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[laylonlor]

2010 cvo streetglide,  woods 400-6 cam , deweys heads, basily rockers, 10.5 comp., tts mastertune, so "exactly" what d and d pipe, should i run?, and what TB should be on this set up, a 54 or a 58?    thanks all   happy thanksgiving 

[sadunbar]

2010 cvo streetglide,  woods 400-6 cam , deweys heads, basily rockers, 10.5 comp., tts mastertune, so "exactly" what d and d pipe, should i run?, and what TB should be on this set up, a 54 or a 58?   thanks all   happy thanksgiving  

The answer depends on the flow rate of your heads.  To maximize performance, you don't want either end (TB or exhaust) to be the restriction of air flow thru the motor.  Talk to your head porter...


A trade off of a large throttle body is more instantaneous throttle response....which can make low speed (parking lot) maneuvering a bit more challenging.. You may not want to exceed a 58 mm throttle body regardless of the flow rate of the heads...

[Heatwave]

2010 cvo streetglide,  woods 400-6 cam , deweys heads, basily rockers, 10.5 comp., tts mastertune, so "exactly" what d and d pipe, should i run?, and what TB should be on this set up, a 54 or a 58?    thanks all   happy thanksgiving 

I don't believe there's a FBW 54mm TB on the market. I suppose your 50mm could be bored to become a 54mm but there's none available that I'm aware of. The only option to increase with a new TB is to go with HD's FBW 58mm TB.

[timtoolman]

i just got a hpi tbw  54 mm two piece t.b.  it out flows  s.e. 58mm by far,  runners can be matched to heads. depending on port size  up to 1.800,  i have    s.e. 5.3g/s  injectors on order,  dont go with the stock  50mm bored out  doesnt do a whole lot, unless runners are split and flowed, hence the 2 piece one,  id stay away from the s.e. 58 mm  t.b. in the stock form,   hpi can make that a 2 piece also with 62 mm runners  or smaller  flowed for much more power if your heads can use it,,   love our 400-6  cams!!!!!     i use fulsac  x pipe

[laylonlor]

thanks for   the info

[Heatwave]

i just got a hpi tbw  54 mm two piece t.b.  it out flows  s.e. 58mm by far,  runners can be matched to heads. depending on port size  up to 1.800,  i have    s.e. 5.3g/s  injectors on order,  dont go with the stock  50mm bored out  doesnt do a whole lot, unless runners are split and flowed, hence the 2 piece one,  id stay away from the s.e. 58 mm  t.b. in the stock form,   hpi can make that a 2 piece also with 62 mm runners  or smaller  flowed for much more power if your heads can use it,,   love our 400-6  cams!!!!!     i use fulsac  x pipe

Unless HPI has a new FBW TB that I'm not aware of, that 54mm TB will not work with any touring bike made after 2008. If you want to add a larger TB thatn the stock 50mm to a 2009 or later Touring bike your only choice is HD's 58MM TB which is fly-by-wire.

[Heatwave]

It appears that HPI's 54mm fbw TB is now available. It is simply a bored out stock 50mm fbw throttlebody. http://lt-lt.facebook.com/note.php?note_id=303558896465

[timtoolman]

depends on which one u get,  the 54 mm  just bored out  wont do i whole lot,  the 2 piece is a different animal.  i love mine

[Heatwave]

depends on which one u get,  the 54 mm  just bored out  wont do i whole lot,  the 2 piece is a different animal.  i love mine

The 2 piece won't work on a FBW bike, essentially all touring bikes since 2009.

[Black Diamond]

The 2 piece won't work on a FBW bike, essentially all touring bikes since 2009.

Looks like HPI is doing a two piece for the newer system now.

Copied from their site:

Fly By Wire Reworked Throttle Bodies

Through a core exchange program, we modify the existing stock units to meet your specific needs.  The stock 50mm FBW throttle body is bored to a 54mm and attached is a custom intake manifold specific to your build requirements.  The stock 58mm FBW throttle body is turned into a large plenum throttle body through a 62mm intake attachment, once again specific to your build requirements.

Available intake port diameters are 1.660, 1.710 and 1.800.  Extended deck lengths are raised .032” or .060” and a file to fit option.  Through these modifications, HPI is able to offer our customers a FBW throttle body solution that is affordable and unmatched in quality

I'm going to contact em to see if they feel having my HPI modified 54mm would be worth while. Their work on the stock 50mm was damn good, attaching it to their manifold may be the cat's ace!

JW

[timtoolman]

heatwave sorry i beg to differ, i have one,  don't mean to start a dissagrement here, and see the fireman

[Heatwave]

heatwave sorry i beg to differ, i have one,  don't mean to start a dissagrement here, and see the fireman

You would definitely know better than me if you own one. I was just going by their website. I must have missed that they now have tbw TBs. Thanks for the update.

[timtoolman]

my question is  i wonder if the T.B.  itself can be updated to a 58mm by just changing  the T.B.  outer piece leaving the 1.800 runner manifold for reuse,

[HD Street Performance]

A trade off of a large throttle body is more instantaneous throttle response....which can make low speed (parking lot) maneuvering a bit more challenging.. You may not want to exceed a 58 mm throttle body regardless of the flow rate of the heads...

TBW progressivity changes can buffer this and actually taylor that to the rider, head flow CFM is not an issue with the 110 head
The stock head inlet port is 1.760
The stock manifold is ~1.67 IIRC
The 58 works fine and is a good pricepoint. There is enough torque on tap with a mid compression 110 with a TW400 that a small hit in the middle s no biggee. I have heard of a few tests done by well respected shops back to back where the HPI retrofit provided no improvment. If the dyno tuner does a run and observes WOT MAP pressure and at max rpm and it is at or near 100 MAP then there is no TB restriction and a change is not going to help anything. A larger injector may be a help, especially if the PW is over 80%at WOT if the size is not overkilled