Torque/hp Gains? this is my plan
Road Master
Joined: Jan 2006
Posts: 918
Likes: 1
From: Bulldog Country
I wouldn't get too hung up on numbers but if you want to see numbers, look here: http://head-quarters.com/html/twin_cam2.html
Seasoned HDF Member
Joined: Jul 2007
Posts: 6,336
Likes: 67
From: SW Minnesota
mnpg that tw 21 cam is supposed to be great for low end torque and starts dropping off at five thousand, so i understand. mine rarely sees five k, as it's designed to be a torque motor. i'm gonna use the tw 21, 26, or the se 255 cams myself. don't need the hi rev help, as i don't ride it there. heck, if i wanted revs, i'd have got a gsxr suzuki, yeow, slap me please and bring me back to my senses.
Exactly. I'm a big fan of both Joe Minton (American Rider) and Donny Peterson (American Iron) and have learned much from both, although sometimes they have conflicting ideas.
Anyone that owns a Harley should be getting both those magazines, if for no other reasons, for their tech articles. Many questions posted constantly on these forums have been answered in detail in either one of those two magazines.
Here is Joe's Minton's articles on torque, and how to get some. Many riders get only "bar stool horsepower," which is absolutely useless on the road, and may actually be detrimental to the rpm range we usually ride in--just study the dyno charts carefully and see where the gains actually are.
http://www.americanrider.com/output.cfm?id=1205749
If you scroll to the end of that article you will find a link to many of his other articles.
The Andrew's 21 has given me two most noticeable gains--how it pulls on the hills, and how it is so much easier to maintain speed in the terrible winds we have in SW Minnesota.
Gas mileage also went up about two mpg.
Ultimate HDF Member
Joined: Aug 2008
Posts: 5,413
Likes: 17
From: eastern oklahoma
in a perfect world, we'd have the absolute recipie, but each of us has our performance and reliability requirements. for me, currently i've got my 08 sg stock 96" with the following, screamin eagle air cleaner, stage one download, rinehart slip ons, and a pre canned map from fuelmoto for same. it runs great and i'm happy. although i think i would even like it more with 103", heads by perhaps branch flowmetrics, and a set of andrews tw 21 cams or the se 255's. any ideas or thoughts on this combo? i am thinking it'd be a good recipie, but any additional input would be of value to me. i rarely go over 5 grand so low end torque is what i'm after. thanks in advance. i can't afford to experiment, and is much cheaper to use someone elses experience with mods.
Ultimate HDF Member
Joined: Aug 2008
Posts: 5,413
Likes: 17
From: eastern oklahoma
mngp and iclick, good useful information, matter of fact, i followed your recommendation on tires for my streetglide iclick, the mu 90-16 sure got rid of the drunk sort of butt wiggle i had with the back of my sg. and mnpg, i also read both american iron and american rider. joe minton has done some great usable power builds with the 88 inch motor which should apply to the 96 i'm thinking. thanks guys you're a big help with this stuff.
Thread Starter
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Cruiser
Joined: Aug 2008
Posts: 211
Likes: 0
in a perfect world, we'd have the absolute recipie, but each of us has our performance and reliability requirements. for me, currently i've got my 08 sg stock 96" with the following, screamin eagle air cleaner, stage one download, rinehart slip ons, and a pre canned map from fuelmoto for same. it runs great and i'm happy. although i think i would even like it more with 103", heads by perhaps branch flowmetrics, and a set of andrews tw 21 cams or the se 255's. any ideas or thoughts on this combo? i am thinking it'd be a good recipie, but any additional input would be of value to me. i rarely go over 5 grand so low end torque is what i'm after. thanks in advance. i can't afford to experiment, and is much cheaper to use someone elses experience with mods.
Extreme HDF Member
Joined: Sep 2005
Posts: 11,615
Likes: 50
From: Baton Rouge, LA
My feeling was that the tech I spoke to didn't think too highly of the TW21, that it wasn't too much different than the stock cam. Looking at the specs I think this is relative, as like the 255 it is a very mild cam--but to get what I wanted a mild cam is exactly what was needed. I do think that a TW21 would be a good choice for someone looking for the effects I wanted. However I do think there would be some loss in the low-end with the TW21's without a CR increase, primarily based on the intake-close spec. The one big spec that caught my attention with the 255's was that one, and at 25° it is the earliest intake close I've seen on any cam. That means low-end torque, but at the expense of stellar top-end numbers. You can't have both without throwing more money at the engine, IMO, at minimum bumping the CR. I want to make clear that HP is higher with the 255's compared to stock, but I don't think the peak-HP increases as much as TQ with this cam.
Last edited by iclick; May 30, 2009 at 07:45 AM.
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Road Captain
Joined: Jan 2007
Posts: 605
Likes: 1
From: Minnesota
103 effect on exhaust noice
mps1168 & iclick. I have almost the same set up as mps1168 (07 Ultra, SE A/C, old SE slipons, SERT) and am going to do the 103 w/SE 255's this winter. I like the way my slip ons sound right now. How much loader did they get when you went to the 103 or upgraded the cams (iclick) to SE 255s?
mps, have you tuned yet? what kind of numbers did you get? At this time, I'm going to try the HD down load for that configuration and have them rich it out a little. They are going to cc the heads and mill accordingly (keeping the compression at 10:1 or lower).
mps, have you tuned yet? what kind of numbers did you get? At this time, I'm going to try the HD down load for that configuration and have them rich it out a little. They are going to cc the heads and mill accordingly (keeping the compression at 10:1 or lower).