Last summer I had my 2010 SG engine spiffied up with a Head-Quarters 107" kit. Unfortunately what was once enough 'giddy up' is now no longer the case, I need to feel more power. Right now I'm getting a respectable 121 Tq and 115 Hp with their head work and cam, all else is stock. Would any of you engine gurus know if going to a larger throttle body or bigger injectors would give me much if any greater gains? In hindsight I should've just gone with an S&S 124 but for now I'm on a budget and want to know if I can RELIABLY squeeze more power from this 107?
Thanks in advance.

 

Depending on your heads You could go a larger TB & change cams to a 625 for example and you might increase hp but you will probably lose tq at the same time or at least not gain any torque ....
If you are not happy not more cubes is probably the way you will have to end up going.

 

A 55mm HPI with an 1.800" intake port, and match the cylinder head port ID to that would be my thoughts.
Scott

 

sounds like to me you are the kind of guy that needs the bottom end built as well! especially if you wanna throw more at her!

 

Ahhh, buyers remorse huh? I hate it when that happens! Sure, you can go bigger on the T/B, etc. but the increase will be marginal and probably won't even register on the butt dyno. Enjoy the power that you have, save your shekels for the S&S 124.

 

Drop down 2t on your transmission sprocket.

 

What actual head work was done?

 

Yup that was my thought as well. Probably the biggest improvement you can make that you would feel.

 

Not exactly sure on the specifics for the TwinCam 107 kit, the work was done about 3000 miles away at head-quarters.com and shipped back to my builder here on the west coast. Here's what their website states about their head work,

High Velocity Ports (HVP) Spin Dropped Heads

This picture illustrates the work done to all stock Twin Cam heads used in our kits, or as done to your own heads when sent in for work. We have removed the valves to show the workmanship

We also ship the appropriate thickness head gaskets out with all jobs to ensure proper piston to head clearance.

- finished heads will have a combustion chamber volumes calculated and machined to yield the desired compression ratios
- we can also adjust the cc volume on special order heads to accommodate different pistons
- can be setup for use on 88", 95",103" or larger engines with varied compression ratios
- for use on carburated or fuel injected models
- heads are fully ported, decked, and have a fully radiused valve job
- they contain new valves (1.900" & 1.625"), guides (manganese bronze), springs (titanium top retainers), and seals (Viton)

These HVP heads are supplied with all of our performance kits

 

Is this something I can do myself with a $39 socket set and a torque wrench, I assume I would need to recalibrate the speedo too? Are there known part numbers for the smaller tranny sprocket, and (I'm guessing) a shorter belt too? This sounds like the direction I want to go, am I losing anything at the top end of the 6th gear's speed range? Is there a negative side to doing this?
Thanks for all the help and input guys!