I've searched quite a bit, and haven't found many actual numbers (or even guesses). The threads tend to be "Advancing timing increases power" with no actual numbers or other information to back it up.

I'm thinking of pushing my timing by 5 degrees or so at the CAS, since NAs are supposedly hard to detonate with, and it supposedly adds some decent kick. Anyone else have feedback on this?

I'd love to get dyno numbers for advances, but there doesn't seem to be a dyno in the middle of Iowa. :-/

-=Russ=-

 

I ran with mine advanced 2-3 degrees after the rebuild, because she idled better with it like that. Just recently I tweaked it back to dead nuts, about 8,500 miles into the rebuild. Can't say as I had THAT much more power with her advanced.

If you've been running with perfectly adjusted timing, tweak her up a couple and see if you notice any results. Don't think I would go 5 right off the bat, though I'm the paranoid type

 

I used to run +15 on my '87 sport w/160k miles, never had a problem. The only thing it really seemed to do for me was get my car to rev up a little quicker, as for the butt dyno, it didn't report anything.

 

If one doesn't have access to a timing light, how does degrees of CAS rotation translate into degrees of advance? I borrowed a timing light to set the initial timing, and it's dead on right now, but I don't have access to a timing light right now.

-=Russ=-

 

Unless someone with experience knows exactly how far to move the CAS for a certain amount of "degrees", I'd say you're going to need a timing light.

IIRC, rotating the CAS clockwise retards the timing, although I could be ***-backwards on that, lol...

 

i wouldn't mess with the timing without a light, in fact i probably wouldn't mess with it beyond factory spec. it does improve performace especially if you have alot of mods, if you don't then it will change so little in power that the gains aren't worth possible detonation and an apex seal freeing itself of it's prison.

 

i thought about doing this myself but alas no timming light. has anyone everd gone higher then 3 degrees advance timming? im willing to go 5 off the back but i don't have access to a timming light to get it right.

 

Technically... running advanced timing and a higher grade of fuel should net you more power, but there is really more to the tuning then that. Keeping an eye on your 02 readings, and properly tuning the car, and yes, I'm sure there's power left to be had there.

 

Other threads have said clockwise increases timing (repeatedly).

As near as I can tell, the CAS:eshaft ratio is 1:1. There are two "prongs" on the bit inside the CAS, so there will be two pulses per full revolution of the CAS. This corresponds directly to the 2 spark events per e-shaft rotation. So... check my logic, but it should be a 1:1 ratio (one degree of CAS rotation to one degree of actual advance).

Current mods are Pineapple racing inserts and a Racing Beat presilencer. I'm planning to put a K&N intake on at some point, but not sure when.

I may go out one of these nights and make use of the long deserted straight roads in Iowa (nothing with curves, but lots of deserted straight roads) and play with the timing to see if I can feel any difference. Borrow a G-Tech or something if I can.

-=Russ=-

 

CAS turns at 1/2 e-shaft speed, IIRC. And yeah, the more I think about it, turning it CW probably does increase/advance timing (told ya I was ***-backwards, lol).

Another interesting question is where are we actually taking these degrees measurements- if at the pulley, it's turning 3 times faster than the rotor, does that mean every 3 degrees at the pulley is actually 1 degree, as far as timing goes in relation to spark??

 

For figuring out degrees when I experimented with this, I just looked at the 2 ticks. Since the first one is at 5º and the second is at 20º, then the distance between the two is 15º, right? Well, when you advance you can kind of "eye" this distance in correlation with how much you want to advance it. Of course this isn't exact at all, but it was the best way I could figure out to do it.

 

Your thinking a bit much into I think there Wayne..

Timing degrees are just a relative measurement, in this case, w.r.t the e-shaft since that is what the spark is made in relation to.

IIRC, the max movement you can make without re-stabbing the cas is 14deg.

At the moment on this rebuild, mine is near on that much. Since it bearly idles with it much below that.

 

buy a timing light I got mine for 20 bux

 

Hey- why didn't I think of that, lol...That's using your noggin, dDub

WhiteFC- you're probably right, I'm trying to dissect it a little too far. I'm old school, and just set the timing by ear after the rebuild, then put a light on it and figured out how far off she was after I got the idle down to 750.

 

https://www.rx7club.com/showthread.p...timing+degrees

 

Or use and advance timing light, set your desired advance on the timing light, and then time the car normally.

 

When's the last time you heard of a street-ported N/A dying from detonation? I have measured audible knock on N/A's... Detonation is only the death-maker in forced induction...
I'm not saying, now, that detonation on an N/A won't hurt your car over time, but unlike a TII, where one decent ping will take out the motor, N/A's don;t blow from it.

 

On the second gen, the distance between the leading and trailing timing marks is 10 not 15 degrees. Since the timing advances the same for leading and trailing at idle, set the light on the trailing side. Rotate the cas clockwise until the front cover marker is halfway in between the yellow and orange pulley mark. You're advanced 5 degrees.

 

to be sure you can remove the cover from the crank angle sensor and watch the shaft while cranking, turn the distributor against the rotation to increase the timing.


i said that because i have seen alot of people go a bit nuts when playing with timing, detonation comes on strong when you are accelerating hard so it really only takes a good shot to kill an apex seal. but whatever, just take it easy on that distributor slider. :p

 

Timing marks are set at 5 degrees ATDC on the leading and 20 degrees ATDC on the trailing on the second gen... 20 minus 5 is 15, not 10.

 

Taken from the FSM:


Halfway between the marks would put you at 2.5 degrees BTDC, or -2.5 ATDC on the leading.

 

Q.e.d.