Will larger throttle body/injectors help?
Thread Starter
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Intermediate
Joined: Jan 2009
Posts: 48
Likes: 0
From: Prague. the Czech Republic
I'm in Woods website looking for the TW6-6 and don't see it, wondering what lift, duration and cam timing are in your set-up. High lift & short duration creates cylinder pressure which creates your torque.
You already know the more air you flow the more power you can make. Cam design & cylinder pressure will be a couple of determining factors in the creation of torque in the rpm range you desire. The horsepower is in the heads. The stock heads are adequete for a stock motor but not much more.
Thats the reason larger injectors or throttle body are not needed. With a set of properly re-worked stock heads you will make more useable power across the rpm band. A 103" upgrade with cam needs more air. Hope this helps.
You already know the more air you flow the more power you can make. Cam design & cylinder pressure will be a couple of determining factors in the creation of torque in the rpm range you desire. The horsepower is in the heads. The stock heads are adequete for a stock motor but not much more.
Thats the reason larger injectors or throttle body are not needed. With a set of properly re-worked stock heads you will make more useable power across the rpm band. A 103" upgrade with cam needs more air. Hope this helps.
Banned
Joined: Sep 2009
Posts: 7,580
Likes: 7
From: The Internet (& Dyer, Indiana)
Many are very happy with that cam (except for some valve train noise).
Your heads are holding you back. Do your heads and then see where you are at.
I find it hard to believe you have low end torque issues. Maybe the tuner needs to spend some more time on it.
Maybe your exhaust is robbing you of some low end. Too much pipe for the build?
It certainly ain't the cam. It's a good cam.
Your heads are holding you back. Do your heads and then see where you are at.
I find it hard to believe you have low end torque issues. Maybe the tuner needs to spend some more time on it.
Maybe your exhaust is robbing you of some low end. Too much pipe for the build?
It certainly ain't the cam. It's a good cam.
Road Master
Joined: Nov 2009
Posts: 1,218
Likes: 0
From: Yakima WA
The stock heads don't flow worth a crap except on a stock motor. They are the weak spot in your setup right now. I am not saying go hog wild on the heads, but a port job and bowl work would allow that motor to flow some air. No sense in going to bigger injectors or throttle body if your heads are still
sportin the stock ports.
sportin the stock ports.
On my 2010 Street Glide stage II 103 project discussed having Baisley do the heads and throttle body (50mm TBW in my case stock). The estimated cost was in the 1K range with estimated gain of 6 hp and 6 tq. Did not seem to cost out bang for the buck in my opinion. The build Latus did on my bike ended up at 92 hp and 106 tq. With the different gearing in the later model bikes it does everything I would hope for it to do and has the torque down low that the OP is looking for. Sounds like a gear change on the OP's application would do better to achieve his target than head work or a throttle body change.
Ultimate HDF Member
Joined: Oct 2005
Posts: 7,279
Likes: 56
From: Union Bridge, MD
Tech specs of TW 6-6 here: http://www.fuelmotousa.com/cams.htm . What´s your opinion?
I am planning to do a simular set-up on my bike soon. I'm not looking for a wild-*** ride, but when I am in the pack and nail it I am going to leave the majority behing and have bragging rights, know what I mean? Its all about the combination of parts & tuning and you are on the right track.
Ultimate HDF Member
Joined: Oct 2005
Posts: 7,279
Likes: 56
From: Union Bridge, MD
Not true of the 2006 and later heads. They flow much better than earlier heads did stock. That is not to say that there could not be some improvement realized with optimizing valve size and cleaning up the ports in the heads. Of course to realize the improvements you would need to do clean up the throttle body as well. All of these "improvements" will not move the torque curve to the left though which was one of the OP's stated goals.
Road Master
Joined: Nov 2009
Posts: 1,218
Likes: 0
From: Yakima WA
Been around drag racing a long time and seen more guys slow down by doing head work than improve. There are guys that know how to do heads and produce results and there are those that do heads. Several guys on the forum that are way more intelligent than I on head and throttle body though, it will be interesting to see if any of them chime in.
Banned
Joined: Sep 2009
Posts: 7,580
Likes: 7
From: The Internet (& Dyer, Indiana)
Mild port job, leave valves stock size (especially the exhaust valve).
If you still lack low end torque after a good tune, then consider a more restrictive baffle in that pipe. Too much pipe will hurt low end torque (as will a too big exhaust valve).
Mild port job and tune. Just do it!
I've never heard of anyone running the TW 6 and complain about low end torque. Not sure any of those had run stock heads either.
Do it! LOL
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Thread Starter
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Intermediate
Joined: Jan 2009
Posts: 48
Likes: 0
From: Prague. the Czech Republic
Definately a better flowing design, but definately respond to mild port work. (They need less work, but they need some).
Mild port job, leave valves stock size (especially the exhaust valve).
If you still lack low end torque after a good tune, then consider a more restrictive baffle in that pipe. Too much pipe will hurt low end torque (as will a too big exhaust valve).
Mild port job and tune. Just do it!
I've never heard of anyone running the TW 6 and complain about low end torque. Not sure any of those had run stock heads either.
Do it! LOL
Mild port job, leave valves stock size (especially the exhaust valve).
If you still lack low end torque after a good tune, then consider a more restrictive baffle in that pipe. Too much pipe will hurt low end torque (as will a too big exhaust valve).
Mild port job and tune. Just do it!
I've never heard of anyone running the TW 6 and complain about low end torque. Not sure any of those had run stock heads either.
Do it! LOL
