08 and up 103 build with your hands tied (Stock pistons, OEM dbw TB with mods)

[strokerjlk]

also look at what the cvo 110's top out at for  HP on a stock T/B when you put compression to them.

[1FSTRK]

I do not know what  a stage 4 does with a stock DBW TB,I thought they included a bigger tb, as far as the 110 remember we are using stock 103 pistons so we can't throw compression at it.

[Don D]

the cap would be with your Street  Pro heads

The throttle body and injectors are done, the constraint isn't the SP heads, on a stock block 103. This happens around 118hp. Pipes can change things a tad and change the shape of the curve but not much more HP

The 110 has the same behavior but has a larger stock injector so can be pushed with just a TB change, plus has the virtue of heads that start with airflow potential

[1FSTRK]

I had not even thought of the stock injector running out. I will have to look and see what injector the 2014 103ci comes with. I just assumed the air and compression would run out first.

[Don D]

M1marty can comment. He is a tuner and was running short with his at about 118sq but his is not a 14. I don't know what injectors they have.

[strokerjlk]

I do not know what  a stage 4 does with a stock DBW TB,I thought they included a bigger tb, as far as the 110 remember we are using stock 103 pistons so we can't throw compression at it.

Same throttle body on the Cvo 110 . The reference is look at where they run out of hp. regardless of compression that gives you a idea where you can push a 103 as far as hp with the same T/B .

[Don D]

remember we are using stock 103 pistons so we can't throw compression at it.

You'd be surprised, just don't detonate it, so a good tune is given.

[bajabob]

103  larry's  1+ heads  dv bored t/b  Andrews 57  10.35 static  pro-pipe chrome  stroker tuned  109/109

[Don D]

This is m1martys dyno but he later added timing and picked hp a few more hp and torque plus the low end moved up. He is on the road now but will post after results when he gets back.

[TorQuePimp]

  You can bore a late throttle body to 51/2.007  and if REALLY careful 51.5/2.027

   Or snag a 08-10 and bore it to 54mm

  HPI did a ton of them a few years back and a build with stock pistons needs as much help as it can get

[1FSTRK]

remember we are using stock 103 pistons so we can't throw compression at it.

You'd be surprised, just don't detonate it, so a good tune is given.

Don as usual you have lost me.
What does "you'd be surprised mean"?
Stock pistons probably down in the hole .004-.008 depending on the bike, you pick the head gasket do your street pro head work and cut the head, how much will you cut off and what is the new static compression?

[1FSTRK]

  You can bore a late throttle body to 51/2.007  and if REALLY careful 51.5/2.027

   Or snag a 08-10 and bore it to 54mm

  HPI did a ton of them a few years back and a build with stock pistons needs as much help as it can get

You do this to the DBW TB?
What do you do for the small spigot end size?

[strokerjlk]

Tuned a ton of the stock 50's bored to 54 hpi from hpi before they offered the 58 upgrade .
The 58 is well worth the little extra cash nowadays .

[m1marty]

79cc heads and ..030 gaskets got me 10.75. Ccp is right around 195-200

[1FSTRK]

79cc heads and ..030 gaskets got me 10.75. Ccp is right around 195-200

Thanks that's all I was looking for.

[dsvracer]

Dan this is the type of thing I was after. Is the 2012 Stock DBW throttle body the same size as the 2014 and up?
The one that strokerjlk posted looks close to this and also has your throttle body work.
The post from Strokerjlk is using a 46-50 mm cable t/body.   the one I used is a fbw that has a little blending inside, nothing special.
yes I think the 12 and 14 are the same.  dsv

[Don D]

remember we are using stock 103 pistons so we can't throw compression at it.

You'd be surprised, just don't detonate it, so a good tune is given.

Don as usual you have lost me.
What does "you'd be surprised mean"?
Stock pistons probably down in the hole .004-.008 depending on the bike, you pick the head gasket do your street pro head work and cut the head, how much will you cut off and what is the new static compression?

Legacy says replace the pistons with forged at 10.5:1 compression. Legacy also used to say stock valve springs were the worst pieces of steel on the earth and roller rockers were essential at .575 lift. We have blown all those paradigms. Real world is they all work fine when pushed a little. This is not just an isolated situation either. M1marty rides his bike all year, rides hard, and so do his buddies that have done the same or very close to the same build. Remember the HD 95" cast high compression piston? Those weren't shattering unless they were hammered or run with a super lean tune. Dealers used the same piston pushed to 11:1 and they seemed to work, albeit not my first choice.
My eyes would be on the bottom end far before this not the pistons or adequate airflow. At least true and pin the crank. If that is already in your plan great, you will at least have addressed the foundation at the 80%+ level. I know the rods pinch and spin bushings but you need to decide if that is a factor worth dealing with.

[1FSTRK]

Dan this is the type of thing I was after. Is the 2012 Stock DBW throttle body the same size as the 2014 and up?
The one that strokerjlk posted looks close to this and also has your throttle body work.
The post from Strokerjlk is using a 46-50 mm cable t/body.   the one I used is a fbw that has a little blending inside, nothing special.
yes I think the 12 and 14 are the same.  dsv

So if I understand correctly you did work to the stock fbw but did not bore or replace the butterfly?

[1FSTRK]

remember we are using stock 103 pistons so we can't throw compression at it.

You'd be surprised, just don't detonate it, so a good tune is given.

Don as usual you have lost me.
What does "you'd be surprised mean"?
Stock pistons probably down in the hole .004-.008 depending on the bike, you pick the head gasket do your street pro head work and cut the head, how much will you cut off and what is the new static compression?

Legacy says replace the pistons with forged at 10.5:1 compression. Legacy also used to say stock valve springs were the worst pieces of steel on the earth and roller rockers were essential at .575 lift. We have blown all those paradigms. Real world is they all work fine when pushed a little. This is not just an isolated situation either. M1marty rides his bike all year, rides hard, and so do his buddies that have done the same or very close to the same build. Remember the HD 95" cast high compression piston? Those weren't shattering unless they were hammered or run with a super lean tune. Dealers used the same piston pushed to 11:1 and they seemed to work, albeit not my first choice.
My eyes would be on the bottom end far before this not the pistons or adequate airflow. At least true and pin the crank. If that is already in your plan great, you will at least have addressed the foundation at the 80%+ level. I know the rods pinch and spin bushings but you need to decide if that is a factor worth dealing with.

OK so the short answer is you cut a lot off the heads to make the compression with a stock piston.
Thanks for all the off topic build advice you threw in for free.
Do 2014 rods even have bushing?

[oldhippie]

Here is mine. 103 cast flattops, Fullsac, Fatshotz, SE a/c, Andrews 54, Hillside stage 1 heads



Lots of folks do better.

[Don D]

OK so the short answer is you cut a lot off the heads to make the compression with a stock piston.
The heads were cut .048" both, is that a lot?

Do 2014 rods even have bushing?
No so that's one thing to scratch off the list.

[strokerjlk]

This is m1martys dyno but he later added timing and picked hp a few more hp and torque plus the low end moved up. He is on the road now but will post after results when he gets back.

this is with a feuling 574 at 10.75 ? nice

[strokerjlk]

maybe this will help vic.
this is a 2008 stock t/b 255 cams SE kompressor heads 10.5 pistons. V&H true duals. cranked 225 ccp.
shows you what kind of peak tq you can get with stock heads T/B  and compression .
heck all he has to do is pick a cam ,and build a pipe 

[Don D]

This is m1martys dyno but he later added timing and picked hp a few more hp and torque plus the low end moved up. He is on the road now but will post after results when he gets back.

this is with a feuling 574 at 10.75 ? nice

Started with the feuling and did close to the same but less torque and ended up with a tman 577

[strokerjlk]

This is m1martys dyno but he later added timing and picked hp a few more hp and torque plus the low end moved up. He is on the road now but will post after results when he gets back.

this is with a feuling 574 at 10.75 ? nice

Started with the feuling and did close to the same but less torque and ended up with a tman 577