NAN777

i wonder............

how does the tuners nowadays determine if the ignition timing is too advanced or too retarded?

as i understand, too advanced will cause knock and ping... too retarded will cause high EGT..

let's put this aside.. if i were runing with a wideband and also relying on the knock sensor of the stock FD.... how do i know if my timing is too advanced or too retarded ?

DaleClark

iTrader: (55)

One way to do it is with a load-bearing dyno that can measure tractive effort, which is a measure of torque. Hold the car in a load cell, advance timing until the torque output evens out or drops, then bring it back a few notches.

Dale

Howard Coleman

iTrader: (6)

^^^^ Dale is on the money.

another way is measuring knock. if you have a power fc datalogit you have the necessary tools. advance the timing until you get the knock acceleration, then back it off. don't overlook what can be accomplished powerwise in the intermediate (medium boost and rpm) cells. use knock to find your numbers.

if you don't yet have a datalogit get one or start saving as they are indispensable and will save you $$ by allowing you to properly tune your motor instead of replacing it.

i maintain a properly tuned and fixtured rotary is every bit as reliable as a piston engine.

howard coleman

BoostFrenzy

+1

this is called maximum brake torque/minimum best timing, there's a point of diminishing returns vs. detonation ceiling when finding your timing curve, i've never tuned a rotary (yet), but in a piston engine adding/removing timing also plays a role in EGT (less timing, more heat), so it's a balance of safe/cool AFRs & timing and having a buffer from detonation in all situations

NAN777

thanks for the information..
i would like to announce that 2 days after i ordered the datalogit....
and today... my engine blew.....

4 plugs soaked with water... death of O ring....
currently sitting at my home waiting to be towed to the rebuilder.

anyway...... thanks for the input... i'll probably stick with datalogit monitoring knock level determine the borderline of my timing.

does advancing timing too much shots up the EGT ?

NAN777

another question.. how many KM of run in i need after i rebuild the engine ?

NAN777

i plan to get RA classics seal... how many KM of run in i need ?

rynberg

Most builders recommend 1000 miles of break-in, so 1600 km.