timing advance, how much?

[burnin240sx]

I know timing is supose to be set at 20 btdc. but i want to bump it up a little for some free ponies. I currntly have it at 30 btdc and it improved my 1/8th mile time. so what is the max I should do this to beside's the ovious until advance slows the et time.

Is there any thing I should watch out for?

[Nismo1182]

Ive had mine bumped to 25*

Watch out for detonation. It sounds like BB's in an empty 12oz soda can.

[s13EastTN]

I've ALWAYS wondered what that sounded like.

You sir are my hero.

[TheOne]

put ~93 octane gas, that should help some when advancing the timing for no detonation.

[burnin240sx]

well I figured that if i do to much i would get detanation.

i know the computer controls timing so i'm just tring to stay within a safe range where the computer wont advance the timing to much. I'll play it safe and keep it at like 25 deg

[cory2081]

I too am running 25 with 93 octane. No problems with knock and the car feels alot more responsive.

[Streets_of_Fire]

so how exactly do you advance timing please? thanks!!

[:: orion ::]

1) Buy timing light, $45

2) Run car until warm, disconnect TPS, make sure idle is at ~650-750rpms and steady.

3) Using the light, check the marks on the crank pulley. They are ( -5, 0, +5, +10, +15, +20)...

(Stock is 20, so you want to move it a little more past the 20 mark, you'll have to estimate.)

4) The distribuotr is held in by 2 10mm bolts...loosen them and rotate the dist until you get the base timing where you want it.

5) Tighten dist bolts, reconnect TPS, test drive.

- Brian

[corn322]

unless you have my car, and when you try to check timing all the marks are like 90 degrees away from where you need them.

If you were looking straight at my crank pulley, the timing shaft that sticks out is at the top right side of the pulley. but hit the timing light, and the marks on the pulley show up on the top left.

any ideas brian?

[:: orion ::]

Did you connect the timing light pickup to the #2 or #3 spark plug wire...?

90* off sounds like you used the wrong wire.

The car WOULD NOT start or run with it that far off. Needs to be between roughly -10 and +40 or so from my experience.

Sounds like user error... :p

- Brian

[:: orion ::]

UUUhhhhh...ou also have an ASP pulley?

Their timing marks are close (but not dead on) for mine...as compared to stock pulley.

Make sure they didn't cut the timing marks on the wrong side of the pulley, compare to a stock one.

- Brian

[Bigrolla]

whats the lowest octane u can run safely at if ur set at 24?

[jmauld]

Has anyone actually ever had a knock problem on a N/A KA?

Just curious, I've bumped my timing up a bit (~26) and have had no knock issues regardless of outside temp or gas octane.

[mackdaddy240]

Ive had mine bumped to 25*

Watch out for detonation. It sounds like BB's in an empty 12oz soda can.

That is the most origional description I've ever heard and its great! and to comment on this.."Has anyone actually ever had a knock problem on a N/A KA?Just curious, I've bumped my timing up a bit (~26) and have had no knock issues regardless of outside temp or gas octane."

Yeah I get hella detonation if I run less then 91, but my compression is at about 10.6:1. So if its set at 20 then I can run 91, but anything else and it only gets 93

Modified by mackdaddy240 at 2:44 PM 12/11/2004
Modified by mackdaddy240 at 2:45 PM 12/11/2004

[rsmithdrift]

I hate to bring up a old arse thread to ask a question I think I already know the answer to, but.......

You turn the dist counterclockwise right???

I don't have a timing light and don't want to screw anything up trying this. I know to listen for detonation to find the right spot, but I don't want to retard it accidentally to a dangerous level and wonder what's going on.

I'd appreciate it. I like the search button.

[rsmithdrift]

Before it gets dark please!!!!!!

[DjPantsSpecR]

yes. CC

if you really need proof, pull off the distributer cap and then think it out. the rotor stays in one spot and then you decide if you are moving the rotor closer to the 1st point or the adjacent point, which i think might be 2

[rsmithdrift]

thank you.......

And is it a bad thing that it can go all the way advanced w/o having any detonation?? That doesn't seem right.....I put it close to the same spot, just slightly farther advanced and it helped out. BTW, I've got 89 in it too. Seems it would be knocking/detonating pretty bad fully advanced?? What's that about??

[DjPantsSpecR]

it can actually be a lot of things. Like was previously said someone was runing 30 with no problems. A tired fuel pump or nasty fuel system can cause lean or knocking conditions especially under timing advance. also a nasty motor with lots of carbon buildup is always more likely to knock due to the hotspots

I used to run a ****-ton. Ive never put a timing light on my motor, because i set it by the timing marks and then just eyeball my advance.

recently i knocked back my timing to about 20 degrees because i wanted to complement the low end of my 240/232 cams, but with 248/232 that advance is invaluable

ive never heard my 240 knock and i used to have a lot of advance. ive heard knock many times on my fathers lincoln and it does sound just like a can full of BBs.

89 octane is more than likely sufficient on your stock compression engine on any reasonable amount of timing advance. i wouldnt go any futher than about 28 degrees though. timing is no big deal, its nice to shift the powerband to your liking and its hard to mess up these KAs by detonation

[rsmithdrift]

it can actually be a lot of things. Like was previously said someone was runing 30 with no problems. A tired fuel pump or nasty fuel system can cause lean or knocking conditions especially under timing advance. also a nasty motor with lots of carbon buildup is always more likely to knock due to the hotspots

I used to run a ****-ton. Ive never put a timing light on my motor, because i set it by the timing marks and then just eyeball my advance.

recently i knocked back my timing to about 20 degrees because i wanted to complement the low end of my 240/232 cams, but with 248/232 that advance is invaluable

ive never heard my 240 knock and i used to have a lot of advance. ive heard knock many times on my fathers lincoln and it does sound just like a can full of BBs.

89 octane is more than likely sufficient on your stock compression engine on any reasonable amount of timing advance. i wouldnt go any futher than about 28 degrees though. timing is no big deal, its nice to shift the powerband to your liking and its hard to mess up these KAs by detonation

So you just said my motor is clean and functioning properly is the reason......K, I'll accept that.

Also, does this just move the powerband around?? Kinda the vibe I'm getting off of your statemnts and I know you are like a guru at cams and timing and whatnot....

I understand the principle of it but it seems to me it'd make more power everywhere by advancing it, but I kinda remember more retarded = more bottom end and more advanced = more top end. Which is it?? Sorry to keep badgering you with such noobie questions, but I can't find any straight answers

[DjPantsSpecR]

everyones a noob sometimes, its jsut that i was a noob long before you were...

yeah, think about it like this. its impossible to destroy or create energy. im talking in generalities and this is a true law. you can not create energy spontaneously. For example the energy you gain from eating plants is actually energy gained from the sun nd so on adn so forth.

so, with that said, by simply twisting your dizzy around you can not create power, you have to lose it somewhere else. Im sure you know this, but things like huge duration cams make power up top and sacrifice it down low. its a trade off, its always a trade off. there are very few mods that do not have a "catch" you dig?

so with all that time of yours wasted. An advance will gain you top end power. a retard will gain you low end.

think for a second. WHen you motor starts to spin at 6k rpm it becomes very difficult to pack in all the events that need to happen, adn the spark adn flame kernal speed do not change as they are limited by their own thermodynamic reaction. Advancing the dizzy makes the spark fire earlier so it can start the flame front a little earlier. it just saves you some time when the events start to happen too quickly. However this same advance wont help you in the low end where the flame kernal had plenty of time.

its kinda confusing but i hope this helps. And im no guru, i owe everything to making mistakes... and NICO, thank you though

[rsmithdrift]

Wow. Sombody should make a thread of all the usefull information on this site concerning engine mods and include that. Good job buddy. Thanks, that makes alot more sense, especially since it explains all my bogging at low end now, I had gone too far assuming more advance = more power. I'll have to drop it back to where I origionally had it .

[SX APPEAL]

OK now I have a question, very good thread btw. Say I was planing to throw some SOHC pistons in my 91 and bump the compression to about 11.2:1. With 91 octane and some booster, could I get away with any timing advance or would it be better to not even bother with it at that point? Or would a little timing retard work better?

forgot to mention- freshly rebuilt motor if that makes any difference

[DjPantsSpecR]

actually its kinda scary at that point. most people knock it back from base to about 18 degrees.

thats two degrees retarded from base timing, or clockwise

i'll be assembling my sohc piston block sometime this summer, and after that im going to knock it back to 18 btdc, and maybe even try 20 btdc. But my main point is, i want to try using 87 and 90, rather than 93 (we get those grades in MN)

there should be a small power gain associated with a lower octane fuel in an HC motor. The faster flame front should create a more violent burn, and extract a tit bit more power. But all the while you have to keep a watchful ear out for knocking.

also using 93 and trying to advance timing is something i want to try. i just need a few bucks here...

Edit: ha, i just read it adn i totally didn answer your question. Me personally, i would try advancing some just for my own research, but in your case, i think you'll be more than hapy with 20 more horsepower to need to fiddle with a maximum of a 3 - 4 horse gain. On a stripped car like mine its still difficult to hear anything, ive never heard mine knock ever, but i just switched from 93 to 90 this month. The potential for damage is too great for a gain of a few ponies. How much top end can you squeeze before you try my 30 dollar intake manifold?

just for some food for thought, normal pressure due to the expansion of gases from combustion is about 1800 psi. However, during knock, those cylinder pressure reach about 4200 psi. So two places to go from there, the crank wants to come out the bottom, or the head wants off the top. How well done is your engine build?

[rsmithdrift]

This correct??? It seems to say the opposite of what was said before.......that counter clockwise is advance and clockwise is retard. This seems to say the opposite......found it in a 240sx article for removing timing chain guides........

[BIGT94z]

that is right...i did mine last week without a timing light.just took off the two bolts and estimated...its about 5-6 advanced...my idle sucks now though

[Bigvinnie]

I know timing is supose to be set at 20 btdc. but i want to bump it up a little for some free ponies. I currntly have it at 30 btdc and it improved my 1/8th mile time. so what is the max I should do this to beside's the ovious until advance slows the et time.

Is there any thing I should watch out for?

If you are using the stock ecu tune your advancement is much too far, and it probably has raised your exhaust temprature too as well.If you are on a stock ecu tune I don't see why you would want to advance more than 5 degrees at the most. Some guy's get risky and go for a total of 8degrees, but they are also using expensive NGK iridium sparkplugs to prevent detonation. Teh only way that you can safely advance any further is by changing the actual ignition, and fuel maps of the ecu. Technically the further you advance the more fuel that would be needed to somewhat cool the cylinder charge. This probably means that you will need increased injector size as well as an ecu tune. Advancing the timing also icreases scavanging as exhaust temprature rises.

[3dKa24]

Teh only way that you can safely advance any further is by changing the actual ignition, and fuel maps of the ecu. Technically the further you advance the more fuel that would be needed to somewhat cool the cylinder charge. This probably means that you will need increased injector size as well as an ecu tune.

On the case of increaing injector size instead of bigger injectors ,is it possible to just increase FP with an adjustable FPR or to use an SAFC to increase the duty cycle. Would this suffice for someone who would want to advance say to 25+BTDC or more. Also heres a chart I found on T-I that show the melting point of spark plugs and it supplements why iridium plugs help when you want to advance timing and to prevent detonation Zinc == 420Aluminum == 660Copper == 1083Steel == 1400-1500Platinum == 1772Iridium == 2410

[Bigvinnie]

1) Buy timing light, $45

3) Using the light, check the marks on the crank pulley. They are ( -5, 0, +5, +10, +15, +20)...

If you buy a Digital Timing light indicator for $95.00, then you don't need to use the crank pulley for refrence.Digital is the way to go less hassle, IMO.....

[Bigvinnie]

On the case of increaing injector size instead of bigger injectors ,is it possible to just increase FP with an adjustable FPR or to use an SAFC to increase the duty cycle. Would this suffice for someone who would want to advance say to 25+BTDC or more.

The initial problem is in the ecu ignition timing more than anything. If you think about it as your RPMS increase so does ignition timing as well. At idle it may run at 20ATDC, but it will increase to something way above 40ATDC. I never really seen how changing ignition timing at the distributor can make a significant difference accept for the gap time between rotor, and ecu ignition spark is brought closer, making the spark stronger in less gap time (probably why you see like 3~5HP gains on dyno charts).Ultimately the real problem is in advancing the distributor to far to where the engine isn't very streetable at idle as it is brought further from it's proper location at 20BTDC. How you calculate an increase to injection to suffice for an increased timing I have no idea where that came from ( you need to change the actual ignition maps and fuel maps to stay more consistant, cam position also has alot to do with the amount of play you get with your ignition timing).KA24de stock ecu tunes increase fuel (HC's) levels as timing advancement is increased to deaden a hot cylinder charge from preventing knock so there is already to much fuel being used. Where it gets dangerous is when you would want to actually decrease pulse width on the stock tune, for the overcompensated fuel that is being used on the hot cylinder charge.Shrinking the pulse width is more accelerative to jumping the ecu ignition timing it just becomes more dangerous as the EGT is increased. This more to where you would probably want to use iridium plugs instead of something like platinum.I don't quite understand your question as far as injector size or bigger injectors? Sounds the same to me....
Modified by Bigvinnie at 9:11 PM 6/27/2006