Kind of funny how seemingly everyone strives for the "100/100" motor build ....

While I haven't done much to my motor performance-wise compared to many forum members, I thought I'd share some data I've collected from 16 May through 18 Oct 2010. I installed a ThunderMax with AutoTune (TMAT) on or about the 28th of April; the TMAT it collects what is termed a 'warranty log' ... it collects Head temperatures and records the amount of time spent in each 100 RPM band.

When I selected the Andrews TW37B I had done some research and determined the most effective range for the cams was 2,200 - 5,800 RPM. According to the Nightrider cam spec table and some other sources, they're good for 88" and 95" motors and expected to produce 80+ HP.

Well, supposedly what is most practical for good streetable motors is a lot of torque down low in the RPM range ... which makes a lot of sense to me.

This is borne out by the data I show below. I entered the raw data from the T-Max output table into an Excel spreadsheet and graphed it ... the PDF files attached show the data in a graphical format. [Figured out how to open the raw data from the files since my original post.]

The first graph shows the cumulative data from 28 Apr - 16 May during which time I rode 472 miles ... the data shows 318 hours, 31 minutes and 6 seconds ... it appeared to me that there must have been some data in the TMAT when I installed it ... so, this is obviously my 472 miles with the preexisting data ....



The second graph shows the 418 hours, 10 minutes and 5 seconds I rode from 16 May to 18 Oct. I rode 6,029.7 miles during that period.



In another post below is a MPH at RPM table I came up with based on gear ratios of the '05 5-speed FXD transmission and the tires I am sporting ....

The conclusion I've reached is that I didn't make too bad a call on the cams ... but, perhaps I should've gone with a 4 degree sprocket to move the cam 400 RPM lower in the range ... or maybe the Andrews 26 would've been as good or better a choice ....

A couple of additional thoughts: (i) the stroker Twin Cam 96" makes more torque; (ii) additional compression increases torque ... although I've been thinking of things I could do to improve the performance of my 88" I am starting to think I just need to put those two to the top of my to-do list ....

Probably do it in reverse order as listed above (ii) first, then split open the cases and do (i) ....

Well, just thought I'd post up some data for y'all to think about and some of my thoughts ....

R/
'Chop

 

Holy crap!! I don't know much about what you're talking about, but damn!! Nice work!! I think!

 

Wow. It sure is nice to see real world numbers rather than a "my crap is better than your junk" thread with no facts to back it up

Thanks, excellent work.

 

The Y-axis represents time in hours ... while it shows I spend a ****-load of time at or near idle ... the real take away is the illustration of where most of my riding is ... between about 1,500 and 2,500 RPM ....

Compare the RPM range to any Dyno graph ... (for example Chad / Redrubicon below) ....



I haven't added up the cumulative time, but my point is that I've spent something like a cumulative hour out of 223 hours above 4000 RPM ... (the log shows I've hit red line 6,400 9 times between May and Sep) ...

So, if you really want to have power (torque) you will use ... get it to come on around 1,800 RPM ....

 

Although this is slightly off-subject in that it doesn't relate at all to cams, I was also surprised at the total time spent at/around idle in your first log. Anything that might explain it during that time period (went to a bunch of rallies, stop and go riding, tweaking the bike while idling in the driveway etc..)? I'm curious if we all spend roughly that amount of time at idle when just doing in/around riding (vs. longer trip as in your second log).

edit: good analysis regardless, very interesting to see in relation to the cam you chose

 

what the hell did i just read diden`t understand a damn thing

 

That warranty log really provided you with some valuable info. Quite a comprehensive analysis... Since cams may be on my winter project list, this is pretty interesting information. Good job!

 

That is some great info. I've really been thinking about some cams but want them to come on in the lower RPM's because that's where I ride the most.

 

Wow.

If you want my +4 advance gear, you're welcome to it at my cost.

 

When I analyzed the data, I was really surprised at that as well ... I'd be interested in what others with T-Max show on their RPM logs ... anyone ...?

Vic - didn't think you still had it ... thought you had a 'taker' for it (since I didn't jump on your offer before) ....

* * *

Did a little more annotations to the graphs to kind of highlight some of the points I was trying to make ...



By looking at the highlighted area of the graph, you can see where I spend most of my time ... for example, I rode to work a lot this summer and there are two routes I take (i) from NWSY (Gate 3) I take I-64 from exit 247 to exit 242, then Hwy 199 to CAX; or (ii) from NWSY (Gate 1) I take the Colonial Parkway to CAX .... taking the first route I quickly run through the gears up to around 75 then around 50 - 60 the rest of the way; whereas if I take the Parkway it's 45 - 55 pretty much the whole way ... also, the first route is about 8.5 miles and the second route is 14.5 miles ....

While I may sometimes skirt the speed limits modestly, I am for the most part a fairly defensive / conservative rider ... for example, I look ahead at the lights and throttle back/coast to a red light so I don't have to stop as much (i.e., the light changes to green before I have to come to a complete stop) ... this may explain the high numbers at or around idle due to the high percentage of 'city driving' I do ....





* * *
One of my points was that everyone gets all excited about the circled portion of the dyno graph, but fail to consider that they spend most of their lives at the highlighted portion of the dyno curve ...



R/
'Chop