I think I can turbo a DS650. The only thing i need to figure is the fuel system, how are the turbo kits supplying fuel ? I know they come with a electric fuel pump but what carb would work on a turbo application for the DS650 ? Like maybe 6-7 psi to start with.

 

is the 6-7 psi, boost pressure you would like to have? or are you refering to 6-7 psi of fuel pressure. The carbs on these bikes will only handle 1-1 1/2 psi of fuel pressure at idle, any more and they flood over. Under operating conditions just be sure your regulator is boost sensitive and stays about 1-1/2 psi over boost. I am going to be using a Tm 45 w/ accl pump for my set up. and it has been redesigned to be a blow through system instead of draw through.

 

Have ya'll talk to Scooby? He's spent alot time on the turbo ds set up. Easier to learn from someone else than run it to the same probs.

 

Scooby has an EFI system- we're talking carbs- totally different set up.. KMS will be releasing their EFI Turbo kit for the DS by the end of Jan 04 for about $4100.

 

My bad, I know nothing about EFI or carb turbos.
Later!

 

Majorecho, yes 6-7 psi of boost. Are you on a turbo setup ? i can easily regulate fuel psi to 1psi with boost sensitive reg. Is that all it takes ? How are you setting up the carb to handle the extra Air in the ratio ? Im very familiar with turbo on EFI but kind of new to carb/turbo setups. Lemme know ! Im thinking i can turbo my DS for $1k. Depending on the fuel setup. What are you going with ?

 

at ONLY 6-7psi you'd want a BIG turbo (large exhaust A/R) to make any significant power.

i think the vents need to be pressurized with boost on the carb. the overflow line might need to be plugged.

 

Scooby 6-7 "only" ? How much boost will stock compression take before det ? I have a coupla big T3's and a t25 on hand. Are you trying to sell your quad ? email me if you are larryct@jps.net. What about that Jr dragster throttle body setup would that work for turbo DS ? I was just thinking 6-7 was a conservative number for stock compression, but as you know boost controllers are quite easily adjusted [img]i/expressions/face-icon-small-smile.gif[/img]

lemme know !

 

There's a lot of factors involved that determine how much boost you can run - size of turbo, if use intercooler, alcohol or gas, ignition timing - woods CDI or programmable CDI with retard, head stock or modified, cams, stock piston or aftermarket, etc. A stock motor stock piston can handle more than 6-7 psi, probably at least 11-13psi without detonation. I've run 15psi on alcohol with stock motor stock piston without detonation. Iv'e run 20+ psi on alcohol with lower compresion JE piston, woods CDI, with 25-30psi not out of the question if clutch will hold.

Jr dragster throttle body setup might work with turbo. Not sure how charge air temperature compensation would work, but when running alcohol, you might be able to get away with no air temp compensation since alcohol is not as sensitive to jetting as gas. An intercooler takes out the air temp fluctuation, but adds restriction and can slow boost rise due to extra volume.

Not sure what I'm going to do with the DS. Right now a few things are being worked on such as lowering center of gravity, beefing up head seal, beefing up clutch, re-programming vortex CDI, etc.

 

I have the KMS turbo on my 400ex. I saw the DS-650 at the dunes with the same KMS turbo on it. He was running 20+ pounds of boost. They have complete engine management systems with the fuel the injection set up, and they are intercooled. I added a purging system and was running mine on Methonal. My 400ex was only set at 8 lbs of boost and I had a problem keeping the front end down (even in 5th gear). I decided to add swing arms and I plan on turning the boost up to 18lbs for my next trip to YUMA/Dunes. I am not sure what kind of HP I will get at 20+boost and Methonal. The Methonal also helps keep the engine running cooler too. Anyway you look at it, it's a nice system.