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Hey H8PVMNT,OK… I’m not sure where you are getting your lean/rich numbers? Although those numbers represent an excellent tuning job without an AFR gauge. 13 and 14 are not typically considered rich, aren't those numbers in the lean to Stoich range?
For max performance at WOT you are shooting for 12.5-13:1. For best idle mines likes 13.3-13.5:1, what about yours?Don't try tuning for 14.7, unless that is where the engine responds best for the condition. I have good response and fuel economy cruising at 16.5-16.8 at 3000rpms 4th gear, timing at 11 deg. btdc.I have removed the powervalve but I have not started tuning yet, I just upped the mains and did a test drive, big difference at low rpm wot, it is not as rich and I have much more torque! I'm pretty happy about that.
I have broke 17 one other time, maybe twice. The gauges help you drive for economy, yes. You can really see what's going on.
.... You do have to drive it right to get 17 mpg, cruise in 4th gear no more than 65. If you do 75 or 80 and use 5th you still get around 14.5-15.5 mpg though and that isn't bad for this truck.
What RPM are you at when you drive 65 in 4th? What does the gauge read? What does the gauge read when you are in 5th gear at 75 MPH and what RPM? Gnarls.
Yes thanks a lot, we all appreciate! What is your a/f ratio aprox. at best idle and full throttle 2000-4000 rpms? Drove mine 3 hours last friday, 45 idles, 145 jets and 160 airs with power valve removed. Drove better than ever, until I ripped the front leaf mounts from the frame on the trail on saturday I need to lower the air correctors 1-2 size still and I'll have it perfect a/f and timing wise, but it will be a while.
Best idle AF hovers around mid to high 13s. I have had the idle around 14.5-14.7 but it seems to like 13s better and I get better off idle torque a little richer. Seems to vary a bit on temp though. I would expect a winter tune is necessary when it gets colder. I also notice the idle speed screw will move around a bit. I am thinking of putting a drop of blue loc-tite on it but I don't really mind adjusting it every once in a while. If you have the idle speed screw open too much it gets richer.WOT I am getting from 10.9 to 13.4, about .When I get in the higher rpms the air correctors really seem to trim it out then it will go to 14.5-15 and I also get into more Vac which seems to be good.
... This has less to do with the carb but it's notable the effect restriction of an air filter has on A/F ratio.
.... I am thinking of putting a drop of blue loc-tite on it ...
65 in 4th is about 3,500 rpm. AF is high 15s to low 16s on flat ground. Vac is around 7-10 Hg. If I try to stay between 60 and 65 in 4th I get 17 mpg.75 in 5th is maybe like 3,250. AF is between 13 and 14. Vac is around 1-5 Hg. If I use 5th I can only get 14-15 mpg, even if I go slower.
I would be worried at 14.5-15:1 afr at full throttle higher rpms though.
Are you talking about the air filter on the rocker cover, or the air filter on the carb?Gnarls.
I should clarify, and I had to look during the drive to work today to verify... I am in the 12s at WOT at high rpms, I only get the -14-15s A/F when I am backing off the throttle to maybe 50% at say 4,200-4,500, like when you drop to third going up a hill and you no longer need WOT. If I floor it at that point I get right back to 12s and accelerate up the hill .
QUICK MATH..If you drove 50 miles at 65 MPH @ 17 MPGGas is $3.00 per gallonYour fuel cost is $8.82You would reach your destination in 46.2 minutesIf you drove 50 miles at 75 MPH @ 14 MPGGas is $3.00 per gallonYour fuel cost is $10.71You would reach your destination in 40.0 minutesAt 75 MPH you would arrive at your destination 6.2 minutes sooner…. but it would cost you $0.30 per minute.It would cost you $1.89 more in fuel driving that distance at 75 MPH.Gnarls. .... stink & pomp
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