Valve Train noise

[George M. Dailey]

What do the torque curves look like after doing these mods? Since the TPI
system is designed to give the maximum tuned effect at a certian point, what
do you really gain?  Bench flow numbers don't give me a rise. Some TPI
system don't even use a MAF. Do they have a _significant_ power advantage
over the MAF equiped tpi? Convince me to butcher my $300 MAF.

Thanks man
GMD

At 09:25 AM 1/20/97 -0600, you wrote:
>I would rather not quote my source;  however, if one looks at the flow 
>characteristics of the stock TPI one finds that it flows approximately 
>435 CFM.  Making slight mods as follows causes significant changes to 
>this.
>Cut the screens off the MAF increases the flow to 512 CFM
>Install a throttle body air foil increases the flow further to about 
>530 CFM (Still not in the realm of what one would consider for even a 
>moderate performance 350).
>Opening up the filter cover and putting a K&N filter in gets us into 
>the 560 CFM range.
>Modifying the MAF (Cutting and polishing the heat sink inside) gets us 
>up to about 585
>As you can see, there is room for much improvement without ever 
>getting out of the air intake.
>
>The MAF, itself flows about 529 CFM stock.  Taking the screens out 
>gets it up to over 700 CFM.  Modifying the heat sink and cleaning up 
>the inside gets it up to about 750 CFM.
>
>Note that all this data is corrected to 20.4 inches of water (What 
>Holley rates their carburetors at).
>
>Since this is a "dry" flow system (no fuel in the air stream), the 
>equivalent to a carbureted engine is about 650 CFM.  NOW we are in the 
>realm of a solid 350.  Further improvements may now be realized by 
>mods to the throttle body, plenum, runners, and base.
>
>
>----------
>From:  Scot Sealander[SMTP:Sealand at clarityconnect.com]
>Sent:  Saturday, January 18, 1997 7:47 PM
>To:  diy_efi at coulomb.eng.ohio-state.edu
>Subject:  Re: Valve Train noise
>
>John Hess wrote:
>
>> The original TPI was designed for the 305 engine
>> and is woefully inadequate for even a mildly built 350.
>
>Do you have a source for this?  How do you know it was designed for 
>the 305,
>and not the 350?
>
>
>> To state that these parts are fraudulent or that the people
>> who sell them are liars is irresponsible and/or stupid..
>
>Maybe not.  Just what does that "air foil" do anyway... ;-)  As far as 
>aftermarket PROMs, the three I have looked at did not do much.  Delay 
>TCC lock
>up by several mph, maybe reduce the ESC attack rate (makes sure of the 
>need
>for 93 octane!)  Change fan turn on temp.... One completely zero'd 
>every EGR
>location..... Basically no ignition or fuel changes.  Not a lot for 
>the 150
>bucks or so they charge!  That is close to fraudulent in my book, and 
>points
>out that GM tunes them pretty well from the factory.
>
>I am sure that some of the aftermarket is great stuff, but the 
>consumer must
>understand what he is buying.  The TPI is a great low/mid RPM intake 
>system,
>and that may not be clear to all consumers.  So if you make changes to 
>your
>350 that increase airflow requirements at higher RPMs, the TPI will 
>not work
>well for you.
>
>Scot Sealander    Sealand at clarityconnect.com
>
>
>
>
>