So, I'll be installing an S&S T111 crate motor. I was planning on using the stock throttle body, but am starting to consider upgrading. What size, and / or manufacturers should I be considering? I think S&S suggests their 58mm. Do I need to go that big? Is it thAt big? Would an SE 50 work?

Thanks in advance.

 

Se 50 does not work very well and will not work on your bike without modifications. There's a kuryakyn 57mm for 01-05 on eBay right now for $275 obo, that would work great.

 

Might find a 2001- 2005 HPI 55mm also.

 

YEPPER HPI is what your looking for, don't worry if you get one that's too big it will work fine with your 111 and be even better if you eventually modify the heads. With the capacity of the 58 at least you can have peace of mind that it's not pumping at it's limit, it will have breathing room if you know what I mean.

 

Maybe this will help
Don't cut it short now, get all you can get.

 

No dyna has ever come with magnetti marelli (thankfully).

Sure hpi is great, but not the only tb out there just cause they're popular online right now. This isn't an all out, high hp, every last 1/2hp counts motor. If you can justify the price of the hpi work of art get a 58. If you want the same performance for almost 1/3 the price, the kuryakyn wild things will work great. Either one will support 140+hp, I'd spend the extra $500 elsewhere, but that's just me.

Edit: there's another one on eBay for $255 shipped, someone should scoop these things up, I'm about to just to have it.

 

I threw out the HPI option thinking maybe XFXDX could find a used one for a reasonable price. I got mine for about $400 with the fuel injectors included but for new, I agree the Kuryakyn sounds like the ticket.

I know there was a thread over at HTT a year or two about going too big on the tbs - some said just go big, some mentioned throttle being too touchy at low rpms. Anyway, I wanted a 51mm HPI but could not find a deal on one so I got the 55mm. I do find that my throttle is touchy, not painfully so but if I had my rathers I would take the 51mm size. Just trying to put out a thought on not going too big.

 

I'm with PILOT. Going to big isn't thenbest always......you may loose bottom end and to big of a TB will be hard to tune.

 

Looks like HTT is going to disect this debate again:

http://harleytechtalk.org/htt/index....c,80651.0.html

 

That's definitely a sweet deal on an hpi, I was just comparing new prices.

Nothing wrong with going big. Not like it's a 95", it won't lose on the bottom. What most people consider "losing on the bottom" is what's seen on a high gear 2k rpm wot roll on, extremely high load, unrealistic conditions. This internet dyno sheet "my d**** bigger" thing has trained people to only worry about that wot sheet instead of how the bike feels. IF it did lose a little there it would never be felt on the street because the bigger throttle blade will gain a ton at smaller throttle position openings where it will be felt. This can make the throttle touchy at low speeds but you get used to it and it also makes it very responsive, most people prefer that feeling. I've had great results with 58s on anything 103 and larger. Nothing at all difficult about tuning them either.