Stock 103 piston/head upgrade???

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Sep 30, 2014 | 05:13 PM

King Papi

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From: Georgia

Stock 103 piston/head upgrade???

I have a 2011 SG, SE h/b, Fatcat, S&S HP103 cam, Evolution 30 tooth compensator, and a Energy One clutch with SE high performance spring.

I want to change out the stock pistons and go with a higher compression piston in hopes that I can gain more torque and hp. I don't know which manufacturer to go with or how hot it will make my bike run. Need advice on that.

I also know that in order to gain more power I need more air. So I'm considering going to a 58mm throttle body. I hear S&S Throttle Hog is the way to go but need some more info. I've seen 58mm kits on Ebay for 600+ but looking to save a few coins if at all possible. Need advice on this too.

SO this off season its either going to be throttle body and pistons for a quick fix. Or just some major head work and build around that as time/money permits.

Looking forward to hearing everyones comments, thanks

Sep 30, 2014 | 05:46 PM

ghostrunner

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From: Joplin, mo

Can raise compression by going to a thinner head gasket I believe.

Sep 30, 2014 | 06:23 PM

0ldhippie

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Joined: Mar 2012

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From: Santa Cruz

Headwork will get ya more than pistons and/or throttle body. In fact a bigger throttle body is a complete waste without headwork.

Sep 30, 2014 | 06:42 PM

Neggy ZRXOA 5248

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From: KMHT KFMY

you are going to do head work, pistons and 58MM TB to get well into the 100/100 club

from the looks of the stuff you have already you should already be pretty close

Last edited by Neggy ZRXOA 5248; Sep 30, 2014 at 06:45 PM.

Sep 30, 2014 | 08:17 PM

King Papi

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From: Georgia

Neggy the cam and the other two components got me 105hp and 113 torque.

Oldhippie so doing just headwork is enough and I won't lose the current performance??

Sep 30, 2014 | 09:04 PM

bagman1

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Joined: Dec 2007

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From: Bay Area

I think a 58mm TB is too much for a 103, 50 should be plenty big, but as long as the air can enter and exit fast enough the better. I have a 10.5-1 with MVA heads, 50mm TB, 585 cams, Arlen Ness inverted AC and Supertrapp 2:1:2 stepped headers with X pipe and 26 discs each, and its making 124/121