timing stock vs advanced???

WRteam200sx · Mar 20th, 2003, 08:22 PM

is it worth my time and effort to advance my timing , im not worried about the gas factor around here cause its not that high ($1.60) for 93 .... but does it make enough difference to do it is what im asking???

also what is the stock timing set at as compared to advancing it to 17 or is there a lower number i should start at... right now my motor work consists of i/h/e and vitek plug wires and plugs wit an optima battery ...

himilefrontier · Mar 21st, 2003, 03:47 AM

While I have no experience with this mod as it pertains to Sentras, I have done this to my older carburated domestic V8's and it is usually worth doing.Just as long as you don't go too far it will improve driveability and throttle response.The whole idea behind timing advance curves,for those who don't know, is to have the combustion process start before the piston reaches TDC.This is necessary because gasoline doesn't combust instantaneously,but rather takes time to reach peak intensity.This time interval depends on the quality of the mixture,and it's cohesiveness.This can be varied with things such as combustion chamber efficiency and quench.For example, a typical Chevy 350 with a set of heads made in the 1960's-70's (I.E. 2.02 fuelies)will like to see 38 degrees of TOTAL timing and one with the more efficient Vortec heads(late 90's truck heads) will only require as little as 28 degerrs total timing.And, yes, I KNOW it is not a Nissan analogy but no other engine was in production long enough to have such a comparison be possible.

bahearn · Mar 21st, 2003, 10:40 AM

Read "Sportbike Performance Handbook" by Kevin Cameron to get a clearer description (with drawings) of what himilefrontier is trying to say.

As for SE-R timing, factory specifies 15º BTDC ±2º. Bumping to 17° is within factory spec for 87 octane fuel and will give slightly better gas mileage and slightly better throttle repsonse. The ECU should still have enough latitude to keep the engine out of detonation. Ignore those who say this mod requires 89 or better octane, I have run 17º on 87 octane for four years without any hint of detonation.

WRteam200sx · Mar 21st, 2003, 02:20 PM

Hmmm , ok ... well i normally run 89 (1.55) around here cause its only like 5 cents more and it seems to give me a slight bit more throttle response... but if it will also give me better gas mileage then hell yeah .. im there.. now i just have to get it done!

zeno · Mar 21st, 2003, 02:23 PM

From www.se-r.net

Quote:

Here is the all time cheapest hop up that anyone can do. Typically most SR20DEs have the timing set to 13 degrees or less from the factory. I have seen as low as 10 degrees on a brand new factory fresh car. You can safely run up to 15 degrees on regular gas on most SR20DEs. For best performance on a stock engine, put in 92 octane and dial in between 17 to 19 degrees. This has been proven by recent dyno testing on a stock car to give up to 6 more hp at the wheels. Remeber if you have your timing turned up this high you MUST use 92 octane fuel. Do not exceed 17 degress of advance if you have a JWT ECU.

Timing is a simple and free (or cheap) mod. that you can do for ~5hp. All you need is a timing light gun to do the mod. yourself which can be picked up at any autoparts store. Advance away!!

WRteam200sx · Mar 21st, 2003, 02:29 PM

Sweet , I might set it over the weekend ... not sure bout 17 though ... maybe like 16 , cause i normally run like 87-89 octane... i drive to much to use 93

NismoPC · Mar 21st, 2003, 09:48 PM

Quote:

Originally posted by WRteam200sx
Sweet , I might set it over the weekend ... not sure bout 17 though ... maybe like 16 , cause i normally run like 87-89 octane... i drive to much to use 93

That octane is fine with 17 degrees. I personally used 89-91 @ 17 and I run 91-93 currently. It is around 18-19 degrees.

Mar 24th, 2003, 10:43 PM

how much does a timing light cost?

zeno · Mar 25th, 2003, 11:19 AM

Quote:

how much does a timing light cost?

~$40-$50