NYCSTEV/DYNO?AFR

[nycstev]

Here is a repeat of yesterdays dyno results which raised a few questions. Contacted Sean and here's what he said:

Hi Steve,

Safe, which means rich, is usually 12.0:1 AF ratio.
Lean is mean and 12.8-13.0 is powerful.
If the motor is really efficient and has the right temperature plugs, it can take 13.0.
Remember, this is read after the fuel is burned and is an indication of how much it burned.
Most people run richer to cover variances.
’d say get it broken in, then maybe turn up the fuel pump booster to max and have the injector pulse turned up a bit. Seems to be plenty rich at the very top, so there should be room to add fuel at lower RPM’s.
Maybe shoot for 12.2, which should still be plenty safe.


Best regards,

Sean

Roe Racing

 

[Scrambler1]

Are those back to back pulls with that much variance in the AFR down low or was that a tune adjustment?

I agree with Sean, I like 12.5 at max myself. 12.2 is better.

 

[nycstev]

Are those back to back pulls with that much variance in the AFR down low or was that a tune adjustment?

I agree with Sean, I like 12.5 at max myself. 12.2 is better.

No. That was the first and last pull, From what I am gathering they pulled back some timing in the upper range to be more safe that accounts for the leanout. He said he could of gone for a little more ( 30HP) but let it be

 

[TNVIPER]

Just follow Sean's advice...get more fuel in...

 

[blackviper]

Just follow Sean's advice...get more fuel in...

I agree.

 

[LitemUp]

Yup. Just need to add a little bit more fuel (or remove some timing) between approx 4750 and 5500 rpm. You definetly have enough fuel from 5500 to 6000 rpm so you should have enough fuel to bring the a/f ration down. Then you'll be golden.:rock: