[Shotimes] New +20 cam dyno results

[Mark Nunnally]

>With a bad tune (lean mixture), I pretty much tied a stock car in peak
torque
numbers on my stage 1 cammed car.

I9ve seen three 3.2L (atx conversion) MTX cars make 211-215 ft/lbs (all on
dynojet) with stock cams (one with 3.2L intake cams) and typical bolt ons (I
believe all had stock runners).  Mine was one of them, on a stock EEC fuel
trim (ie richer than it should be).

I9ve never seen another factory 3.2L (ie not high compression, etc) make
more than that with any cam.  I9ve always said I think the stock cams, and
stock runners (not EH) are tuned pretty darn well to make the MOST torque
over a broader range of rpm (great for drag racing, and for a street car).
There is only so much 3bang2 you can get out of the power stroke at a given
displacement n/a engine, and hard to improve on with a pretty efficient 4
valve motor that already makes pretty decent torque for it9s given
displacement.

Don9s 89 though is more of track toy, so IMHO I9d think he9d be (and those
of us with track cars) would be pretty much ingoring any numbers below 5k
anyway.

Don you mentioned torque increases from these cams from other folks using
them?  Links to any graphs?  I haven9t seen that on any of the +20 or +40
cam installs...

The best torque curve I9ve seen on a factory 3.2L longblock (with SS stage 2
cams) is on lance chaney9s 92.  I got the graph somewhere.  I rode for a few
laps at thunderhill in it, and it really pulled good from 4k up. (and his
nice torque at low revs).  He did a lot of fiddling with the overlap w/
josh9s adjustable sprockets.  I9ve only ever messed with the intake cam
sprockets (retard and advance the whole set) with stock cams.  Btw full
retard on stockers is worth 7 whp at high rpm, similar torque curve effects
to swapping in biggger cams.  Ie a poor man9s cam open track setting :)

I was only after a 5000+ rpm torque increase anyway, so I9ve been pretty
happy with them.  At any given place on the track (compared to the stock
cams) I9m running several hundred more rpm.  More rpm is more speed.  The
lap times back that up.

Mark

Ps rode in a dyno9d ~400/400 RWHP-TQ  Z06 this weekend at Road Atlanta, talk
about a flat torque curve.  I think you could leave it in 4th gear for the
whole track and still run in the high 1:409s there.


>
>> >Stage 1 3.0L car with a bad tune (no tune at all and a 255lph pump on a
>> stock regulator)
>>
>http://memimage.cardomain.net/member_images/9/web/225000-225999/225912_302_f
>> ull.jpg
>
> can9t read it :)
>
>> >Completely stock SHO
>> >http://hosting.superhighoutput.com/autosho/dyno_pfi.jpg
>
> This is all before I bought my TwEECer and learned to tune.  I'm sure the
> numbers will look much better now, but I don't plan to take the blower off
to
> find out.  It used to feel like I had another set of "secondaries" a 5k
rpm...
> It would put you back in your seat harder at 5k than it would anywhere
else.
>
> Jason
>
> On 5/29/05, Mark Nunnally <marknunnally@joimail.com> wrote:
>> I've never seen a dyno graph of SHO aftermarket cams that made more peak
>> torque than the stock ones.
>>
>> For a track car though, (and being aggressive), you probably won't be
below
>> 5k much at all.  So as long as you are making more torque in THAT rpm
range,
>> you'll be faster.
>>
>> With my 89, on a track like road atlanta where it's just wound up all the
>> time, the stock cams are just gasping all the time.  I'd venture to say my
>> sheer peak torque is probably down vs the stock cams, but from 5k-8.5k
it's
>> no contest.  It's just where you want to bias your torque.  Even though
the
>> +40's don't make MORE torque, they do make more torque (probably 30
ft/lbs)
>> at really high rpm...so if you stay there all the time, it's faster
>>
>> If you drive it aggressive though and really wind on it, it'll be quicker
>> out on the track.  I realize you not wanting to really spin it, but with
>> fresh rod bearings, I wouldn't worry  about the high mileage.  These
things
>> are bullet-proof in N/A form!
>>
>> 7300 rpm isn't that high of reving, so you should be able to lean it out
>> more.  One of Josh's tweecers should fix you up anyway you need to go.
Easy
>> to take a little fuel out up top (I've got mine set to 13:1 all the way to
>> the top)
>>
>> Mark
>>
>> PS for a street car I'd always stick with the stock cams, my .02
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