going on the dyno this week

[leanburn]

we finally got a chassis dyno in town, i'm hopeing to get on sometime this week. i have a ton of expierience with sleds and quads but not cars. my last sled took over 50 pulls before i was happy, i definately don't have that kind of money to do that with a chassis dyno at $125/hr. the way the guy operates is he only operates the machine, i do the wrenching and running the car so i would like to pick your brains on what the most efficiant way to get what i want. my plan was to play with the timing first, play with the jetting on the 670 avenger thats on it now, i have a 750 demon i want to try and then finally i was going to try open headers.
 any advice would be apprieciated.

[The Cuda Guy]

Did I miss a previous post?  What is the engine details your running?

Don

[leanburn]

it is a 340 with eddy heads, no porting, 10.4:1 compression, hughes cam .543/.563 lift 242/248 duration,
edelbrock rpm intake, 727 with 370 gears.

[Chryco Psycho]

makes sense to me get the timing peaked then dial in the carbs

[leanburn]

so when i'm playing with the timing i was going to start on the low side, say 30 degrees and go up by 2 until i start to lose then go back one or two until it peaks. as far as the jetting i would assume that i should concentrate on the secondaries more than primaries due to the fact i have done some plug burns at cruise and i'm thinking i'm dialed in for cruising, am i right?

[Chryco Psycho]

I would start at around 38* & back it down 2* to see if it changes , it will save you pulls
 I would do a cruise pull if you are on a mustang type dyno & check the mixture at cruise & then go wide open to dial it in

[Changin Gears]

Bring a freind to speed up jet changes, get the most out of an hour.  This is also a time you can watch to see when vacuum secondaries are opening.  Just don't stand in front of the car or in line with the fan belts.

If you do the pulls in high gear you can easily exceed the speed rating of your tires.  People do it all the time, but I was chicken.  You can do pulls in high gear and then a lower gear to see loss in the trans.

You can try the with/without air cleaner also.

[73Chally]

Don't forget about dialing in your A/F ratio, too!