The TRX900 Project kicks off

[andyaber]

Hi Lenny

Thanks for that.

The first method sounds simpler so may give that a go next time the bike is in bits.
Does your current method give better results?

Cheers, Andy.

[coxylaad]

the first method only works if you are running an engine with an emissions based air injection system on the exhaust - like the TDM 900 lump. Unfortunately no one cared about the environment when the 850 motor was designed so it was not a consideration.

Excellent info though Lenny, I am excited about the idea

[fung]

i spoke to Rex Bunn via email and sent him views of the TRX system.
,and he has asked me this:

quote " Hi Dean, a few points-

1/ The second breather line from the airbox is presumably a drain?{the airbox breather line}

2/ The housing supporting your new banjo

trxforum022.jpg

…is the alternator under this case or e.g. an outrigger flywheel? I think I can see it communicates well with the sump. Is this correct?

3/ is there by chance any other existing port or union site where we might connect a third breather line? This can be on any compartment having an airway with the sump.

4/ Also yes, can you advise the ID of the existing breather pipes.

5/ She’s a dry sump with two pumps and an oil tank in unit with the gearbox: Harley-style. Can you see how the oiltank breathes and advise?

6/ Does the crankshaft rotate in the usual direction i.e. counterclockwise when viewed from the left side engine?"

so, as my motor is 'virgin' and unsplit, may i ask the boys who have had their donks apart to help with some info?

cheers
fung

[coxylaad]

Couple of bits of progress today:

Took the plunge and chopped the back end off.




also pretty much finished the modifications to the TDM900 oil tank. Wasnt too bad really.
Need to fit a breather then get the lot powder coated.

[coxylaad]

little bit more progress tonight. The TDM900 oil tank is definitely a goer.
Its sat nicely in there fully functioning with all pipes and sensors, just needs taking back out and tidying up and painted now. I will do that once I have completed my trial build.
pic:

[Quan-Time]

1st off, great work on being a "do-er" rather than a keyboard warrior !.

I do have to ask tho, are you trying to achieve anything specific with the engine swap ? EFI, power, or "because thats how TRX should be" type deal ?

Theres much easier ways to get 900cc and EFI onto a TRX. Either way, good work and keep it up !

[Killerwhale]

1st off, great work on being a "do-er" rather than a keyboard warrior !.

I do have to ask tho, are you trying to achieve anything specific with the engine swap ? EFI, power, or "because thats how TRX should be" type deal ?

Theres much easier ways to get 900cc and EFI onto a TRX. Either way, good work and keep it up !

My mech´s first comment was, that gearbox is SO...SOOOO much better than the TRX fiver.
...no/very little oil consumption

[Quan-Time]

Yeah, im aware of the extra gear, and the claimed oil consumption. Didnt phuk have a donk which drank almost no oil ?

Been too long to remember the reason, but im sure theres reasons why its the way it is.

[Killerwhale]

Yeah, im aware of the extra gear, and the claimed oil consumption. Didnt phuk have a donk which drank almost no oil ?

Been too long to remember the reason, but im sure theres reasons why its the way it is.

And although having almost the same power curve the 900 gives more top power with less compression than my 878cc kit did. Not surprising though as they do as standard as well. But i´ll be upping the comp soon.

[Quan-Time]

from my experimenting, a bit over 900cc is a limitation of the throttles a certain rpm. 42mm really opens up torque available and aids in a few other things. Why many people like the 42FCRs so much.

I will say tho that some engines can benefit from bigger again.

Bit too off-topic tho.
good work coxylaad. Keep it going.

[coxylaad]

1st off, great work on being a "do-er" rather than a keyboard warrior !.

I do have to ask tho, are you trying to achieve anything specific with the engine swap ? EFI, power, or "because thats how TRX should be" type deal ?

Theres much easier ways to get 900cc and EFI onto a TRX. Either way, good work and keep it up !

Thanks Quan, well, it all came about when I used to own a TDM850, and test rode a TDM900. I was mega impressed how clean and responsive the 900 was compared to the 850. The gearbox was in a different league, and it pulled well from really low down. I just liked it a lot.

This was in 2002 or something, fast forward 10 years, and after watching Cafe Racer on the discovery channel I decided it looked cool and fancied trying my hand at building something myself.
with the 900 experience ringing in my head I decided it would be an interesting little project to fit a full 900 setup into the TRX racer, and use the injected motor as a base.

I know you can get really good results from the 850 engine - infact, I bought a race prepped 850 bike just before christmas with 41mm flatslides, 878 big bore and cams, but I passed it onto my missus's dad as he fancied a project too.

The other thing is that I am doing this on a tight budget. I have managed to work it so the engine and injection system, clocks and 900 gubbins has cost me nothing as I bought the full running bike and broke it.

The TRX itself I bought with no engine for 400 quid, and the rest has just been graft. I have even managed to claw some of that back selling unwanted bits of the TRX off. profiteering is not my aim though, this is just enabling me to build the bike I want.

Where I go once its built I am not sure. I loved your information on boring (boaring?) the TDM900 throttle bodies out, I would like to do that (or buy a set of bigger ones from an R1 or something and bastardize those) maybe a set of cams and up the compression. maybe... Its not about outright power, I have a fazer 1000 which is always going to be a lot faster than the TRX, its about enjoyment and the project I suppose, and also I am going to use it on track this year once its done.

If it goes well I would mind starting to restore a few old bikes as a bit of a hobby. Obviously I would more than likely have to sell them on at the end as my soon to be wife will probablies divorce me once my garage is full of rusty old crap lol

Any input you have on the bike would be great Quan - or if you could just send me across some of those bigger throttle bodies that would be great

[Quan-Time]

If you can source a set of TDM900 throttles, i can bore em out for you and flow them if you really want. I understand you are on a budget, and i TOTALLY understand that.

Biggest commitment is the new butterflies. If you were to make 50 of them, cost would be great, BUT when you only order 2 at a time, its REALLY expensive. They are marginally oval (elpitoid) shape, and the cut edge isnt square. Its off by... 2deg ? I cant remember. So it would be almost impossible to cut conventionally. Can be done, but a major hassle.

I had the chance ages ago to get a TDM900 donk with loom. I turned it down because of a few issues you are now finding. I had the resources and skill (?) to do what i did to my bike. If i was to ever go back and revisit it, i would buy a TDM engine in a heart beat.

If anything id buy a TDM9 and convert it BACK to a trx rather than a trx into a tdm. If that makes sense. Not sure how the fuel tank would go.

Either way, ive sub'd to this thread. Really keen to see what direction it turns and how it ends up.

thumbs up for having a go.

[coxylaad]

ah never even considered the butterflies - how much is a lot of money? I do have a spare set of TDM900 throttle bodies that I got with the bike that I could send to you as it goes!
If its not going to be ridiculous it will certainly be something I will consider.

To be honest the whole project has not been that difficult so far really. I have not had a great deal of time on it, and the engine is sat nicely in there. I like to find out things myself rather than be told whether things will fit or not, like the TDM900 oil tank etc. The hardest part of the job was welding on the lug to the cylinder head. I got someone else to do that as I cant weld aluminium. (don't really trust myself to weld steel either!)


Re the fuel tank, I am not sure how that is going to go either! I am planning on cutting a hole in the bottom of it, brazing in some sort of flange so I can bolt in the fuel sender. I will keep you updated on how that goes.

[adamcrofts]

Hey Coxy, any more progress on the beast? Am hanging out for the next installment.
Cheers

[coxylaad]

Nothing too noteworthy at the moment, been putting a lot of graft into sorting my house out as we are looking like moving (there is a certain irony in living in a half finished house for 13 years, then turning it into a show home when you go to move out of it!)

I have the material to fabricate the mounting lugs for the rear subframe, so when I get back on it this week that is the first thing I will be doing.

Need to sort out some sort of fairing, which I am working on