throttle body???
Thread Starter
|
Tourer
Joined: Nov 2010
Posts: 400
Likes: 10
From: Buckeye State
throttle body???
I have an 07 ultra classic. It is a 96" with a se air cleaner, stock tb, woods TW555 cams, stock heads and compression, Dragos dragula exhaust. I was wondering if I was to bore out my throttle body from 46 mm to 48 mm or even to 50 mm (if able) and do a port and polish of the intake runners if that would help me much. I know you can have too much intake and the low end will suffer but didn't know how much. I was looking at Fuel Moto's website and it looks like the newer bikes with the same cams and stock heads were making quite a bit more power than my bike.
thanks in advance
matt
thanks in advance
matt
HDF Community Team
Joined: Jun 2006
Posts: 12,774
Likes: 2,606
From: san antonio
I have an 07 ultra classic. It is a 96" with a se air cleaner, stock tb, woods TW555 cams, stock heads and compression, Dragos dragula exhaust. I was wondering if I was to bore out my throttle body from 46 mm to 48 mm or even to 50 mm (if able) and do a port and polish of the intake runners if that would help me much. I know you can have too much intake and the low end will suffer but didn't know how much. I was looking at Fuel Moto's website and it looks like the newer bikes with the same cams and stock heads were making quite a bit more power than my bike.
thanks in advance
matt
thanks in advance
matt
Last edited by djl; Dec 8, 2012 at 10:50 AM.
Sponsor
Joined: Dec 2007
Posts: 12,084
Likes: 829
I have an 07 ultra classic. It is a 96" with a se air cleaner, stock tb, woods TW555 cams, stock heads and compression, Dragos dragula exhaust. I was wondering if I was to bore out my throttle body from 46 mm to 48 mm or even to 50 mm (if able) and do a port and polish of the intake runners if that would help me much. I know you can have too much intake and the low end will suffer but didn't know how much. I was looking at Fuel Moto's website and it looks like the newer bikes with the same cams and stock heads were making quite a bit more power than my bike.
thanks in advance
matt
thanks in advance
matt
For the dollar spent vs the power gained, that would be your most cost-effective upgrade at this point.
Naturally, a cylinder head that hovers at/near the 160 cfm mark, would also bring more to the party, and help maintain a cool running powerplant as well.
Scott
Advanced
Joined: Aug 2008
Posts: 68
Likes: 0
From: Connecticut
bigger throttle body
Taking the stock 46mm t/body and boring it out to 50 mm is a very common upgrade around here. It is fairly easy to get 155 cfm through the t.body and into the heads with a little work. The 46 to 50 mm upgrade will flow more than a stock 50mm from the factory. for more info check out danvanceracing.com
HDF Community Team
Joined: Jun 2006
Posts: 12,774
Likes: 2,606
From: san antonio
I didn't think the 46mm TB can be bored to 50mm but did some digging and found that Johnsone Engineering Technology can bore the 46mm TB to 51mm. Dyno testing shows power increases across the rpm range and not just at the upper end. Not huge gains but looks like 8HP/5TQ for $365 is fairly reasonable on a $$/HP-TQ basis.
As I understand, just boring the TB could hurt performance. JET usesepoxy after boring to shape the intake and increase the velocity of the air flow to get the results. Follow the link for details.
http://www.johnsonenginetechnology.c...ttle-body.html
Boring your cylinders to 103" and fitting a set of SE cast flat top pistons is also a good bang for the buck. About $400 if you DIY the job; that's about $40/TQ-HP; pretty cheap power.
Why not bore to 103" and bore the TB to 51mm?
Don't worry about dyno numbers you see around the internet; if you are happy with your bike; be happy and look for cost effective ways to get a bit more power. Check into changing the trans pulley; those six speeds were geared a bit tall. Dropping a tooth, or two, on the trans pulley will help as well; work intensive and I wouldn't do it for one tooth but everyone I hear from that has done it is happy with the results. One tooth drop, OEM belt will accomodate but two tooth drop will require a new belt; or so I have been told.
As I understand, just boring the TB could hurt performance. JET usesepoxy after boring to shape the intake and increase the velocity of the air flow to get the results. Follow the link for details.
http://www.johnsonenginetechnology.c...ttle-body.html
Boring your cylinders to 103" and fitting a set of SE cast flat top pistons is also a good bang for the buck. About $400 if you DIY the job; that's about $40/TQ-HP; pretty cheap power.
Why not bore to 103" and bore the TB to 51mm?
Don't worry about dyno numbers you see around the internet; if you are happy with your bike; be happy and look for cost effective ways to get a bit more power. Check into changing the trans pulley; those six speeds were geared a bit tall. Dropping a tooth, or two, on the trans pulley will help as well; work intensive and I wouldn't do it for one tooth but everyone I hear from that has done it is happy with the results. One tooth drop, OEM belt will accomodate but two tooth drop will require a new belt; or so I have been told.
Before I got on a suspension kick, I was in communication with Jamie (FM) about his TB porting service. He advised me that just cleaning up the stock size TB has has been very favorable for his 107" builds. Bigger may be better (and they don't bore TB's) but $175 ain't bad. Being only 110 miles away, he advised they'd do parts and labor for $275 while I wait. Still something to consider come late spring ....
Trending Topics
Thread Starter
|
Tourer
Joined: Nov 2010
Posts: 400
Likes: 10
From: Buckeye State
I was thinking that being a machinist that I could bore the TB out myself and blend and smooth the intake to help my poor poor 96" until I could buy the 107. If I have it down to the block i might as well do it right and go all out on it with port polished heads at that point so it will take a little while to put the $$$ aside to do that... maybe next year...
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
