Throttle Body Cam Design
Throttle Body Cam Design
(OP)
Hi all,
I have a mate in my motorsport team that is having to design the throttle cam. He has 22mm of cable travel available and he has also determined a relationship between frontal area of the throttle butterfly compared to its degree of rotation.
Any ideas or suggestions as to what to do interms of designing the cam??
All help is much appreciated.
I have a mate in my motorsport team that is having to design the throttle cam. He has 22mm of cable travel available and he has also determined a relationship between frontal area of the throttle butterfly compared to its degree of rotation.
Any ideas or suggestions as to what to do interms of designing the cam??
All help is much appreciated.





RE: Throttle Body Cam Design
Throttle plate size matters, too. I do know that an overly large throttle combined with a quick early opening linkage makes for some difficulty in modulating the power output, especially while exiting slow/lower gear corners even when the pavement is smooth.
Norm
RE: Throttle Body Cam Design
should read
"overly large throttle combined with a quick early opening linkage and lots of available torque makes . . ."
RE: Throttle Body Cam Design
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Throttle Body Cam Design
Like i said previously, the guy has a curve comparing degree open with frontal area of the space between butterfly and throttle body casing. This rleationship isnt linear but has a slight curve to it.
I was personally thinking that the inverse of the curve could essentially be the shape of the cam which would inevitably linearize the previous relationship.
RE: Throttle Body Cam Design
There comes a point when more throttle makes no difference.
Regards
eng-tips, by professional engineers for professional engineers
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RE: Throttle Body Cam Design
Linear will work, but most throttles are set up to move slower from idle where better control is desirable. You don't need much control at or near full throttle, so most move quicker past about 50-75% open. The ECU may need re-programming for the new TPS readings.
RE: Throttle Body Cam Design
It depends on what you want, if you want the car to feel 'sporty' and 'urgent' then a faster ramp rate from closed throttle will give this. If you want it to feel tractable then the opposite is true......Anywhere in between is down to taste!
Try the 3 types, sporty, tractable & linear and then decide.
Dont worry though, the TPS wont need recalibrating.
MS
RE: Throttle Body Cam Design
We know we want the cam to have an increasing ramp rate (slow at closed - faster at open) and it is just the mathematical approach to determining the cam radius that is becoming annoying.
RE: Throttle Body Cam Design
Hope this helps...