What A/F ratio is too high.

[RX1DERFULL]

Looking for input from the GuRoo's on this one.

I am wondering what A/F ratio would be too high for 1/4 mile ashphalt pulls (10 psi boost). Runing straight 110 torco race fuel. OAT is between 4°C to 30 °C. Engine temperature is approximately 165°F after returning from the run (I drive the sled back the return road).

Currently running in the 9.7 range and the wideband says 12.5 - 12.8. I have read that 12.5 at WOT is as high as you should go on trail sleds, but was wondering if people are going higher when racing.

More importantly I am wondering if I'm currently running on the ragged edge of distruction if the wideband is saying 12.8.

It is an AEM O2 gauge.

 

[adrenalator8]

When tuning 12.5 is where the max torque is made,if your only running 10 ib's of boost with stock timing and 110 fuel then you should have no problems.

The aem gauge is the best your going to find for your application and it is a very good tuning tool.

I would not temp fate to much and run the sled on the high side of 12.5. unless there's money on the line then all bets are off.

When I am tuning big hp sleds with large boost, 25Ib''s and up I shoot for A/F in the 11.8, I have found that this to be a safe #.and have used this on engines over 500+hp

Cliff yeatman
Advanced Dyno

 

[Ted Jannetty]

Looking for input from the GuRoo's on this one.

I am wondering what A/F ratio would be too high for 1/4 mile ashphalt pulls (10 psi boost). Runing straight 110 torco race fuel. OAT is between 4°C to 30 °C. Engine temperature is approximately 165°F after returning from the run (I drive the sled back the return road).

Currently running in the 9.7 range and the wideband says 12.5 - 12.8. I have read that 12.5 at WOT is as high as you should go on trail sleds, but was wondering if people are going higher when racing.

More importantly I am wondering if I'm currently running on the ragged edge of distruction if the wideband is saying 12.8.

It is an AEM O2 gauge.

Don't rely soly on the wide band, READ your plugs then use the wide band as a monitor after you achieve the right plug color with your jetting.

Wide band O2 guages can be off and is common.

In 1/4 mile you want to monitor your charge air temps because of the distance your running and also your EGT, especially with small exhaust housings, EGT can go out of sight in that distance.

Ted.