Here are some various images comparing the OEM Milwaukee Eight 55mm throttle body to the Screamin Eagle 64mm throttle body. A couple points to note: the OEM throttle body uses a composite/plastic manifold where the SE unit uses a cast aluminum manifold that is considerably larger. They both have 1.800" inlets. Like other SE TBW throttle bodies the M8 64mm unit does not include the map sensor or injectors which must be swapped from the stock unit.

 

Jamie, would it be worthwhile to upgrade this throttlebody, and injectors? Just stage 1 at the moment. Reason im even thinkinv about it is i had just had my intake gasket tare. Dealer is saying its because of the plastic throttlebody? Have you heard of or experienced this? Or is this something to be done with like the 117 kit and not stock 107? Would it help or hurt the 107? Thanks

 

its a real shame that the new manifold isn't also composite

 

That thing is a pos

 

Curios on upgrading to the SE 64mm TB as well. Current setup is SE Torque CAM, Fullsac MX Heaser, Fullsac 2.0" baffles tuned by SE tuner and auto tuning module. What would be the benefit to upgrading to this throttle body? Would I notice any improvements and if so where?

 

Usually if you increase the throttle body size you will see your torque suffer at low rpm's. Bigger motors pass more air and require more air flow for the motor to perform at peak, so a larger throttle body is required. If you install it on an engine that can't utilize the size it will probably bogg when you take off from a stop until it gets to higher rpm's.

Horse Power Inc. does sell the manifold for their 58 mm separately and it will bolt right up to the stock TB, but it isn't on their website as a separate item, so you will have to call them. Your bikes would come closer to handling the 58 mm throttle body than the 64 mm. Either way you are looking at needing to tune, so there's another 3-4 hundred dollars for that. The manifold by itself wouldn't require a tune.

 

Sounds like I'll be leaving mine alone as it's running top notch with gobs of low-end.

 

Thanks for the info. I called HPI, but they are travelling this week. I have an email into them. I traded emails with Jamie at Fuel Moto and they have not tested the 107 with the rest of the mods I have with the 64mm upgrade, so he would not be able to send me a map So I will just upgrade the manifold and see if HPI can also offer a better flange/seal set up than the factory set up. Crossing fingers and toes...

 

It does not take away from low end torque. I swapped to the SE 64MM with no other changes and gained 3-4 torque starting from idle and across the board and 4-5 hp up top. It is worth the money.

 

Would one of these be worth it for a m8 107 with the heavy breather, 447 SE torque cam, fullsac headpipe, and Rinehart slipons? Running canned/v tune file for the time being, getting a dyno tune in a few weeks when I get home. Sitting at 33k miles now, may do a big bore kit at 100k if I don't trade in, so it would be needed then.