Hi,

A local tuning shop had a car cruise last weekend and they were offering dyno sessions/runs for $50.

I decided to put my 69 350 Camaro on their Dyno (Mustang Dyno) to see what was my output at the rear wheels.

To my big surprise and disappointment, my car started to in the mid - 4K RPMs. The Dyno curves (HP & Torque) shows starting to go down around 4,000 RPM while the curves would be expected to be still climbing until it start reaching the 5,000 RPMs.

While speaking with other friends of mine that went the shop earlier that same day, they told me that most of the cars that they saw on the Dyno were also missing at high RPM.

The questions I have are:

1) What would cause my car to be missing on the Dyno.

2) Will my car be missing on all Dynos.

Thanks,
Daniel.

not enuff air to the carb?????

just a guess

Did they run an air/fuel ratio on it as well? That would tell you alot. I am a little confused........you say your car is missing.........then you state your dyno numbers start going down around 4k. Do they drop suddenly or gradually go down? If they gradually go down a couple of things come to mind.

1. Fuel curve is going lean at high rpms....check fuel delivery

2. RV cam maybe.......that is only good for around 4-4500 rpm?

3. Intake/head air restriction or exhaust restriction.


More than likely its going lean on top end. Put a fuel gauge on it and monitor it thru the power curve. Torque and hp should cross on the graph around 5200 rpm. Hp going up and tq going down.

What was your wrhp? Mine did not do very well either.......I only got 278 wrhp and 378 wrtq.

Unfortunately they did not run any air/fuel ratio.

Your are correct on the 5200 RPM, again unfortuanetly they let go the gas at about 5,000 RPM and both curves are going down from there above each other. Can't really tell due to the graph resolution, although they do seems to meet at 5,200.

Thanks,
Daniel.

all dyno sheets you will see the torque and hp cross at the 5250 rpm mark always........if it doesnt cross here the graph is not real.....


is your car still missing now?

The car never missed while driving on the road or at the track.

It only missed that one time on the dyno, this was also the first time that I was putting my car on a dyno.

Thanks,
Daniel.