It won't transition into boost correctly or reliably unless you're using a Pitot tube. I use modified Thunder Power jets for the pitot tube, so it's adjustable on the fly. If it doesn't transition right, you just adjust the knob on the thunderjet until it transitions correctly. That said,I don't even think Blow-Through is worth the hassle anymore, either keep it simple with a draw-thru setup or just go EFI like you did. Blow-through can be a nightmare to dial in right, not to mention if the float sticks, your whole motor is going to be flooded with gas.
Great tip on the adjustable jet for pitot tube. I did look at the snowmobile and jet ski turbo carb setups too and tried to replicate those but once setup and going it was really hit or miss. I don’t know how people tune these things without a dyno or your method with the knob. Efi seemed like the only option!
@@hillbilly-engineeringif you ever try it with a carb again modify a mikuni hsr42 and install an AFR wide band unit with data logger and it will save you a ton of Dyno time when tuning
I'm fixing to start a blow through build myself. Mainly because it's old school, plus I was advised not to and it was hard (for me) to find the info I needed on the carb. The guy I got all my info from said he never needed the pitot tube. He picked up boost signal from a fitting in the back of the plenum. I haven't made it that far due to health issues but I may very well have to install a pitot tube before it's over. I was told installing a AFR unit with a data logger would make life a lil easier when it comes to tuning. Plus I'm making it more difficult by running the turbo on the left side. 58yrs old now if I don't get it I'll die trying.
Did you get this running good? Blowthru isn't that difficult to make work well. And well worth the little extra adjustment IMO. As long as you have nitrile tipped float needle and use a pitot tube for pressurising the float bowl. To me The time consuming part was finding the right spot in the boost pipe. Closer to turbo=richer, further=leaner. Turboed my single carb yamaha xv1600 about 7y ago. All i changed was blocked the breath tube above diaphram, blockes the airjet at the mouth of carb, pressurised bowl with pitot and used a wideband AFR, fuel side. Runs like stock, good AFR and no problems. Other performance mods include barnett clutch, 2 tooth smaller front pulley and dyna3000 CDI with 5k limiter. Made 100hp/200nm from tire with 0,6bar.
Never did with the carb. At least not to my standards. The best I got was lots of hesitation and terrible AFR curve. Just not enough control over the fuel. I went through a few different pitot tube setups, fuel pump with boost reference pressure regulator, and it had all the standard mods you’d need to get a blowthru setup working. I ended up building a fuel injection setup for it then tuned it for e85. I ran about 8lbs boost (maxed out injectors) but it was quick by the time I sold it
Did you try mounting the carb into the turbo to build a draw through system? If I was going to turbo charge a carbed bike, that's the way I would do it.
I did think about it, but the look I wanted was the spinning compressor wheel being what you see haha also, if you think about when you do a quick rev, it’d take awhile before the accelerator pump fuel makes it to the motor (normally you want the carb as close to the chamber as you can get it )
He took the intake drilled a hole in the bottom and tapped it for a ss non tapered nipple with a hose running all the way to the back of the bike to release that pressure
It’s the stock turbo from a Subaru wrx, known as a TD04. If you just google Subaru td04 you’ll get tons of hits. You can buy Chinese copies for super cheap but I’d try to find an actual used one so you get the oem quality 👍
I just rebuilt the engine, cleaned everything up and put it back together. Still stock bore size. It’d be pretty sweet to go big bore though! I have no idea how fast the top speed is, every time I floored it my eyes were on the road haha I would say with the carb (which wasn’t really working right) it was 30% faster. It didn’t feel like it made a bunch more torque down low but you could definitely feel the added power up top. Before turbo it just felt like I was making a bunch of noise and after it felt like I was really going somewhere
With stock cylinders on a Sportster you can only bore to 1212 or 1214cc. After that they have 1250 and 1275 big bore kits. They have a 90" kit but it's not a bolt on you have to disassemble the complete bottom end and have the cases bored. 75cc isn't a lot, you can make that up with boost pressure. I know of someone with a drag bike that's running a stock 1200 bore and a blow through setup using a S&S carb. He runs between 14-17 psi boost and makes 176hp
What are the sizes or part numbers of the charge tube assembly that you put together (the two 90 degree silicone elbows and the section of bent pipe)? Also, is the carb adapter offset slightly to the left side on the carb ? It's a nice clean install for a diy project 👍
Hey thanks. The turbo has a 2” outlet so it’s a 2” 90 degree coupler, then a 45 degree 6061 aluminum bend, then a 2” to 3” 90 degree coupler. I used my plasma cutter to make the carb flange with enough material to offset the 3” tube, this way one of the screws is inside the intake but everything lines up and barely clears. Hopefully that helps!
If you want to mount a turbo on an engine with a cardurator, you must place the carburetor on the intake in front of the turbo. The carburetor works with vacuum, it is not able to work with turbocharging if it is connected in the pressure part of the intake. Otherwise, if you put it in front of the intake, the turbo will work as it should, only with a longer response to the gas, even with a long intake.
They call this setup draw through or suck through, instead of blow through. I do think this would have worked but yeah it had too many downsides for my taste. The big one was aesthetics, I really really want the turbo blades exposed haha
Yeah, that would have worked, I’m pretty sure if I kept messing with it I would have gotten the carb setup working, but now that it’s efi I have no regrets and a lot of tuning capability :D
@@hillbilly-engineering just want to get an opinion on my set up. My exhaust is routed so my turbo is on the driver's side save everything else is in the passengers side. I. Running a electric fuel pump and a carburetor
Well... your carb setup needs a pitot tube,that enrich mixture when turbo spools.... Everyone uses stock carbs in sports bike's with turbo.... no issues there...
Nice observation. I did actually have a pitot tube installed and played with the size but just couldn’t get it running right during spoolup. Sometimes it’d make it through the sputtering but most times not… my fuel pressure regulator had to be JUST right too and I had to roll into it a certain way. I also read that the cv diaphrams don’t hold up under boost and since I’m more comfortable with efi I just went that route instead. Another thing I read is the pitot tube works better with small turbos like those on watercraft but larger ones tend to be more fickle? Can’t verify that but it factored into my decision also.
It won't transition into boost correctly or reliably unless you're using a Pitot tube. I use modified Thunder Power jets for the pitot tube, so it's adjustable on the fly. If it doesn't transition right, you just adjust the knob on the thunderjet until it transitions correctly. That said,I don't even think Blow-Through is worth the hassle anymore, either keep it simple with a draw-thru setup or just go EFI like you did. Blow-through can be a nightmare to dial in right, not to mention if the float sticks, your whole motor is going to be flooded with gas.
Great tip on the adjustable jet for pitot tube. I did look at the snowmobile and jet ski turbo carb setups too and tried to replicate those but once setup and going it was really hit or miss. I don’t know how people tune these things without a dyno or your method with the knob. Efi seemed like the only option!
@@hillbilly-engineeringif you ever try it with a carb again modify a mikuni hsr42 and install an AFR wide band unit with data logger and it will save you a ton of Dyno time when tuning
I'm fixing to start a blow through build myself. Mainly because it's old school, plus I was advised not to and it was hard (for me) to find the info I needed on the carb.
The guy I got all my info from said he never needed the pitot tube. He picked up boost signal from a fitting in the back of the plenum. I haven't made it that far due to health issues but I may very well have to install a pitot tube before it's over. I was told installing a AFR unit with a data logger would make life a lil easier when it comes to tuning.
Plus I'm making it more difficult by running the turbo on the left side.
58yrs old now if I don't get it I'll die trying.
Can you help me out with my turbo set up on my Harley? I can't find anyone local that will even touch it
Can you recommend an EFI set up?
Where do you get your oil from and where did you put the oil return?
I giggled a little when I first heard it spool 😊
Did you get this running good?
Blowthru isn't that difficult to make work well. And well worth the little extra adjustment IMO. As long as you have nitrile tipped float needle and use a pitot tube for pressurising the float bowl. To me The time consuming part was finding the right spot in the boost pipe. Closer to turbo=richer, further=leaner.
Turboed my single carb yamaha xv1600 about 7y ago. All i changed was blocked the breath tube above diaphram, blockes the airjet at the mouth of carb, pressurised bowl with pitot and used a wideband AFR, fuel side. Runs like stock, good AFR and no problems.
Other performance mods include barnett clutch, 2 tooth smaller front pulley and dyna3000 CDI with 5k limiter.
Made 100hp/200nm from tire with 0,6bar.
Never did with the carb. At least not to my standards. The best I got was lots of hesitation and terrible AFR curve. Just not enough control over the fuel. I went through a few different pitot tube setups, fuel pump with boost reference pressure regulator, and it had all the standard mods you’d need to get a blowthru setup working. I ended up building a fuel injection setup for it then tuned it for e85. I ran about 8lbs boost (maxed out injectors) but it was quick by the time I sold it
Did you try mounting the carb into the turbo to build a draw through system? If I was going to turbo charge a carbed bike, that's the way I would do it.
I did think about it, but the look I wanted was the spinning compressor wheel being what you see haha also, if you think about when you do a quick rev, it’d take awhile before the accelerator pump fuel makes it to the motor (normally you want the carb as close to the chamber as you can get it )
The CV Carb is perfect for blow through Turbocharging if u know small things about it. Up to 80 ci w/small ballbearing turbo it´ll work fine.
I've been thinking of doing the same thing, im thinking of a draw_through on the carb.
How does this video only have 300 views serious the algorithm screwed you
At least you got to check it out, thanks for the comment!
@@hillbilly-engineering keep it up I’ve been making videos for three years you have a talent
Literally am only here because I was looking up odd ball turbo bikes (initially a Goldwing) before directly searching for a turbo sportster.
What are you doing at 2:20? Turning up the boost?
Year my bro needed to drill an additional hole in the carb for to ease pressure when under boost, I can't remember exactly how he did it though.
He took the intake drilled a hole in the bottom and tapped it for a ss non tapered nipple with a hose running all the way to the back of the bike to release that pressure
What size piping are you running?
Great vid broski
Great setup bro 🔥
Thank you!
You could also just add a fuel pump. The vaccuum wont keep up with the boost without it
Good work Bro
Can you post a link of what turbo that is bc I have the same bike
It’s the stock turbo from a Subaru wrx, known as a TD04. If you just google Subaru td04 you’ll get tons of hits. You can buy Chinese copies for super cheap but I’d try to find an actual used one so you get the oem quality 👍
Hey buddy how did you run your oil feed line
You can run a carb but you need to run it pre turbo. And jet it up a bit past boost levels so it runs rich
Hillbilly Engineering how much faster did it go fastest speed have you had it at? Di you bore the engine at all or just turbo?
I just rebuilt the engine, cleaned everything up and put it back together. Still stock bore size. It’d be pretty sweet to go big bore though! I have no idea how fast the top speed is, every time I floored it my eyes were on the road haha I would say with the carb (which wasn’t really working right) it was 30% faster. It didn’t feel like it made a bunch more torque down low but you could definitely feel the added power up top. Before turbo it just felt like I was making a bunch of noise and after it felt like I was really going somewhere
With stock cylinders on a Sportster you can only bore to 1212 or 1214cc. After that they have 1250 and 1275 big bore kits. They have a 90" kit but it's not a bolt on you have to disassemble the complete bottom end and have the cases bored.
75cc isn't a lot, you can make that up with boost pressure.
I know of someone with a drag bike that's running a stock 1200 bore and a blow through setup using a S&S carb. He runs between 14-17 psi boost and makes 176hp
What are the sizes or part numbers of the charge tube assembly that you put together (the two 90 degree silicone elbows and the section of bent pipe)? Also, is the carb adapter offset slightly to the left side on the carb ? It's a nice clean install for a diy project 👍
Hey thanks. The turbo has a 2” outlet so it’s a 2” 90 degree coupler, then a 45 degree 6061 aluminum bend, then a 2” to 3” 90 degree coupler. I used my plasma cutter to make the carb flange with enough material to offset the 3” tube, this way one of the screws is inside the intake but everything lines up and barely clears. Hopefully that helps!
I believe a Carb works with a Turbo where The carb sucks air due to the turbo, as opposed to compressing air thru the carb.
If you want to mount a turbo on an engine with a cardurator, you must place the carburetor on the intake in front of the turbo.
The carburetor works with vacuum, it is not able to work with turbocharging if it is connected in the pressure part of the intake.
Otherwise, if you put it in front of the intake, the turbo will work as it should, only with a longer response to the gas, even with a long intake.
They call this setup draw through or suck through, instead of blow through. I do think this would have worked but yeah it had too many downsides for my taste. The big one was aesthetics, I really really want the turbo blades exposed haha
Awesome video! 1200 dollars 😱 the cheapest used sportster 1200 in Denmark are around 14k USD 😭
You got to put your carburetor before the turbo so it use the vacuum
Yeah, that would have worked, I’m pretty sure if I kept messing with it I would have gotten the carb setup working, but now that it’s efi I have no regrets and a lot of tuning capability :D
Are there any experts on here? I need advice tuning my turßoed bike.
There’s hillbillies here, what’s your question boss
@@hillbilly-engineering just want to get an opinion on my set up. My exhaust is routed so my turbo is on the driver's side save everything else is in the passengers side. I. Running a electric fuel pump and a carburetor
@@RitzCaraldo I had trouble with my carb setup, it was blow thru tho. Suck through is easier for sure. How you checking afr?
@@hillbilly-engineeringcan you recommend an EFI set up?
Well... your carb setup needs a pitot tube,that enrich mixture when turbo spools.... Everyone uses stock carbs in sports bike's with turbo.... no issues there...
Nice observation. I did actually have a pitot tube installed and played with the size but just couldn’t get it running right during spoolup. Sometimes it’d make it through the sputtering but most times not… my fuel pressure regulator had to be JUST right too and I had to roll into it a certain way. I also read that the cv diaphrams don’t hold up under boost and since I’m more comfortable with efi I just went that route instead. Another thing I read is the pitot tube works better with small turbos like those on watercraft but larger ones tend to be more fickle? Can’t verify that but it factored into my decision also.
Hell yeah baby so cool
Dude I’m so lame but hell yeah turbo Harley BABYYYY
Hell yeah baby!!!
👌
Harleys always idle as if they are jusy about to stall.
A lot of people idle them down intentionally to get that "cammed" sound which can starve the engine of oil. Then again there's a lot that are cammed