dyno and tweecer results

cool good to know so my fuel curve is a lot leaner now around 13.0 -13.2 all across the board..

final5-0 said:
Cats will make a sniffer wb show lean.

My wb is mounted in the collector of the lt's and it showed about a full point richer than the sniffer wb the dyno was using.

Not bad numbers for your first shakedown run.

Later
Grady
 
hey, why would rpm's matter? good question, at torque peak where the motor is most efficient you want to give it a bit more fuel, say 12.8:1 A/F ratio.. moving away from the torque peak in both directions (to 0rpm's and to 6500rpm's) you can lean it out in almost an inverse proportion to the torque curve towards a target A/F of 13.5:1 but that's theory.. :)

as for power dropping off that's my rev limiter.. yes, my car is actually a bit too small, I've thrown so much timing at the car after torque peak that its very visible the cam doesn't have enough duration.. peak power comes on @ 5800, should be 6200!! And you're right, the intake is doing its job..

As for the EEC, that thing has a ton of functions, it was a long while getting the part-throttle driveability, WOT tuning is almost easy (spark and fuel).. I spent more time nailing down my idle @ 750rpm.. haha

mo_dingo said:
Yep, I second that.

You are running too rich across the board. You want 13.0-13.5 for the entire RPM range. Why would the RPM's matter when it comes to a/f ratio? Each cylinder combustion is stand alone; Meaning that no matter if you are running 10000 rpm's, or 1000, 13-13.5 a/f ratio for each cylinder combustion creates the maximum explosion, which makes the most power.

But great numbers for the first time at the dyno. It definately takes a lot of work to understand how our EEC works and how to tune it properly.

What are the specs on your cam? Your power drops off way to early. The intake is not at fault. Seems to me you need some more duration in that cam.
Scott
 
jetuomi said:
cool good to know so my fuel curve is a lot leaner now around 13.0 -13.2 all across the board..

More like 11.0-11.2. Grady said...

My wb is mounted in the collector of the lt's and it showed about a full point richer than the sniffer wb the dyno was using.

That means the sniffer the dyno was using was showing a leaner A/F than what is actually occuring up before the cats.

Jake
 
haha, I meant, I've used my tweecer to lean it out a 5% more across the board.. :)

Man do you have a great time with your car, 110mph, nice combo !!!

GTJake said:
More like 11.0-11.2. Grady said...



That means the sniffer the dyno was using was showing a leaner A/F than what is actually occuring up before the cats.

Jake
 
jetuomi said:
haha, I meant, I've used my tweecer to lean it out a 5% more across the board.. :)

Man do you have a great time with your car, 110mph, nice combo !!!

Ok...I must've missed something. Thanks, too bad I can't race in this cool weather and squeeze some more out before next summer.

Jake
 
no that's me just typing away and not fully explaining myself, haha.. (I think I have AADD, the Adult ADD).. :rlaugh:

what cool weather, in Toronto we're having the hottest days of our summer almost.. didn't race all year now its fall I'm going 2x this week !! :nice:

are you feeling effects of the hurricanes??

GTJake said:
Ok...I must've missed something. Thanks, too bad I can't race in this cool weather and squeeze some more out before next summer.

Jake
 
jetuomi said:
no that's me just typing away and not fully explaining myself, haha.. (I think I have AADD, the Adult ADD).. :rlaugh:

what cool weather, in Toronto we're having the hottest days of our summer almost.. didn't race all year now its fall I'm going 2x this week !! :nice:

are you feeling effects of the hurricanes??

Hurricanes??? I'm in Minnesota! Well, Michigan right now. I mean in the next few months right before the track closes and it's getting real cool.

Jake
 
Hey, the reason I said that (haha) was that they said Hurricane activity would be felt to almost north tip of Michigan, causin cooler wetter weather.. I guess I had a few too many drinks already.. :)

(where in Michigan, I was born in Canada just opposite the UP (Soo MI))

GTJake said:
Hurricanes??? I'm in Minnesota! Well, Michigan right now. I mean in the next few months right before the track closes and it's getting real cool.

Jake