From: (Eric Youngblood)
Subject: Re: ???Just how fast(er)???
Reply-To: Peon w/o Email priv (Eric Youngblood)
Organization: Bell-Northern Research, Richardson, Tx
Distribution: rec
Date: Thu, 13 Aug 1992 22:00:20 GMT

In article <1992Aug7.142144.14311@vax5.cit.cornell.edu>, gv9j@vax5.cit.cornell.edu writes:
|> I modified a '71 Camaro SS, and I'm interested in how well it's running.  Does
|> anyone out there have a similar setup and some time slips?
|> 3.08 open rearend
|> 235 60R14 Eagle GT's
|> Saginaw wide ratio 4-speed
|> >
|> .030 over 350, Torker II manifold, Torker Plus camshaft(.487 lift I & E, 308
|> advertised duration, 252 @ .050 lift), Hedman 1 5/8" headers, Holley 4010
|> 600cfm double pumper, Crane Hi Intensity(bleed down) lifters, 1.94 iron heads,
|> 10:1 compression ratio. 
|> >
|> The car weighs right around 3000lbs (no air conditioner, manual trans)
|> >
|> I've read that the engine setup should make about 330 HP gross (290 net), but
|> it seems a bit slow.
|> >
|> The best 1/4 mile I've done (I'm not a really good driver) is 14.8 @ 100mph. 
|> This seems like a decent trap speed, but a pitiful e.t.
|> >
|> I know the gears and transmission ratios are not optimal, plus the GT's aren't
|> very sticky (God they smoke if you look at them wrong), but 14.8? That seems
|> too slow.
|> >
|> So, if anyone has a similar setup, or has heard of someone with one, what sort
|> of times do they get (unexaggerated)?
|> Will 3.73 gears really take a second of my e.t.?
|>        -Brian

That does seem a bit off, I would expect to see you running mid to high 13's if
your shifts are clean. At what RPM do you make your shifts? Your cam looks like
it can breathe like a hurricane in the top end. You may be shifting before your
engine gets a chance to build good useable power. What rpm ranges does it *feel*
strong at? 

I've got a 77 TA w/ the Pontiac 400 cid engine. It was overhauled(.030 over) 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 (a higher stall
would improve launch but this is a daily driver) 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 (or should I say lack of traction :^)
is provided by Goodyear ST P235R15 radials. 
Track times indicate extreemly sluggish 60 foot times in the 2 second range,
0-60mph is acheived in ~6.1  and  1/4 mile at ~14.6@93mph. (*best times to date*)

The main thing I have going for me with this setup is huge amounts of low-end
torque, (exactly what an automatic needs). A high rpm cam/induction would be 
less effective here as the relatively long 3.75" stroke limits safe high rpm
operation to about 5600 revs. So... pulls *hard* off the line, then we all yawn
and wait for 3000 rpms to build at which time the automatic will hit the shifts
perfect every time, thus keeping the engine in its *optimal* 3000-5200 rpm power
range. gear ratios are fairly wide 1st:2.52, 2nd:1.50, 3rd:1.0 

The point of all this rambling is that with a little tuning and/or tailoring of
shift points to make the most of what you've got you'll be able to blow some
doors off. 

$0.02
Ericy 








 
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