We used to go to Cecil in October around Columbus day. Now it is September. October is way better. I've been at Cecil when the DA was negative. The cars fly. September is usually warmer and the DA suffers.
Question about WOT A/F ratio's Would I get an accurate indication of WOT A/F ratio if I were to hammer it on the highway for a couple seconds or no? Im thinking no Im theorizing it goes rich initially then as rpm climbs and air thru the venturies increases it reaches a point where it stabilizes while on the track, but I cant duplicate that on the highway going WOT for a couple seconds What do the pro's say? Larry told me a story Friday about Ford racers leaning it out and their engine went BOOM
Most motors if too lean I think would fall on its nose in the upper rpms b4 going boom. Alky is different than gas for sure. One of the most important area I work on to be clean is right on the line. When I listen to your video you posted, I dont really hear any dead spot in the rpms or big sounds. The rpms do seem flat and not climbing right out of the gate, but after watching it a few more times I think that's more of a gear/smaller motor thing. You go about 300 ft b4 finding 2nd gear. The rpms just are not going to race up like a car that finds 2nd gear 80ft out. I can't give you any info on a/f meter reading, I do all my tuning by egts
I tune mine for the race rpm, 4k-6k. The carb is a compromise, the ideal af ratio at a given rpm wont work across the board.
Best way is to peek at the AFR at the track in high gear at WOT. Lean can induce detonation and that is what causes engine damage at the track. Another reason to mix in some race gas.
I'll mention it again, use the recording feature on a cell phone to video to know what's going on start ti finish.
I kinda noticed that too about the rpm outta the hole, it doesn’t seem to “flash/jump” like it used too with my old combo, seemed to pull harder outta the hole before. Wonder if JW could restall this convertor
That would be something you would to talk to him about, but I wouldn't do that first till I tried all other avenues first. When tuning I always add gas first to ve safe........but slow out of hole often ends up being a temporary over rich condition especially when foot braking a car without alot of gears in it. My car for example with 4.10 goes into 3rd gear about 80-100ft before the 660 line, yours went into high gear about 1000ft it looked like in the video........so it's a little apples to oranges how it pulls through the gears. Motors can make more power being a little lean, but you better know how to walk that line and be willing to accept the fate if your wrong. Sometimes it's better to leave a little safety net, leave a little on the plate, not many of us are heads up racing Solo passes are great to record this though because you get to gear your car only
IF I’m interpreting these time slips correctly going from the Q- Jet and dual plane and 413 cam to more compression, roller cam, SP3, and AED 850 DP I haven’t lost much if any low end, in fact I gained a bit, especially on the top end. These were with my JW 9.5” convertor.
You need more accelerator pump shot with a single plane intake. They also like more initial timing. These are things to test when you can make lots of passes. How often does your A/F meter refresh? It should every 1/4 second or so. wide open thru first gear and into second is more than enough to get a good reading for wide open throttle. You can also check it at cruise speed and idle to tune the fuel curve thru the full range of throttle settings. Always recheck at wide open if you make changes to any circuit. Congrats on the new best. You got some tuning to do. And please check your tach against another.
Thank you Steve Yes much tuning to do! My A/F while cruising @3200 rpm is 13.3 13.5 13.8 it fluctuates between there. Updates same as O2 crosscounts? if so yes it changes quite often. Its a cool gauge, probably my favorite
Some nice solid gains there, .021 in the 60 .005 in the 330 .063 in the 660 .141 in the 1000 .207 in the 1320 If you look at the incremental. You slowed down alot between the 60 and 330. Almost gave it all back, the regained it again by the 1/8th. That's an area I would work on, cause you actually have a full tenth swing in there....getting as a steady gain or at least not losing and you will be mid 30s. The long over rev could be part of it seeing your not getting into 2nd till 330 almost
Thanks for interpreting those numbers Ben! I see what your saying between the 60, 330, then 660, it slows then recovers, never noticed that in the numbers, or seat of the pants. That's what I TRY to explain to the guys at work, its more than flooring it on the track, theres actually a lot of precise math involved, technique, tuning, examination, theory. Its not just a bunch of greasy guys hammering on their cars