Does anyone have any proof to go against this? I run a 52mm Holley with
modest mods, and it definitely runs better than the stock unit, although I
do not know if the 50 mm would have more power. Anybody used both?
----- Original Message -----
From: <chris@slowcar.net>
To: <dakota-truck@buffnet.net>
Sent: Sunday, July 29, 2001 12:36
Subject: Re: DML: RE: MP 4bbl throttle body ?
> | I'm sure the 4bbl TB would flow far to much air out of the box for my
engine
> | size/mods, but I was thinking that I could get a restrictor plate to cut
down
> | the CFM to whatever worked best.
>
>
> I still haven't bought the argument that you can over TB an engine
> like you can over carb one. The downsides to a to big tb would be
> mainly loss of throttle granularity (e.g. a 1% change with a 4bbl is like
> a 5% change with a stock 2 barrel, so you loose some of the "precision").
> It's not like a carb'd engine where vacuum over the ortifice meter's
fuel -
> that's done independently.
> As for the velocity argument - the airs going into a plenum - once it
hit's
> that, boom, it slows down anyway. If it were a velocity stack setup it
might
> be difference.
> I don't think the TB will help much either (at least on a stock
displacement
> engine) - pumping losses really aren't an issue (which is what the TB
helps) with
> the CFM that would be turning.
> I think a restrictor plate would be more trouble than it's worth
honestly. If
> you want the 4bbl just do it - you probably won't pick up any power, but
it
> shouldn't hurt anything. I would definitley consider the progressive
linkage
> that Brend mentioned earlier!
>
> | Any chance you could post a picture of the mod you did to the 4bbl TB to
> | adapt the TV cable?
> | Also, what engine setup are you running (ie. year, cubes, mods, obd 1 or
2)
> | In addition, what valve sizes do you recommend?
>
> I will try and get a picture of it and post it - I really just drilled
a small hole,
> tapped it, ran some threaded rod in it, and fixed the TV cable connection
> over it. But will try and get some pics.
> Old engine was a 318 with heads+Cam, M1. OBDII, but has a haltech DFI
> piggyback computer that handles fuel and spark. New engine is a solid
> roller 408.
> Valve size I would stick with a 1.625 exhaust, no reason really to go
bigger.
> On the intake I would like a bit more valve, but honestly anything bigger
than
> a 2.00 valve and I don't think you can do a good valve job. My head
porter
> tried first with a 2.02 and with a 5angle valve job hit water (not good).
Honestly
> with a good valve and valve job you aren't giving up a whole lot with the
smaller
> valve, and on a smaller cube motor it's definitley the way to go anyway
(try
> and keep velocity up).
>
>
> Chris Bennight
>
>
>
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:02:14 EDT