THUNDERZ Posted September 26, 2003 Share Posted September 26, 2003 Does advancing your timing to maximum before pinging make you lose MPG ? Quote Link to comment Share on other sites More sharing options...
zbuild Posted September 26, 2003 Share Posted September 26, 2003 advancing your timing to "just before pinging" should make your engine more efficient and if anything should improve your miles per gallon. . .be careful though you DONT want pinging, especially in a turbo engine. Quote Link to comment Share on other sites More sharing options...
Dan Baldwin Posted September 26, 2003 Share Posted September 26, 2003 This is a poor method to set timing. Twice I've been to the dyno and gained power by backing off the timing, though it hadn't been pinging. Each time I've wound up at around 34 degrees max timing with mechanical advance fully in. Quote Link to comment Share on other sites More sharing options...
THUNDERZ Posted September 26, 2003 Author Share Posted September 26, 2003 Dan thanks for the input. Do you mean the best timing setting was 34 degrees? I have a vacuum advance wich I should probably get rid of too. I am running triples. Jim Quote Link to comment Share on other sites More sharing options...
JMortensen Posted September 26, 2003 Share Posted September 26, 2003 Every post and every book Ive read about max power and timing says something like 34-36 degrees. If you went 34 you'd be right in there. Disconnect the vacuum advance and alter the breaker plate inside the dizzy so it can't move. The diaphragm is probably broken anyway so it is just a vacuum leak, and it only advances the timing under cruise or idle. Nice for mileage, but not nice for performance. You can play around with spring weights to have the advance come in earlier if you want. I think Dan actually lessened the total advance from the mechanical by JB Welding or brazing the advance slots so that they are shorter, and ran more static timing. Isn't that right Dan? Did you change the springs too? How did that all work out for you? Jon Quote Link to comment Share on other sites More sharing options...
Dan Baldwin Posted September 26, 2003 Share Posted September 26, 2003 Yes, best timing for my engine was ~34 degrees at full mechanical advance (+/-2 accuracy on my reading, at best). You may as well get rid of the vac. advance, as it's probably not doing anything with the 3x2s anyway. Mine is still on the dist, there's just not a vac line going to it. Vac advance is just for part-throttle cruise mpg, anyway. A stock 240Z distributor will give ~35 deg at rpm with only 10 deg. at idle. Like Jon said, I filled in the inside of the slots in the mech adv. to run more initial advance. Running about 15 at idle now, I think. Some like to run more like 20 at idle with triples. I didn't change the springs. I believe all my mechanical advance is in by maybe 3200. Dan Quote Link to comment Share on other sites More sharing options...
JMortensen Posted September 26, 2003 Share Posted September 26, 2003 What distributor are you running Dan? The 280ZX EI dizzy has about 17 degrees mechanical advance. I've got mine running 18 degrees BTDC with stock springs and I JB Welded the breaker plate to keep it from moving, but did not close up the advance slots. Check this site out: http://home.att.net/~jason510/dizzy_specs.htm Degrees advance and rpm are distributor degrees, so double for crank degrees and rpms. I know this is a cheesy half @$$ thing to do, but when I found this site I just set my initial advance and ass-umed that the page was correct. Perhaps I should double check my total advance... Jon Quote Link to comment Share on other sites More sharing options...
Dan Baldwin Posted October 2, 2003 Share Posted October 2, 2003 240Z distributor, with a Pertronix pickup. Definitely check your advance at elevated rpm. I drove around for quite a while, on and off the track, with ~18 idle/43 max total advance. WAY too much. Aim for 34-36 max total and you should be in the ballpark. I've checked out the jason510 site, that's what I sorta went by in modding my distributor. Pretty good reference. Quote Link to comment Share on other sites More sharing options...
THUNDERZ Posted October 2, 2003 Author Share Posted October 2, 2003 Sorry to sound like a moron, but the only way I know to check timing is at idle. Are yoo saying to set it at a higher RPM? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 2, 2003 Share Posted October 2, 2003 Yeah, you have to have a timing gun that has a dial or buttons to plug in the total advance, then you set the timing to O (because the gun is figuring in the advance) at 3000, or whenever the timing maxes out. Jon Quote Link to comment Share on other sites More sharing options...
Dan Baldwin Posted October 2, 2003 Share Posted October 2, 2003 To check advance at higher rpm, you rev the engine while checking the timing, and either mark the pulley up to 35 degrees (mine is marked at 0, 5, 10, 15, and 20), use an adjustable timing light, or just approximate. It's really more important to know what it's doing at higher rpm, as that's where detonation is less likely to be noticed, and more likely to do damage. Also, higher rpm is more likely where you really want to optimize it anyway. Much better to be running at 10idle/35max than 18idle/43max. Better for longevity AND power production. Knowing what the advance is at idle but not at elevated rpm is better than not knowing the advance anywhere, but perhaps not by all that much! Quote Link to comment Share on other sites More sharing options...
THUNDERZ Posted October 2, 2003 Author Share Posted October 2, 2003 uuuuhhhh....yeah. OK need to get better timing light, mark crank pulley up to 35-40, and hold at around 3000rpm to set? How does the timing light connect to the distributor? Sorry again...this is all totally new to me.. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 2, 2003 Share Posted October 2, 2003 It connects to the battery for power, then clips over #1 spark plug for the strobe. Jon Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 2, 2003 Share Posted October 2, 2003 Make that spark plug wire. Sorry. Jon Quote Link to comment Share on other sites More sharing options...
THUNDERZ Posted October 3, 2003 Author Share Posted October 3, 2003 I know how a normal timing light is hooked up. I was refering to the before mentioned hook up to distributor. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 3, 2003 Share Posted October 3, 2003 Just hook it up the normal way. I have never heard of, or seen in the previous posts, a way to hook a timing light to the distributor directly. Jon Quote Link to comment Share on other sites More sharing options...
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