Turbo WR450 Motard

[Flying Spanner]

I really miss my old Motard.

It was a KLX 250 that had a big bore 400cc (ish) kit fitted to it by the previous owner. It went like stink and was a lot of fun.

After Seeing this link on another post http://www.mpfab.com/wr250/ it has gotten my creative juices flowing. I had a hand in turbocharging my mates FZR 400 so this is within my grasp.

Ok so Here's my plan.

Purchase a road legal WR450 from my local Yamaha dealer. I should have that done by the end of next month.

RGV250 17" wheels from bike wrecker. I'll have to machine up adapters to make them fit but should be ok.
I could just buy a kit from Vroom.co.nz but they're a bit cost prohibitive.

Front Brakes. RGV 250 Disc and stock caliper with custom made adapter. Or alternatively I may adapt a 4pot car caliper onto the bike. I've heard rumours of Nissan callipers working well, I have a pair of Series 4 RX7 4pot calipers in my stash of parts. I may use one of them.

Rear brakes RGV Disc and stock caliper.

Suspension
This is where I will spend money on aftermarket parts.

I plan to re-spring the front shocks myself with slightly stiffer and lower springs and use slightly thicker oil. (15wt istead of 5w)
Rear probably similar deal stiffer and slightly lower spring.

Engine
I could spend a fortune going for a big bore kit but after the success we had with the Turbo FZR and seeing that very tidy Turbo-Tard WR250 on the previously mentiond link. I reckon this is the route to go.

I have a CT9 Turbo off my old GT Starlet. Unless I can find a smaller turbo in good cond for the rite price I'll use what I've got.

For the Turbo FZR build we got a steel shim made to lower compression. We simply bolted the head down with the shim sandwiched between 2 head gaskets. This lowered compression enough to avoid the huge detonation problems we were goin to have. That bike has just clicked over 1000km since the conversion without any problems.

Dunno how this will work on a Thumper though. I'll try this metheod to start with as I'd like to avoid getting a custom piston made as I am definatly on a shoestring budget.

I plan to make a pressure box enclosing the entire standard carby out of stainless. Jetting will be tricky but achievable. I'll keep the boost low (5-7psi above ambient) for the sake of reliability. The exhaust I'll fabricate also out of stainless. The Muffler I plan to use is a Boy racer spec dumpy stainless muffler meant to be fitted to a car. It has a 2" inlet (another unused item in the shed).

Any suggestions would be much appreciated. I'm interested to know of any wheel/brake combo's that people have seen used on WR's.

And before someone ask's no I'm not simply dreaming. I'm sourcing parts as I write this thread.

To me building and modifying cars/bikes/boats is half the fun. The pleasure of driving/riding a one off you built is the other half.

This bike should be heaps more fun than my 600 Bandit I've just sold. I can't wait to see the look on people's faces when they realise the monster I'm creating!!!

[cheesemethod]

Good on ya, should be a bit of a laugh. I'd be a bit iffy about using the CT9 tho - a turbo designed for a 1300cc 4 pot might be a bit too big for a 450 single? Perhaps something you could find on a kei car might be a little more suited for this. Suzuki Capuccino had a 600cc 4 pot turbo, that kinda thing might be a bit easier to spin with a small engine.

[TOTO]

Fantastic man. Go do it ! Will follow your progress with huge interest :D

[CookMySock]

I've begun on a similar project. I also wonder about smaller turbos off little diesels 2000cc ish - they should spool up nice and early.

Suggest also, there might be less stress and expense by spacering below the cylinder rather than under the head.

On the FZR how did you get on with your oil return? It's a bit of a mission to get the turbo outlet high enough above the oil level in the crankcase.


Steve

[Leviticus]

Good on ya, should be a bit of a laugh. I'd be a bit iffy about using the CT9 tho - a turbo designed for a 1300cc 4 pot might be a bit too big for a 450 single? Perhaps something you could find on a kei car might be a little more suited for this. Suzuki Capuccino had a 600cc 4 pot turbo, that kinda thing might be a bit easier to spin with a small engine.

You would get too much lag from a bigger turbo, keep it small and it will spin up much easier.

this is a link from another site that turbo'd an XT660

http://www.xt660.com/showthread.php?t=7454&highlight=turbo

I'm sure yours will be a fun ride. Good luck, and keep us updated

[CookMySock]

Theres a trick to reduce lag too, and thats to add a bypass flapper valve (similar to a 2strokes reed valve) on the inlet manifold, so to help the engine get past the boost transition point. While the turbo is off boost, there is quite a restriction on the inlet manifold - and the bypass valve allows direct access past the turbo.

Steve

[Flying Spanner]

Thanks for the replies guys.

Progress already. I may have found a suitable WR450 on TradeMe. I'll see how the bidding goes, If it goes for too much I'll simply keep looking.

[R6_kid]

FWIW I'm pretty sure they are using the new WR250 which is fuel injected and also has much longer servicing intervals than the previous models. I'm guessing it's not in your budget but the 2009/2010 WR450 would be a much better starting point.

[Flying Spanner]

Replies to comments/questions
Dangerous bastard & Cheesemetheod. Yeah I agree this turbo will be a bit big for what I need. I'm trying to track down a turbo off a Daihatsu charade or suzuki ignis but they aren't very common cars here in NZ.

Dangerous bastard
The CT9 comes out in several forms and trims. The one we used on the FZR was off a Toyota 2C Turbo diesel engine. It doesn't spool up too bad but it's still a bit laggy.

The suggestion for the shim under the cylinder is a good one. To be completely honest it had never occured to me. We regularly make shims (as I described) when we turbo old engines like 4K Toyota's etc. Since this is a metheod we're used to it's the route we used on the FZR. but for the Tard the simple sollution of under the cylinder makes a lot of sense. I'll have to investigate this one.

[Flying Spanner]

FWIW I'm pretty sure they are using the new WR250 which is fuel injected and also has much longer servicing intervals than the previous models. I'm guessing it's not in your budget but the 2009/2010 WR450 would be a much better starting point.

Yeah EFI makes these games much more simple. We fitted quad throttle body's off a 20Valve Toyota engine and a link computer to the FZR it made tuning much easier. As much as I wish I could afford a nice brand new EFI WR they cost about as much as my entire budget for this build. (I had a druel over a spankers WR450 this morning).

I may end up adapting a single point injection setup of an early mazda or something. The pressure carby setup works fine for low boost (less than 15psi) and once the tuning hassles are dealt with doesn't work too bad.

[klxmerida]

Hey just noticed you are in Nelson, a turbo WR450 would be mint to see roaming round the streets, will deffinately keep an eye on this.

[CookMySock]

The CT9 comes out in several forms and trims. The one we used on the FZR was off a Toyota 2C Turbo diesel engine. It doesn't spool up too bad but it's still a bit laggy.I think the bypass valve would help with that. It allows the carbs to drink directly from atmosphere rather having to suck through a laggy off-boost turbo.

How did you get on with your oil return line? I read lots of horror stories about that.

Thats nearly the same turbo I'm using on my 650 project. They are pretty small..

Model TBO2/22 (Garrett T25 - standard config)

Compressor
wheel trim 60
Wheel Dia 1.46/1.89" (37/48mm)
A/R 0.48
Flow 21

Turbine
Wheel trim 57
Wheel Dia. 1.39/1.85 (35.3/47mm)
A/R 0.47
Hose:2.0 inlet/2.0 outlet



Steve

[orangeback]

you might want to look at this then

[SMOKEU]

Put an external wastegate on it and a screamer pipe. Don't forget the vent to atmosphere blow off valve either.

[.produKt]

http://www.trademe.co.nz/Trade-Me-Motors/Car-parts-accessories/Performance/Turbos/auction-278063324.htm
this one should be about right?

[CookMySock]

http://www.trademe.co.nz/Trade-Me-Motors/Car-parts-accessories/Performance/Turbos/auction-278063324.htm
this one should be about right?Will be PROBABLY ok for a 750cc or larger bike.

Steve

[stig]

This one could be a good base to start from,
http://www.trademe.co.nz/Trade-Me-Motors/Motorbikes/Motorbikes/Dual-purpose/auction-279340193.htm

[.produKt]

So the idea is to turbocharger a Medium single banger?

Aren't the exhaust pulses too far apart to properly spool the turbo?

[CookMySock]

Aren't the exhaust pulses too far apart to properly spool the turbo?Just use a smaller turbo and bigger intake plenum.


Steve

[T.W.R]

This was done through RS performance in England

Supercharged putting over 85hp at the wheel

[stig]

Sounds like a real cool project.
Just thinking out loud here,

How would you setup the carb on a blow through system?
you'd need to seal and pressurise the float bowl to get the venturi effect through the carb.
In which case you'd run out of fuel quick as the float bowl is gravity feed, so you'd need to add a small pump in.
most carb pumps only do a few psi.

You'd need a real small turbo like a gt12,
Am I alone in thinking that turbo lag power delivery would be contrary to what makes a motard fun, being sharp and nimble.

What about a suck through supercharger setup?
with the supercharger wedged between the carb and the head.
Jetting would be simplified, and throttle response would be retained.
something like a AMR300 would do the trick (on some small subaru's and off the shelf)
Or may turn a smog pump into a poor mans supercharger.
Does a WR450 run a dry stator and flywheel?

[CookMySock]

you'd need to seal and pressurise the float bowl to get the venturi effect through the carb. In which case you'd run out of fuel quick as the float bowl is gravity feed, so you'd need to add a small pump in. most carb pumps only do a few psi.You feed plenum pressure to above the diaphragm, and into the float bowl, and then you need a fuel pressure regulator to keep the bowl fed with plenum pressure plus a few psi. Than you need a higher pressure fuel pump to feed the pressure regulator.



What about a suck through supercharger setup? with the supercharger wedged between the carb and the head. Jetting would be simplified, and throttle response would be retained.Draw through turbo designs are usually the laggiest. Theres no real reason to draw through, unless you like the way they behave - cranky and bitchy.



Or may turn a smog pump into a poor mans supercharger.Now that's an interesting idea.



Does a WR450 run a dry stator and flywheel?Even if it's wet, its not bathed in oil while its running. Maybe an oil slinger and seal will allow you to a shaft out of it.


Steve

[stig]

You feed plenum pressure to above the diaphragm, and into the float bowl, and then you need a fuel pressure regulator to keep the bowl fed with plenum pressure plus a few psi. Than you need a higher pressure fuel pump to feed the pressure regulator.
a system with an FPR and return lines and all that goes with it would be pretty involved. What psi would overcome the floats ability to hold the needle valve shut?



Draw through turbo designs are usually the laggiest. There could be many reasons for lag on draw through turbo systems dependant on the setup, long lengths of intake pipework delaying response, fuel condensing on an intercooler if one was used. But there is no lag on a blower setup so no problem.


Theres no real reason to draw through, unless you like the way they behave - cranky and bitchy. Draw through on a blower setup is the most common. A carb is designed to work at n/a pressures.



Even if it's wet, its not bathed in oil while its running. Maybe an oil slinger and seal will allow you to a shaft out of it.
It would be easier if it was dry, extending the shaft might require an extra bearing for support and that could be hard with only a thin walled case cover. It would add extra width to the engine right by your left leg as well.

Have you found a bike to work from Spanner?