When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hey guys, I'm a noob when it comes to tuning but I really want to learn the way it works so I've been doing quite a lot of reading and video watching. my problem is when reading online it says that as engine speed increases so does timing but when looking at merlins diy as the load increases timing decreases, ie timing advance and timing retard. So I've come to the conclusion that as engine rpm increases timing is advanced and as load increases timing is decreases, I'm I correct? Just got confused looking at timing retard looking at the table left to right, any help would be very much appreciated About this subject, thanks!
Hey guys, I'm a noob when it comes to tuning but I really want to learn the way it works so I've been doing quite a lot of reading and video watching. my problem is when reading online it says that as engine speed increases so does timing but when looking at merlins diy as the load increases timing decreases, ie timing advance and timing retard. So I've come to the conclusion that as engine rpm increases timing is advanced and as load increases timing is decreases, I'm I correct? Just got confused looking at timing retard looking at the table left to right, any help would be very much appreciated About this subject, thanks!
You are correct, as load increases timing has to decrease due to the increased pressure of boost. As boost increased the risk of detonation increases so you had to pull timing to prevent knock. as the RPM increases timing has to increase because the spark does needs more time to ignite the fuel since the engine is spinning faster
You are correct, as load increases timing has to decrease due to the increased pressure of boost. As boost increased the risk of detonation increases so you had to pull timing to prevent knock. as the RPM increases timing has to increase because the spark does needs more time to ignite the fuel since the engine is spinning faster
Red arrow - hard start, max load, max pressure and fuel molecules closer to the mixture burns faster.
Green arrow - soft start, min load, min pressure, fuel molecules further the mixture burns longer.
Attached a picture, you might find it useful.
Fuel combustion is divided into three stages.
1- igniting
2-burning
3- combustion
The first phase ends when 6 ... 8% of the total volume of the mixture in the combustion chamber burns out. The temperature rises so much that, starting from point 2, the pressure rises sharply, the main phase of rapid combustion begins (section 2 ... 3). The flame propagation speed in the middle of the combustion chamber reaches 60 ... 80 m / s. Along the walls of the chamber, the combustion rate is lower and the combustion is incomplete. The duration of the second phase for high-speed engines is 25 ... 30 ° of the crankshaft rotation angle. In this phase, the bulk of the heat is released.
The third phase Q3 is the combustion phase of the mixture in the peripheral sections of the chamber during the expansion stroke. Point 3 is taken as the beginning of this phase. The pressure in the cylinder at this moment will be maximum.
