Bigger Throttle Body
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Road Warrior
Joined: Nov 2007
Posts: 1,984
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Bigger Throttle Body
I would like some input on bigger throttle bodies for 08 FLSTF.
Stock modified heads, stock heigth cylinders.
I am leaning toward the Kuryakyn Wild Thing # 469 with #467 flanges. Mainly cause seems to be a bolt on with ability to use all HD stock type aircleaners. and price.
I would appriciate any thoughts on this whole subject, not just what I am leaning toward.
Thanks
Old Gunny
Stock modified heads, stock heigth cylinders.
I am leaning toward the Kuryakyn Wild Thing # 469 with #467 flanges. Mainly cause seems to be a bolt on with ability to use all HD stock type aircleaners. and price.
I would appriciate any thoughts on this whole subject, not just what I am leaning toward.
Thanks
Old Gunny
Last edited by Old Gunny; Dec 19, 2008 at 03:44 PM.
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From: Hollis
I would like some input on bigger throttle bodies for 08 FLSTF.
Stock modified heads, stock heigth cylinders.
I am leaning toward the Kuryakyn Wild Thing # 469 with #467 flanges. Mainly cause seems to be a bolt on with ability to use all HD stock type aircleaners.
I would appriciate any thoughts on this whole subject, not just what I am leaning toward.
Thanks
Old Gunny
Stock modified heads, stock heigth cylinders.
I am leaning toward the Kuryakyn Wild Thing # 469 with #467 flanges. Mainly cause seems to be a bolt on with ability to use all HD stock type aircleaners.
I would appriciate any thoughts on this whole subject, not just what I am leaning toward.
Thanks
Old Gunny
Last edited by NTrat; Dec 19, 2008 at 03:50 PM.
Thread Starter
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Road Warrior
Joined: Nov 2007
Posts: 1,984
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107 with 4.375 crank and 3.0937 bore.(106.5 really)
Thats the thing I need imput on. The SE big bore TB is 51.
Will it fit, bolt up?
The Zippers sounds good but you got to buy their Air filter backing plate to use theirs. For another chunk of change.
Thats the thing I need imput on. The SE big bore TB is 51.
Will it fit, bolt up?
The Zippers sounds good but you got to buy their Air filter backing plate to use theirs. For another chunk of change.
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From: Hollis
Last edited by NTrat; Dec 19, 2008 at 04:54 PM.
Thread Starter
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Road Warrior
Joined: Nov 2007
Posts: 1,984
Likes: 7
I know from automobile engine preformance fooling around the intake module's got bigger and bigger. Fuel injection tuning got better and better to handle.
Had a Chevy with Tuned Ports (long intakes for torque) in 1990. Had speed density like our Harley's. Today same engine, sort of, with giant intakes puts out the same low or hang on high RPM.
I know with carborators there is both Air and Fuel. Have to think about volicity. With FI there is just Air. I know Air has weight but I wonder if a big TB can be tunned to keep low end?
See 72 and still wondering, never stops.
So it's 50 SE or 55-58 other brands?
And yeah those BCheads are differend.
Had a Chevy with Tuned Ports (long intakes for torque) in 1990. Had speed density like our Harley's. Today same engine, sort of, with giant intakes puts out the same low or hang on high RPM.
I know with carborators there is both Air and Fuel. Have to think about volicity. With FI there is just Air. I know Air has weight but I wonder if a big TB can be tunned to keep low end?
See 72 and still wondering, never stops.
So it's 50 SE or 55-58 other brands?
And yeah those BCheads are differend.
Last edited by Old Gunny; Dec 19, 2008 at 04:39 PM.
Banned
Joined: Oct 2008
Posts: 164
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From: Hollis
I know from automobile engine preformance fooling around the intake module's got bigger and bigger. Fuel injection tuning got better and better to handle.
Had a Chevy with Tuned Ports (long intakes for torque) in 1990. Had speed density like our Harley's. Today same engine, sort of, with giant intakes puts out the same low or hang on high RPM.
I know with carborators there is both Air and Fuel. Have to think about volicity. With FI there is just Air. I know Air has weight but I wonder if a big TB can be tunned to keep low end?
See 72 and still wondering, never stops.
So it's 50 SE or 55-58 other brands?
And yeah those BCheads are differend.
Had a Chevy with Tuned Ports (long intakes for torque) in 1990. Had speed density like our Harley's. Today same engine, sort of, with giant intakes puts out the same low or hang on high RPM.
I know with carborators there is both Air and Fuel. Have to think about volicity. With FI there is just Air. I know Air has weight but I wonder if a big TB can be tunned to keep low end?
See 72 and still wondering, never stops.
So it's 50 SE or 55-58 other brands?
And yeah those BCheads are differend.
The larger the port diamater the more you reduce port velocity, you have to find a good balance to keep velocity up without reducing overall volume.
Not sure what your talking about with the BC throttlebody but it bolts right up to the stock heads and sensors, no mods necessary.
Tourer
Joined: Aug 2006
Posts: 484
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From: Indianapolis
The stocker runs fine on my bike. The thing you have to think about is how you ride you will deffinately lose bottom end hp & tq if you go bigger. I would think about bigger injectors before replacing the throttle body.
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From: Hollis
Depends on the TB he uses, bigger injectors wouldnt be needed on a dual runner intake TB. If anything, he could go smaller.
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Tourer
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the kury works fine, as does hpi (what I run), and some folks have had good results with zippers...mixed reviews of dual throat...some say hard to tune
the screamin eagle t/bs do not flow well
the 51mm horsepower inc and s.e. injectors is good for 125 or more hp on an '08 big twin
I'm very happy with my setup...mpg did suffer a lot, even after setting afr to 14/1 from 20% throttle down...and it will bog if I whack the throttle at too low rpm...throttle response improved a lot, and I gained 11 horsepower...it is a bobbed dyna and I weigh 170, so I'm not concerned about losing a few points of torque
the wood 7 is more of a torque cam...it will be interesting to see what you gain, and at what rpm
I am not selling anything, just sharing my experience/opinion
the screamin eagle t/bs do not flow well
the 51mm horsepower inc and s.e. injectors is good for 125 or more hp on an '08 big twin
I'm very happy with my setup...mpg did suffer a lot, even after setting afr to 14/1 from 20% throttle down...and it will bog if I whack the throttle at too low rpm...throttle response improved a lot, and I gained 11 horsepower...it is a bobbed dyna and I weigh 170, so I'm not concerned about losing a few points of torque
the wood 7 is more of a torque cam...it will be interesting to see what you gain, and at what rpm
I am not selling anything, just sharing my experience/opinion
Last edited by skyhook; Dec 20, 2008 at 04:49 AM.
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From: Hollis
the kury works fine, as does hpi (what I run), and some folks have had good results with zippers...mixed reviews of dual throat...some say hard to tune
the screamin eagle t/bs do not flow well
the 51mm horsepower inc and s.e. injectors is good for 125 or more hp on an '08 big twin
I'm very happy with my setup...mpg did suffer a lot, even after setting afr to 14/1 from 20% throttle down...and it will bog if I whack the throttle at too low rpm...throttle response improved a lot, and I gained 11 horsepower...it is a bobbed dyna and I weigh 170, so I'm not concerned about losing a few points of torque
the wood 7 is more of a torque cam...it will be interesting to see what you gain, and at what rpm
I am not selling anything, just sharing my experience/opinion
the screamin eagle t/bs do not flow well
the 51mm horsepower inc and s.e. injectors is good for 125 or more hp on an '08 big twin
I'm very happy with my setup...mpg did suffer a lot, even after setting afr to 14/1 from 20% throttle down...and it will bog if I whack the throttle at too low rpm...throttle response improved a lot, and I gained 11 horsepower...it is a bobbed dyna and I weigh 170, so I'm not concerned about losing a few points of torque
the wood 7 is more of a torque cam...it will be interesting to see what you gain, and at what rpm
I am not selling anything, just sharing my experience/opinion
A little heads up, but dual runner TB's like the BC Gerolomy TB is actually much easier to tune. Reversion, cam/cylinder overlap etc between cylinders is now eliminated. Tuning becomes much easier when the injectors send fuel to the cylinder intended.
Skyhook, if you "whack" the throttle quick and your engine "bogs" down with a low pitched exhaust tone, its just a sign that your running too large of a throttlebody and your combustion burn is suffering from it. Your intake charge just isnt what it should be. When it comes to carbs and throttlebodies, bigger is not necessarily better, many/most times its actually worse.