MSefi.com read only forum (Jan.15,2018)

I apologize for not being able to find this again, but there was a static page somewhere that had all kinda of information about OEM injectors and now that my ECU is built, I'm ready to start building the configs and such data would be very handy...

Thanks again!

Robert

designed to keep you from having super jerky throttle response

That makes sense, and explains the "drivability" leanings in the sales brochures.

Thanks!

I will also be removing the secondary butterflys and shaft.

I think I'll leave mine in for future use. I doubt it will block enough air to affect my 550.

I believe they are 38mm?

Yes, 38mm...

I'm about 85% sure I will have to fabricate an intake tract no matter what... The OD of intake port side of the XJ550 carbs is substantially smaller than on the TBs. If I have to do that anyway, I suppose I can bend and twist it to fit the Keihin's without ...

I don't think I ever mentioned that the sub-throttle equipped throttle bodies I have are removed from a 2003 Kawasaki ZX636R. I presume there is more of this on factory EFI than I was aware of. Then again, I am quite a newbie to EFI.

Robert

Most of what I have found via Google is in review and spec stuff, rather than engineering details, touting why they use it rather than how it works. For example, this snippet from a review of the 2006 Vulcan 2000:

To provide sharp throttle response at any rpm, the Vulcan 2000’s electronic ...

Is a sub throttle like the Ford SHO's had?

Not being very familiar with FI car stuff (yet), I don't know about that, but the sub-throttles in my TBs is basically a second set of butterflies on the atmospheric side of the throttle plates, operated by a stepper motor and equipped with its own ...

Has anyone ever done any experimenting with the sub throttles on many TBs rather than just ignoring them or removing them?

It is my understanding that they help with throttle response much like a CV carburetor does.

Robert

Hello!

Has anybody used this throttle body in a retrofit?

I got a set for what I hope was a good price on eBay. They are spotlessly clean. and they were well packed for shipping.

I plan to install them on an '82 Yamaha Maxim 550 and they are the first piece of hardware in the gathering of bits ...