread on this forum....
After four years of riding my turbo kit, I think I have some long term knowledge to share with you....
It has performed really well and I'm very pleased with the performance and reliability!
Powerwise:
Boosting 0,7 bar or 10 psi, delivering 96 rwhp.
The engine requires a lot of modifications such as a custom made low compression piston, heavier studs, high flow water pump and a reinforced clutch.
Peak power is not the first I would like to point out. I'm really impressed that it delivers tons of torqe! Full boost @ 5k rpm, max torque 85Nm or 65 lbft@ 6.600 rpms
Wide ratio transmision is better on this powerband. It pulls hard no matter of gear.
The 500 has a fairly short rpm-range hitting the revlimiter in less than 9.000 rpms.
Maybe a high reving 450 delivers a better and wider usable powerband?
I'm a flatlander and can't give you any riding impressions at altitude. We all know that turbos should deliver about the same power at altidude as at sealevel.
Reliability:
Have ridden this turbo kit for +100hrs with no rebuild or mayor breakdown on my 2012 500EXC. Upgraded to a 2016 EXC bike last fall.
My buddy that has the same turbo kit suffered a big end rod bearing failure. We're not sure what was the cause but the 2012 has a roller bearing. 2013-16 has a plain bearing that we think is stronger.
I've had some minor issues like a blown head gasket but these are things you might expect when you're designing and building your own turbo kit. A tested and refined production kit would have these issues ironed out.
As a rider you have to listen to your engine and try avoiding overrevs. With such power on tap, you just can't keep it pinned.
Found this video clip on youtube. Listen and hear how the rider on the first turbo bike keeps it pinned. It backfires and on the revlimiter. I say that this engine will not last very long. You cant blaim the turbo in this case.
http://youtu.be/9YUS-WPoh3Q
Cost:
As I built the turbo kit myself, the cost wasn't as much as a production kit. I just paid for the parts. For a turbo kit manufacurer, focusing on only a few bikes, for example KTM 450 and 500, will simplify production and cut cost compared to offering kits to all dirt bikes, brands and models. All in all, turbos will never be a standard snowbike accessory for every snowbiker.
But if you talk about $/hp, turbos is starting to look promising compared to other ways of tuning. Turbos offers at least 50% horsepower improvement.
A regular Big Bore will only get 10-15% power gains and those kits dont come for cheap.
A nitrous system has its obvious limits and no way nere the power of a turbo.
My conlutions:
A proper designed turbo kit, using good fuel and a rider that "listen to the engine" can be a good big power soluition with great reliability.
Don't reach for +100 hp power. You would loose reliability in the long term.
Wide ratio tranny is prefered on turbos.
If you be modest and only go for 0,5 bar or 7-8 psi and 85-90 hp, you will have a fun and reliable setup and at the same time requiring less engine modifications.
Use good oil quality, max 10 hrs/oil change.
Go for a bike with plain big end rod bearings and high pressure lubrication. Roller bearings are weaker and has shorter lifespan under higher load.
Dont run Rekluse, it will slip.
Use only race fuel. Pump gas is not the fuel for reliability. Race fuel may be pricy but these bikes cunsume so little fuel that cost of fuel is resonable despite high $/gal.
Put this topic in this perpective: I buy a large barrel of race fuel for the same cost as a sledder pays for only a couple of CVT-belts
Hope that some other turbo users can share their experience and opinions.
Am I the only snowbiker that is happy with my turbo?
Sometimes, turbos comes up as a solution to big power snowbikes.
I can see some people having skeptisism in turbocharging snowbikes. Lag, reliability and cost looks to be the things that many people think is the downside in turbocharging.
There seem to be not much real knowledge or discussion in turbocharging snowbikes. Maybe there are too few turbokit manufacturers or too few boosted snowbikers out there that can share the opinions, reliability issues and performance?
So far, we've seen only two production turbo kit manufacturers, Boondockers and KMS. Different solutions, price point and marketing. We all hope seeing more manufacturers get in to the market.
Have seen many second hand Boondoker kits for sale. Maybe this is an indication that many users aren't satisfied with the performance, tuning or reliability?
KMS offers a BD upgrade kit that more or less replaces everything but the turbocharger in order to get it to work properly. It tells me that BD haven't made the proper R&D to get it to work....
First of all, don't consider my nickname on this forum as I'm an expert in turbocharging. I picked this as I live in sweden and like turbo engines
I've designed and built a homebrew rear mount turbokit on my KTM500 snowbike. Maybe you've seen my build thread on this forum....
After four years of riding my turbo kit, I think I have some long term knowledge to share with you....
It has performed really well and I'm very pleased with the performance and reliability!
Powerwise:
Boosting 0,7 bar or 10 psi, delivering 96 rwhp.
The engine requires a lot of modifications such as a custom made low compression piston, heavier studs, high flow water pump and a reinforced clutch.
Peak power is not the first I would like to point out. I'm really impressed that it delivers tons of torqe! Full boost @ 5k rpm, max torque 85Nm or 65 lbft@ 6.600 rpms
Wide ratio transmision is better on this powerband. It pulls hard no matter of gear.
The 500 has a fairly short rpm-range hitting the revlimiter in less than 9.000 rpms.
Maybe a high reving 450 delivers a better and wider usable powerband?
I'm a flatlander and can't give you any riding impressions at altitude. We all know that turbos should deliver about the same power at altidude as at sealevel.
Reliability:
Have ridden this turbo kit for +100hrs with no rebuild or mayor breakdown on my 2012 500EXC. Upgraded to a 2016 EXC bike last fall.
My buddy that has the same turbo kit suffered a big end rod bearing failure. We're not sure what was the cause but the 2012 has a roller bearing. 2013-16 has a plain bearing that we think is stronger.
I've had some minor issues like a blown head gasket but these are things you might expect when you're designing and building your own turbo kit. A tested and refined production kit would have these issues ironed out.
As a rider you have to listen to your engine and try avoiding overrevs. With such power on tap, you just can't keep it pinned.
Found this video clip on youtube. Listen and hear how the rider on the first turbo bike keeps it pinned. It backfires and on the revlimiter. I say that this engine will not last very long. You cant blaim the turbo in this case.
http://youtu.be/9YUS-WPoh3Q
Cost:
As I built the turbo kit myself, the cost wasn't as much as a production kit. I just paid for the parts. For a turbo kit manufacurer, focusing on only a few bikes, for example KTM 450 and 500, will simplify production and cut cost compared to offering kits to all dirt bikes, brands and models. All in all, turbos will never be a standard snowbike accessory for every snowbiker.
But if you talk about $/hp, turbos is starting to look promising compared to other ways of tuning. Turbos offers at least 50% horsepower improvement.
A regular Big Bore will only get 10-15% power gains and those kits dont come for cheap.
A nitrous system has its obvious limits and no way nere the power of a turbo.
My conlutions:
A proper designed turbo kit, using good fuel and a rider that "listen to the engine" can be a good big power soluition with great reliability.
Don't reach for +100 hp power. You would loose reliability in the long term.
Wide ratio tranny is prefered on turbos.
If you be modest and only go for 0,5 bar or 7-8 psi and 85-90 hp, you will have a fun and reliable setup and at the same time requiring less engine modifications.
Use good oil quality, max 10 hrs/oil change.
Go for a bike with plain big end rod bearings and high pressure lubrication. Roller bearings are weaker and has shorter lifespan under higher load.
Dont run Rekluse, it will slip.
Use only race fuel. Pump gas is not the fuel for reliability. Race fuel may be pricy but these bikes cunsume so little fuel that cost of fuel is resonable despite high $/gal.
Put this topic in this perpective: I buy a large barrel of race fuel for the same cost as a sledder pays for only a couple of CVT-belts
Hope that some other turbo users can share their experience and opinions.
Am I the only snowbiker that is happy with my turbo?
