Head work and low end....
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Road Master
Joined: Nov 2006
Posts: 758
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From: Winston Salen, NC
Head work and low end....
Would some light headwork help my low end power. I just installed the HQ-TC-500-HC cams and the tuning is now correct. We had a lean condition at the 2% and 5% throttle position and it now runs great. My main goal was achieved by getting more torqe and power in the 2500 to 4500 rpm range but I actually lost a bit of low end compared to the stock set-up. I do not want bigger cams and massive head work but I am curious if some moderate head work would wake up the low end. And if so what would that involve?
Really, this is the last thing I want to do.
I promise.[sm=badbadbad.gif]
2007 Street Glide
2/1 Thunder Header
Big Sucker
SERT
HQ-TC-500-HC Cams
Really, this is the last thing I want to do.
I promise.[sm=badbadbad.gif]
2007 Street Glide
2/1 Thunder Header
Big Sucker
SERT
HQ-TC-500-HC Cams
Road Captain
Joined: May 2006
Posts: 692
Likes: 1
From:
RE: Head work and low end....
are you running dual? if so just changing to 2-1 should help. Im not exactly sure how much tho.... Im sure someone with that cam experience will chime in. Also I would give Doug a call at HQ and see what he says. He does support his products
Elite HDF Member
Joined: Mar 2006
Posts: 4,722
Likes: 5
From: Biddeford, Maine
RE: Head work and low end....
www.bigboyzcycles.com will take care of your headwork for $400. Bean will port/polish/valve job for $299, cc and mill for equal compression and bump the compression for another $95. With that cam, you want to be in the high 9's to 10-1 CR.
Your Thunderheader isn't helping much either............they are known to have a low-end torque dip. There is a baffle mod that is supposed to help, you bend 3 out of 4 tabs on the square baffle to create more back pressure.
Steve
Your Thunderheader isn't helping much either............they are known to have a low-end torque dip. There is a baffle mod that is supposed to help, you bend 3 out of 4 tabs on the square baffle to create more back pressure.
Steve
Ultimate HDF Member
Joined: Feb 2006
Posts: 5,939
Likes: 3
From: TX
RE: Head work and low end....
Steve makes a good point about the T-Header.
Also, on the 07/08's, the piston is "in the hole". If you are still running the 96", simply going to a 103 (bigbore) w/a set of HQ pistons for the 07/08's will do two things - 1) increase displacement to 103 & 2) resolve the deck height issue so the pistons come up flush with the top of the cylinders.
The result is "proper" quench, more cubes, and increased compression. All three will help you!
Spike had a GREAT suggestion... call Doug & talk to him about it.
Are you confidnet that the SERT tune is "right"?
Also, on the 07/08's, the piston is "in the hole". If you are still running the 96", simply going to a 103 (bigbore) w/a set of HQ pistons for the 07/08's will do two things - 1) increase displacement to 103 & 2) resolve the deck height issue so the pistons come up flush with the top of the cylinders.
The result is "proper" quench, more cubes, and increased compression. All three will help you!
Spike had a GREAT suggestion... call Doug & talk to him about it.
Are you confidnet that the SERT tune is "right"?
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Road Master
Joined: Nov 2006
Posts: 758
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From: Winston Salen, NC
RE: Head work and low end....
I will call Doug and see what he recomends to bring out the bottom end. The cams provided exactly what I asked for but I was not expecting the low end loss. I may look into the tab mod on the TH as well. I love the pipe andwill not even consider starting to swappipes until I find the perfect match. That would be a recipe fordestruction as the wife would for sure cause some destruction on my butox.[
]
I feel the tune is right but I really have no clue. Nothing to compare it to. As many have stated, the bike rides and feels very well. The bit of low end loss that I am refering to is very minimal. Jim @ HD has spent an additional 3 hrs tweeking the low end to make me happy and has told me to bring it in again if I thought it needed more. All this with true desire to get it right and no additional charge. It does not get much better than that in my book.
If Doug says some head work will wake those cams up over the full range and get the bottom end up to snuff, that would be great. My wife wants me to get the bugs workedso we will have a better understanding of what to do with her RKC as long as I don't replace stuff I just put on.
I will let you know what Doug says. Thanks for all the help. It is all good like it is but I just want to get the most out of what is there and I feel I may have left a little on the bench that can be got for not much more effort or cost.
]I feel the tune is right but I really have no clue. Nothing to compare it to. As many have stated, the bike rides and feels very well. The bit of low end loss that I am refering to is very minimal. Jim @ HD has spent an additional 3 hrs tweeking the low end to make me happy and has told me to bring it in again if I thought it needed more. All this with true desire to get it right and no additional charge. It does not get much better than that in my book.
If Doug says some head work will wake those cams up over the full range and get the bottom end up to snuff, that would be great. My wife wants me to get the bugs workedso we will have a better understanding of what to do with her RKC as long as I don't replace stuff I just put on.
I will let you know what Doug says. Thanks for all the help. It is all good like it is but I just want to get the most out of what is there and I feel I may have left a little on the bench that can be got for not much more effort or cost.
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