Big Valve Trx Dyno Results

[trixynut]

Mark,

A healthy boost from 74ish up to 90ish is good, and it is all about rideability anyway, as you say.

All dynos are different too.

Heres a thread with my chart from just fcrs and pipes/cans on a std motor...

viewtopic.php?f=6&t=7866&p=80869&hilit= ... art#p80869

If anything, I think all this highlights the restriction that the std headers have on the motor.

Keep up the good work.

Dave.

[sanddune51]

Silver,
I'd place money that I'd be behind you and your "std nail" at Cadwell. One (of a few ) tracks I could never get on with. Always blew up or fell off there and the long drive from the South East didn't endear the place to me. Always seemed traffic to be jams at Sleaford.
Everyone I spoke to who could get there in under 2 hours loved the place. Maybe I should try again next summer

Trixy,
Looks to be a fine curve, but again so hard to compare against other
graphs when a mph base is used. 61 lb-ft of torque is good . It's difficult to see how many revs the motor holds it for though.
Yes, you're right I know my pipes are holding back my engine from being all that it could be . I'll just have to test it with Phils Akra fitted to determine just how large the advantages might be. Can't wait.....


Mark.

[coxylaad]

Be nice to get out on track with you two and my std nail and see how far back i am. Cadwell anyone? he he!
Dave

ME ME ME! I am in for that to throw a TDM900 FI engine with stock internals and extensive induction/exhaust mods for the comparison

[misterdimwiddy]

Phil

It would be great to do a dyno run with your Akra on my bike. I have a hunch that my (hopefully) high flow head would benefit from a free flow exhaust more than a std head would. It would be really good to check that this is actually the case, thanks for the offer .
Agreed the fun that derives from a tuned Trx can't be overstated,so agile and torquey and real world fast.

Yes the valve I sent you was indeed a centre one. You can see how a valve in this state would close up the tappet clearance somewhat .

Cobba,sorry you have lost your local dyno house. Hope you don't have to travel too far to find a good one when your motor is fully rebuilt. Roll on mid December. I might have even sorted myself some sort of pipe by then .


Mark.

Plan to swap my own head after Brands on 30th Sept.

Would then get a dyno run on mine with Akra and head mods plus similar run on your own with my pipe for comparison. We'll organise this before the end of the year.

Pics of valve will be on here tnt.

I will see you at Cadwell at some point Dave. Never been there but it is next on my list of new tracks.

[trixynut]

Plan to swap my own head after Brands on 30th Sept.

WTF!!!!

Really???

Ya mean like Wurzel Gummidge used to do?

[misterdimwiddy]

You've lost me..............could Wurzel swap his head then?

I can only vaguely remember him doing things with Aunt Sally.

[Bikemike]

Great work there Mark.
Now, how about the tdm...

[NWS870R]

Not bad results there matey ........... and I don't want to put a downer on this, but.....

With that spec, tbh I would have hoped for a little more BHP.

Yep, we all know different dynos read differently, but I put just some FCR41s and pod filters on a bog standard motor just with a bigger bore 2 into 2 renegade system and got 89.

Phuk and Honk and steve speed (and maybe others) had similar specs to yours (cams, head work, overbore, fcr's, BUT also akra headers and free flowing cans) and got between 98 and 101 iirc.....?

Maybe its time to look at your headers and cans....???

Still, good work so far.

Phuk & Honks bikes both used the TPS bypass to break the magical 100 ponies which robs the engine of low/mid power but stacks the curve at higher RPM. I tried the same mod for around 300 road miles & hated it as it made the power less accessable for anything other than straight line dashes which imo defeats the object of a twin? I'm far happier with TPS connected & 95 BHP but a broad spread of torque.

Each to their own i guess - depends on what you want?

[cobbadiggabuddyblooo]

a great penis extension in my eyes (torque is what gets you there,Hp is what holds you there) . It's not how big but what you do with it..

[spondontrx]

Hi
A bit late but here's a chart from my bike which has a TDM3vd engine , the bigger valves off course , Keihin carbs , JE pistons , top end power could be better but i'm surprised by the torque 0f 101Nm , the Dyno operator did 4 runs which had almost the same result .

[Killerwhale]

Bit strange Nm starts fall as early as 6k rpm?

[spondontrx]

Bit strange Nm starts fall as early as 6k rpm?

I'm not sure how accurate the rmp scale is , because the operator did not connect the engine (pulses) to the computer . also the fuel/air was a bit to rich up to 7000 rpm.
Top end power seems to be a bit low on the rpm scale to me to..
He did 4 attempts and the gave almost the same results (EEC corrected) ,
I can't complain because the run was for free (a day at the Dutch exhaust factory Bos with the TDM/TRX club) .