Dyno plots

[misterdimwiddy]

Have attached recent data plots from Tagg Racing in Kent.

Pretty much the same as other similar spec motors that I have seen posted.

878JE, stock head and cams, FCR41 (160 mains) with Ramair filters over bell mouths, Akra headers + Devil can,

Looks like a dreadful hole in the torque and HP at about 3000rpm; he tells me that it bogged down when he did the 3rd gear run and I believe him as I have never felt this when riding. Pulls like a train from low revs in all gears.





Quick way to finish off a tired crank a week after this run.

[sanddune51]

Thanks for posting those up Phil. They're always interesting,especially so to me as I'm using the same dyno to chart the development of my own motor.
Hope your rebuild is on course .

Mark.

[Snod Blatter]

For reference I thought it'd be fun to post up the sheet for mine that is a standard engine with Motad Venom cans, a K&N filter and some Dynojet stuff (I don't even know what exactly) in the otherwise standard Japanese spec carbs. Blue is standard jetting, red is Dynojet..



Sorry for the poor picture (as always..) but the main camera in the house has a flat battery! Anyway, as I understand it the flatter curve is for torque and the slope is for horepowers? If so I'm surprised at how close they are, particularly up to around 5K, after that the mods seem to pay off but does it really feel that different? Would the FCRs or big bore headers be that noticeable on the road?

[misterdimwiddy]

Nice to see curves for a relatively standard TRX.

I don't get too hung up on the absolute numbers. Dyno calibration status is often (always?) going to be an unknown and so caution is needed unless runs are performed on the same dyno. Measures will not be reliably comparable from different sources.

Sounds like I'm making excuses for my 88rwhp. I'm not. Money well spent for me at least but then it is my passion away from family life and it is by far the most fun bike I have owned.

When I ride my TRX with the mods listed it does not compare to how it was with a stock motor. It still amazes me how I can stay with so much modern machinery (1000's, 600's etc) on track despite having <100hp. The power delivery is what does it for me and the ease with which you can ride it fast. High corner speed, great brakes (YZFUSD's) and torque to pull you out of the turns. Lovely.

[Snod Blatter]

Dyno calibration status is often (always?) going to be an unknown and so caution is needed unless runs are performed on the same dyno. Measures will not be reliably comparable from different sources.

Ah okay, I'm not so up on all this - I don't have the money

If it does transform it then that's good, but if it's only for the track then I have no need to bother, particularly if it ruins cranks.. You lot can carry on though of course!

[Mincehead]

Ah well there`s the thing it DOESN`T ruin cranks, what does is negligent ownership (in general).

[skull-candy18]

When I ride my TRX with the mods listed it does not compare to how it was with a stock motor. It still amazes me how I can stay with so much modern machinery (1000's, 600's etc) on track despite having <100hp. The power delivery is what does it for me and the ease with which you can ride it fast. High corner speed, great brakes (YZFUSD's) and torque to pull you out of the turns. Lovely.

Does it stay with the modern bikes on the straights ok ?

[Mincehead]

A modern 600 will touch 170 MPH so no, not balls out.

[misterdimwiddy]

Ah well there`s the thing it DOESN`T ruin cranks, what does is negligent ownership (in general).

You're are of course right Mince.

Did not mean to suggest that 90hp will be too much for the bottom end.

Just happened to be the last straw for mine which had been neglected.

170mph it won't do on any straight but in the turns and on the brakes is where I get my thrills. Plus with 90hp there is far less chance of high-siding yourself into A&E.

[Tarwetijger]

8<

When I ride my TRX with the mods listed it does not compare to how it was with a stock motor. It still amazes me how I can stay with so much modern machinery (1000's, 600's etc) on track despite having <100hp. The power delivery is what does it for me and the ease with which you can ride it fast. High corner speed, great brakes (YZFUSD's) and torque to pull you out of the turns. Lovely.

I couldn't agree more! Well said.

[skull-candy18]

Deffinately not bothered about 170,I get scared after 90
I just meant in between the corners on track.

[cobbadiggabuddyblooo]

I'm finding I'm sticking with most of the bikes on those short straights inbetween those corners and the perfect opportunities to pass being better under brakes and holding corner speed for the exit.. But come the main straight the bigger cubes would whizz by but I'd pull that back under brakes again... Anyone can go fast in a straight line but that's not where the fun is...

[cycloneranger]

I'm finding I'm sticking with most of the bikes on those short straights inbetween those corners and the perfect opportunities to pass being better under brakes and holding corner speed for the exit.. But come the main straight the bigger cubes would whizz by but I'd pull that back under brakes again... Anyone can go fast in a straight line but that's not where the fun is...

What he said
The most fun i ever had on a track was on my NSR250 track bike. It was only putting out 60hp at the wheel but it could stop on a sixpence, and you could throw it on it ear and carry mad corner speed. On a tight twisty track you could murder R1s GSXR Blades etc over a complete lap. And as was said before you could just pin the throttle out of a bend, it might slide a bit but never came close to a high side. All the hyper sport jockeys would still be faffing around with the throttle while the 250 just drove away. And when the rain came the manic grin just got bigger !

[spondontrx]

Here mine (106hp) , but i must ad that for street riding I wouldn't take it that far , the standard engine is easier and smoother to ride .

[sanddune51]

Theo,106 hp is a hell of a lot for a Trx
The graph could tell us so much more if it was plotted against engine speed instead of road speed.
Is it also possible to post a torque curve?
Is that curve with big valves fitted?



Mark.