On Wed, 23 Jul 1997 08:59:12 -0500 Andre Mauboussin
<andrem@cyberramp.net> writes:
>jaallis wrote:
>
>> > over the past several quarters we have had several 3.9 customers
>> send us
>> > their changed out V8 tbis to exchange for modified MPI 3.9s as
>they
>> did
>> > not like the performance with the v8 they put on. soft bottom
>ends,
>>
>> > poor in traffic performance, stock worse than modified 3.9s.
>> >
>> > we milled 1/4" off an intake runner and measured it on a superflow
>> 600
>> > set on a 420 scale. the monometer showed NO movement of the fluid
>> > level... ie, no cfm gains! imo, based upon extensive work in the
>> > manifold and tbi area the milled runner may give some gains at WOT
>> with
>> > a built engine, but for the "regular" guy... it will be a costly
>> > exercise with little or no effective gains. there are other ways
>to
>>
>> > wake the 3.9 and it IS easy to get it to out run a stock 5.2 or a
>> 5.9...
>> >
>> > to say you will get significant gains with above referenced info
>> from
>> > the mag article is a misrepresentation of the facts..., ioo
>> >
>
>In the magazine, RC Performance Engineering was talking about milling
>the entire length of the protruding ridges of the manifold runners
>(about 3-4" NOT 1/4"). This should make for a significant flow
>increase.
>They also suggest reducing the plenum volume by adding fabricated
>plenum
>boxes. I have no doubt that a 1/4" milling wouldn't do much of
>anything.
>Has Jules tried milling the entire ridges off and dynoing the results?
>I'm sure RC Engineering (who build and race magnums professionally)
>have
>documented the results. Until Magnum Performance actually does what
>these people have suggested and tests the results, they should quit
>criticizing their claims. Oh yea, you can ask Karl Moltzan how much
>improvement he got with the MP throttle body and $500 1.7 roller
>rockers
>Jules sold him. NONE! When you call MPI, keep a tight grip on your
>wallet. JMHO.
>
>Andre Mauboussin
>
>
>
>
Thanks for the info on magnum perf. This list is great. We get to hear
all sides.
Richard
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