From: bpita@ctp.com (Bob Pitas)
Subject: Re: Increasing power?
Date: Wed, 29 Jul 1992 16:05:48 GMT
Organization: Cambridge Technology Partners

In article <1992Jul24.133816.20347@bnr.ca> Peon w/o Email priv (Eric Youngblood) writes:
>
>Does anyone have any ideas on how to increase the power produced by a normally
>aspirated V-8 engine?
>
>What I've got is a 77 TA w/ the Pontiac 400 cid engine. It was overhauled about
>10k miles ago which included a mild performance street cam (intake .465 / 214 dur
>@ .050, exhaust .480/224 dur @ .050). The heads had a "street-comp" port and valve
>job (whatever street-comp is?). It has forged aluminum pistons and runs at 9.0:1
>compression. The entire crank assembly has been balanced & bluprinted.
>Its induction starts with the open scoop at the base of the windsheild through a
>K&N cotton/wire mesh air filter, Holley 650 vac sec "emission" legal carb. It has
>the original stock Pontiac manifold. The exhaust begins at 1-5/8" Hooker headers
>w/ 3" collectors and includes a crossover pipe. The dual exhaust is 2-1/4" and
>uses high flow mufflers.
>The TH350 is driven by the stock 1200-1800 stall torque converter. The governor
>is adjusted to provide WOT shifts at 5000 rpm. The power is transmitted to the
>wheels through a GM-posi 10-bolt 3.07 differential. Traction is provided by
>Goodyear ST P235R15 radials. Track times indicate an extreemly sluggish 60 foot
>times in the 2 second range, 0-60mph is acheived in ~6.1 & 1/4 mile at ~14.5 secs.
>
>I would like to push the 0-60 time down into the high five second range and
>hopefully reduce the 1/4 mile time into the low 14's is this possible or am
>I about at the maximum for a "street" configuration.
>
>I still have the original 800 cfm Q-jet on the shelf in working order, it doesnt
>get as good gas mileage as the Holley (currently 14mpg city/ 18 highway) but I
>was wondering if the larger flow capacity would boost power? What about intake
>manifold? Are there any that give good low rpm torque but allow better high rpm
>breathing? Is there any evidence that synthetic motor oils can provide a small
>increase in mechanical efficiency?  
>
>Any experience or suggestions appreciated
>
>Thanks,
>
>Ericy

The best way to think of an engine is that it's basically an air-pump...  If
you have any restrictions in the pump, it's not going to flow as much, period.
You've gotten rid of the restrictions in the exhaust, heads, and valves, from
what you've said, so now try and open up the front end a bit.  650cfm might
be a bit restrictive for a warmed 400ci engine, so try the 800cfm Q-Jet on 
it, just for the hell of it.  Also, toss the stock intake manifold, and throw
in a nice Performer RPM manifold from Edlebrock.  It should give you nice
low-end and also has nice high-rpm flow too.  Your 60' times are probably 
more a function of the weight of the car vs the tires you're using.  My car
was a 10th slower 60' on stock (225/60r15) goodyear eagles, and yet I went
through the trap 4 10ths quicker.  My car is extremely light, at 3100 (with
the pull-out stereo & radar detector pulled out...), so that helps my launch
even with the wimpy little goodyears...  On the other hand, some of my buddies
with slicks on get 1.7 60' times, but I usually beat them out of the hole 
when we race on the street.  Slicks alone could probably lower your 1/4 times
into the low 14s/high 13s, but I'm not talking from experience, since I'm 
one of those people who are too worried about my drivetrain to use slicks! 

You didn't mention what speed you came through the traps at, so I can't guess
how much bhp your car is making, but I would say that if you et'd at over
100mph, you'll probably break into the 13s with that cam, heads, exhaust, and
a good intake combination.  My car only has a ported carb, torquer II intake,
and custom exhaust through dynomaxs, and I run *very* close to 13s on the
stock tires.  I haven't touched the heads or valves, either.  You should be
able to blow through the 14s barrier easy with a good intake/carb combination.
If you get a new intake manifold, tell me how it turns out, since I'd be
interested to see how big a difference it makes...


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       / _ \                 '85 Mustang GT                        Bob Pitas
      /    /USH              14.13 @ 99.8                      bpita@ctp.com
     / /| \                  Up at NED, Epping, NH           (Cambridge, MA)

"If you go fast enough, driving in traffic is like driving in a parking lot"
Disclaimer: These opinions are mine, obviously, since they end with my .sig!
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