Re: 16v throttle body on an 8v intake?? And Ramblings

[Brad Sheridan <brads@mindspring.com>]

> 
> not sure about the 16v but the Audi 5000 one works.
 
  I've heard someone here mention using it. The Neuspeed and Audi tb have a
secondary(larger plate) that is 52mm in diamater. I think the 16V is the
same, although I havent measured mine.


> speaking of T-bodys. The one on my 2.0L 16v block is angled
> a bit, not at a 90deg angle like my 16v 1.8 is. is the 2.0L TB larger
> that the 1.8? I've even head of someone installing a Neuspeed large
> t-body to their 2.0L, with Motronic ignition. I was looking over
> the TB from my 2.0L, and say i take it to a machine shop, have
> them enlarge the opening 1 or 2mm (as i think thats all they can go)
> and have them cut out new plates the same diameter, will this
> increase anything assuming I also go with the 50mm intake runners?
> Is it worth it?
 
  Only if the throttle body is impeding the air flow. For example, say
you roll the window of your car down half way. You then begin peeing out 
the window. Now if you open the window any further, will you be able to pee
more out of the window? In this case the limiting factor is not the window,
but rather the amount of pee that you can deliver per unit time. Understand?
With that in mind, I can't say if a big bore tb will make a difference. It
probably won't on a stock engine, but maybe it will if you're making alot
more power than stock. Velocity sells overbored TBs, I think with a 56mm
secondary.


> basically correct me if i'm wrong on my cis-e. I step on the pedal, 
> the tb opens, the crank turns and starts sucking in air, which pulls
> the fuel regulator plate thingy up, which dumps the appropriate
> ammout of fuel in according to how much air is being sucked in.
> so what if the 2nd opening started to open sooner. would that give 
> more oomph at low end? if they were bigger it would allow more
> air to flow into the combust chamber easier/faster? Also is there 
> some mathematical importance to the length of the runners? why
> hasn't anyone come up with a shorter path from the fuel distributor
> to the t-body to the head?
 
  Longer runners are used to tune the power band. The runners length, width,
as well as the plenum volume are important in determining how your engine
breathes. Shorter runners might allow for more peak air flow, but that could
be at an RPM that is what your engine can run. Longer runners give more
torque down low, at the expense of power up top.

Adjusting the tb so that the secondary plate opened sooner would be the
exact same as just pressing the gas pedal more. It would make it feel a
little more responsive, but there would be no difference in performance.

Brad
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