SOHC pistons in my KA24DE. Would retarding the timing help?

[Didderson]

http://toyotaperformance.com/fuel_octane.htmIs the only site that I've found that talks somewhat about what I'm trying to figure out here. If anyone else has SOHC pistons in their KA24DE, let me know what degree timing you are running. I'm currently at 20deg. right at stock. I'm wondering if i should retard my timing because the compression ratio boost changed the point at which the fuel mixture is now ready for detonation.Any help on this issue would be appreciated it's tough to search nico for a topic as specific as this!

[neverlift]

what year was the piston from? if your using the flat top ones you should be ok, maybe pull a degree or so at the dizzy...

have you drove it and your getting det? was the gas used 93? IIRC you should be dead on or close enough that 93 will take care of the detonation. so how is it? fun? what kinda power does it make?

[Didderson]

I drove it to the gas station after draining the fuel, and I had to have my brother escort me since my car's not registered/insured. I just slapped on a fake lic. plate and yea... I'll be registering/insuring/inspecting it soon so I'll definitely be able to tell you then. It sounds like a BEAST, I have a 248 intake cam too. I'll keep the timing where it's at since you said that, but it just seemed it was a little hard to start up. but maybe thats cuz my plugs are fouled because my timing was off when i first started it up. (since then i borrowed a light from my friend white comet to be exact and it's been fine).

Running 93 octane, i need a custom exhaust, with the more compression it seems it's popping through the down pipe where it connects there and after 4k rpm changes tone to popping straight pipes sound. So it's leaking hah.

I believe the pistons are from the 90, they're flat top, but not QUITE flat flat. Like 1-2 millimeters shaved in around the center. Just a bit.

edit, and i'm not getting det. anymore . the 93 fixed that. I have a lightweight flywheel and an UR crank pulley, it really revs fast. I love it. Can't wait to get my s15 output shafts and get 'er on the road ..... legally