Author Topic: CB500 ATP turbo kit.. Whats it worth? (Read 5646 times)

garretcb750 · « **on:** January 18, 2010, 01:18:39 PM »

I'm thinking about selling my turbo kit for a cb500. I know its pretty rare and pretty well complete. It will need a rebuild kit for the bendix zenith carb and some exhaust pipe work. The header is good its the end thats banged up. easy fix. Theres no wastegate which it most likly will need. Any ideas?? I know its worth whatever someone will pay for it But what do you guys think?

BLUE71TURBO · « **Reply #1 on:** January 18, 2010, 02:17:03 PM »

What ever someone is willing to pay. What turbocharger do you have ? Is the manifold the cast A.T.P. one ? PICTURES ?

garretcb750 · « **Reply #2 on:** January 18, 2010, 02:53:17 PM »

rajay turbo with a machined alum intake. The exhaust to the turbo is there, missing the tailpipe from the turbo but I have a flange to fab a new one.

CaféElite · « **Reply #3 on:** January 18, 2010, 03:07:05 PM »

Pictures and turbo specs please.. I picked up a CB750 kit that I plan on trying to adapt to my 550 so anything your provide will be able to help.

Depnding on the condition of the parts and the completness of the setup I could see people paying anywhere from a 100 to a 1000. I payed 50 for my CB750 setup at a swap meet this summer

but then again I dont think he knew what he had considering the oil temp bypass and cooler is worth more then that.

BLUE71TURBO · « **Reply #4 on:** January 18, 2010, 03:30:35 PM »

The major value is the turbocharger and the intake manifold. Do you know what condition the turbo is in ? Is there any free play ( up and down ) in the turbo shaft ? Can you spin the impellers ?

garretcb750 · « **Reply #5 on:** January 18, 2010, 05:23:30 PM »

impellers look great, spins freely. My only concern would be how the seals held up.

JLeather · « **Reply #6 on:** January 18, 2010, 07:21:55 PM »

I recently had Mr Turbo go through my RayJay and check it all out. Disassembly, cleaning, spec'ing, and reassembly with new gaskets was like $175 including return shipping. mine didn't need any hard parts. I'd definitely recommend going through any turbo before installing it unless it's spotless. Something made someone remove it.

jaguar · « **Reply #7 on:** January 18, 2010, 10:01:48 PM »

if it was a 750 kit i would be all over it. im really looking for one

i dont know many 500 kits sure $500-1000 would be about right as far as asking price. but as it was said value has no meaning, its all about finding the right guy that has money or finding the price that you want

von_Wanderlust · « **Reply #8 on:** January 18, 2010, 11:14:22 PM »

Quote from: JLeather on January 18, 2010, 07:21:55 PM

...Something made someone remove it...

Maybe just good old-fashioned fear of dying??

garretcb750 · « **Reply #9 on:** January 19, 2010, 06:31:42 PM »

OK... still tossing it around. What exactly was the requirments for these kits. Direct bolt on for about 3 or 4 psi? Did they work? drivabilty? I have access to a good stock motor freshened up. Could I realistically have the turbo and carb rebuilt and bolt this on at a low psi. Or will I need something like a dyna 2000 ignition.

BLUE71TURBO · « **Reply #10 on:** January 19, 2010, 06:44:35 PM »

On a stock cb750 you can run up to 8 lbs of boost with the water/alcohol injection setup and be ok.

garretcb750 · « **Reply #11 on:** January 19, 2010, 10:04:42 PM »

what about timing? anything else need to be modified?

BLUE71TURBO · « **Reply #12 on:** January 19, 2010, 11:29:07 PM »

I'm not up on the cb500/550's. Rods, forged pistons, head work, on and on. It all boils down to how much boost you want to run and how really deep your pockets are !! $$$$$$$ !!

garretcb750 · « **Reply #13 on:** January 20, 2010, 06:08:40 AM »

what about compression ratio's? would I be better off using a 650 head to lower the compression?

NitroHunter · « **Reply #14 on:** January 20, 2010, 09:08:37 AM »

Here's my .02, for what it's worth...
Beware of going too low on the static compression, as that little motor doesn't have a bunch of torque to begin with. It would be a dog until you came up on boost. And since you probably have a B-25 unit, I'm certain that won't happen until late in 2nd gear. The IHI units were better sized to the small motors; quite frankly, the B-25 is oversized (CFM / % efficiency) when you run out the lines on a compressor map.

OK now all that being said, this can be a fun toy once you accept it's limitations. I'd keep the compression right where it is with stock pistons. Unless you want to fork out real $$ for forged units. Your #1 enemy here is detonation, don't rattle the motor and you won't break it. That means GOOD GAS. No exceptions.
The better the fuel, the more boost you can get away with. More boost = more fun. Start low and continue to ease upwards with your boost settings, and don't rattle the motor. Gee, did I already say this?

Make sure the carb doesn't starve for fuel EVER.

With proper tuning it would surprise most folks as to just how much pressure a stock motor can safely endure.

754 · « **Reply #15 on:** January 20, 2010, 09:18:45 AM »

Keep in mind,
Nitrohunter is probably the only person in the world that got a CB 750 to do a very low 10sec 1/4 mile..(under 10.1)

..with STOCK PISTONS..

... knows what he is talking about..

NitroHunter · « **Reply #16 on:** January 20, 2010, 01:35:28 PM »

It would have been more exciting if it ran in the 9's...

garretcb750 · « **Reply #17 on:** January 20, 2010, 03:01:22 PM »

Now I'm thinking about keeping this kit... So if I install it... I would use a stock motor, bigger cam maybe, modify the petcock to flow more fuel, rebuild the turbo and carb , and install a 3 or 4psi wastegate and I should be good to go?

garretcb750 · « **Reply #18 on:** January 20, 2010, 03:03:57 PM »

OH yes.... and THANK YOU for all the help. Would a 550 or 650 cam improve much? I know the 550 head has the pins for the rocker shafts.

BLUE71TURBO · « **Reply #19 on:** January 20, 2010, 03:07:03 PM »

The least expensive way is to do a compression test, if everything is good then just bolt it on. If not, do a valve job, new seals and
do a ring job. Leave the cam alone.

As for what NITROHUNTER stated, he's totally right. I myself would not use the rajay turbocharger on that small cc'd engine. A smaller turbo like the IHI type would be best.

NitroHunter · « **Reply #20 on:** January 20, 2010, 03:25:26 PM »

BLUE71TURBO · « **Reply #21 on:** January 20, 2010, 03:25:52 PM »

Hey JLEATHER ! Did ya get the info i sent ya ?

garretcb750 · « **Reply #22 on:** January 20, 2010, 04:05:29 PM »

GREAT!!! I started building the cb500 awhile back, picked up a set of borrani 18" wheels and spokes from buchanans. molded a fiberglass seat pan and such. I think I got worried I was wasting my time with the old turbo kit. The impeller doesn't turn really easy like you would think it would have to. There seems to be abit of drag to it? this normal. If you give it a good twist with your fingers it doesn't keep spinning for very long. I should try pumping some oil though the lines with my oiler.

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Author Topic: CB500 ATP turbo kit.. Whats it worth? (Read 5646 times)