I am not so sure that size of the throttle body directly correlates with torque
level! Perhaps when on a full throttle run it does though. The throttle body is
variable in it's flow ability anyway (with the opening and closing of the
butterfly). I assume that if you had a masive throttle body, then at low rpm,
peak torque might be gained with only 75% throttle as opposed to 100% throttle.
Kinda like how F1 cars control their throttle these days.
zac
> Thanks Trev, I have 36 mm chokes in my webers at the moment and I figured
> out the crossectional area(combined) to be 40.71cm^2 on my 2L motor and its
> not too doughy down low at all. With the RB30 throttle body the entire
> cross-sectional area is 23.75 cm^2 which means on a 1.8L litre it should go
> pretty well and have plenty of low end torque compared to the setup on the
> 2L. Thanks for the advice
>
> Daniel Kroehn
> Recommending Datrats, supplying quality Datsun performance parts
> www.Datrats.com.au
>
> ----- Original Message -----
> From: Pooley, Trevor <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Thursday, June 28, 2001 1:02 PM
> Subject: RE: Throttle Body size??????
>
>
> > Daniel,
> >
> > You should be able to work it out theroetically.
> >
> > I haven't done the maths yet but will have to investigate. Should be
> easier
> > to work out for a NA motor than a boosted intake but simular principals
> > should apply. Think about main venturi's in DCOE weber's Small ones
> increase
> > air speed at low revs (ie throttle response) but at the expense of
> outright
> > flow at higher revs (hence their common description of Chokes).
> >
> > Have look at some racing cars F2/3. They have a small resticter in front
> of
> > a massive plenum (Which must stuff up flow at higher engine speeds). The
> > outright rally cars have a restricter and only make 10hp or so more the
> > Group N.
> >
> > OK so what is the reverse of all this. Poor low rev throttle response.
> Also
> > why go big if there is a restriction in other areas. Ports, valves,
> > intercooler, intake plumming also consider manifold length, diameter and
> > plenum size etc.
> >
> > Bottom line is everything must work together and going too big with the
> > thottle body may make it undriveable at low revs. It may make the system
> > mismatched in other areas making the whole thing worse.
> >
> > Regards
> > Trev
> >
> >
>
>
