Track day on standard NX4

Moderators: trixynut, Mincehead, dicky, phuk72, Jak, Kevtrx849

Post Reply
coxylaad
Site Sponsor
Posts: 1211
Joined: Fri Jan 21, 2011 12:30 am

Re: Track day on standard NX4

Post by coxylaad » Wed May 30, 2018 8:24 am

sounds rough. hows the body/ bike?

User avatar
Racer-unk
TRX-Enthusiast
Posts: 286
Joined: Fri Mar 03, 2017 5:28 am
Location: Port Elizabeth, South Africa

Re: Track day on standard NX4

Post by Racer-unk » Wed May 30, 2018 3:21 pm

i saved it every time.....must be my enduro racing experience....or lack of funds for repairs
Busy making the new rear sets now, using the original TRX shift rod, along with my push-type quick shifter.
Will be GP shift ....will have to go learn the 1 up 4 down business..... :shock:


the shifting rod was pointing about 40 Deg upwards, tight against my gear-lever and when I go into a left turn and shift my weight, i would put weight on to the shift-rod that resulted in unwanted shifts on corner entry.....shitting oneself comes naturally at the time, especially when it is a downshift....Yoshimura gear lever also 20 mm shorter than anything else I own.....making a new adjustable one to achieve proper ergodynamics.

User avatar
Racer-unk
TRX-Enthusiast
Posts: 286
Joined: Fri Mar 03, 2017 5:28 am
Location: Port Elizabeth, South Africa

Race day on standard NX4

Post by Racer-unk » Sun Jun 24, 2018 5:08 am

took leave on Friday and went to go learn how to ride with the gears upside down.
The track had been resurfaced and was still quite slippery. Some guys had some serious issues with tearing on the rear tyres.
I had some tearing on one outing but seemed to cure it by dropping my tyre pressure a little.
All in all I did not gel with the bike at all.

Early start on Saturday for qualifying and track surface was damn cold. Put in a quali time, but not a great time...was an allround thing....nobody wanted to push hard.
Changed to dogbones back to 176mm fom the 170 i had in. Went out for race 1 and immediately felt more comfortable braking and corner entry. Really enjoyed that race with a couple of ding-dongs with the hoard of 400 hondas.

Race two was frustrating as i was being held up by some of the guys....they faster through some corners but slow me in other areas and I could not make safe moves on the inside of these 400's because they have much better mid and exit speed than i do......(well most of the time) Maybe I am too nice.....but the majority of us are over 50, and safe fun racing takes preference over results.

Race 3 was a disaster....very late start as the sun was staring to go down and I actually did not even want to go out.....again frustrated by this time one rider holding me up and I could not keep him behind me when I past him..... then I started making mistakes....forgetting to change up instead of down, and running wide because of the light etc......finished well down in the field.

prize giving and the pub was great as usual......i left late, but early enough to avoid getting into trouble (if you know what i mean)


This brings me to my problem:
To get good drive out of the two slow corners I have to gear down to second gear. That means I need to wait for the bike to settle before I can turn in which makes my corner entry and mid-corner speed slower than those pesky 400's and 650's. They also get onto the gas earlier than me....
My proposed solution:
When I fit my FCRs I should have a bit more power. I am thinking of going 520 conversion with a bigger sprocket at the back (short track anyway) and trying those corners in 3rd gear, using a bit more front brakes than engine braking and getting a smoother faster entry. well thats the theory anyway.
will have to study the gear ratio tool.

cobbadiggabuddyblooo
Site Sponsor
Posts: 6809
Joined: Thu Aug 28, 2008 9:19 am
Location: Brisbane,Australia

Re: Track day on standard NX4

Post by cobbadiggabuddyblooo » Sun Jun 24, 2018 7:33 am

Lakeside where I do my trackdays is a shortish curcuit too with 200-215 kph averages down the straight because those pesky nuggets slowing my exit onto the straight.. :lol: :lol: sometimes not even finding top gear...
Originally the 17/41 it was a similar issue with a couple of corners being 2nd gear and going to 16/41 allowed me to tackle them in 3 Rd with enough torque to pull away plus now I can easily run top gear down the straight.
laughter is the best medicine

User avatar
Racer-unk
TRX-Enthusiast
Posts: 286
Joined: Fri Mar 03, 2017 5:28 am
Location: Port Elizabeth, South Africa

Re: Track day on standard NX4

Post by Racer-unk » Mon Jun 25, 2018 10:09 am

on the interesting front......one of the guys is no longer riding his trick 1098 Ducati with us, but has purchased a post 92' 900 Ducati.
Now this bugger has money and has already ordered his FCR41's and has had custom pipes made in Europe.
Yet, he will instantly become my real competition......
The pre-99 FZR1000's and R6-es are too fast with a capable rider. They just rock up and take the throphies.

User avatar
Racer-unk
TRX-Enthusiast
Posts: 286
Joined: Fri Mar 03, 2017 5:28 am
Location: Port Elizabeth, South Africa

Re: Track day on standard NX4

Post by Racer-unk » Sun Jul 08, 2018 6:13 am

with the new track surface it has become quite evident that we will have to manage tyre pressures throughout the day.
Yesterday. started cold but warmed considerable midday with a decline in the afternoon. Midday I was rearing the tyre on one side only....not cold tear...seeing tyres picked up 0.5 bar from cold pressure. My last session the track was a bit cooler and I dropped rear by 0.2 bar and it still felt good. left side was being overworked seeing all the left turns are sweeps and we mostly on full throttle. Right turns are mostly tight and after hard braking or running against compression.


Changes made for the day:
11/16 Nissan radial master cylinder: seems to be good....not stronger brakes, but better feeling
16t front sprocket........why oh why did i not do this last year already
Fixed gear lever position on my new rearsets: feels good
pulled standard forks another 5mm through the yokes............very positive feeling.....can actually get my knee down on
the track now. the one slide was so long i shat myself and pick the bike up like #93......i is a sensation i need to get used too
Front fork internals...adjusted......but there is no point of talking about the proverbial "family member in jail".....they must just go......next time i will have the slingshot RSU forks on the bike. Can see at least two seconds a lap with a front-end that I can trust.


I am feeling confident....hopefully by the end of the week coming, will the grace of God, I will have the FCR carbs. (must get them through our customs dept first)
Must just be carefull that confident does not turn into cocky.....else i might end up sliding through turn 7 again.... [-X

cobbadiggabuddyblooo
Site Sponsor
Posts: 6809
Joined: Thu Aug 28, 2008 9:19 am
Location: Brisbane,Australia

Re: Track day on standard NX4

Post by cobbadiggabuddyblooo » Sun Jul 08, 2018 8:20 am

I’ll let you know how I go with the modified std Yamaha MLS head gasket.
That will sneak your compression up to 11:1.
No leaks so far wth 100km riding but giving it a work out tomorrow and a good hard 300+ km through the mountains and out on Long country roads.
With FCR’s and decent exhaust + extra compression I feel it should find 90 Hp.
I was finding 87hp with stock compression.
laughter is the best medicine

User avatar
Racer-unk
TRX-Enthusiast
Posts: 286
Joined: Fri Mar 03, 2017 5:28 am
Location: Port Elizabeth, South Africa

Re: Track day on standard NX4

Post by Racer-unk » Mon Jul 09, 2018 4:16 am

have you degreed the standard cams yet?

cobbadiggabuddyblooo
Site Sponsor
Posts: 6809
Joined: Thu Aug 28, 2008 9:19 am
Location: Brisbane,Australia

Re: Track day on standard NX4

Post by cobbadiggabuddyblooo » Mon Jul 09, 2018 8:25 am

Well head gasket has no leaks after 400km and plenty of spirited riding today.
I separated the std MLS head gasket , removed the centre shim , cleaned up the 2 outer spring seal sheets and recoated them with Blue Hylomar.
I have another cunning plan for cams.
I’m in the process of discussions about getting a number of cams reground. 8) 8)
Unlike the Kent Yam 9 cams they will be not be a square 240/240 with an extra 0.3mm lift but a staggered like the std cams.
Incorporating the added compression with head gasket mod it will allow me to run a little more overlap with the staggered duration as std so best of both worlds.
In theory it should have a similar lower/midrange gains over the Yam 9 Kent cams with little more top end too. Bit like a simplified Over/V2 cam just not asymmetric.
So should work well with std carbies and may just have to tune and modify the inlet horn on the airbox.
laughter is the best medicine

User avatar
Racer-unk
TRX-Enthusiast
Posts: 286
Joined: Fri Mar 03, 2017 5:28 am
Location: Port Elizabeth, South Africa

Re: Track day on standard NX4

Post by Racer-unk » Fri Aug 24, 2018 8:21 am

had a quick practice session on Wednesday in preparation for Saturday"s National race day. ( i am doing our normal club races)
First time out with the FCR carbs and the bike felt quite flat although when warmed up and keeping above 5000 rpm it was quite OK.
The change from 20W to 10W oil was a waste of time and money.....must get my ass into gear and finish my other front-end.

By the time i finished the 3rd session I was quite distraught with the bad handling despite getting my knee down consistently The big problem as i discovered is, that the click/detent adjuster does not click anymore and somehow it rebound dialed itself out over time and the rear was quite pogo-y. Will find out tomorrow in qualifying how the bike handles with the rear slowed..... :shock:

Back to the Carbs, for starters I just replaced the small Engco fuel filter for a larger VW one. The Bike was running a little hotter so maybe a touch lean? Exhaust a little too black.

coxylaad
Site Sponsor
Posts: 1211
Joined: Fri Jan 21, 2011 12:30 am

Re: Track day on standard NX4

Post by coxylaad » Fri Aug 24, 2018 9:56 am

black sooty type deposits on the exhaust usually says the engine is running rich?

cobbadiggabuddyblooo
Site Sponsor
Posts: 6809
Joined: Thu Aug 28, 2008 9:19 am
Location: Brisbane,Australia

Re: Track day on standard NX4

Post by cobbadiggabuddyblooo » Fri Aug 24, 2018 11:27 am

Too heavy handed on the throttle down lower/midrange with FCR's causing fueling and your black pipe and flat response.
Roll on progressively and you'll get the feel after a short time on just how fast you can open the throttle in the lower/midrange.
Temp rise is due to extra fuel/air and power so nothing unusual.
laughter is the best medicine

coxylaad
Site Sponsor
Posts: 1211
Joined: Fri Jan 21, 2011 12:30 am

Re: Track day on standard NX4

Post by coxylaad » Fri Aug 24, 2018 11:39 am

this is why I am an advocate of fuel injection :lol:

User avatar
Racer-unk
TRX-Enthusiast
Posts: 286
Joined: Fri Mar 03, 2017 5:28 am
Location: Port Elizabeth, South Africa

Re: Track day on standard NX4

Post by Racer-unk » Fri Aug 24, 2018 12:32 pm

coxylaad wrote:this is why I am an advocate of fuel injection :lol:
we old school... :munky2:
Imagine the bike was perfect....what would i do at night when I get time to go to the garage.... :-k

coxylaad
Site Sponsor
Posts: 1211
Joined: Fri Jan 21, 2011 12:30 am

Re: Track day on standard NX4

Post by coxylaad » Fri Aug 24, 2018 2:28 pm

you'd end up doing what I do and make up problems that don't exist :lol:

Post Reply