HOW MUCH TIMING WORKS BEST?
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Pro
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From: clovis ca usa calif
HOW MUCH TIMING WORKS BEST?
Just got my new Corvette Fever magazine. Page 37 sez GM recommends 6 degrees timing for 85-88 cars,but Chris at Corvette Clinic in Sanford Fl sets them at 0-2 degrees. He sez they run smoother and have better low-end torque. Whats the story?
Former Vendor
Joined: Jun 2001
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From: St Marys PA
Re: HOW MUCH TIMING WORKS BEST? (james holley)
Every engine setup needs a different amount.
I start on the low side ~29* and work my way though in 2* incriments. You really need a good way to gage the output, to be sure. Once its found leave it alone. For a stock car I would say leave it at 6*.
:thumbs:
I start on the low side ~29* and work my way though in 2* incriments. You really need a good way to gage the output, to be sure. Once its found leave it alone. For a stock car I would say leave it at 6*.
:thumbs:
Drifting
Joined: May 2002
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From: Hazel Park MI
Re: HOW MUCH TIMING WORKS BEST? (james holley)
James, that info is from that mag way back in the mid-late 80's. I found out about it from the forum. :cool: So, I moved mine from 6* to 2*. Big throttle response difference. But I also tried 8*, because some forum members have better response with that. Mine is WAY stronger at 2*. But engines are as different as people, and that mag timing article was specific about the 85 model. Other L98s may be different. 2* works for me and my mods the best. :seeya
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From: Yukon OK
Re: HOW MUCH TIMING WORKS BEST? (jmrl98)
Well, this might be an area where my knowledge is outdated or based on prior unverified information. But it seems to me I recall setting timing at the maximum advance without getting serious ping. The 85 manual lists a number of problems including overheating for timing retarded too much. My stock 85 seems to like 10-12 degrees advance. On the lowest octane gas that is where I just start to get knock counts and hear ping under load and moderate acceleration.
Back in the "old" days (before I could afford any test equipment) we used to disconnect the vacuum advance and set timing by the best overall idle. Tended to be about right. On my 85 that ends up at about 14 degrees.
Guess I am missing the point. Is the 2 degree setting just to improve low end? What happens at the upper end? I might just go try it and see. Never had it set that low.
Back in the "old" days (before I could afford any test equipment) we used to disconnect the vacuum advance and set timing by the best overall idle. Tended to be about right. On my 85 that ends up at about 14 degrees.
Guess I am missing the point. Is the 2 degree setting just to improve low end? What happens at the upper end? I might just go try it and see. Never had it set that low.
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From: Athens AL
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Re: HOW MUCH TIMING WORKS BEST? (LaVidaLoca)
Mine seemed to like 8*-10*
Youll have to test this stuff yourself.
Youll have to test this stuff yourself.
Racer
Joined: May 2001
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From: San Antonio TX
Re: HOW MUCH TIMING WORKS BEST? (TA)
I thought the GM recommendation was for regular gas. Since I only put 93 octain in, I upped it to 10* base. I have plenty of kick in the 'ol L98. But, then again, when I first started whoever had it before had it based at 4* retarded. ECM isn't counting a lot of knocks and I may try 12* base soon.
Drifting
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From: Gloucester Va
Re: HOW MUCH TIMING WORKS BEST? (Topless87)
All you can really do is try both ends of the scale and see how it works out for you. As you can see from the few post already every engine is different. Live by the following rule of thumb when tuning your engine and you will help in the long run. Don't tune your engine to what others have tuned their's to, give your engine what it likes. If it likes 14* then give it. If it loves 2* give it that. It's like a woman. You don't give your woman something she hates just because your friend gave his woman the samething. You give her what makes her happy, and what happens? You get rewarded.
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Pro
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From: Yukon OK
Re: HOW MUCH TIMING WORKS BEST? (88_vette)
It's like a woman. You don't give your woman something she hates just because your friend gave his woman the samething. You give her what makes her happy, and what happens? You get rewarded.
Instructor
Joined: Oct 2002
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From: Smithfield VA
Re: HOW MUCH TIMING WORKS BEST? (LaVidaLoca)
Okay, I am new to this whole timing theory. I had an 1989 dodge van that I took the engine cover off and adjusted the timing while I drove it. I tweaked the timing until I just lost the spark knock and left it there. I had no timing light or anything fancy.... just an ear. Well, now I have a timing light since I can't adjust while driving.... my car knocked a lot recently and I found the timing at +4... so I put it at +6 and it is MUCH better, but I still have some light knocking when leaning into it hard. So, by observation I have concluded that advancing the timing helps spark knock. Is this correct? Also, I thought that the engine was most efficient if timed to the point that the spark knock is just gone. Correct? I can see how a engine that is older would need different timing settings than new with timing chain wear, etc. So, since I hear slight knock at +6, I was thinking going to +8. Does this make sense? When the posters here say put the timing where the engine likes it, are they referring to the absence of knock?
Wondering,
Skip
[Modified by SkipI, 9:42 PM 10/11/2003]
Wondering,
Skip
[Modified by SkipI, 9:42 PM 10/11/2003]
Drifting
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From: Gloucester Va
Re: HOW MUCH TIMING WORKS BEST? (SkipI)
Most of the time you back the timing off to get rid of knocking. It's caused by to mch timing normally, of course there are other factors but for times sake, an increase in timing will cause knocking. One thing to keep in mind is this. THe ECM already pulls a good amount of timing out when it hears a knock. If you are still getting knock then it's pretty bad. Some cars will pull as much as 20* out and it you are pulling 20* out of timing and still getting a bad knock then you may have a problem somewhere else. THis is just a side note to keep in mind.
Racer
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From: Lancaster Lancashire
Re: HOW MUCH TIMING WORKS BEST? (88_vette)
Saw that article and tried it on my 87. I found 2* gave a slightly smoother idle, but didn't feel as crisp.
I finished up at 10*-12*, but used 98 RON octane (UK) fuel and found this felt best. (Butt dyno) I think if you advance it to this level without increasing the octane rating of the fuel, you risk the engine management pulling timing back and it feeling worse than the base setting of 6*. If you have a scanner, that is ideal in that you can check for knock retard. I don't have one, so can not verify whether I encountered knock retard or not. It felt crisper, so I left it that way. :steering:
I finished up at 10*-12*, but used 98 RON octane (UK) fuel and found this felt best. (Butt dyno) I think if you advance it to this level without increasing the octane rating of the fuel, you risk the engine management pulling timing back and it feeling worse than the base setting of 6*. If you have a scanner, that is ideal in that you can check for knock retard. I don't have one, so can not verify whether I encountered knock retard or not. It felt crisper, so I left it that way. :steering:
