12A dyno numbers

[tom_sprecher]

Earlier this week I took my car to http://www.dynolab.net/ to make sure the carb I built performed as well as the Yaw carb the car came with. After two hours of swapping carbs, jets and airbleeds I was able to get 111 HP and 101 ft#'s. This was a little better than the Yaw at 107 and 99 but with more time & $$$ who knows what the end result could be however the engine is on it's 4th or 5th season.

I tried doing some searches but with the 4 letter term minumim became frustrated so I have a couple of questions for the more experienced Rotarians on this site. What kind of numbers should a good 12A put out? How do you kow when it's time for new end seals? What is the target A/F ratio or should I be looking at EGT instead? I did not have time to change the timing and wonder what the typical setting for that is?

It was nice to see that my Yaw copy performed well and now the Yaw is my spare.

[JeffYoung]

Tom, I'm not an RX7 guy, but that is 10-15 down on the "average" numbers I hear and a bit more on the "best."

[tom_sprecher]

Now I'm bummed out.

But, I've never built a rotary before and that didn't stop me from trickiing out the top end on my Harley. I prefer to take on projects I've never done before.

Plus, since I'm the slowest guy iin the slowest class in my group, who's gonna notice me being 10-15 or more HP down.

[tnord]

yeah....you're way down.

my SM makes a good 5hp more than that with more restrictive rules.

[lateapex911]

Tom, you've got guys down there that make way more power than I do, so i'd think they'd be more knowledgeable. Crush is reeeaaaly fast down the straight..he's making lot's of ponies.

I checked the site out...different dynos make different numbers. Looks like you're on a dynojet, not known for conservative numbers.

So, what's the exhaust set up? The standard advice is to tune the carb for power and note the A/F ratio, as well as the EGT, then use EGT readings at the track to compensate for weather.

How do you know when you're engine is in need of seals? They say it's when it cranks a lot before catching on start up. But they also say they are fastest right before they blow.

Remember the basics. keep the carb cool, keep the engine cooldraw fresh air, not superheated air. And the exhaust has a large role in power production as well.