Yamaha TRX850 Enthusiasts Forum

G'Day guys,
Just had the TRX on the Dyno.
Chart attached.
Seemed too high to me. But the mechanic pulled up thee stock standard TRX charts and they varied from 76 hp to 78hp, so how should I interpret the 101hp?

The engine has
- std headers
- Staintune cans
- K&N filter
- opened up airbox
- FCR 41s
- intake all opened up to 41mm
- TPS disconnected

I was expecting 90hp.

What do you all reckon?

If the cams are standard, you don't have a big bore kit & the other dyno charts were made on the same dyno, than that's bloody amazing!

The fueling looks really good, bit on the lean side though...

This is my run from a few weeks back, K&N filter & Slipons, otherwise stock. Running very rich.

Redog1 wrote:What do you all reckon?

Be chuffed but apply a pinch of salt Try another dyno? Or just bask in the knowledge that you have a 101bhp TRX. I'd be properly chuffed, me.

I am going to do a track day in a couple of weeks, so I'll see how it goes against my mates TRX's who have dynos in the low 80's.

i was expecting 90hp, but was encouraged by his other TRX readings which were about right.
Anyhow, i think I will just believe the 101 and enjoy the fact.
no point in checking against another Dyno, might spoil the moment.

cheers

I was told i am the massiah not just a naughty boy so I might just not spoil the moment too

M.V. wrote:The fueling looks really good, bit on the lean side though...

It's lean down the bottom and rich up top- there's more hidden in there if you can be bothered to mess with the jets

Kayla wrote:

M.V. wrote:The fueling looks really good, bit on the lean side though...

It's lean down the bottom and rich up top- there's more hidden in there if you can be bothered to mess with the jets

Yes, I will probably try a smaller main jet and get a bit more top end.
I really only did the Dyno to be sure I wasn't doing any damage from being too lean.

I'll leave it al alone and see how it compares at Eastern Creek.
I wonder how much effect carving mountains of aluminum from the intake made? I was left with a disturbingly large pile of silver dust.

Cheers

Thats a very good total power output for that set-up

I chucked a set of FCR41s and big bore headers/race cans on mine, nothing else tinkered with apart from TPS mod, and it put out 90bhp

Chart looks a little 'lumpy' low down but that may be the TPS mod which sets ignition to full advance (but is worth 1-2 bhp) ad fuelling, like Kayla sez.

Not too shabby though

Don't want to spoil the party, but...

My bike's having the 878 kit, full race system, TDMR40s, short stacks without airbox, Kent cams, flowed head, squish optimised, manifold matched etc etc and being just shy of the 100,i find the figures hard to believe. (Or ihave wasted my money ) Rumour is there is a version of the DynoJet SW that shows too high figures, later updates should have corrected this, that can be a part of the explanation?

Main thing is the curve looks smooth and nice (although the scale can be deceiving), so congrats

Redog1 wrote:G'Day guys,
Just had the TRX on the Dyno.
Chart attached.
Seemed too high to me. But the mechanic pulled up thee stock standard TRX charts and they varied from 76 hp to 78hp, so how should I interpret the 101hp?

The engine has
- std headers
- Staintune cans
- K&N filter
- opened up airbox
- FCR 41s
- intake all opened up to 41mm
- TPS disconnected

I was expecting 90hp.

What do you all reckon?

Well, as yamaha bible states 76-ish HP on the crank (can´t remember exact figure as it was many moons ago i had a look at it) and that is what he has showed you as far as bog standard TRX i would believe that you have 101 on the crank. take away 13-ish% from that and you should have some idea of what rearwheel power your bike is making.

Well mine`s got pretty much the same set-up, apart from single foam pods on each FCR41 and very stubby carbon cans, the Over system is yet to go on as I`ve more to do on the bike in general before tackling freeing my corroded on front pipe flanges!
I`ve also matched inlet diameters through the stubs and into the inlet tracts and my old girl makes a shade under 90 at the wheel on a well respected dyno at YPE east of Edinburgh.
Lounge in the warmth of 101 bhp, I would.

I reckon he sent you out for a cuppa, strapped a 1.4 Rover K series to the dyno and gave you that sheet............

Did the dyno guy say it was crank or rear wheel output?

Mince's rear wheel 90 is pretty dammed good and makes my lightly tooned TDM900 seem weedy on the same dyno.............

dandywarhol wrote:Did the dyno guy say it was crank or rear wheel output?

Mince's rear wheel 90 is pretty dammed good and makes my lightly tooned TDM900 seem weedy on the same dyno.............

Rear wheel HP.
Aren't all rolling road dynos measuring rear wheel HP.
I have always assumed that the mechanical loss of power transmission would be different for each bike.
Cheers

Most dynos have the facility to give a crank DIN output - I guess yours is crank power...............still a good result