ESE's works engine tuner

**philou** · 8th November 2021, 18:59

I am curious to know the result behind this form ?

**jonny quest** · 9th November 2021, 06:35

Originally Posted by Frits Overmars

Well spotted Philou. You might even call it cheating

Not familiar with this model bike. Center bodies look to be removed drastically shortening pipe. Why do you mention this as "cheating " ?

**wobbly** · 9th November 2021, 08:41

There has only been one specific engine application where having no dwell section created any usefull power - and it sure wasnt a Honda NX
Any other use of this design is a complete fuckup and will never make any power - end of story.
I wouldnt take those pipes if you gave them to me,

**Frits Overmars** · 9th November 2021, 22:16

Originally Posted by jonny quest

Not familiar with this model bike. Center bodies look to be removed drastically shortening pipe. Why do you mention this as "cheating " ?

How would you call it when someone offers 'Honda NX5 pipes' that will be completely worthless on a Honda NX5 (or on any other bike for that matter) ?

**SwePatrick** · 10th November 2021, 00:45

No good camera angle, but you can hear the sound, last pull was out of juice in the battery for ignitech(even though i said something different)
And still it produced 83whp in that pull, might have been 84 if it didn´t get low voltage.
However, the pipes are designed to be run with nitrous oxide(not activated in these pulls), thereby the 'low rpm', but i recon 83whp is quite good at only 10599rpm

And when i was about to show you the graphs, i forgot to klick to show the power, it only showed exhausttemps, my bad, but you can see the numbers.

**jonny quest** · 10th November 2021, 03:13

Originally Posted by Frits Overmars

How would you call it when someone offers 'Honda NX5 pipes' that will be completely worthless on a Honda NX5 (or on any other bike for that matter) ?

I see what you mean. The seller is "cheating " a buyer out of their hard earned money.

And yes, I knew at first glance those pipes were junk. And after Google told me what an NX5 was, I really knew these were worthless. Cheating, how I perceived it at first, was bending some racing rule by modifying the pipes that way. I was curious how that modification could benefit anything.... because I was "almost" positive it couldn't.

**wobbly** · 10th November 2021, 08:58

SwePatrick , that has to be one of the nicest jetted engines I have ever heard when blipping the throttle , wow.
But as I am always slinging shit at riders who come into the pit and I hit max recall , and it shows 14980 , when the red dash warning light comes on at 14600, you cant tell me you couldnt see
that headlight size white warning come on ( just joking ).

**SwePatrick** · 10th November 2021, 17:37

Originally Posted by wobbly

SwePatrick , that has to be one of the nicest jetted engines I have ever heard when blipping the throttle , wow.
But as I am always slinging shit at riders who come into the pit and I hit max recall , and it shows 14980 , when the red dash warning light comes on at 14600, you cant tell me you couldnt see
that headlight size white warning come on ( just joking ).

Thanks =)

I pulled all the way to revlimiter, but shiftlight was setup early as the driver i had actually didn´t see it

If you look real hard when blipping the throttle on the screen, the rpm gauge is almost instant at revlimiter.
The gauge on the bike is way to slow to keep up

Setup on this bike is really simple acutally, an early tzr250 engine (1kt)
With a spacerplate so it accepts the latest oem tzr250 cylinders(3xv)
Ofcourse they are ported, 194/188/130/134/134 are the timings.
B-ports are opened up quite a lot as the 'runners' do accept this as they are way to big oem.
Modified the combustionchambers with RSA in mind.
Woessner YZ125 pistons
The exhaust 'runner' is quite small also, only 34mm in diam.
The auxports are opened up as much as the piston allows(188 duration)
YPVS is blocked fully open, powercurve is above oem all the way from ~7500-12000rpm
V-force 4 reeds, but with polini 0.4 petals(oem can't take ethanol/methanol)
Keihin PWK 39mm carburetors(cheap as shit in Sweden due to they are mounted oem on snowmobiles)
Stainless steel pipes of own design(in MotaX)
Ignitech ignition
Modified clutch as oem didn´t take the power, with 8 springs instead of 4, and carbon discs from yzf250f.

**katinas** · 10th November 2021, 21:45

Cylinder from first street NSR 250 MC16. Interesting, C floor is 3.5mm higher than BDC.

**katinas** · 10th November 2021, 22:45

Tests with a quick removable exhaust insert, that mimic Jan’s idea of a higher exhaust floor. Of course there is some leakage through insert sides, so its not very accurate replication. Just general feelings of engine reaction.
Comparisons with and without insert on Honda RS cylinder, without any other adjustments.

1. Insert height 11mm, imitate exhaust floor height nearly at the level of the transfers top.
From 0 to 8000 rpm much better, but worse at top end.

2. Insert height 7.5mm, midrange and top similar to std, but top end revs increased by 300-400 rpm. This repeated every time after insert was installed.
Without the insert, only too retarded ignition add similar rpms, but power started to drop.
Changes done directly on the road in 5min.

**TZ350** · 11th November 2021, 11:18

.

Originally Posted by pete376403

Now you need the F81m ignition rotor instead of the monster that is standard

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I hear what you are saying. I will be using the smaller rotor from a Chinese after market CDI unit. Mostly so I can re wind it for 14 Volts @ 75 Watts. The bigger rotor is from the Kawasaki F5/9 250 or maybe it is Suzuki TS250. Anyway a big mass saving over std 250 rotors.