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heavier springs to advance higher rpms?

Old 04-11-13, 06:04 AM
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heavier springs to advance higher rpms?

have my 12a racing IT7/A - Well since I never could get a answer about timing a 12a with locked dist I finally think I found my answer with estimated 2 hours research. Thanks guys.

However it seems the general consensus is the mechanical advance is full at 4k rpms. Has anyone put heavier springs so the timing advances from 5k to 8k instead of 1k to 4k? Or does that system only matter if I am going for gas mileage and not full power. Do I just want max advance at 24 the entire time?

And also what about my redline? I finally tested the car on a back road and it pulls souch harder from 7-8k rpm. Seems like I could even hit 9k. I know factory accessories sometimes are the limiting factor but does anyone spin their 12a in stock for to 9k all day at the track?
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Old 04-11-13, 09:56 AM
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if your distributor is locked then you have no timing advance.

the stock timing curve, which is in the shop manual, Foxed.ca - Mazda RX-7 Manuals

for most cars doesn't advance fast enough, most people want max advance sooner, for example Peejay took a spring out.

if your 12A has the original iron apex seals in it, keep it to 7000, give or take, they WILL come apart over that sooner or later. if you have carbons then 8500 is probably ok.
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Old 04-11-13, 10:53 AM
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The engine was out of a wrecked 84 the guy said he had about 30k on the rebuild. So it might have iron seals but I know they are not the original from factory. It was rebuilt about 7 years ago.

How is the power curve for these things? Am I just immagining things or does it really pull harder after 7k rpms? Why would they design an engine to have a fail point before max power? I.e. my corvette begins to fall off power wise befor redline so there is no point taking it past the limit....

Thank you for responding. I'm glad to see there are two people now on this forum that are active.
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Old 04-11-13, 11:03 AM
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peak power is around 6k...
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