Forced Induction Superchargers | Turbochargers | Intercoolers

The power (Literally) of ignition timing

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Old Dec 20, 2012 | 11:29 AM
  #21  
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Anyone notice that the graph got smoother each time too.....
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Old Dec 20, 2012 | 12:29 PM
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Originally Posted by Louis
Be careful! This LSA is a 9:1 compression engine, so you can reach MBT easier before spark knock. Just pull your plugs and keep an eye on everything

If this was a or 11:1CR setup, Id be lucky to get 12* in it!
Thanks. To be honest, the car runs really nicely, with more power than my tires can hold on the street at this point, so most likely I'll just leave it alone. About the only time I would do that is on the dyno for a pull or two to see what it does.

Thanks again for posting your results.
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Old Dec 20, 2012 | 04:52 PM
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Originally Posted by Louis
I would run 19 and 14* timing

Boost and timing can both be detrimental. Its hard to say with such little increases. I would have to say that less boost and more timing would be safer, but more boost, depending on the efficiency of the setup, it may make more power with more boost.

i hear ya. on alcohol, e85 or methanol, where do you typically find the limit on timing
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Old Dec 20, 2012 | 06:34 PM
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in to learn.
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Old Dec 20, 2012 | 06:34 PM
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Liljohn why's the power smooth out w/ more timing?
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Old Dec 20, 2012 | 07:12 PM
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Originally Posted by LilJohn
Anyone notice that the graph got smoother each time too.....
I've noticed this when adding timing before but never really understood why.
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Old Dec 20, 2012 | 09:34 PM
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I honestly dont know why. Its a phenomena ive noticed too....

I just call it "gettin happy". Theres probably some kind of relationship with the flame front, pressure waves and valve events that setting up the surge effect you see. If you start the flame front at different times via differsnt timing events...you change where in the combustion cycle the mechanical events take place.

Ive also seen it start going back the other way when the motor ends up over timed too.

I set timing at the track. You can get close on a dyno but not perfect. Keep putting it in till the car slows down. Then put it where it ran the best mph.

Plugs and timeslips tell you more about whats going on than anything else. Doing WOT shut downs and plug readings will get you up on your tuneup quicker than anything.
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Old Dec 20, 2012 | 10:34 PM
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I thought you were supposed to add timing till **** burns up and then back it off a little lol
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Old Dec 20, 2012 | 11:12 PM
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Thats for the nitrous guys... wrong section....lol
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Old Dec 21, 2012 | 01:07 AM
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I usually run 16* in my car on E85 but if I am feeling good i'll put 24* in it. I have had 26* in it several times lol. Cant even describe the difference
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Old Dec 21, 2012 | 02:53 AM
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Originally Posted by LilJohn
Thats for the nitrous guys... wrong section....lol
Old habits are hard to break

Why such a cold plug in this setup? 7's should be plenty IMO
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Old Dec 21, 2012 | 05:38 AM
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extra insurnace, as well as, we typically overdo things in FI
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Old Dec 21, 2012 | 06:01 AM
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15.5 Degrees of timing vs 17.5 when I had my tc76 at 7lbs. Only thing changed in the tune was timing and the afr richened up quite a bit with more timing.

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Old Dec 21, 2012 | 07:50 AM
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Originally Posted by AutomagicLS1
I usually run 16* in my car on E85 but if I am feeling good i'll put 24* in it. I have had 26* in it several times lol. Cant even describe the difference
how much boost?
et/dyno numbers to show the difference
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Old Dec 21, 2012 | 08:29 AM
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Originally Posted by LilJohn
Anyone notice that the graph got smoother each time too.....
This is something you can really see on higher boosted honda turbo setups. They HAVE to add timing to get it to smooth out up top.

Also IMO, timing is harder to hook than boost, we run REALLY low timing down low on the street tires to make it hook, sad how much boost we can shove down it if the timing is low and still stay hooked on a pure street tire lol.
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Old Dec 21, 2012 | 10:06 AM
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Originally Posted by skinnies
This is something you can really see on higher boosted honda turbo setups. They HAVE to add timing to get it to smooth out up top.

Also IMO, timing is harder to hook than boost, we run REALLY low timing down low on the street tires to make it hook, sad how much boost we can shove down it if the timing is low and still stay hooked on a pure street tire lol.

Timing is such a great traction tuning tool, because you can catch the slip very quickly, and add it back it, again, very quickly.

If we remove timing you can imagine the power loss. We are talking a 150-200 hp loss at the 600 hp level, thats equivalent of 8-10 psi of boost, but you can ramp it back in in a split second


As for the timing causing the oscillation in the curve, its just an incomplete burn due to the lack of compression, lack of timing, and the mixture.
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Old Dec 22, 2012 | 06:16 PM
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I was always told to drop the timing a little near peak torque. Is that what you are doing or no?
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Old Dec 22, 2012 | 08:39 PM
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I have always done the same. I have found the motors I have personally tuned will tolerate less timing at peak torque than at redline. As mentioned previously I would have several degrees less timing at peak torque and raise it as it went towards redline.
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Old Dec 23, 2012 | 01:27 PM
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Originally Posted by BAKED
Old habits are hard to break

Why such a cold plug in this setup? 7's should be plenty IMO
People have become accustomed to running too hot of a plug in forced induction applications, especially on this website. Any car that we build at our shop similar to this power level and boost would have a TR8 plug in it.

Contrary to popular belief there is no power loss by using a colder plug and you can actually 9/10 run more timing with the colder plug.

Good thread Louis.
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Old Dec 23, 2012 | 07:30 PM
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I went with a Tr8, non-protuding tip with my rebuild and no issues at all. I had TR7's in it before.
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