Spark Advance jumps +20 when decel to 0%TPS.

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hsv08
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Re: Spark Advance jumps +20 when decel to 0%TPS.

Post by hsv08 »

You think thats bad, This is a factory 09 L98 VE SS - people wonder why the RPMs hang.........
09 SS L98.png
JohnDee68
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Re: Spark Advance jumps +20 when decel to 0%TPS.

Post by JohnDee68 »

I guess at least they are in the green and yellow, not red :)
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Re: Spark Advance jumps +20 when decel to 0%TPS.

Post by In-Tech »

I don't know how the non US GM cals work, but I bet similar. Biggest thing I do is raise up all the mph parameters so it forces idle strategy sooner, helps with the decel drop to idle stuff.
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Re: Spark Advance jumps +20 when decel to 0%TPS.

Post by vlad01 »

Interesting, never seen an LS spark table before. Looks similar at high loads as the ecotec figures. Are LS engines knock limited?
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Re: Spark Advance jumps +20 when decel to 0%TPS.

Post by delcowizzid »

Ls have efficient heads and run lower timing like ecotec
If Its Got Gas Or Ass Count Me In.if it cant be fixed with a hammer you have an electrical problem
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hsv08
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Re: Spark Advance jumps +20 when decel to 0%TPS.

Post by hsv08 »

vlad01 wrote:Interesting, never seen an LS spark table before. Looks similar at high loads as the ecotec figures. Are LS engines knock limited?

Yep they are knock limited under WOT.

Factory ish
LS1s will take around the 24* to 26* mark

L98s can take a little more

LS2 likes a little less then LS1

The E38s knock strategy is really excessive

You can have 1 degree to much timing and it will pull 4 or 5 degrees and flatten advance enough to feel it through the whole pull.
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Re: Spark Advance jumps +20 when decel to 0%TPS.

Post by vlad01 »

Interesting. The kidney style cambers seem to be knock limited. The wedge type like VN-VR v6 are right on the edge of knock limit with 91 but fairly tolerant with 98.
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Re: Spark Advance jumps +20 when decel to 0%TPS.

Post by delcowizzid »

Most of the ls stuff we have on the dyno like 20-22 before you start gaining nothing buick 28ish
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Re: Spark Advance jumps +20 when decel to 0%TPS.

Post by vlad01 »

Compression ratio has a bit to do with it too. My VP dropped to 20º after increasing it to 10:1, even with a bigger cam but the cam timings are pretty wacky compared to the norm.
I'm the director of VSH (Vlad's Spec Holden), because HSV were doing it ass about.
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