Doug Brandon

Going to a local race engine shop tomorrow to have some fun with their chassis dyno. I want to optimize my carb and timing. We will do an initial pull as a baseline, then start checking A/F readings. Their machine has a feature which allows them to hold the car at say 50 mph, and then vary the load so I can check the carb at part throttle and full throttle. This will be the first time I have done this. I plan to bring an assortment of jets, power valves, squirters, and shooters. What else can I prepare beforehand to get the best bang for my buck? Any suggestions on things during the dyno runs to try or to avoid? Is it smart to tune for peak torque on a street car or focus on peak hp. I want to improve the driveability, throttle response, and overall power.


[Modified by Doug Brandon, 3:38 PM 7/10/2003]

Hobbes Blk '80

Try not to launch your car off of the dyno and through the concrete wall.

After your done tuning your rear tires, see how much horsepower you can get out of the front axle. :lol:

Good Luck :thumbs:

gkull

If it's being done with a exhaust pipe sniffer.
Get your motor up to temp.

Then run spray carb cleaner to clean out the carb. and manifold of varnish.

Clean out the PVC valve.

Next hold it at 2500 rpm or so and pour about a quart of water slowly into the carb to knock all the carbon out of the cylinders and off the valves.

Change your motor oil and filter. Of course a clean air filter.

All these things will cause artifically high hydrocarbon readings. Which would make you think that your off on the jetting.

Set your initial idle timing as high as you can without exceeding 38 degrees total with the vacuum advance plugged.

You haven't told me specifics about you motor so I can't comment on carb or plug gap.


[Modified by gkull, 4:08 PM 7/10/2003]

Matt Gruber

http://community.webtv.net/MATTGRU/D...eat/index.html

Doug Brandon

Thanks for the info. Info on the motor is: .030 over 427, .527/.553, 224/232 @ .050 hyd cam. 9.3:1 CR, oval port heads, 2.19 valves, air gap dual plane, 750 cfm BG Silverclaw dp (76/82 jets), 35 degrees total timing, MSD 6A, .045 plug gap.

gkull

That is a pretty mild cam. Your jetting is how it came out of the box. depending on how it runs driving around. I would try 75/81 with a 6.5 power valve. and advance the ignition to 39 total without the vac. ad.