Author Topic: TZR125 4DL TRACK BIKE  (Read 11294 times)

Martin77

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Re: TZR125 4DL TRACK BIKE
« Reply #375 on: May 06, 2018, 08:57:40 PM »
The V force made a very nice gain on mine at the top end...

I'm sure you've read a lot of info on the web about ratio of lengths, and rough diameters etc.. so I will just say personally I would aim for a total length from flange to the end of the baffle cone of about 900mm would be about right. This is to match the current curve peak rpm. (I would also suggest 32mm start diameter, 110mm belly, and 22mm stinger..but perhaps make an adapter at the tail end so different stingers can be slotted in and tested)

When I measure curvy pipes I break it down into sections, (header, then the diffuser etc), measure around the outer edge, then inner edge, add them together and divide by two to get an average. It's still really hard to be 100% accurate!


2stroke

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Re: TZR125 4DL TRACK BIKE
« Reply #376 on: May 07, 2018, 07:27:31 PM »

That is good info for me regarding the rs125's, Interesting thing about the carbs, do the rs125 riders have good results with the use off a 34mm carb or do they all use the 28 or 30mm?
35Hp seems far away for the tzr125 at the moment.

Once, I've read on a technical magazine that a tuning specialist obtained 37,5 hp out of a RS 125 using a 37mm carburetor with handmade reed valve! ;)
 
The Sport Production Championship in Italy during the 90's obliged all the bikes to have a 28mm carburetor. So the factories developed this solution with excellent results, expecially because on the tracks they are looking for maximum power at the highest RPM. So the 28mm with a perfect carburetion plus a racing exhaust did amazingly the job.

Since there was this limitation, almost nobody brought the 34mm carburetor solution to its limits :  so who can tell if a 28mm works better of a 34mm?    ;D

The only one remark we can do regarding the Yamaha 3MB/4DL bikes is that the 32mm VHSA is more a "racing" solution than the 34mm VHSB. Another remark is that the TDR 125 R with the same (stock) engine and 28mm carburetor instead of 32mm, has 4hp less than the TZR 125 R. These four hps come straight from the carburetor and the exhaust.  8)

About the V-FORCE 4, this reed valve has twice the useful area for the flux of the air-fuel mixture: reed's stiffness and thickness are calibrated in relation to this peculiarity. The differences using a 34mm versus a 32mm carburetor could be minimal. This is a great upgrade. (-P)

By the way, I am preparing my new intake manifold with optimized and revised flows to make the most of the pressure waves and the original reed valve. We'll  see how it will go in the first tests, I'm really curious!  8)
As soon as I'm ready, I'll post something more on the forum to get you all involved.  (-P)

casal-fan

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Re: TZR125 4DL TRACK BIKE
« Reply #377 on: May 09, 2018, 02:23:31 PM »

If someone has suggestions pleas let me know. The more info/ideas I get the better it will be

Ok, here it goes, you asked for it :)
Louis, have you tryed to check if main jet air correction on the dellorto can be changed?

Will try to explain myself, and please notice that this is only my opinion.
You got good results on the midrange by going bigger on main jet with the 34mm. This could be, and I underline could be, because the lower temperature on the pipe at midrange caused by the richer jetting, got the pipe working better in the midrange… but then the topend got rich and you loose both pipe efficiency as well as revs that also give you HP.
A bigger main jet air correction could maybe bring you the top end power back, if not more?
Hope you understand what I mean.

Anyway, the results are already very good in my opinion.
« Last Edit: May 09, 2018, 03:10:03 PM by casal-fan »

Louis

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Re: TZR125 4DL TRACK BIKE
« Reply #378 on: May 10, 2018, 09:32:00 AM »
Hello Martin,

Quote
The V force made a very nice gain on mine at the top end...
That would be great if that does the same on my bike.
I don't aspect much gain, but if it creates a solid 27,5HP I'm happy

Quote
I'm sure you've read a lot of info on the web about ratio of lengths, and rough diameters etc.. so I will just say personally I would aim for a total length from flange to the end of the baffle cone of about 900mm would be about right. This is to match the current curve peak rpm. (I would also suggest 32mm start diameter, 110mm belly, and 22mm stinger..but perhaps make an adapter at the tail end so different stingers can be slotted in and tested)
First I'm gona try something stupid ::) if that works I know witch dimensions I need to play with.
If its not working as expected, then I'll go back to the drawing table and I will be consulting you with the designs I created
« Last Edit: May 10, 2018, 09:52:18 AM by Louis »
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Louis

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Re: TZR125 4DL TRACK BIKE
« Reply #379 on: May 10, 2018, 09:38:59 AM »
Hello 2stroke,

Quote
The Sport Production Championship in Italy during the 90's obliged all the bikes to have a 28mm carburetor. So the factories developed this solution with excellent results, expecially because on the tracks they are looking for maximum power at the highest RPM. So the 28mm with a perfect carburetion plus a racing exhaust did amazingly the job
Do you know how much power those bikes had? Where they all above the 30HP

Quote
The only one remark we can do regarding the Yamaha 3MB/4DL bikes is that the 32mm VHSA is more a "racing" solution than the 34mm VHSB. Another remark is that the TDR 125 R with the same (stock) engine and 28mm carburetor instead of 32mm, has 4hp less than the TZR 125 R. These four hps come straight from the carburetor and the exhaust.  8)
That is one way to see it :)

Quote
By the way, I am preparing my new intake manifold with optimized and revised flows to make the most of the pressure waves and the original reed valve. We'll  see how it will go in the first tests, I'm really curious!  8)
As soon as I'm ready, I'll post something more on the forum to get you all involved.  (-P)
Im interested to, still have my own special engine to build.
Would be nice to see in what direction in need to go
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Louis

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Re: TZR125 4DL TRACK BIKE
« Reply #380 on: May 10, 2018, 09:48:35 AM »
Hello Rui,

Quote
Louis, have you tryed to check if main jet air correction on the dellorto can be changed?
The 32mm has the bleeding emulsion tube, sadly the 34 does not have the bleeding type. (it has the closed emulsion tube)
I can't change jets

Quote
Will try to explain myself, and please notice that this is only my opinion.
You got good results on the midrange by going bigger on main jet with the 34mm. This could be, and I underline could be, because the lower temperature on the pipe at midrange caused by the richer jetting, got the pipe working better in the midrange… but then the topend got rich and you loose both pipe efficiency as well as revs that also give you HP.
A bigger main jet air correction could maybe bring you the top end power back, if not more?
Hope you understand what I mean.
I know exactly what you mean. But sadly I can't change this on this carb

Quote
Anyway, the results are already very good in my opinion.
Thanks, with a bid off luck I can dyno the V-force this weekend
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Louis

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Re: TZR125 4DL TRACK BIKE
« Reply #381 on: May 12, 2018, 03:02:03 PM »
As Promised, tested the V-force today :)
Must say, they work better than a modified one.
On average they gain 0,4 a 0,5HP more and let the engine rev about 200 a 250rpm longer

Green V-force Red modified oem reedblock

A  bid more here: http://www.tzr3ma.com/dyno-results-v-force.html

Currently at 27,7HP with oem ignition and shorted stock pipe.

Next step is doing something stupid ::) if that works I report back ;D
If it not working you will be reading it somewhere on my site placed in a corner :-\
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nic fan

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Re: TZR125 4DL TRACK BIKE
« Reply #382 on: May 12, 2018, 05:00:06 PM »
cool about time you had some positive results Louis after all the work you've put in.
TZR125r 4DL1 Belgarda

Martin77

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Re: TZR125 4DL TRACK BIKE
« Reply #383 on: May 13, 2018, 11:33:04 AM »
Is that with the 34mm carb? Would be interesting to try it with the 32mm as that seems to work best so far. Good improvement, though not as much as you'd like..

Louis

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Re: TZR125 4DL TRACK BIKE
« Reply #384 on: May 13, 2018, 08:23:53 PM »
Hello Steve,
Quote
cool about time you had some positive results Louis after all the work you've put in.
Thanks, they are small steps. But in the end I will get there :)

Hello Martin,
Quote
Is that with the 34mm carb?
Quote
Yes this is with the 34mm Dellorto.


Quote
Would be interesting to try it with the 32mm as that seems to work best so far.
Quote
If my stupid nexst step is not working ill try the 32mm again


Quote
Good improvement, though not as much as you'd like..
Quote
Of course I had hoped a little more, but on the other side 0,5HP for only changing the reedblock is not bad either.



We could say the inlet is free off restrictions now (not much more can be done,without disable the whole engine)
Think the exhaust is limiting the HP's right now

« Last Edit: May 13, 2018, 08:35:26 PM by Louis »
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