Hi guys. I've been searching thru 15 pages of threads related to timing to answer the following question:

Why does everyone max their timing advance at 19* when SCC mag bumped their project se-r timing up to 21* to obtain 6 whp?

2* extra is enough to notice a difference for sure, so why did 19* become the standard? Has someone used their ecu datalogger to see when timing gets pulled back with stock ecu programming / 91+ oct, and 19* was the magic #? I understand from searching that with JWT programming 17* is the max, but the stock programming seems to be able to handle more timing advance.

Here in ATL I run 93 oct and I want to squeeze out max hp, but I don't want to advance til detonation at 7500 rpm occurs. I know 19* is safe (I currently run it), but SCC claimed they had no problems with 21* with 91 oct.

Is there any solid data on this out there (datalogged info) and does anyone run 21*(or more) timing advance? I'm looking for data / dyno proven answers, not just "you'll blow your motor if you go higher than 19*".

Thanks in advance for any info!!

i think out of people's experiences of bumping the timing too high will cause power loss. you have to run a higher octane. its been dyno proven plenty of times. you can try advancing up to 21* to see what it does and feel. as long as you use that 91 your ok and wont blow your motor. the only that could happen is that your plugs will go out faster. but its cheap like a combo meal ;)

fwiu, 19* is the most efficient setting. Power gains above 19* are minimal to none.

"Advancing the timing is synonymous with "free horsepower." This is the cheapest modification that you can do to an SR20DE engine. SR20DE engines come with the timing set from the factory anywhere between 10 to 15 degrees BTDC. If you advance the timing, then you will at the least gain crisp throttle response and at the most gain horsepower. But how much timing do you need to advance? In their July 1999 issue, SCC advanced the timing of their 1991 Sentra SE-R to 21 degrees and gained 6 hp. They claim that there was no detonation what-so-ever. Mike Kojima, however, believes that there is no horsepower to be gained beyond 19 degrees. As such, he suggests advancing the timing between 17 to 19 degrees and using 92 octane gas. I think Mike's advice is safer than SCC's 21 degree timing. Mike insists that you use 92 octane gas. So please do so. If you do not detonation might destroy your engine." - http://www.geocities.com/MotorCity/Track/9085/

http://www.vems.co.uk/forum/index.php?topic=97.0

Read the third post about ignition timing. There is a point where you gain little to no HP, yet still manage to avoid detonation. There is no point in being in this area, so timing is usually backed off 2 degrees without loss of HP, giving a gain in detonation avoidance.

Well..... LOL.... I have been over this time and time again. Not knowing if there is something wrong with my distributor. But mine is at 21+ right now. And the only thing I have noticed is plugs going bad after time. Other than that, the power is there.

Those are some great links. I now understand after researching those links that SCC's article had some really flawed #'s in it. So their info is clearly unreliable...

So this now raises a new question for me, if SCC's dyno timing mod #'s are flawed, is there really any power to be gained in advancing timing, or does timing advance only increase throttle responce?

Does anyone have any dyno #'s they can post of pre- and post-timing advance?

Hopefully mike will chime in here...

Back when my SE-R was NA, running S4's, I dyno'd it at 21*, 19*, 17* & 15*, and it made the most power at 19*.

The best way to do this is to set the timing at 21*, and use a Consult cable & software, which allows you to retard the timing from your laptop, so you can change the timing accurately & immediately.

C

Hi.
I have probed both, 19º and 21º. I have done this in RR engines with SE-R ecu, it looks so far by the dyno sheets, that the car is more solid with 21º at top (power drop is softer), specially on almost stock engines. When you put a good header on the car, usually get less reponse to timing changes, so far it happens that using a Tri-Y header the car draws almost the same line with 19º vs 21º. It happens in some cases that there is no difference at all. If I were you, i would keep 19º until i have the chance to go to a dynometer to probe that. As far as i know car will support 21º without knocking.

Engine response to timing depends on how is your engine built. All these test were done with 97 oct RON mesure

hope it helps

PS: i will upload some dynos later after work, i had some with timing playing (from 13º to 23º)

Back when my SE-R was NA, running S4's, I dyno'd it at 21*, 19*, 17* & 15*, and it made the most power at 19*.

The best way to do this is to set the timing at 21*, and use a Consult cable & software, which allows you to retard the timing from your laptop, so you can change the timing accurately & immediately.

C

Awsome info, that's exactly what I was looking for....

PS: i will upload some dynos later after work, i had some with timing playing (from 13º to 23º)

Cool, look forward to seeing those...

Awsome info, that's exactly what I was looking for....
By the way, you can only decrease timing through the Consult port. Even though most programs have + and -, only - actually does anything. And you probably already know this, but the timing modification is only active while you're in the program.

C

kinda new to this timing thing but advancing the timing to 19* with 93 octane gas would be fine on a stock sr20de? please correct me if i'm wrong thanks in advance

kinda new to this timing thing but advancing the timing to 19* with 93 octane gas would be fine on a stock sr20de? please correct me if i'm wrong thanks in advance

Yes, that is the general timing bump recommendation. You'll like the throttle response after.

I run my timing at 17. It seems to provide the best balance (I live at 4k+ above sea level though). 21 caused me to lose to much bottom end - although the top end recieved a noticeable power increase.

the problem with running too much advance is two possibilities, first your knock sensor may be deaf, and secondly if it isnt, the "retard under knock" in the nissans is quite aggressive.

Mike

oh i didn't know 19* was good i was going to go 17* but from the remarks here i'm thinking a 19* advance would be a better route for me thanks guys