Topic: cb550 turbocharged bobber build

[madScientist]

Holy ish-balls! That is nuts!

[Dr. Noisewater]

This is amazing! I'll admit I had my doubts when I clicked on the thread but wow, those are some serious fab skills. Nice work!

[evanphi]

That thing sounds meeeeeean.

[jpfrk2001]

Been looking at the turbo builds here. I like how you did yours. I like it. What size did you go with? (the turbo size).

I turbo'd a motor awile back. So I understand how it all works. But I sold that toy to fund my CB550 build.

Looking good.

thanks, the turbo I used is a td04 9b. they come on factory twin turbo'ed mitsubishi 3000gt's. I had a buddy upgrading to larger turbos on his car, so i traded a case of beer for the turbo i'm using.

Freaking nice!! Hows the response? Any lag? I Dont see a wastegate, but I also see that its a draw through and no butter flys to close on it while it is under pressure. I hate to see you shatter your compressor due to a surge while shifting gears.

[turboguzzi]

just came upon this.... now, dont want to sound negative and i do appreciate your interesting building skills, but, running stock compression and a turbo sized for a 3000 c.c. motor on a 550 c.c.? mmm...

dont doubt it runs, but would expect not much boost until you are hitting  high revs and then problems with detonation when it kicks in.

will be interesting to see how it behaves on the street.

good luck in any case

[jpfrk2001]

just came upon this.... now, dont want to sound negative and i do appreciate your interesting building skills, but, running stock compression and a turbo sized for a 3000 c.c. motor on a 550 c.c.? mmm...

dont doubt it runs, but would expect not much boost until you are hitting  high revs and then problems with detonation when it kicks in.

will be interesting to see how it behaves on the street.

good luck in any case

Well, If you look at the donor, It did come off of a Twin Turbo system off of a 3.0 motor. So would that mean, that turbo is sized for 1500 CC displacement? Still a bit large for a 550CC Displacement. So It would come on probably at mid range at full throttle maybe. I to understand the math involved with proper turbo sizing for internal combustion motors.  This will be interesting to see the performance this bike gives.

[swansmaa]

This is amazing! I'll admit I had my doubts when I clicked on the thread but wow, those are some serious fab skills. Nice work!

Thanks a lot, I'm pretty happy so far with what I have done, without many fancy tools and a small budget. This is also my first bike project so I'm learning a whole lot.

Freaking nice!! Hows the response? Any lag? I Dont see a wastegate, but I also see that its a draw through and no butter flys to close on it while it is under pressure. I hate to see you shatter your compressor due to a surge while shifting gears.

it seems decently responsive, but there is still a lot of jetting/tuning to do. The carb is from an 800cc 2 stroke twin which is a completely different animal. The plan is to work on the seat and controls and all that good stuff for a while so I can do some test runs with load on the engine. There is an internal wast egate on the turbo, and the actuator is mounted on top of the intake. Should open around 6psi. I do not have a blow off valve though, because with a draw through setup you would be venting air fuel mixture to somewhere and that wouldn't be a good deal. I'm hoping that the 6lbs or so of boost will be low enough that i won't have to worry about compressor surge. Only one way to find out!

just came upon this.... now, dont want to sound negative and i do appreciate your interesting building skills, but, running stock compression and a turbo sized for a 3000 c.c. motor on a 550 c.c.? mmm...

From what I hear about the twin turbo vr4's that my turbo came from, is that the turbo's are pretty undersized and build boost almost instantly. Also, Im banking on this sohc4 handling a few more rpm than the 3.0 vr4 engine. And like jpfrk2001 said, this turbo was only feeding 1.5L of the 3.0L vr4 engine. Still I agree that this turbo is not ideal, but hell what do I expect when i got it for a case of beer. I may end up adding more cylinder base gaskets to lower compression (hopefully before major top end carnage)

thanks again for everyones input!

[ivanhoew]

yup , the base gasket thing is what I did on my 400/4 .

 re boost onset , it should basically come in  at the same airflow. so if its for a 1500cc ,and you put it on a 500cc , it should be 3 times where it came in on the 1500 .
eg , 1500cc comes in at 1500 rpm .so on yours it would come in at 4500 rpm etc . 2000 rpm on the 1500cc would be 6000 rpm on yours .
my 400 comes in at 5300rpm , and works well that way .

regards
robert

[turboguzzi]

hei robert, was expecting you'd step in

in theory you are right, it just that with one third of the exhaust flow but take into account also the fact that the main idea behind twin turbos is that you reduce the rotational inertia of the impeller/ turbine (smaller diameter assembly)

the 1500 cc turbo sized 9b will eventually rev up but i believe that it will take  quite  bit of time with only 550 cc supplying the ex flow. There would be quite a long turbo lag effect.

But like Swansmaa says, if its done for the price of a beer crate....

[swansmaa]

yup , the base gasket thing is what I did on my 400/4 .

 re boost onset , it should basically come in  at the same airflow. so if its for a 1500cc ,and you put it on a 500cc , it should be 3 times where it came in on the 1500 .
eg , 1500cc comes in at 1500 rpm .so on yours it would come in at 4500 rpm etc . 2000 rpm on the 1500cc would be 6000 rpm on yours .
my 400 comes in at 5300rpm , and works well that way .

regards
robert

hey, I read through your turbo 400 thread not long ago and was really impressed. I was also pretty surprised at how similar our setups looked, very similar exhaust header and such. Do you recall what turbo you used? Also, I'm sure i read it and forgot, but how much boost were you running? and what compression ratio did you end up with?

heres how it sits now, hopefully i'll have s time to work on a seat this week. I originally planned on finding a sportster tank or some sort of peanut tank, but this big ol' blue thing is starting to grow on me. And its free, which leaves a little more cash for the necessities. I plan on building a springer seat and forward controls. I'm 6'3" and 210. I haven't really decided on bars yet. I like the look of clip ons, but i'm thinking they might be a little too low with forward controls. I'm thinking maybe drag bars. Any suggestions or opinions? I dont plan on riding this thing across the country or anything, but i'd like to have a reasonably comfortable position.

[ivanhoew]

yup , the base gasket thing is what I did on my 400/4 .

 re boost onset , it should basically come in  at the same airflow. so if its for a 1500cc ,and you put it on a 500cc , it should be 3 times where it came in on the 1500 .
eg , 1500cc comes in at 1500 rpm .so on yours it would come in at 4500 rpm etc . 2000 rpm on the 1500cc would be 6000 rpm on yours .
my 400 comes in at 5300rpm , and works well that way .

regards
robert

hey, I read through your turbo 400 thread not long ago and was really impressed. I was also pretty surprised at how similar our setups looked, very similar exhaust header and such. Do you recall what turbo you used? Also, I'm sure i read it and forgot, but how much boost were you running? and what compression ratio did you end up with?

heres how it sits now, hopefully i'll have s time to work on a seat this week. I originally planned on finding a sportster tank or some sort of peanut tank, but this big ol' blue thing is starting to grow on me. And its free, which leaves a little more cash for the necessities. I plan on building a springer seat and forward controls. I'm 6'3" and 210. I haven't really decided on bars yet. I like the look of clip ons, but i'm thinking they might be a little too low with forward controls. I'm thinking maybe drag bars. Any suggestions or opinions? I dont plan on riding this thing across the country or anything, but i'd like to have a reasonably comfortable position.

I ran 8:1 I think , the turbo was a ihi rhb5/31. this was the smallest I could get ,and I bought it brand new in 1982!! blimey ,that's a long time ago lol.i was only 18 though.

interestingly , honda then went and copied my choice by putting the same turbo on the cx500 ,barstards !! ;-)

I went with a Stromberg carb ,then the xs650 one ,which was much more responsive .then the high speed enrichment which turned it from a hoot to an animal . 13 psi usually ,15 psi was what made the clutch spin up dramatically at 85 bhp ,and only around 8500 rpm ,so well below power peak rpm....

the clutch was heavily springed and packed with washers to the max .but 85 bhp at 8500 so 53 lbs.ft odd was the max it would cope with.

hi tg, that's the great thing about experimental turbo installs. until you get on the thing ,and ride it up the rd , no one on the planet knows whats about to happen ,this is the best fun .(unless its my 500 which gave me the shock of my life lol.)

regards
robert

[Cragdog]

Wow, holy friggin crap! That thing sounds baaaadd! I'm following this one fer sure. Looking forward to seeing how this thing finishes up and what all the tweaks you need to do to tune that turbo into this monster. Very impressed with your creativity and fab skills too. Great inspiration thread.

[turboguzzi]

mmm... just out of curiosity went to check, turns out that an ihi rhb/5 is super common in european cars like the old fiat uno turbo up to current small turbodiesels.... might be of help for some of you, who knows. plenty of them in local secondhand lisitings (not ebay...)  at around 100-200$

[ivanhoew]

mmm... just out of curiosity went to check, turns out that an ihi rhb/5 is super common in european cars like the old fiat uno turbo up to current small turbodiesels.... might be of help for some of you, who knows. plenty of them in local secondhand lisitings (not ebay...)  at around 100-200$

bear in mind the rhb5 series covers compressors from 31mm up to around 41mm I think .  its a bit like t3 in the garret world , a huge mass of varying specs under one umbrella.
on mine dropping the a/r from p7 to p5 brought the boost onset down from 7k to 5.3k . a decent pulsing separate tube exhaust manifold  like I have on the 500 ,would drop that to 4 to 4.5 k ish I think . on the 500 I have a relatively huge t25 , and it starts at 3800 rpm.:-)

[swansmaa]

well its been a while, but I've been playing with the project again lately. Still a ways to go, but a lot closer. check out the video!
  https://youtu.be/CaVHN-DM6GQ

[ivanhoew]

2 years !! thats a lost of lag !

[swansmaa]

Well it took a bit, but this thing is about as done as it will ever be! Have a good 100 or so miles on it. Builds plenty of boost after 7k, gets up to 14lbs or so by 12k. Engine handles it great so far with a 7.6:1 compression ratio and 91 octane pump gas.

[Jimray23]

It looks like u might of had a small fire on or at the fuel valve.

--------------------------------------------------
Jim
1979 kz1000b ltd
    stage 3 cams
    pod air filters
    4-1 open exhaust(no muffler)
    full rewire
    dyna-s ignition
    dyna 3 ohm coils

[swansmaa]

It looks like u might of had a small fire on or at the fuel valve.

--------------------------------------------------
Jim

Ha I suppose I did, the dual outlet peacock got replaced with a brass ball valve. Braized in a 1/4 npt bung for this.

[Jimray23]

O I C

--------------------------------------------------
Jim
1979 kz1000b ltd
    stage 3 cams
    pod air filters
    4-1 open exhaust(no muffler)
    full rewire
    dyna-s ignition
    dyna 3 ohm coils

[Jimray23]

I like the bike. I would like to do something simular  (turbo wise) to my kz1000

--------------------------------------------------
Jim
1979 kz1000b ltd
    stage 3 cams
    pod air filters
    4-1 open exhaust(no muffler)
    full rewire
    dyna-s ignition
    dyna 3 ohm coils