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TMax DX on Dyno ?

Posted: Mon Aug 05, 2019 11:27 am
by Tmaximus
Hi Guys

Its been a while since I was last on here, but see a few of the old names are still on the go ! I need some help .... has any one run up a TMax DX on a dyno ?, and if so was switching off the traction control all you had to do, or did the ABS need to be disabled as well ?

Thanks for any help

Dougie

Re: TMax DX on Dyno ?

Posted: Tue Aug 06, 2019 3:17 am
by fullcirclemax
Can’t see the abs affecting anything. Mind you, I don’t see a strapped down bike needs the traction control off as it’s not going to activate.

Re: TMax DX on Dyno ?

Posted: Tue Aug 06, 2019 7:09 am
by EvilRacer329
fullcirclemax wrote: Tue Aug 06, 2019 3:17 am Can’t see the abs affecting anything. Mind you, I don’t see a strapped down bike needs the traction control off as it’s not going to activate.
Every traction control system is a little different, but if it works by measuring the difference between front and rear wheel speed and detects that the rear wheel is accelerating faster than the front then it'll activate and cut power. A motorcycle only spins a rear roller and the front doesn't turn, so you have to disable the traction control to stop it freaking out.

Nick

Re: TMax DX on Dyno ?

Posted: Tue Aug 06, 2019 7:31 am
by Ralph
If you put my Xmax on the main stand and spin it up the traction control objects but turn that off and it just spins up
the abs does not seem to affect it, if you try this make sure the rear wheel cant touch anything or the bike cant fall off
the stand or it's going to lunch it's self. The Tmax may not be the same.

Re: TMax DX on Dyno ?

Posted: Thu Aug 08, 2019 3:01 pm
by Tmaximus
Hi Guys

Thanks for your replies, next week I am having a Polini variator, SC Projects pipe & module fitted, and hope to have it run up on the dyno before and after. The reason for asking the question was because my Honda X-ADV that does not have traction control could not be run up on the dyno as the ABS was not happy seeing different wheel speeds.

Cheers

Dougie

Re: TMax DX on Dyno ?

Posted: Fri Aug 09, 2019 5:24 am
by EvilRacer329
Let us know what the results are! I didn't choose the T-Max because I wanted power, but it's always interesting to see what the curve looks like...

Nick

Re: TMax DX on Dyno ?

Posted: Thu Aug 15, 2019 11:10 am
by Tmaximus
Short update on TMax dyno runs with SC Projects pipe and module, and Mallossi variator with 19g touring weights, rather than the 16g weights. As standard it seems like Yamaha have got the TMax very well sorted and it is hard to get big gains throughout the entire rev / speed range, with the above fitted I have the same peak at around 44hp but have gained almost 4HP in the first half of the curve up to 60mph, with a nicer curve shape than standard. A 200 mile ride today seen the TMax more urgent accelerating from a stand-still or lower speeds, and even at high speeds it felt better, but this might also be due to the substantial weight loss having removed the standard pipe. With the touring weights fitted the revs at high motorway speeds drop from around 6000rpm to 5500rpm and this is very noticeable and welcome.

Re: TMax DX on Dyno ?

Posted: Thu Aug 15, 2019 12:36 pm
by EvilRacer329
Fascinating; you were able to get lower revs at motorway speeds *AND* faster acceleration? I need to go have another look at my tech manuals and get my head around that...

The weights are propelled out by centripetal force, pushing the pulleys together and increasing the drive ratio sooner, which *should* slow acceleration - it'd be like changing gear sooner on a manual transmission. What am I missing here folks?

Nick

Re: TMax DX on Dyno ?

Posted: Thu Aug 15, 2019 1:40 pm
by MrGrumpy
Tmaximus wrote: Thu Aug 15, 2019 11:10 am Short update on TMax dyno runs with SC Projects pipe and module, and Mallossi variator with 19g touring weights, rather than the 16g weights. As standard it seems like Yamaha have got the TMax very well sorted and it is hard to get big gains throughout the entire rev / speed range, with the above fitted I have the same peak at around 44hp but have gained almost 4HP in the first half of the curve up to 60mph,
Firstly which version Tmax have you got?
I'm puzzled that you could get 44bhp at the wheel (I presume) as its only supposed to produce 47bhp (mk2 to 6) at the crank, and I'd expect transmission losses of anything up to 12%! I remember a T&G article of an early dyno test on a mk1 Tmax that whilst power at crank was 40bhp (according to spec) there was only 35bhp at the wheel. The Malossi variator they tested gave another bhp or so at peak, though with a better shape. The mk2 was a bit more efficient for some reason.

I'm assuming you are testing a mk6? If not, the rest of the post may not be relevant!
If correct, your results are interesting. I've always been astonished at just how well the mk6 Tmax goes, compared to earlier versions. It feels like a 750 or something. I've always assumed that this is due, as you say, to the mk6 variator being very well set up, and possibly due to the Computer controlled throttle. Its always struck me as curious that tested alongside the Kymco AK550, it gives the same performance figures, despite the Kymco having 53bhp compared to the official Tmax figure of 47. If your figure of 44bhp at the wheel is accurate, I'm beginning to wonder if the official power output figure of the mk6 is actually a fiction so that it can still be ridden on an A2 licence, and the real figure at the crank is something like 50bhp or maybe a couple more! After all, its damned hard to test power output at the crank...

It would explain a lot.....

Re: TMax DX on Dyno ?

Posted: Sat Aug 17, 2019 3:13 pm
by Tmaximus
Hi Guys

This is my 4th TMax, I have owned them since they first came out around 2002, and my latest one was bought new in March of this year and is the DX version. I have "tweaked" all my previous TMax's and the last 530 had a full Termi race system ( at great expense ! ) 16g DR Rollers in the standard variator, and a high flow air filter. I would say that this new DX was faster out of the box than any of my previous TMax's even after my "improvements" !

The 44hp figure is rear wheel as set up and measured on the PM Tuning dyno, and they are a very capable outfit well used to scooter set up. The 19g weights with the pipe and module have given improved acceleration, and almost 4hp over standard up to 60mph, 16g weights might have further improved this. I can also confirm reduced revs at motorway cruising speeds, on the way down to PM Tuning from Glasgow I made a point of noting revs and they were typically around 6000 to 6250 and on the return journey at similar speeds 5500 to 5750rpm was the figure. I dont know the weight of the standard Yamaha weights, if anyone else does then that might shine some light on the improvements achieved

I also have a Honda X-ADV and would say that "as delivered" the TMax was 99% as fast as the Honda on acceleration, so maybe Yamaha are being a bit coy with the HP figures, I dont know but all I can say is that the latest TMax is very very good.

Hope the above is of interest

Cheers