"TurboMax" the build.

1981 Yamaha Maxim 650.
Parts From: Harley Sportster. VMAX. Suzuki GS. Seca Turbo. Moto Guzzi.

Just some Pics. Got Questions just ask.

 

Sportster seat fits pretty good on there...any major mods to make it work? Any plans on getting the front to lay nice on the tank?

 

The seat front has been modified along with the mount. In the pictures I don't have it slid under the groove where it will actually go. When it's in it's complete mounted position it sucks down nicely with no gap.

It the picture it's relaxed just sitting there. Not pulled down like it will be when done. Hard to explain. Did I make sense or confuse you?

The sportster seat worked better with my XS850 with the taller tank but will flow with the line when finished.

 

Nice project!

Just wondering... What paint did you use for the rear peg bracket and exhaust?

 

I believe that may be hammer paint.

 

What did you use to paint the engine case with?

 

How are you going to get oil to return to the oil sump from the turbo?

 

Looks like he's using a turbo engine (from the tall front studs in the front of the valve covers, where the air scoops go, and the mic wire hanging off of the front).

Are you planning on using the stock airbox, plumbing, carbs, and TCI from the Turbo Seca too? How does all that fit in a 650 Maxim frame?

 

It all bolts in for the most part

 

Peg Brackets and wheels are Silver Vein Powder Coat.
The black Wrinkle on the fenders/exhaust and soon to be tank is a Black Wrinkle Powder Coat. I do my own powder coating.

The engine is 2k AeroSpray Black Ceramic from
The Eastwood Company.

The engine is almost a bolt in. Just a coupe places a shim was needed for mounting.

The oil system is from the stock Seca Turbo and everything was used from the Seca. Just a bracket for the turbo had to be fabbed up to mount it to the frame.

I won't be using the stock air box. Still working it out how to filter from the turbo inlet. May have to build me a box that fits under the swing arm. The right side muffler will not be used. (This isn't actuall a muffler. It's for the waste gate air. The waste gate will be blocked off with a hole drilled the same size as the stock opening in the muffler. Everything else fits besides the air box. Maxim frame is a little narrow to fit battery, turbo plumbing and electronics.

 

http://www.youtube.com/watch?v=f0wDXAGGseE

Done while holding IPhone in my left hand and kicking up the gears. 12psi This the 1982 Seca Turbo of mine.

 

vesparider, you might already be aware:

The "air box" on a turbo seca is actually two pieces, unlike the other XJs. One half is a filter box (which could be fitted with any kind of filter really, but it'll be hidden under the seat) and the other is a surge tank, which has a set of reed valves that let in 1atm air when the turbo isn't producing boost, but shut when it is.

The filter box also filters the turbo air (important for longevity of your turbo)

If you are using the Turbo carbs, that surge tank, or something very much like it, is a must. And there's not a lot of space to fab something else up. If you don't let 1atm air bypass the Turbo, you're going to end up with hella lag as the compressor will choke your intake flow until is spins up.

And you then need two inlets, one for pressurized air, and one for 1 atm air, and a way to shut off the 1 atm air when producing boost

 

Wow crazy build! Keep it up!

 

The surge tank, turbo carbs are being used. Only the filter box is not. The reed blow off can vent to atmosphere as most aftermarket blow offs do.

I'm also eliminating the right side muffler which is actually for waste gate exhaust. A block off plate will be used with a hole drilled in it to keep debris out.

All I lack really is a good filter that is large enough to allow enough air and small enough to fit under the swing arm. I think I found a 6" x 3" x 1.5"I'd Uni that will work perfectly

Pics of carbs and surge tank

 

sweet build.
i am doing a similar one. check it out.

regarding the blow off valve you said:

'The reed blow off can vent to atmosphere as most aftermarket blow offs do.'

I assume you mean the little round spring disc, not the reeds that only suck air in when there is no boost. However, please note that this disc doesnt act like a true blow off valve. It is merely a pressure release once boost exceeds the spring pressure. A true Blow off Valve opens each time you are in boost and you release the throttle, venting the charge air and preventing it backing up to the compressor. The stock disc doenst do this and the reeds do not act this way either.

On my build I eliminated the spring disc and ran a true BOV on the charge piping. The wastegate should be used to control boost, not that circular pop off valve.

Also, i found that the stock lid for the plenum box had the filter outlet too far over to the right side of the bike and would hit the stock maxim battery box. So i fabbed up a new aluminum cover that had the outlet on the opposite side so that the secondary filter could fit under the seat. I will get a picture for you.

Otherwise good job looking forward to seeing it go.

 

Great info.

The reeds are to allow atmosphere in under normal conditions and close under boost and the round plunger is actually the escape for over boost?

I had suspected that atmosphere air had to get into the plenum somehow other than through the turbo inlet.

I will probably go ahead and build me a battery tray that puts the battery along the inner rear fender going cross ways in the frame. This will allow me the room for the outlet on the plenum that you mentioned. Plus open up some room for a possible cone style filter from the turbo in front of the battery.

You're killing me and my budget. Here I thought I was gonna try and just keep the induction stock and you tell me how to go about getting around the fail safe and giving the idea of a true BOV. Lol

Thank You for the information. Looks lie going through the wiring tis weekend and see what I can eliminate from the stock harness. I was gonna try to use the maxim harness but the ignition etc is different enough and the Seca wiring has all the information warning stuff in it. Any suggestions and what did you end up using for your build?

 

its not the idea of a true bov... its the fact you really do need one if you want your turbo to last.

i was able to use the maxim harness but unpinned the connector to the stock maxim module , and plugged it into the turbo seca harness connector.
ill get a pic so you can see what i mean.
i also had to run the knock sensor and map sensor wires. and added another relay for the fuel pump.

does anyone know. does the fuel pump start on the turbo seca once the key is on, once it starts cranking or? is it turned on much like the headlight, once it cranks over fast enough the headlight turns on?

or is there a wire coming out of the stator or engine that only gives 12v when the bike is running? I think the fuel pump on the stock seca shuts off once the bike stops runing?

 

The pump starts when the engine starts cranking and while running. It's wired through the relays to start when cranking, stay on while running and shut off with the kill switch or key. You can also put the bike in gear and hit the starter to make the pump run, without cranking the engine.

 

Tank is done with Modification for the Turbo Petcock.






Garmin Nuvi. Autometer Boost Gauge. and a simple Oil Light will be the instrumentation.

 

I have decided to use the seca turbo wiring harness. It's complete and almost perfect. I'll probably disassemble the gauge cluster and dissect what I need out of it once bike is running.

 

The turbo bikes also had a "tip over" switch that killed the electrics to the pump and coils and (????) if the bike fell on its side.........

 

just a pic of the blocked off stock pop off valve, and the plate i made to reloate the outlet to the center.

i have one more plate if interested, you would need to make the standoff though.

if this project works out i would almost want to replace the reed valve plate with one from a snowmobile, way more area for the carbs to pull from when not in boost, could help spool up even more....

 

Bike is assembled. Fuel system is plumbed. Starting the wiring today.

Spent all day yesterday going over the wiring diagram to see if I can eliminate any of the extras. The Information center, Fall over switch, E stop etc. There was a reason the seca turbo had a fairing. To hide all the wiring. I don't have a maxim harness to start with so I'm just gonna reduce and reuse what I need from the seca harness.

This isn't my strong point. I hate motorcycle wiring. LOL

 

Just back to the Project from a few months off. Started back in on the wiring. Eliminated the information center and did away with some copper wiring weight. Hopefully some progress in the next day or two.

 

You have a nice looking ride so far! Im interested in knowing which sportster seat you have. Im not too keen on Harleys and i dont know if one seat fits them all but i imagine they dont.

 

Not exactly sure what the seat or model Harley it fits. I bought it at a swap meet for $30.

Started the bike for the first time tonight. Was able to ride it a short distance but it was dark and i haven't put the new headlight in it yet. I'll post some video tomorrow with lighting.

http://www.youtube.com/watch?v=Ahi8iCDAnQU

 

Been busy and been riding. Thought I'd update the topic.



Bike runs great. Have put about 3000 miles on it since January. Maxim was also a hit at the indoor show in february winning its class.