Turbo Setup?

[Wolf]

Anyone here running a turbo or 2 on their CBX? Interested in pics, diagrams, and just general info on how you did it, problems, tuning, etc.

[Roger]

I have a Mr. Turbo on my "X" but there may be other mfg"s out there. Although they claim its all bolt on, I had to slightly modify my exhaust to make it bolt up. Not a big deal though. Always change the connecting rods as the stock rods will break under increased h.p. I use M.T.C. rods but there are others available. The transmission gears will have to be undercut to keep it from jumping out of gear.Vance&Hines did mine. Works great. I use stronger cylinder studs and a copper head gasket, O-ringed the cylinder, kevlar base gasket. If your serious about a turbo, go to Hard Racing.com. They have a CBX setup thats pretty sweet. They can answer all your questions. Have fun and "hang on".

[Guest]

Its a treat riding one but if your setup is wrong....its not.

[sr71cbx]

Wolf,

I use an ATP kit on my '79 turbo with a STOCK engine,if it is tuned correctly,it won't kick rods.Roger,I see where you're coming from,if your turbo X is stepped on pretty hard,yeah,get some rods,pistons,& all the good stuff in there,but,a stock engine will live quite nicely with a hairdryer behind it.I know,I put about 40,000 miles on my previous engine with the turbo setup on it and,12 years later,the reason for failure was a burnt valve!! I have seen beefed-up engines come unglued from improper tuning too,keep the metal mites out of it,as detonation will tank the pistons & rods real quick.

If the advance curve is reduced down to about 10 deg.total instead of 31 deg.total with a stock X engine,you can run more initial advance and less total,allowing the engine to run quite happily on pump gas off boost and not detonate itself to death under boost.You will need to modify the advancer unit to accomplish this.I use about 6-8 psi boost with a stock assembly and around 36 deg.total,it pulls HARD in all gears and is easy on the engine.

The stock clutch will hold up fine,too,just put some heavy duty springs in it.I use GS1150 dragbike springs from V&H and get no slippage.

Turbo oiling works out best with use of no bigger than a dash-3(3/16") oil supply line,I use this size with a restrictor in the fitting down to about .090" and this keeps the oil in the main galley where it belongs.This is one of the trouble sources with the CBX engine,if you take away from the main oil supply too much,you will starve the outer bearings and,yes,it will kick a rod! Also use at least a dash-8(1/2")return line from the turbo to crankcase and return oil above the oil level to prevent puddling up in the turbo center housing.

As far as undercutting gears,this should not be necessary unless you plan on really throwing the coals on it.My turbo bike has never had any shifting problems to speak of;I'd do that if I had a hi-HP setup for racing but it makes for a notchy-shifting trans in normal use.

Use a good set of coils,preferably a complete Dyna S ignition system,this will light the fire and not blow the spark out.

Keep good oil,preferably synthetic 20W-50,in it,and keep it changed often,a turbocharged engine is murder on oil especially if it's air-cooled! The CBX oiling system works very well but benefits also from an oversize oil cooler installed on the bike.I use a 13 row Earl's unit,it keeps it cool in the hottest temps and adds to the capacity too. :)

OK,this should supply the basics for turbo installs,I use my turbo bike for all the local ICOA runs(and not so local ones too!)and it's totally reliable.Roger,sounds like you got a pretty bulletproof turbo X,that's way cool!There is no other feeling like a cool morning and 8 psi or so on the boost gauge getting on the hiway! :twisted:

Let's hear some other ideas too----any of you guys out there got one that still runs? (just jokin'!)I'd like to hear some more ideas too!