6G Celicas Forums

Feed it lead paint chips

there should be two bolts on your distributor that bolt it to the head, one on the top left and one on the bottom. This is how it is on the 5SFE but I imagine the 7afe is similar if not identical. Loosen them with a 12mm until you can just barely turn the distrubutor by hand. Turning the distributor clockwise will advance it and spinning it counterclockwise will retard it. Also, the idle will raise up when advanced and slow down when retarded. You could probably go 5 degrees advanced for some more power but make sure to listen for knocking and pinging at higher rpms. And make sure to mark where the distributor was before you moved it if you dont have a timing light, just scratch a mark around the dist hold down bolt.

Another thing to note is that on the later models(maybe 97 and up?) the distributor does not spin and cannot be mechanically advanced or retarded

Thankyou for the info. Ill have to take some time to mess with it later.

with 15 degrees total base advance (+5 from stock) I highly suggest just running 89 octane fuel. I had much higher knock counts on 87 than 89 and even lower on 93 but not that much lower than 89 vs 87.

Well and besides the price of higher octane, lower octane fuel has more joules of energy within it. So always run the lowest octane that doesnt make your engine knock. See that sign that says "may contain up to 10% ethanol" next to the pump? Well ethanol is 120 octane i think, so all they do is water down your premium gas with more ethanol to raise the octane rating. That and super/midgrade is just a mix of premium and regular because they only have two tanks in the ground for unleaded.

Sry I just like people knowing the truth about gasoline...

This post has been edited by Special_Edy: Apr 21, 2012 - 2:14 PM

So you can advance up to 15 degrees with the distributor? How far would you recommend going on a stock motor?

I think it'll turn all the way to 25 but the gains pretty much end at 15 from what I was able to research.

The more retarded you make it the more low end grunt you will get. The engine will run cooler and the power band will be shifted down with the engine producing less horsepower. The more advanced the engine is the sooner it will fire the spark plug on the compression stroke before the piston reaches top dead center and makes full compression. Firing sooner yeilds more power because the flame front of the combustion coming off the spark plug burns more of the vapor in the cylinder and compression is boosted by the combusting gas.
Because the flame front of the burning gas/air vapor travels at a certain speed(however many feet per second) and piston speed is relative to rpm, higher rpms need the spark sooner(more advanced) and lower rpms need it later(more retarded). If you advance it too much then the explosion will happen too early and compression will be increased so much that it will actually try to push the piston back down in reverse. This will make the engine impossible to start as every combustion trys to turn the engine backwards and it will cause detonation at higher rpm. Adding higher octane will combat this predetonation but at this point your not gaining anything. 15 degrees advanced will probably give your engine a little more hop but realize that the ignition is already electronically advanced so dont overdue it. If you hear any predetonation then dial the distributor back a hair and retest around the neighborhood. You will feel it if its too advanced.

Sorry for the long post but I hope its helpful

This post has been edited by Special_Edy: Apr 23, 2012 - 1:36 AM

Sometimes longer post yeild more information. And thus better understanding. Thankyou for a clear response. Gunna have to take an hour to ight to mess with it.

Sometimes longer post yeild more information. And thus better understanding. Thankyou for a clear response. Gunna have to take an hour to ight to mess with it.

I found 15 deg gave me more low end actually, there are plenty articles online about this.

Just advanced the timing. Did it a little bit at a time driving it after each time. Didnt really notice much. Little more get up at 5k. Advanced all the way with no knocking. Idels at 900 smoothly. Im thinking the computer is getting the best of the timing.

What year is yours? I never heard knock, I monitored it with a SAFC2.

http://www.contactmagazine.com/Issue54/EngineBasics.html

I read that, did a little voodoo math which I've long since forgotten, and figured the best gains to be around 15 deg. Read some stuff at Celicatech about the 3S/5S-FE and it agreed about 15 deg. F heads are all similar regardless of block, chamber design plays a big role in flame propagation.

Its 95 7afe(stock except intake and exhaust), on a 94 chassis and ecu. Turned the distributor all the way clockwise and running 87(basic pump fuel).

Did you set the base timing correctly and check with a timing light or just turn the distributor? You have some extra steps beyond just turning the distributor, you have to be in the base timing adjust mode.

umm IIRC correctly its TE1 and E1, in the dieg port.. jump those two and it will set it to the base timing... then use a timing light and set it to what you want.. i would suggest 16* no more. hope you are not driving like that cus you will be well in excess of 20* advanced.

Another thing to add- make sure your idle is 650-750 and the motor is at operating temperature. Even with E1 and TE1 jumpered the electronic advance will kick in and screw up your timing at anything above an idle.

indeed, and assuming that the tension on the throttle cable is correct, and the idle set screw is correct, and that the idle up valve is functioning correctly, at *normal* Base timing setting your idle should be 650-750... @ 16* base advance your idle should be purring along at 900 RPM...

Ha more things to do then i thought. Ive been driving all day without a problem. Today idel was right around 700. Havent changed anything sense last night.

But did you have the pins jumped on a hot engine when setting timing? If not, then you did not set timing.