A Royal Enfield forum for the people

[Street_Kleaver]

My general rule of thumb is that the gearing is correct for top speed if you can hit redline rpm in top gear.
However, for comfort purposes, some prefer other gearing.
It sounds to me like the 18 is good for your bike. I always downshift for overtaking anyway.

It doesn't quite hit redline/rev limiter in top gear, it's like 150-200rpm shy of it. I found out in 4th gear pulls yesterday it actually has a rev limiter. Haha.

But that could be down to the tune or gearing. I did have the top end pretty rich at first at 12.7 target AFR. But since then trimming it back to 12.9-13 the map hasn't changed much at all in that area.
So I'm leaning towards gearing.
I still have a feeling I have to go a tooth lower in the front.

Done a little calculation with gearing commander. Especially knowing Taurim's bike hits 100mph/160kmh with the gear at 18x36 and the standard 130/70x18 tyre size. (639mm diameter)
Although I have a lot taller tyre using the Bridgestone accolade 4.00x18 (663mm Diameter) along with standard gearing at 18x36.
Larger diameter tyre is 24mm larger in diameter acting like taller gearing in itself. I'm basically chasing RPM sweet spots now.

Here's a graph I did on gearing commander.



So possibly switching to the smaller 17 tooth will just free it up that little more to reach redline in top gear. The rpms will also be in a sweeter spot just as the cams are starting to wake up at 3600rpm at our highway cruising speeds.
I'm not sure if it will hit "the ton" with the 17, maybe?

I'll give it a try and see how it feels when I give it a service/oil change/filter and check and re-set timing gear lash.
Can always change it back. Just a pain with that outer cover. Haha

[Guaire]

Here comes the autotune paste in --

The Autotune kit is a universal product that can be utilized on any model using the PCV and which has a 12v power source. The system is not NOT intended to disable, eliminate, or replace stock OEM O2 sensors that may or may not be present on the vehicle.
Installing the Weld Boss
Many stock and aftermarket exhausts come equipped with an O2 sensor. If your system uses a M18x1.5mm thread then you can simply use this location for the Autotune sensor. If you have to drill a hole for a new bung (mild steel bung included), we recommend doing so before the catalytic converter (if applicable). Positioning the weld bung in a location where multiple cylinders collect is the preferred location. If your application has a “2-into-2” design, it’s recommended to position the weld bung/sensor approximately 6-inches from the exhaust port on the respective cylinder you wish to tune.
Mount the weld boss in a manner that reduces the risk of moisture contamination on the sensor. Condensation can build up in the exhaust pipes and potentially damage the sensor. Ideally, you should orient the
weld boss so the sensor is between the 9 o’clock and
3 o’clock position. A 10° inclination off the horizontal plane should be considered a minimum.
Note: Verify you have adequate clearance for the sensor and wiring harness. Make sure the O2 sensor harness is as straight as possible. If you must secure the harness to keep away from danger make sure you do not squeeze the sheathing of the harness.
Installing the Autotune Module
1 Install the Autotune module near the PCV.
2 Connect the Autotune module to the PCV using the supplied CAN cable. It does not matter what port the cable is connected to.
3 Connect the O2 sensor cable to the O2 sensor and route the cable to the Autotune module ensuring the cable will not get pinched or damaged by the exhaust. The cable can be trimmed shorter if desired.
4 Connect the O2 sensor cable to the Autotune Module.
5 Connect the BLACK wire from the AT200 to a good chassis ground using either one of the supplied Posi-taps or ring lug. The negative side of the battery is a good location.
6 Connect the RED wire of the AT200 to a switched 12v source using the supplied Posi-tap. The power for the tail light is a good location. Most PCV install guides will tell you the wire color for this location.
7 Block or disable the clean air injection system if applicable (see tech tips).
2 AUTOTUNE SINGLE CHANNEL MODULE
INSTALLATION GUIDE

[Guaire]

One pic is my Bullet B5 with the M12 stock exhaust gas and the M18 bung for the AT200 AutoTune. The other pipe will be on my CGT 535.
The location is where the Dyno tech support suggested.

[Street_Kleaver]

Interesting. The manual that came with my AT200 kit mentioned no distance at all where the 02 sensor was supposed to be mounted. Even the DynoJet Tutorial videos were vague.
So I looked up the Bosch 02 sensor and it's recommended distance. Which was 1M from the header. It ended up about 750 from the head.

Even my "old" Dyno tuner said too close to the head the flame front can mess with the readings and life span of the sensor on certain engines.
More ideal would of been at the 2nd bend down low in front of the RH side engine case. But admittedly said where it's mounted now is in a safe location for sensor life. But just have to be mindful of the fresh air reversion sucked in from the silencer. No big deal he said, just have to change the tuning method. He's been Dyno tuning with Dynojet gear for 20 years. But I just missed out.

But I'll be changing my method as his recommendation and just tune specific areas. Just the same as a carburetor.
On the next tuning run after the service this weekend. I'll target key areas.
Setting AFR targets on 80% and 100% Throttle position columns only at all rpms from low rpms roll ons top redline in 3rd and 4th just like on a dyno.
Next only select the 60% and 40% throttle opening columns and perform another auto tune session focusing on those areas.
Working my way down the throttle positions and only riding in those areas.
Then it won't try and change the all the columns on the overrun etc if all areas are selected.

Once I'm happy with the tune I'll be removing the auto tuner. It's been a fun learning curve!

[Guaire]

Yes. The goal of installing the AutoTuner is to take it off!
I can call directly to Dyno support phone line. The recommend an even closer location for HDs. But, you know the performance is telling when you're getting adjustments right.

[Street_Kleaver]

Yes. The goal of installing the AutoTuner is to take it off!
I can call directly to Dyno support phone line. The recommend an even closer location for HDs. But, you know the performance is telling when you're getting adjustments right.

Absolutely. My background is tuning carburetors. Predominantly 2 stroke motocross race engines. So this is a new learning curve but a fun welcome one. I much prefer this way than being on the side of a road with tools, pocket of jets and messing with a hot engine!

[Street_Kleaver]

What's a engine build without teething problems?
Over the weekend I was doing it's 1000km post rebuild service. Oil, Filter, Cam gear lash and general check over for anything out of the ordinary.
Which one those 1hr service turned into a 4hr ordeal!

Came across this! Luckily it was now, not later!
It would of been a big failure.





The inlet valve push rod had been making contact with a casting sharp edge protrusion of the push rod tunnel. Which was about 1mm thick.
It did have clearance upon assembly, but the scoring is only 1/3 the way around. Possibly at higher rpms during the higher speed runs it may need a little more wiggle room with those things vibrating around all over the place!
The inlet side has a lot less room compared to the exhaust side.
So I took some material away and made a bit more room and tidied it all up. Thankfully I could use the standard inlet push rod while the new one arrives . Its still within spec with the rocker block to head tolerance HMC specifies with the lifters with only 0.5mm difference between the two.

Apart from that minor hiccup, The cam gear teeth look good, cam bushes still look like new, there wasn't any metal filings in the mesh screen and minimal dust on the sump magnets. The 500km service seemed to get all that.
Just have to duck down to the shops today and get a new gasket, oil filter and oil and hit the road for fine tuning sessions!

[Street_Kleaver]

Back on with it.

17 tooth sprocket on the front. Fresh oil and filter and everything checked and re-set.



Today was a RDO so I took the opportunity to get out and really give it a good tune targeting specific throttle areas and AFR targets.
I took a more methodical approach. Very much the same as I'd tune a carburetor and it yielded excellent results!

Lowering the front sprocket from a 18 to 17 was a good improvement. Took the load off the engine and at highway cruising speeds it feels very effortless. With the 18 it felt it was laboring just a little bit.
The bike still reached "the ton". Just got there a little sooner and revved out more compared to before it couldn't quite get to redline.

To know I was in the correct throttle position. The program displays (when the key is on) where the throttle is positioned.
Which I marked on a piece of tape on the throttle housing with all the target throttle percentages.
Each time I headed out I'd make multiple runs at a target throttle range from as close to idle as possible in a few different gears on road conditions.

#1 Run : Targeted the 60,80 and 100% throttle ranges with a target AFR of 13.2 to 3000rpm, then gradually richening up to 12.8 in the higher rpm ranges.
#2 Run : Targeted the 15,29 and 40% throttle ranges. These are typical cruising ranges. AFR target was at 13.2 for most of this area and 13.3 on the highway cruising rpm (3250,3500,3700) then set to 13 AFR from 4000rpm and higher.
#3 Run : Targeted the 5 and 10 % throttle ranges. These were 13.2. Mainly in 1st, 2nd and 3rd gear pulls at these range to try get the bike to rev as high as possible. Which was around 4500rpm.
#4 Run : Targeted the 2% column. Basically 1st and 2nd gear little pulls in a quiet area in my local industrial estate.

I didn't touch the 0% column. That would be set so there won't be any lean popping on over-run.

This is the end result. No big rich spikes in any cells which was from the bike on over-run (lean) and the auto-tuner trying to correct it by richening cells from previous tune runs.
It feels very crisp all the way off Idle now. There's no dull spots and has a very nice strong, smooth linear pull to 3500rpm then it really starts to sing all the way to 5000rpm.

After todays Session



Vs Hitchcocks Base Map



Vs Autotune Targeting all cells



The 40,60,80 and 100% areas haven't changed all that much. But the main improvement was the smaller throttle opening percentages. The response is a lot more crisp and no weird spikes due to over run.
Targeting and tuning to only specific areas made it tune a lot quicker. You could feel the change after a few pulls until no more change was felt, then on to the next range and so on.
Comparing the base map to my new tuned map. It seems to have taken fuel away in areas. My tuner informs me that is due to the combustion being more efficient in those zones due to the modifications.

Here's plug looking healthy. Running a colder BPR7ES due to the raised compression ratio. Next will be a iridium.



So in all that. I'm very happy with the result and how its running!
I'll fiddle with a few more 60,80,100% runs. But that has to be during "quiet" traffic times. Haha

[Guaire]

Are these the settings and not the TRIMS?!

[Street_Kleaver]

Are these the settings and not the TRIMS?!

These are the maps after being trimmed.
The very top map is final tuning.