Supercharged Bike engine
Discussion
Big CC racing said:
The Rotrex Charger is not a good unit.
Wrong, for a supercharger the rotrex is the best out there. I've got one of TTS rotrex setups in my CTR and it is performs very well(doubled the power). I think there is a 3 year warranty for the supercharger. As for performing worse than standard low down on the engine you tried it on it certainly doesn't lose power low down with a car engine. Big CC racing said:
The Rotrex Charger is not a good unit. I have seen several spill the oil into the intakes, the step up ratio generates heat & on the bikes I have dynod they generate less power than a standard bike up to 4500rpm.
If you own a heavy old Volvo car then a small turbo is ideal for fast spool up to get you going, but on a bike it will plant you on your arse hence larger turbo units are generally preffered with a slightly lazier spool giving controllable power delivery which also assists in the combat of higher inlet temperatures. As bikes can not successfully fit intercoolers under their bodywork.
That being that a 6psi boost run on a typical turbocharged Hayabusa slaughters everywhere on a dyno overlay 10psi of boost from a Rotrex. Figures typically from the rotrex are 220 to 230bhp & the turbo running 4 psi less boost is 250 to 260bhp.
Even taking into account belt losses the Rotrex has a shabby showing.
1st post on PH Big CC and you criticise another product that competes with yours. Not a good showing is it ? If that's you Sean, I'm surprised, we spoke about turbos a while ago and you seemed a reasonable enough chap but sIf you own a heavy old Volvo car then a small turbo is ideal for fast spool up to get you going, but on a bike it will plant you on your arse hence larger turbo units are generally preffered with a slightly lazier spool giving controllable power delivery which also assists in the combat of higher inlet temperatures. As bikes can not successfully fit intercoolers under their bodywork.
That being that a 6psi boost run on a typical turbocharged Hayabusa slaughters everywhere on a dyno overlay 10psi of boost from a Rotrex. Figures typically from the rotrex are 220 to 230bhp & the turbo running 4 psi less boost is 250 to 260bhp.
Even taking into account belt losses the Rotrex has a shabby showing.
gging off the opposition doesn't look good and I thought you were better than that. There are downsides to every product - the Rotrex busa engine will have less power than a stock engine below 3500-4000rpm because it's driving the supercharger and that's not generating any boost at that point, but if you're wanting power you don't run any bike engine that low do you. A bigger turbo doesn't start generating boost until what, 5000rpm ? So below that you've got a standard engine and if you've lowered the cr you've got a few bhp less. Same stuation - if you want power keep the revs up, this is basic stuff.
My Rotrex engine in my car is beautiful, the power delivery is exactly like a larger engine, there is no discernable torque hike as you get with a turbo, just a long, smooth torque delivery that's ideal for a bike.
The max power can be changed with different pulleys and different superchargers, same as you can with turbo's, although a turbo engine is probably easier to change in this respect.
Spilling oil into the intake ? I can't remember how many turbo's I've seen that have blown oil seals, worn bearings etc, all requiring a rebuild or scrapping. Happens to them all, the Rotrex is just a turbo compressor on a gearbox so will suffer some of the same problems as a turbo.
No disrespect Busa Rush but just because you have one fitted to your car and its all hunky dory doesnt mean they work in all applications, sure, you may think you know a fair bit about them but for a second, ignore what Seans says and pop over to either 200mpg.org or the ukbusas site and see what agro people have had with supercharger installations in the real world...they have a poor reputation for good reason...and calm down dear!
podman said:
No disrespect Busa Rush but just because you have one fitted to your car and its all hunky dory doesnt mean they work in all applications, sure, you may think you know a fair bit about them but for a second, ignore what Seans says and pop over to either 200mpg.org or the ukbusas site and see what agro people have had with supercharger installations in the real world...they have a poor reputation for good reason...and calm down dear!
It all depends where you look, not everybody posts on 200 or ukbusas, last time I looked on ukbusas it seemed to be inhabited by a load of 16 year olds who all claimed to have done 250mph on their mates bike, just a handfull of the posters semed to have been anywhere near a busa, let alone a forced ind busa.sam919 said:
Turbo charging seems to be the cheaper option going by Holeshot racings prices. Supercharging seems to be is slightly more expensive.
The choice between the two is going to have to be supercharging as the smoother the drive the more consistent the lap time. The low down torque will also be an advantage on the tracks i usually race, top end wise the torque factor will fit in with adjusting outside tyre diameter or gear ratios.
Thanks for your comments
You're using a 'Busa or a ZX14 as a track bike? And you want to supercharge it?The choice between the two is going to have to be supercharging as the smoother the drive the more consistent the lap time. The low down torque will also be an advantage on the tracks i usually race, top end wise the torque factor will fit in with adjusting outside tyre diameter or gear ratios.
Thanks for your comments
I'm all for individuality. Each to their own, and all that. But surely the idea of a track bike is to get the best lap time? You'll be whupped by every 1000 out there, and probably most 600's as well. Unless your 'track' is 440 yards long and has no corners...
Busa_Rush said:
Beemer-5 said:
A turbo is a far better bet for a Hyabusa or ZX14, etc.
For doing what ? Can't be better at everything or have you invented the perfect device 
Plain as!
As with Caterhams and the like, big low-end torque isn't really an issue with a bike, because of the very low weight, compared to a coupe or even a supercar.
Superchargers drain a lot of power wheras turbos run on free air, if you like.
My ZX14 ran fairly low boost, was dead easy to ride around town, etc., and returned 30 mpg, yet had over 300 bhp.
[quote=Busa_Rush
1st post on PH Big CC and you criticise another product that competes with yours.
[/quote]
I didnt read it like that at all .
Thankfully for the buying public , some dealers will tell you how it is rather than just sell you what they have and need to sell.
Sean is one of those , no bullst , just fact . If it worked well it would be featured on his drag bikes for sure .
I think you misunderstood his comments .
I could put you in contact with somebody who wouldnt be half as kind as Seans comments , and that would be from their own experience
1st post on PH Big CC and you criticise another product that competes with yours.
[/quote]
I didnt read it like that at all .
Thankfully for the buying public , some dealers will tell you how it is rather than just sell you what they have and need to sell.
Sean is one of those , no bulls
t , just fact . If it worked well it would be featured on his drag bikes for sure .I think you misunderstood his comments .
I could put you in contact with somebody who wouldnt be half as kind as Seans comments , and that would be from their own experience
Which ever you go for (turbo is more developed) you need to treble the cost the tuner quotes you as you WILL spend alot more than they initially say! If you bear that in mind you will enjoy. Also - no one does a true ride in ride out service, you will be told to do this and that and generally have to do alot of checking yourself all the time but this comes with the terratory, you want high HP, it does not come cheap. Do not go for the high HP kits either, or the buy big now in case you want alot more down the line, over 300ish on the road is simply not usable in the real world, the American Velocity kits whilst not the pretiest anymore are very tried and tested and do do what they say on the box with very little messing about once it fitted and running. IMHEO anyhow.
Richard just reminded me today that I posted on here & got shot by someone. Not been back since so sorry for delay.
Busarush I can see how my comments are construed as being negative on an alternative product with a bias to my own. In that light I will say no more regarding our negative experiences of that product. Your right its improper.
To make you smile, we have even done some charger work ourselves with Procharger.
What I will explain to you is general Supercharged v turbocharged.
1/ A Supercharger being belt driven has its boost related to crank speed not throttle position. So if you are accelerating fast or slow or cruising or decelerating the charger is force feeding air into the engine albeit some being dumped off. The temperature of that air is the issue here.
A turbo only boosts under a loaded condition. When you wanna go quick pull the throttle & it builds boost accordingly. So off boost its as reliable or more reliable as a stock bike with its lower comp motor.
2/ A charger can only generate boost according to what the pulleys are set at. so if you want a street bike to make a max safe 12psi at 11000rpm you put the pulley ratios on for that. But your only making 12psi at that cos at 10000rpm it may be only 11psi & 9000 it maybe only 10psi & 7000 it may be only 7psi & at 4000rpm it may be only 3psi etc.
A Turbo set to 12psi may start to boost at 3500rpm but it will achieve the 12psi by 7000 & hold all the way to the redline. Now think of how that affects the performance difference.
3/ If your Supercharged boost is too little or too high for track conditions whats your solution. Less throttle?
A turbo you simply adjust it via boost control on the wastegate. so you can drive/ride a 500bhp monster quite easily at 220bhp if you so wish by simply having it through a controller.
Power for power facts from Big CC dyno
Turbo Busa 10psi = 310bhp to 320bhp (GT30 ball bearing)
Supercharged Busa 10psi = 225bhp to 235bhp
Turbo Busa 16psi = 370 to 380bhp
Supercharged Busa 16psi = 240 to 245bhp
I have no reason to invent figures other than selling turbos that you can buy from anywhere. However there are plenty of other dyno centres like DSD & Holeshot & JW that can either independantly confirm or discredit the above as they have also had the experience of both.
But those power figures lead to the most important fact.
4/ With a turbo you can run less boost which equals more reliability but still have more performance!!!!
ill get my coat
Busarush I can see how my comments are construed as being negative on an alternative product with a bias to my own. In that light I will say no more regarding our negative experiences of that product. Your right its improper.
To make you smile, we have even done some charger work ourselves with Procharger.
What I will explain to you is general Supercharged v turbocharged.
1/ A Supercharger being belt driven has its boost related to crank speed not throttle position. So if you are accelerating fast or slow or cruising or decelerating the charger is force feeding air into the engine albeit some being dumped off. The temperature of that air is the issue here.
A turbo only boosts under a loaded condition. When you wanna go quick pull the throttle & it builds boost accordingly. So off boost its as reliable or more reliable as a stock bike with its lower comp motor.
2/ A charger can only generate boost according to what the pulleys are set at. so if you want a street bike to make a max safe 12psi at 11000rpm you put the pulley ratios on for that. But your only making 12psi at that cos at 10000rpm it may be only 11psi & 9000 it maybe only 10psi & 7000 it may be only 7psi & at 4000rpm it may be only 3psi etc.
A Turbo set to 12psi may start to boost at 3500rpm but it will achieve the 12psi by 7000 & hold all the way to the redline. Now think of how that affects the performance difference.
3/ If your Supercharged boost is too little or too high for track conditions whats your solution. Less throttle?
A turbo you simply adjust it via boost control on the wastegate. so you can drive/ride a 500bhp monster quite easily at 220bhp if you so wish by simply having it through a controller.
Power for power facts from Big CC dyno
Turbo Busa 10psi = 310bhp to 320bhp (GT30 ball bearing)
Supercharged Busa 10psi = 225bhp to 235bhp
Turbo Busa 16psi = 370 to 380bhp
Supercharged Busa 16psi = 240 to 245bhp
I have no reason to invent figures other than selling turbos that you can buy from anywhere. However there are plenty of other dyno centres like DSD & Holeshot & JW that can either independantly confirm or discredit the above as they have also had the experience of both.
But those power figures lead to the most important fact.
4/ With a turbo you can run less boost which equals more reliability but still have more performance!!!!
ill get my coat
The turbo argument looks cut and dried, but I guess the jury is still out on power DELIVERY.
When you are cranked over on a track and you turn the throttle with a supercharger, you will know how much power will feed in and it will be immediate like an NA engine. With a turbo charger, boost will build and the throttle may feel slightly elastic (ie less fine throttle control). Personally I find this fun in a car on track as I like sorting out oversteer and drifting. On a bike though, I generally find it scary when the back starts to slide under power!!
Personally, I would go for the turbo though and adapt my riding style to square of the corner more and only really use the power when the bike is not far off upright. You'd still do this with a supercharged engine, but probably less so as your throttle control would be better.
On a lot of tracks, this change of style would make you slower though (Brands Hatch, Thruxton etc.)
If you are looking for track times - as others have said - buy a 1000cc sports bike and chuck some money at cams, fueling, suspension, light wheels etc and you'll most likely be putting in a lot faster times than a 300bhp Busa anyway at the majority of tracks.
When you are cranked over on a track and you turn the throttle with a supercharger, you will know how much power will feed in and it will be immediate like an NA engine. With a turbo charger, boost will build and the throttle may feel slightly elastic (ie less fine throttle control). Personally I find this fun in a car on track as I like sorting out oversteer and drifting. On a bike though, I generally find it scary when the back starts to slide under power!!
Personally, I would go for the turbo though and adapt my riding style to square of the corner more and only really use the power when the bike is not far off upright. You'd still do this with a supercharged engine, but probably less so as your throttle control would be better.
On a lot of tracks, this change of style would make you slower though (Brands Hatch, Thruxton etc.)
If you are looking for track times - as others have said - buy a 1000cc sports bike and chuck some money at cams, fueling, suspension, light wheels etc and you'll most likely be putting in a lot faster times than a 300bhp Busa anyway at the majority of tracks.
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