michaelnyden

iTrader: (15)

approx. how many degrees of timing are added for every 1:1 step of AFR when adjusted on a SAFC?

BigDogJonx

iTrader: (7)

The SAFC by Apexi does not adjust timing. It manipulates the output signal to the PCM of the MAF to control your air/fuel ratio. There are no 1:1 steps.

Dixit

Y2KevSE

iTrader: (13)

Timing is indirectly affected. When you go negative, you are tricking the ECU into thinking that the engine isn't getting as much air as it really is so the ECU will increase timing. Go REALLY negative and you can blow something up if you're boosted.

This works the other way also. If you make the % more positive, timing will be decreased.

BigDogJonx

iTrader: (7)

Kevin I beg to differ on this because when you are WOT you are using one row on the timing table and the airflow adjustments that you would be making (small increments) will probably not affect timing at all.

Dixit

DA-MAX

iTrader: (10)

reducing MAF voltage via the AFC or any MAF/MAP manipulating device indirectly increases timing since "technically" its causing the MAF to see less air. its been a debated topic for a bit, but it seems the concensus across many forums

michaelnyden

iTrader: (15)

so does anyone know approx how many degrees are added as I lean out every 1:1 or so of AFR with a SAFC II?

I saw it a while back on here...but I searched and searched and can't find it anymore...

Nealoc187

iTrader: (23)

Check SR20DENs thread, its almost at the top of the all motor section.

I30tMikeD

iTrader: (8)

Like I posted in the your other thead in the all motor forum, corrections with an SAFC will indirectly effect timing. But it takes a fairly large amount of correction to make much of a timing change. As TPS voltage and MAF voltage increases timing advance is reduced. An SAFC is just a MAF hack. Intercept the MAF signal before it gets to the computer and either raises or lowers the voltage a little. Less voltage and timing will increase, more voltage and timing will decrease.

From my general personal knowledge and from what I have read it takes alot of % correction to do much to timing. I know SR20 did some datalogging with this, and that is the only way to know for sure from car to car. In my expierence, boosting 8-10 psi on stock timing (pushing the limit on timing) when I pull 20% fuel or more I get a bit of detonation from the extra timing that is inadvertantly added.

I may use this timing retard/advance via the SAFC to my advantage this spring if I can't or don't get JWT to make me new timing maps or my JWT ECU.

When I run my stock ECU all I use is a Z32 MAF, 550cc injectors and an SAFC for fuel management. It has worked very well for me, not the best tune by any means but it certainly works. With this set up and no SAFC corrections I get a 10:1 AFR or lower throughout my power band. I have to use up to 20% corrections on my SAFC to get me to a low 11:1 AFR, but when I do that I add in some timing which is not good when running stock timing at 9-10 lbs of boost. 9-10 lbs of boost puts me at 350-370 whp/wtq. I have a little bit of detonation issues when running like this in the summer heat and/or at the top of 4th gear. Not enough detonation to do much or any damage since I have ran like this for a while now with no issues. But it is just not good to run so much timing advance with as much power as I am making.

An easy tune would be for me to either get some 500 cc injectors or an AFPR and get my AFR to be at 12:1-12.5:1 with no SAFC corrections on the stock ECU (stock timing). Then add fuel with the SAFC, thus reducing timing a bit, to get me to a low/mid 11:1 AFR. In the spring I would like to try this. I hope to maybe pull 4-5 degrees of timing this way, which would be just enough timing retard for my power levels. If I have been able to push 350-370 whp on slightly advanced timing with just a hint of detonation, then I should be golden on that same power level with just a few degrees of timing retard.

This would is also very inexpensive and easy way to get that much power out of a turbo maxima/I30.

Z32 MAF $100
DW inectors $300
maybe an AFPR if needed $100
Used SAFC $200


Now this would only be good for those of use not looking to break any power records. mid to higer 300 whp/wtq is all that is usefull with our cars short of being on a preped track with slicks anyhow.

jcy98maxse

iTrader: (8)

Mike- This is actually what I'll be doing. I already have all of the components to do this once I install the turbo next week:
Z32 maf/DW 500cc/AFPR/SAFC/Zeitronix WB
I also have an J&S however I will not run it unless I'm boosting over 10psi ( that will be in spring).
With the setup above (less J&S) I hope to be able to boost around 9-10 psi without any detenation that you experienced so I will keep everyone updated on how this goes.

C MAX

iTrader: (4)

why wont you install the J&s until your boosting over 10 psi detonation can occurt at any psi, better safe than sorry.

jcy98maxse

iTrader: (8)

Yes I understand but I won't be boosting anywhere near 10 psi right now anyways, its in the teens here every night and the only reason why I'm installing the turbo right now even is cuz I have a guy doing custom piping for me next week so I have to install the turbo and IC just so he will know where it will be to weld the pipes. I'm going with the bare minimun to have the car run boosted: (boosting on a 5psi WG only) and once its warmer or man enough to work in the cold, I will install the J&S and EBC...
I already have the injector, z32, safc, AFPR and wideband installed so that is also why I didn't want to wire the J&S in to the picture to test the setup when I'm ready to.

MardiGrasMax

iTrader: (14)

Mike, I ordered my 100oct JWT chip this week. Hopefully it will be allot more advanced.

Nealoc187

iTrader: (23)

Did you ask them what the timing is set at on the new chip?

JClaw

iTrader: (17)

How many other people have the 100oct chip?

MardiGrasMax

iTrader: (14)

I did ask but they said the engineer (who ever that is) has to work on it first. From what Ive researched on street gas 14-22 deg advance depending on rpm looks good. I had numerous in depth e-mail exchanges with JWT. I am hoping they are good to me. This new chip is $100. I will data log it and if its to conservative I will send the data to JWT and try again. I cant be too upset with them right now for the timing I have, I do have my engine managment quite basterized using the E-Manage to convert the 516cc injector program to work with the 740cc injectors. This time they will prorgam for what I actually have Z32 MAF and 740cc injectors and hopefully after my pleading provide me with aggressive ignition timing. It says right on my sales order that Ben e-mailed me "customer has requested more aggressive timing". Even with that a tune for 100oct has to be more aggressive than 91oct... If the weather is good I'll let you guys know soon, but JWT is closed for the week of Christmas to New Years so it may not be until January until I get the chip.

C MAX

iTrader: (4)

i understand not doing the extra work now but also if installed the J&S wont interfere with anything else you maybe working on. you can send it out of range and it will never even activate. you can make it come on after 10 psi which your not gonna see anyway until later. i see you have a plan but just letting you know just in case you didn't. good luck with the project it looks interesting. matt good luck with yours too, you know im always waiting for new info from you.

michaelnyden

iTrader: (15)

so anywhere from 14-22 degrees of advance is okay depending on the climate and weather, and octane...

since I am in socal and only have 91 octance, and since it's usually pretty warm out here...I should probably run less advance then most of you guys leaving ou in the midwest and such!

I30tMikeD

iTrader: (8)

I think it is a good idea to install the basics and get it running first at low boost then go from there. That is what I have done have not had any major problems with my car due to being turbo

I30tMikeD

iTrader: (8)

I assume you will do some data logging with timing? Please share the results with me. I would like to get some stock timing graphed, the basic JWT boosted program timing, and the JWT 100oct timing.