I am currently building a mini drag bike. I am using a predator 212 non hemi style. I have removed the govorner as well as installing a billet rod and flywheel. I want to use forced induction but can't make a desision on which type to use. I am looking at the GT0632SZ Garrett turbo or the AMR300 supercharger. I have seen mini bikes on youtube with turbos making 7-10psi, but have only seen one supercharged bike (with the AMR300). The guy was running a gx390 and claimed it made 20psi. I have no idea on how true this is. Any suggestions on which to use or which would make more power would be very helpful.
supercharging vs turbo
- Thread starter chadwickkev
- Start date
- Tags build minidragbike supercharger supercharging turbo
A turbo will make horse power easier than a supercharger. The turbo uses the exhaust gas to spin the turbine, which is free, where with the supercharger the engine itself spins the supercharger to make boost , so it takes some horsepower to spin the supercharger. I believe that the hardest problem is fuel supply on boosted small engines and more importantly ignition timing. Most boosted engines pull timing out as boost increases. Hope this helps.
Did someone say MegaSquirt?
A supercharger will be easier to implement, that's for sure.
The GT06 has an integrated exhaust manifold and turbine housing intended for some Indian micro car. Unless Garrett starts making a universal turbine housing available, the GT06 isn't even an option. Their GT12 model is the next smallest option with a standard housing, but even it's on the big side for a sub-40hp engine.
Are you only concerned with making maximum power? If so, turbos are generally a better choice.
The exhaust energy is not free. It comes at the expense of increasing exhaust pressure that the engine has to pump against. Turbos cost engine power to run, but fortunately it's considerably less than a supercharger.
Yeah, but a draw-though blower doesn't need much for fuel pressure. A carb can just about remain stock in that case. Blow-through would require a high-pressure pump and 1:1 regulator plus some other tricks to keep fuel going where it should.
A rule of thumb on timing is about 1° per psi, but that is highly dependent on the engine design and configuration.
The amount of power it takes to compress air to Xpsi depends on the air volume. 50cfm at 10psi might take 1hp or less; 10psi at 800cfm could take 50hp. That's about what it takes to run the supercharger on a 600hp engine.
A supercharger will be easier to implement, that's for sure.
The GT06 has an integrated exhaust manifold and turbine housing intended for some Indian micro car. Unless Garrett starts making a universal turbine housing available, the GT06 isn't even an option. Their GT12 model is the next smallest option with a standard housing, but even it's on the big side for a sub-40hp engine.
Are you only concerned with making maximum power? If so, turbos are generally a better choice.
The exhaust energy is not free. It comes at the expense of increasing exhaust pressure that the engine has to pump against. Turbos cost engine power to run, but fortunately it's considerably less than a supercharger.
Yeah, but a draw-though blower doesn't need much for fuel pressure. A carb can just about remain stock in that case. Blow-through would require a high-pressure pump and 1:1 regulator plus some other tricks to keep fuel going where it should.
A rule of thumb on timing is about 1° per psi, but that is highly dependent on the engine design and configuration.
The amount of power it takes to compress air to Xpsi depends on the air volume. 50cfm at 10psi might take 1hp or less; 10psi at 800cfm could take 50hp. That's about what it takes to run the supercharger on a 600hp engine.
BINGO, I'm far from any small engine expert but have had some dealings with both on drag cars/trucks and couldn't have said it better. I does kinda irk me about how everybody seems to think turbos make all this so called free power but you explained it to the T.
Personally for a "lawn mower" engine I would shoot some NO2 in it. As much as I dislike bottle babys I think it will be much easier than forced induction. But my main dislike for juice is the idiots that shoot up a basically stock engine till the top ring seizes up and blows the top of the piston off. They then bad mouth everything but their stupidity for not building the engine correctly for NOS, no not naws thats another book...
Personally for a "lawn mower" engine I would shoot some NO2 in it. As much as I dislike bottle babys I think it will be much easier than forced induction. But my main dislike for juice is the idiots that shoot up a basically stock engine till the top ring seizes up and blows the top of the piston off. They then bad mouth everything but their stupidity for not building the engine correctly for NOS, no not naws thats another book...
Very Good Info guys! Im very interested in boosted engines altho I have always run all motor I see non of you guys are in the Cen Tex area, But I would love to have you guys come on by my new page! My members would love this kind of info/talk!
https://www.facebook.com/groups/844624059001076/
-Devan
https://www.facebook.com/groups/844624059001076/
-Devan
Dude, it's not cool trying to funnel people from this forum over to your FB group. Not. Cool.
I think people just hear "waste energy" and think it's like pulling power out of someone else's trash.
One consideration with nitrous is that it's limited by the engine's volumetric efficiency. All that really happens is air gets replaced with nitrous oxide that has a lot more oxygen in it. It is still pushed into the engine by atmospheric pressure in most cases. Once all the air in the intake charge has been displaced with nitrous, the power ceiling has been reached.
With boost, there is no real limit to the possible charge density except maybe the point at which air is compressed enough to become liquid. Parts will melt and fuels will 'detonate' long before that.
I think people just hear "waste energy" and think it's like pulling power out of someone else's trash.
One consideration with nitrous is that it's limited by the engine's volumetric efficiency. All that really happens is air gets replaced with nitrous oxide that has a lot more oxygen in it. It is still pushed into the engine by atmospheric pressure in most cases. Once all the air in the intake charge has been displaced with nitrous, the power ceiling has been reached.
With boost, there is no real limit to the possible charge density except maybe the point at which air is compressed enough to become liquid. Parts will melt and fuels will 'detonate' long before that.
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