Porting a throttle body ?
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Road Captain
Joined: Oct 2007
Posts: 743
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From: Morris, Il
Porting a throttle body ?
Doing a 107, would porting the throttle body be benifitial. Had 103 with head work. Bad leak down taking apart going to do 107. Would having the throttle body ported help with power.
Thanks
Thanks
Extreme HDF Member
Joined: Sep 2010
Posts: 14,744
Likes: 402
From: Phoenix '53, '88, '09 Big Twins
maybe, maybe not depending on what the rest of the motor is doing.
1.) a larger TB means lesser velocity which affects lower rpm cylinder fill
2.) it was found on evos that a rough casting on the intake tract actually flowed more air than a smooth bore. like a golf ball, the rough areas held air which acted as a buffer to allow the air in the center of the TB to move more quickly
mike
1.) a larger TB means lesser velocity which affects lower rpm cylinder fill
2.) it was found on evos that a rough casting on the intake tract actually flowed more air than a smooth bore. like a golf ball, the rough areas held air which acted as a buffer to allow the air in the center of the TB to move more quickly
mike
Outstanding HDF Member
Joined: Dec 2007
Posts: 2,403
Likes: 20
From: Indy
A match ported will be more efficient no doubt, if the intake ports are not lined up, then you will most definitely gain, but to get it right you need the heads ,and the intake, or mark the intake to where it needs to be opened up.
I have ported heads on a 1600cc buggy engine, he ran it for a while, and then took the intakes off , and had me port them, he said it had power it never had before.
I have ported heads on a 1600cc buggy engine, he ran it for a while, and then took the intakes off , and had me port them, he said it had power it never had before.
Stellar HDF Member
Joined: Oct 2007
Posts: 2,314
Likes: 31
From: Eastern PA
I am having a stage 4 installed on my 2012 that comes w/ a 58 mm TB ...I am installing a 54 mm because I believe the 58 to be to large and bog in-low rpm's...I have no math fact on bikes but on small block such as a 340 if you put a 750 double pump on, you will get bog at lower RPM's when going straight to full throttle. If you put a 650 on, the performance off a rolling bottom take off is much improved. And such my theary...a 113 can barely handle a 58 mm TB. IMHO
Road Master
Joined: Dec 2007
Posts: 885
Likes: 14
From: SoCal
I am running a 117" with a 58mm HPI TB. I had it matched and ported along with my heads by Dan Vance Racing and it is awesome! Plenty of low end torque early on and is a blast to ride. It all depends on the build. Planing out your build before you start will make you happy.
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FM ports/hones the stock TB for their 107" build. Jamie mentioned in some thread here that the stock 50mm TB is big enough for that CI displacement....
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Road Warrior
Joined: May 2008
Posts: 1,513
Likes: 6
From: SC
Cam profile will also be a factor in how efficient a throttle body works. The velocity of air flow into your engine can be enhanced with porting work if your looking for high rpm use. I had my stock 50mm ported to a 54mm for my 117". Its always smooth and provide great response at rpm ranges I use when riding.
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