Problem SE Stage IV kit/58mm Throttle body

[dolt]

will the 50mm bolt on in place of the 58mm? I have this same kit. Mine runs fine. Tuned by doc's hd in St.Louis I was told I couldn't change because a smaller tb would not bolt up to the larger ports. My only reason for changing would be to see if I can get a little faster throttle response.

I would look elsewhere for a solution. I believe when you refre to throttle response you may actually be experiencing the tall gearing of the '09 model as well as the softnes of the 260/259 cams that were installed with the kit.

A cam change and/or a trans pulley change to a 30T, or both, will wake things up.

 

[jlbeebe]

I am running woods tw400 cams already. A 30t pully might be just what I'm looking for.

 

[dolt]

I am running woods tw400 cams already. A 30t pully might be just what I'm looking for.

The SE kit you make reference to, IIRC, includes the 110 heads with 95cc combustion chambers combine with 22502-07 domed pistons for 10.5:1 statice compression. The MoCo uses fuzzy math and that piston dome volume has been measured at 11cc-11.4cc. Plugging those numbers into a compression calculator, assuming pistons are down in the hole .005"-.007", and stock head gasket, your static CR is below 10:1. I am thinking that if you were actually seeing 10.5 static, your butt dyno would register better "throttle response". All speculation on my part and I could be way wrong. The earlier intake close of the TW400 helps, not doubt but I think you need to see a true 10.5 or better to wake that motor up.

Having said all that, a 30T pulley should help; don't know if it will get you where you want to be but worth a shot. BTW, you will need a shorter belt to make that swap, or you will need to purchase a 68T wheel pulley as well to retain the OEM belt.