Thread: post ur 4tec engine AFR
01-19-2011, 08:59 PM #1
post ur 4tec engine AFR
hope all frend have a air fuel ratio meter at their jetski post their afr reading,, we all compare with engine setup,,
01-19-2011, 09:17 PM #2
idle should be around 12
Midrange cruising around 13+
wide open throttle 11.7 to 11.9
If your air to fuel ratio is not close to the above then tuning adjustments need to be made.
01-19-2011, 09:51 PM #3
i run my idle a little leaner 13ish.....and run my cruze at 12.5 to 12.7 then anything abouve 6 8 psi it starts dropping...to the 11.7 ish..
01-20-2011, 01:09 AM #4
Remember that up until you see boost the engine is effectively NA so can be run a lot leaner. As soon as you get some boost you need the extra fuel.
I will eventually be doing this in the Haltec but it's a lot more complicated as there are 5-6settings that you have to use for the transient throttle settings.
01-20-2011, 04:23 AM #5
01-20-2011, 06:42 AM #6
LES ecu, 48"s and R3
This was before i rebuilt my engine. I am now all over the place because i stuffed my timing up.....
01-20-2011, 07:16 AM #7
you will pick up 2 to 300 rpm if you get your at to 11.8 wot over 11.3
01-20-2011, 10:17 AM #8
- Join Date
- Apr 2005
for a turbo or high boost SC setup, close to 12:1 is absolute save, just as 12.6-12.8 is save and makes lots of power on a lowboost high compression setup.
I open more then 40 engines every year, and the pistons on a 12.8 AFR setup that have been racing in offshore for long time WOT are absolute perfekt, no melting no deto.
But you also need the perfekt EGT value.
@abi lah, why you want to compare AFR settings if your stock hull RXP-X is running 96 mph, with a GT28
As Jerry posted, AFR is not a option , there is only 1 AFR that is save an makes power.
01-20-2011, 04:37 PM #9
01-20-2011, 05:42 PM #10
Sounds like he is saying 12.1 is safe for high boost regardless of the ECU system providing EGT's are acceptable. Ive been told that 12.2 is "Max Power" but it is best to stay in the 11.9 Range.
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