Turbo on the hawk 250?

zanoknight · 09-25-2018, 06:09 PM

So before I go too far deep into the rabbit hole I have a few questions.

First: is there any benefit on adding a small turbo on a small engine?
Second: I have the aftermarket oil cooler already installed on my hawk, can I tap into that to cool my turbo?
Lastly: is it more beneficial to make it a blow through or suck carb?

Thanks to everyone who responds. I kind of want to try this over the winter. I am graduating in December and I will have a lot of free time and extra cash from graduation gifts.

slowroller · 09-25-2018, 06:46 PM

A efi tunable bike would be 100x better to start with if its a have to have thing.

zanoknight · 09-25-2018, 07:14 PM

I would love to try this but that kinda project is out of my comfort zone. I’d rather do an engine swap then trying to convert this one from carb to EFI.

Tashka · 09-25-2018, 07:18 PM

yes turbos will definitely increase engine performance on a small engine. You're essentially increasing the displacement of the hawk, which would drastically increase performance, even if you were to do a moderate blow through.

The stock hawk has a pretty low compression ratio already, supposedly 9:1, however I have a large suspect that it is actually even lower. the tt250(which is the same engine) has a compression ratio of 8.7:1, while at the same time having a thinner head gasket. so i think the hawk has an even lower ratio than that.

You would need to buy the world's smallest turbo, the RHB31. this website sells clones of it for not too expensive of a price. http://www.ecotrons.com/products/sma..._turbocharger/

You can turbo a carburetor, and there are tuning ways to do so, however it's likely you'll run into fuel issues, as it needs different amounts of fuel depending on how fast the turbo is spinning. Id definitely go fuel injection, they have a lot, although it is expensive, it'll probably save ypu from blowing up an engine

But to be fair, one large issue you may run into is cooling. turbos produce alot of heat, and an intercooler of some kind may be necessary to keep combustion temperatures down. Id definitely run as rich as you can, especially at WOT.

I've thought alot about doing a turbo on my hawk. i decided a supercharger would be better for an off-road purpose bike(less intense power bands generally, don't have to get it spooled up), but the biggest thing stopping me is the price.

If you were set on doing carbs and turbo, I say blow through for better throttle response

Tashka · 09-25-2018, 07:21 PM

a turbo on this air cooled engine would probably put it right on the edge of blowing up the engine, or putting a hole in the piston tbh. it's a price to go fast. EFI will help, by ensuring you never run rich.

But I'd install an electronic fuel shutoff valve, aswell as an oil temperature gauge, both for safety reasons.

roundhouse · 09-25-2018, 09:53 PM

I always thought it would be cool. I have seen several vids in the past of guys with pit bikes who turbo them.

zanoknight · 09-26-2018, 05:04 AM

Quote:

Originally Posted by roundhouse

I always thought it would be cool. I have seen several vids in the past of guys with pit bikes who turbo them.

Honestly what made me want to do it was this barbie gokart that had a turbo. It's an awesome video

pete · 09-26-2018, 05:55 AM

Quote:

Originally Posted by zanoknight

So before I go too far deep into the rabbit hole I have a few questions.

First: is there any benefit on adding a small turbo on a small engine?
Second: I have the aftermarket oil cooler already installed on my hawk, can I tap into that to cool my turbo?
Lastly: is it more beneficial to make it a blow through or suck carb?

Thanks to everyone who responds. I kind of want to try this over the winter. I am graduating in December and I will have a lot of free time and extra cash from graduation gifts.

you can't blow though with the carb...hows the fuel going to come up from the main jet when pressure is
going down into the fuel blow blowing the fuel out the over flow all over the motor.. could also make
a kool bubbly sound in the tank...

can build a presurised box around the carb.... still have the kool bubbly sound... i quess you will need a fuel pump...

you use the oil to lube the turbo bearing not cool it...

...

bogieboy · 09-26-2018, 06:55 AM

Quote:

Originally Posted by pete

you can't blow though with the carb...hows the fuel going to come up from the main jet when pressure is
going down into the fuel blow blowing the fuel out the over flow all over the motor.. could also make
a kool bubbly sound in the tank...

can build a presurised box around the carb.... still have the kool bubbly sound... i quess you will need a fuel pump...

you use the oil to lube the turbo bearing not cool it...

...

Pete, you can infact do a blowthru carb. Requires careful orifacing of the vent of the carb into the intake tract (so the fuel bowl is also under pressure, slightly higher than the intake charge)

But it can be done....LOL

**JerryHawk250** · 09-26-2018, 09:05 AM

As bogieboy stated it can be done with a carb but I wouldn't recommend it. Very tricky tuning. To easy to have it run lean and then Boom! If you are going to do a turbo , EFI is the way to go. You have to be able to control fuel mixture under boost. I've had plenty of experience in tuning with turbos on car engines. The thought has crossed my mind on doing it with the Hawk but the cost killed that idea quick. If i'm going to sink that kind of money on a complete turbo system it won't be on a 250cc engine.

I'll sit back and grab a bag of popcorn and watch this one.

Tashka · 10-05-2018, 10:35 AM

i encourage you to do this though, I'd really love to see it.

Weldangrind · 10-05-2018, 11:27 AM

Quote:

Originally Posted by Tashka

i decided a supercharger would be better for an off-road purpose bike(less intense power bands generally, don't have to get it spooled up), but the biggest thing stopping me is the price.

A smog pump can be used for a small engine blower; check it out on Youtube. The issue on a bike is figuring out how to spin it. You could machine a hole in the left side cover and figure out how to adapt a pulley to the end of the crank, but it would be cumbersome. The good news is that smog pumps are cheap.

Here's a fun vid of a smog pump installed on a scooter:

roundhouse · 10-05-2018, 03:55 PM

I would like to see if that actually worked. I wonder how many CFM a smog pump can push?

wheel spinner · 10-08-2018, 07:11 PM

I am in favor of superchargers over turbos.... I have had several cars with superchargers and lowered the pullies to make them faster... my wife has blown several Turbos in the past... but never a supercharger... Now.. Fitting this on a bike... hmmmmm I would need to think hard about this one... but trust me.. it can be done... but you need a shaft to spin the pully... you would need to take the crank to a machinist... a good one... and have him fabricate a shaft on the end of it.. and need to make a hole through the crankcase... and go from there...... a lot of trial and error...

I am sure that a motorcycle speed shop will have a good idea if they haven't already done it....

timcosby · 10-14-2018, 01:56 AM

i have a pic of one on a ktm if i can find it ill post

09-25-2018, 06:09 PM	#1
zanoknight Join Date: Mar 2016 Location: Chicago, IL Posts: 46	Turbo on the hawk 250? So before I go too far deep into the rabbit hole I have a few questions. First: is there any benefit on adding a small turbo on a small engine? Second: I have the aftermarket oil cooler already installed on my hawk, can I tap into that to cool my turbo? Lastly: is it more beneficial to make it a blow through or suck carb? Thanks to everyone who responds. I kind of want to try this over the winter. I am graduating in December and I will have a lot of free time and extra cash from graduation gifts.
	0

09-26-2018, 09:05 AM	#10
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,553	As bogieboy stated it can be done with a carb but I wouldn't recommend it. Very tricky tuning. To easy to have it run lean and then Boom! If you are going to do a turbo , EFI is the way to go. You have to be able to control fuel mixture under boost. I've had plenty of experience in tuning with turbos on car engines. The thought has crossed my mind on doing it with the Hawk but the cost killed that idea quick. If i'm going to sink that kind of money on a complete turbo system it won't be on a 250cc engine. I'll sit back and grab a bag of popcorn and watch this one. __________________ 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S 2004 Honda ST 1300 2016 Black Hawk 250 (sold) Keihin PE30 carb,125 main,38 slow.Pod filter,ported & decked head 10:1 CR,Direct Ignition Coil,15/40Sprockets,NGK DPR8EIX-9,De-Cat,Dual Oil Cooler,Digital Cluster 2016 Cazador180 XL 2014 Coolster150 JerryHawk250.com My YouTube Channel
	0

10-08-2018, 07:11 PM	#14
wheel spinner Join Date: Nov 2017 Location: Suffolk Va. Posts: 146	I am in favor of superchargers over turbos.... I have had several cars with superchargers and lowered the pullies to make them faster... my wife has blown several Turbos in the past... but never a supercharger... Now.. Fitting this on a bike... hmmmmm I would need to think hard about this one... but trust me.. it can be done... but you need a shaft to spin the pully... you would need to take the crank to a machinist... a good one... and have him fabricate a shaft on the end of it.. and need to make a hole through the crankcase... and go from there...... a lot of trial and error... I am sure that a motorcycle speed shop will have a good idea if they haven't already done it.... __________________ 2006 Roketa DB-07-200 Dual Sport 2007 Monte Carlo SS 5.3 2010 Challenger Hemi 5.7 2004 Isuzu Rodeo 1998 Kia Sportage 4x4 2004 Toyota Tundra 2016 Ford Escape Guitars 1970 Gibson SG mint Condition 2005 Epiphone white Custom SG Les Paul L/New Fender Banjo New Condition BC Rich Bitch - Like New\ 3 Jay Turser SG Good Condition Amps Marshall vs100 Good Condition Acoustic 261 very good condition Boss GT-6 Pedal effects Like New
	0

10-14-2018, 01:56 AM	#15
timcosby Join Date: Nov 2016 Location: robertsdale alabama usa Posts: 1,007	i have a pic of one on a ktm if i can find it ill post __________________ 1991 harley heritage softail classic 2016 hawk kaw h1 400 tripple 13' long chopper in progress 2009 johnny pag bar hog 2004 hd electra glide ultra classic shriner edition 1997 harley davidson 1200 sportster 1972 harley davidson amf sx250
	0

09-25-2018, 06:46 PM	#2
slowroller Join Date: May 2018 Posts: 77	A efi tunable bike would be 100x better to start with if its a have to have thing.
	0

09-25-2018, 07:14 PM	#3
zanoknight Join Date: Mar 2016 Location: Chicago, IL Posts: 46	I would love to try this but that kinda project is out of my comfort zone. I’d rather do an engine swap then trying to convert this one from carb to EFI.
	0

09-25-2018, 07:18 PM	#4
Tashka Join Date: Aug 2018 Posts: 158	yes turbos will definitely increase engine performance on a small engine. You're essentially increasing the displacement of the hawk, which would drastically increase performance, even if you were to do a moderate blow through. The stock hawk has a pretty low compression ratio already, supposedly 9:1, however I have a large suspect that it is actually even lower. the tt250(which is the same engine) has a compression ratio of 8.7:1, while at the same time having a thinner head gasket. so i think the hawk has an even lower ratio than that. You would need to buy the world's smallest turbo, the RHB31. this website sells clones of it for not too expensive of a price. http://www.ecotrons.com/products/sma..._turbocharger/ You can turbo a carburetor, and there are tuning ways to do so, however it's likely you'll run into fuel issues, as it needs different amounts of fuel depending on how fast the turbo is spinning. Id definitely go fuel injection, they have a lot, although it is expensive, it'll probably save ypu from blowing up an engine But to be fair, one large issue you may run into is cooling. turbos produce alot of heat, and an intercooler of some kind may be necessary to keep combustion temperatures down. Id definitely run as rich as you can, especially at WOT. I've thought alot about doing a turbo on my hawk. i decided a supercharger would be better for an off-road purpose bike(less intense power bands generally, don't have to get it spooled up), but the biggest thing stopping me is the price. If you were set on doing carbs and turbo, I say blow through for better throttle response
	0

09-25-2018, 07:21 PM	#5
Tashka Join Date: Aug 2018 Posts: 158	a turbo on this air cooled engine would probably put it right on the edge of blowing up the engine, or putting a hole in the piston tbh. it's a price to go fast. EFI will help, by ensuring you never run rich. But I'd install an electronic fuel shutoff valve, aswell as an oil temperature gauge, both for safety reasons.
	0

09-25-2018, 09:53 PM	#6
roundhouse Join Date: Sep 2017 Location: N Texas Posts: 706	I always thought it would be cool. I have seen several vids in the past of guys with pit bikes who turbo them.
	0

10-05-2018, 10:35 AM	#11
Tashka Join Date: Aug 2018 Posts: 158	i encourage you to do this though, I'd really love to see it.
	0

10-05-2018, 03:55 PM	#13
roundhouse Join Date: Sep 2017 Location: N Texas Posts: 706	I would like to see if that actually worked. I wonder how many CFM a smog pump can push?
	0