TMAX and 107"s

[7hogs]

I am looking for comparisons for AFR settings plus timing. Any of you guys interested in sharing and I would send you mine?

[7hogs]

bump me up scotty

[mayor]

didn't look like you got too much attention with this thread, so maybe we can get some basic data flowing.     there's a few ways to get to 107", so what bore and stroke are you running.  what map did you use for your base map? 

most main timing maps I've seen on T-max has the timing to far advanced in the mid rpm areas when dealing with higher compression engines.  you having any issues with ping?

[7hogs]

[

didn't look like you got too much attention with this thread, so maybe we can get some basic data flowing.     there's a few ways to get to 107", so what bore and stroke are you running.  what map did you use for your base map? 

most main timing maps I've seen on T-max has the timing to far advanced in the mid rpm areas when dealing with higher compression engines.  you having any issues with ping?

4"x4.25".......... pining? Very little to none after it adjust the fuel in that area .......... I have been working with the AFR Correction vs Temp and it is running much better. This is a 107" Zippers kit, Timing was from Ron at Axtell, the bike runs cool and smooth now but the upper rpms AFR from TP 45.77 to WOT is 13. Trying to get some ideas on where that should be and at cruise also. Accel Fuel is set 11.5.

[Admiral Akbar]

I'm using 13.2 WOT and 13.8 cruise.. I think that its the stock map settings but am not sure where they came from. on a 95 ci high comp bagger I get 44+ in the mountains. 40 in town..

Accel Fuel is set 11.5.

How did you do this? I only see a accel fuel timing in milliseconds..

Max

[mayor]

Accel Fuel is set 11.5.

How did you do this? I only see a accel fuel timing in milliseconds..

Max

I'm guessing he's talking about 11.5 milliseconds.

I varied the afr for each rpm range of my map based on what I usually saw in tps% (using a marked tape on the throttle).  Here's the afr map @2k that I'm currently running on my 88":

A wide open throttle AFR from a dyno run yielded 13.5afr based on the above AFR map.  Here's what I did to the timing:


edited to insert newest timing map..

[axtell]

20 degrees timeing has hurt a lot of engine parts.....

[mayor]

20 degrees timeing has hurt a lot of engine parts.....

are you suggesting that's too much or too little? 

[axtell]

too little...really heats exhaust side of cylinder bore up...drys/burns too much of the oil out of the liner and this dry running wears rings out fast....We are see a LOT of this. Ron

[7hogs]

Ok how do you get the data images on here?

[7hogs]

11.5 is correct and I am getting about 37-40 in town and upper forties in the mountains

[Admiral Akbar]

Max, I'm trying using the L function...so far it seems to be kicking my butt.   Embarrassed

All you got to do is

1.select one cell
2.move to where you want
3.press "l"
4.select the next cell you want
5.move it where you want
6.press "l"

The software will draw a straight line between the 2 cells of all the cells that are in between.

Max

[7hogs]

That will work above the the line at TP close but below it I found out on mine it tiers it down a section at a time.

[mayor]

too little...really heats exhaust side of cylinder bore up...drys/burns too much of the oil out of the liner and this dry running wears rings out fast....We are see a LOT of this. Ron

cool, I'm on the right track by thinking I need to increase the timing then. Thanks Ron. As you can see, the base timing on my 88" map originally had my WOT at about 18 degrees but my cruise was only 22 degrees.  I'm thinking of shifting my whole timing chart to the right 2-3 boxes (advancing the timing more), ...sound about right?  It seems to me that most of the base timing on the base maps are low from about 2.3k and down, but high in the 2.8-3.8k range (especially high for higher compression builds).  You seeing the same thing?

Ok how do you get the data images on here?

I'm using the print screen method, then hosting the pictures on my photobucket account. If your going to post pictures, using a hosting service like photobucket is the easiest.


thanks Max...will try later tonight.  you back in So. Cal yet?  did you see someone was asking for you in the general section?

[axtell]

I want my timeing to reflect what the bore size would need...You can look @ a small block ford or chevy with a 4' bore and go from there.....Granted we are aircooled and will need more fuel to help cool than a watercooled engine but the timing should be similar....if I have to move the timing very far I take a step back and try to figure out why....Over the years we have had a lot of success modifying the combustion chamber shape to resist detonation and allow some tuning wiggleroom.....(is that a word? :
I have been testing a 20 degree piston (10.2) on a 97/98? dyno mule engine for about the last month. Used 2000 casting with no portwork at all...1.900 intake...stock exhaust valve.....chamber cut to 20 degrees.used a bucketload of cams and got some real nice numbers...never below 28 degrees timing......We just installed a 4.375 flywheel set and change to the same dome configuration and will run this 107 until winter gets here....fun....Ron   

[Admiral Akbar]

As you can see, the base timing on my 88" map originally had my WOT at about 18 degrees but my cruise was only 22 degrees.

Here is the timing I'm running on the 95 with 10.9 to 1 cr. Notice I'm backing off the curve a little..Was getting a slight rattle...

I'm using the print screen method, then hosting the pictures on my photobucket account.

Go here to capture images..

http://www.mirekw.com/winfreeware/mwsnap.html

Max

[mayor]

good stuff Max.  here's where my timing is for my stock 88" at 2.5k:


I made several changes to the base timing map (for those not familar with the software, the yellow dots are were the timing was set at on the base map).  This was the map that convinced me to try more timing at the lighter tps areas on the 2k and 2.3k maps.  This rpm range was about where the engine started running smooother at the light throttle positions.

edited to add latest timing map info..

[nc-renegade]

We just installed a 4.375 flywheel set and change to the same dome configuration and will run this 107 until winter gets here....fun....Ron   

Hi Ron,
I would be real interested in what you find with this combination in regards to timing.  This is the build I'm going back to.

[nc-renegade]

This rpm range was about where the engine started running smooother at the light throttle positions.

This is a common complaint for the T-Max and what you and Max are showing is exactly what needs to be done to get light throttle to be smooth.

[7hogs]

This rpm range was about where the engine started running smooother at the light throttle positions.

This is a common complaint for the T-Max and what you and Max are showing is exactly what needs to be done to get light throttle to be smooth.

I almost got it fixed and I will let you know when I got it. I am about 90% there but it is raining and supposed to rain all day.

[7hogs]

Here is mine at 2560

[Admiral Akbar]

Well that looks pretty aggressive... Max

[7hogs]

Runs great. That is what I thought but it runs very cool compared to the MAP's timing and also runs very smooth.

[7hogs]

Runs great. That is what I thought but it runs very cool compared to the MAP's timing and also runs very smooth.

Compare to the original MAP's Timing.

I should learn to proof read.

[notlost_nc]

This is very interesting.  Have you come to these settings based on data logging or just test driving ?