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DBW throttle body size recommendations

PostPosted: Tue Jul 10, 2012 8:22 pm
by 20B
I'm looking for a 50mm size butterfly DBW throttle body to use in a custom application, any recommendations ?

Re: DBW throttle body size recommendations

PostPosted: Wed Jul 18, 2012 11:55 am
by JamieA
how much power are you trying to achieve?

Re: DBW throttle body size recommendations

PostPosted: Wed Jul 18, 2012 9:40 pm
by 20B
Jamie,
Power irrelevant, i am looking at re-doing my cable driven triple 50mm throttle body setup with a DBW4 driven setup so just need 3 x 50mm sized units.
Honda 2008- 2012 Jazz is all I have found so far but they look good for the money and should have a calibration already from Motec ?

Re: DBW throttle body size recommendations

PostPosted: Thu Jul 19, 2012 6:30 pm
by 20B
Another question to add, the OEM RX7 used a nice multistage opening throttle body to assist with low speed drive-ability which opens the primary throttle plate first then opens the secondary ( larger ports ) butterflies at around 8% TPS to aid in air velocity and scavenging. This was done with a nifty OEM throttle linkage system.
Is there any way to replicate this with a DBW4 ?
One smaller DBW throttle body opens first then the remaining three start opening at a set TPS from the first unit ?

Re: DBW throttle body size recommendations

PostPosted: Thu Sep 06, 2012 5:53 pm
by Blu302
Maybe look at the E46 M3 DBW(S54 engine). They run an ITB setup with the cable pull replaced with a DBW motor and linkage. the motor is seperate to the ITB's and the ITB's are 6x single units linked together.

Re: DBW throttle body size recommendations

PostPosted: Mon Sep 10, 2012 11:31 am
by 20B
Blu302,
Been there done that with the BMW system, I built a test rig and everything but just couldn't get it to work with my system. Once you change the throttle bodies to something custom it throws out the PID control on te motor as its been calibrated for that OEM setup. Just felt too dodgy changing stuff to try and make it work.
The DBW4 will solve my problems as its effectively a 'sealed' unit with everything integrated so I can concentrate on tuning it rather than messing with custom PID settings.
I have found the late model Honda Fit (Jazz) has the size (50mm) I'm after and the throttle bodies can be purchased on eBay for less than building a system with conventional mechanical multi throttle anyways !

Re: DBW throttle body size recommendations

PostPosted: Tue Sep 11, 2012 9:06 am
by Scott@FP
20B check your PM's.

Re: DBW throttle body size recommendations

PostPosted: Wed Sep 19, 2012 8:26 pm
by Blu302
Thanks for that bit of info. I was looking at adapting it to drive a different ITB setup. If it doesn't work, I won't put in the effort just to fail. Maybe Motec could do a custom PID if the whole setup was sent to them?

Re: DBW throttle body size recommendations

PostPosted: Mon Oct 01, 2012 12:26 pm
by MattW
Check out mark's webinar video On PID tuning. Tuning PID
If you have access to an oscilloscope you could do it all yourself.

Being able to PID tune is a good skill to have, so it's worth learning.
You will then be able to do your idle and boost control. :)