V-Twin Forum banner

1 - 4 of 4 Posts

·
>>> The Curmudgeon <<<
Joined
·
352 Posts
Discussion Starter #1 (Edited)
Got this chart from Doug Lofgren. According to him, this is "after a lot of time on the dyno". This is all I know about it, but I think we can assume the usual CR, headwork, intake (EFI, I think), etc.

Well shaped torque curve. Hangs in there well, but it seems to wake up kinda late. Somewhat biased towards HP, but actually a little better than I expected. All in all, fair compromise, imo.

If it were in my own bike, I might consider advancing this a little and see what happened.

Added these specs 12/12/05:
The attached dyno chart is an 80CI engine with 10.5:1 CR, ER-2 cams, 1.9" inlet valve and very good porting. The bike has Thunder-cone slip-ons on the stock headers and an S&S 'G' carb and air cleaner.
 

·
Banned
Joined
·
5,114 Posts
barrybasinger said:
Got this chart from Doug Lofgren. According to him, this is "after a lot of time on the dyno". This is all I know about it, but I think we can assume the usual CR, headwork, intake (EFI, I think), etc.

Well shaped torque curve. Hangs in there well, but it seems to wake up kinda late. Somewhat biased towards HP, but actually a little better than I expected. All in all, fair compromise, imo.

If it were in my own bike, I might consider advancing this a little and see what happened.
Wonder why the graph starts out at a 60mph roll on?? What is lurking in the lower rpm range that they don't want to show us??
 

·
Registered
Joined
·
2,589 Posts
What's really surprising is that in spite of two drastically different AFR bands, the lines for each run are virtually identical. ?????
And as for lower end calcs, I suspect with that cam there is a saddle in there big enough to fit Ozzies fat ass into! (At least before he started his diet.)
But remember that we don't know what this build is, so could be good peaks.
 

·
>>> The Curmudgeon <<<
Joined
·
352 Posts
Discussion Starter #4
GRock said:
What's really surprising is that in spite of two drastically different AFR bands, the lines for each run are virtually identical. ?????
And as for lower end calcs, I suspect with that cam there is a saddle in there big enough to fit Ozzies fat ass into! (At least before he started his diet.)
But remember that we don't know what this build is, so could be good peaks.
I noticed that there was little change in power despite the big change in AFR also. No real answer for that, based on what is known. As to rollon at 60 or so, I am giving the benefit of the doubt, and assuming that he didn't want to go full throttle below 2500 (??) or so RPM. 5th gear roll-on?

I was hoping that you two would chime in on this, as the chart kinda wasn't what I expected given the cam specs. I thought I'd see something more like an EV-51, with a big dip in the bottom. I did expect more of a bias to the top end, given the intake timing and the overlap. Kinda confused by the exhaust too, unless what's his name expects only a very good exhaust system on bikes using his cam.

Unusual...Anyone got any rationale for the timing on this cam, now that we've seen a chart? I'd really like to hear comments.

ER-2
Intake .560 26 50 256 102
Exhaust .510 52 20 252 106
 
1 - 4 of 4 Posts
Top