Ignition tuning

[FastKA24DE-T]

I been playing with the aem for over a year now, and seems that ka24de likes to be retarded a lot.
For example at 8 psi i would have my timing set too 17-18 does that sound about right.

[Kfred]

What turbo?

With a standard t3/t04e 50trim my car seemed to like 24* timing on 93 octane at 8psi. I don't start pulling timing until ~6psi.

[FastKA24DE-T]

What turbo?

With a standard t3/t04e 50trim my car seemed to like 24* timing on 93 octane at 8psi. I don't start pulling timing until ~6psi.

T3/T04E
Wow your timing is high 24-26 is about stock full loud.

[Kfred]

18* for 8psi would be 1* retard per pound of boost, thats super retarded.

1/2* of retard per psi would be 22* of total timing at 8psi which is much more reasonable and plenty safe.

If your motor seems to like 17-18* of timing then stick with it. Make sure your logger value matches the actual timing with a timing light. Aem is known to have cas problems on the ka...

[8-bit]

1/2 per psi is probably closer to 'plenty safe' on 93 octane. Here in cali with 91, its prolly a better idea to bank on 3/4 (.75) per psi until you are tuning with a knock light or have some kinda knock info.

[sdaigle240]

What turbo?

With a standard t3/t04e 50trim my car seemed to like 24* timing on 93 octane at 8psi. I don't start pulling timing until ~6psi.

dang, where were u when i was asking about this in the calum thread. on person said they tried it and for whatever reason ended pulling starting at 1psi. did you do any expirimentation? i dunno, it makes sence to me.

[Kfred]

Well, i ran 8psi for a long time with a fmu and 18* base timing.

When i switched over to a built motor (8.8cr) and had the ability to tune my own timing curve, i left the distributor at 18* and left the timing map stock at 8psi. On the dyno we found this to be the mbt at 8psi with the 50trim, (logged total timing value ~24deg). We tried it with 20* base timing and gained like 2hp (no knock), then at 16* and we lost a good bit of power.

So,i bumped the base timing to 20* and started pulling 1* per psi at 6psi (still 24* total at 8psi). It just seemed logical to do it this way from what we saw on the dyno. At 12psi i ran ~ 20* and at 15psi ~15*.

I got knock around 17-18* at 15psi according to my txs knocklite.

This was all on 93octane with 8.8cr pistons. But with the stock slugs i ran 24* total timing at 8psi for years with no ill affects.

[8-bit]

for 8psi, you're probably pretty right on actually. A biiiiiigtime car nut I know says that most engines, with stock ECU can run 7psi w/out tune.

next 240 I own I'll try to pull maybe only 1 degree total for the first 6psi, then pull timing after that at some experimentally-derived rate.

thanks for the insight. I hope and wonder if others are reading this.

[FastKA24DE-T]

Even on dyno the guy that first tuned my car at 6.37psi sat the timing at 17 i think and i made 233whp.

[ppctx]

Man, these timing levels seem high to me. I've always had stock 9.5 compression pistons and 93 oct on a t3/t4e .60 trim. At 11psi, I would get small but very repeatable, blips on the XS knock light, at 16*, then at 14 psi i would get small blips at 13*. Checked my timing this weekend and found that I was actually about 2* advanced at the dizzy in addition to what I was logging so lowered it down to equal what I am logging. All minor blipping has gone away since lowering it at the dizzy by the 2*.

SO.. this tells me I really just about at the limit of knock (if I am to believe the XS knock light) which puts me at way more retarded than what you guys are getting??? In my head, I don’t think I'm getting bad readings from the knock light, being that it signals at one setting then goes away with a small reduction in timing.

[Kfred]

Your timing numbers sound about right for a stock compression motor, my timing numbers are with 8.8cr.

Your running 13* at 14psi and i'm running around 15*, this seems reasonable due to the compression difference. Every motor will be a little different even with the same cr due to iat's, carbon build up, afr's, etc...

Start safe, advance until you quit making power or get knock. If you get knock run ~2* retarded from that amount. Your motor will tell you what it likes/dislikes listen to it and your txs knocklite.

[s-14]

Your timing numbers sound about right for a stock compression motor, my timing numbers are with 8.8cr.

Your running 13* at 14psi and i'm running around 15*, this seems reasonable due to the compression difference. Every motor will be a little different even with the same cr due to iat's, carbon build up, afr's, etc...

Start safe, advance until you quit making power or get knock. If you get knock run ~2* retarded from that amount. Your motor will tell you what it likes/dislikes listen to it and your txs knocklite.

Are you guys talking about 13* BTDC at idle? whats ur base timing at idle? running 11psi what should i set my timing to at idle to get a good safe total timing setup? Give a guesstimate? stock compression...

[FastKA24DE-T]

This map is for aem but it shows you good idea what it should look like.
I made this map so its up to you to use it but i think with 1 degreee you will be safe.

1st is .75 degree retard per psi



2nd is 1 degree retard per psi

[tom550]

ok i know this forms hassnt had any action for a while. but can some one please explain what timing does and why you need to change it with boost.
no matter what i read i cant figure it out. i need the explanation very simple.
please help.

i plan on having a ka24et with a z31 turbo at 7 or 8 psi with a fmu. just if you might be able to explain off that.

it could be that im stupid but im completly lost when it come to this.

[undesiredshoe]

ok i know this forms hassnt had any action for a while. but can some one please explain what timing does and why you need to change it with boost.
no matter what i read i cant figure it out. i need the explanation very simple.
please help.

i plan on having a ka24et with a z31 turbo at 7 or 8 psi with a fmu. just if you might be able to explain off that.

it could be that im stupid but im completly lost when it come to this.

http://www.efi101.com/forum/

Ive learned a lot from that forum

[Xylemer]

Great forum... a ton of good info!