Mustang Tuning / AFR / Timing Help!

Adam95GT

New Member
Aug 14, 2006
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Burlington, NJ
Mustang Tuning / AFR / Timing Help!:

Today i got the car actually running right. Chris and i restabed the ditsy so it wasnt hitting the intake and we could move the timing around... We twisted it to advance the timing and the car woke the hell up!!!!!

No here is the thing what should you set the base timing at? i know 10* is stock, do i set it at stock base??

Also we finished the wideband install and started it up again... it was idling at 17-18 AFR and would spike as high as 20.... Where do i want the AFR at idle on a HCI car????

Im waiting to get my quarter horse back from moates so i can tune the car better

Currently its set up with a Pro M maf calibrated for 24lb injectors

But every once in awhile i could hear the intake pop... i know it does need tuning work im just looking at a starting point.

th_MVI_0360.jpg
 
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I don't think it's going to matter much where you set the timing. Most of that will be adjusted through your moates. I would just get it to run as well as you can on base timing. Maybe like 12 degrees is my best guess.

Kurt
 
I don't think it matters too much. But why advance it manually when you can do it thru the QH. I have mine set at 10* then I used the global spark adder to add 2 more, which is the whole way across the rpm/load table. Now I'm going back into the tables and adding 1 until I hear it detonate then take 2 away to be safe.

Mine idles right at 14.7, a little leaner probably wouldn't hurt but it's not like it's going to save gas mileage unless you sit in a lot of traffic. Don't forget a lot of gas has 10% ethanol now which is stoich at 14.1:1. I just changed my tune for E10 fuel and it idles alot better now, only surges on cold start-up until it gets to 160* ECT.

Once you get the QH working and can start playing with it you will have a lot of fun. Takes a bunch of patience but is very rewarding when people ask why I have a laptop in my car. Especially at the track, the carb guys drool when I show them the timing/fuel curves.

I just found a local gas station that has ethanol free gas 93 octane, and it's $0.10 cheaper then all the E10 places 93 octane.
 
I don't think it matters too much. But why advance it manually when you can do it thru the QH. I have mine set at 10* then I used the global spark adder to add 2 more, which is the whole way across the rpm/load table. Now I'm going back into the tables and adding 1 until I hear it detonate then take 2 away to be safe.

Mine idles right at 14.7, a little leaner probably wouldn't hurt but it's not like it's going to save gas mileage unless you sit in a lot of traffic. Don't forget a lot of gas has 10% ethanol now which is stoich at 14.1:1. I just changed my tune for E10 fuel and it idles alot better now, only surges on cold start-up until it gets to 160* ECT.

Once you get the QH working and can start playing with it you will have a lot of fun. Takes a bunch of patience but is very rewarding when people ask why I have a laptop in my car. Especially at the track, the carb guys drool when I show them the timing/fuel curves.

I just found a local gas station that has ethanol free gas 93 octane, and it's $0.10 cheaper then all the E10 places 93 octane.


Thanks for the heads up... I havent been able to play with the QH enough to find all that... i was just loading stock and already modified tunes to the car. I really need to learn how to bump the timing and change everything... but like i said it idles lean. Could it be all the injector cleaner we dumped in the talk :shrug: lol


Im decent with computers so i guess we will see how fast i pick this up.
 
You'll have to fine tune the MAF curve most likely. Especially with that nice CAI setup you have(is that custom).

I'm still twEECing mine, it was pretty good except at idle it was terribly lean. Where did you get your MAF curve from? Did pro-m send you the 9 point and you converted it with BE?
 
You'll have to fine tune the MAF curve most likely. Especially with that nice CAI setup you have(is that custom).

I'm still twEECing mine, it was pretty good except at idle it was terribly lean. Where did you get your MAF curve from? Did pro-m send you the 9 point and you converted it with BE?

Intake is 3'' mandrel that i cut.

When i get the QH back im going back to the stock maf. :nice: That pro M is calibrated for 24lb injectors... it was running off the stock ECU with the proM today

I dont know crap about tuning maf curves so ill have to learn that :(


I see that that video was not working!

Here is the link!
http://s28.photobucket.com/albums/c236/blindfoldedhope/?action=view&current=MVI_0360.mp4
 
It should be fairly easy with a WB. I'm using the keep alive memory (kamrf) which shows up as less then 1 is rich, greater then 1 is lean.

Sounds like it idles pretty smooth. When I first did my motor with stock eec and 30# inj with 80mm for 30# it wouldn't idle for more then 5 seconds. I have the dreaded X cam with 110* lobe separation though.
 
the computer expects it to be at 10. twisting the dizzy to mess with the timing defeats the whole purpose of being able to change the tune by tweaking parameters used by the computer.

set it at 10 and control the timing with the computer. or get a carb.

just my personal opinion.
 
base timing is 10. set it to 10 and make all the other timing changes in your tune. an idle afr of 17 is around 15% lean. add 15% to all the points below 1 volt and that should bring the idle down to around 14.5. just multiply by 1.15 and that will give you your 15%. pretty much the same across the whole curve. figure out what percentage the target afr is lean or rich and then add or subtract that amount.
 
Ah, Hi port heads on a 331cid engine????? That's going to be like a whale breathing through a coffee straw. That stock one flows ok, but it's not going to be enough for that engine.

Kurt
 
i was told by my friend/tuner for my car that he wanted base set at 10 and he would tune from there. stock maf? sounds like the straw analogy may be true in your case. stock is ok for some setups but i think you could use something that flows better.
 
If your wanting to stay with a stock maf I would get a LMAF or even a 4.6 mustang maf as they flow more. FYI I was at around 4.3v at 4-4500 rpm with a 4k valve issue (collapsed lifters). That was with ported gt40 heads on a 306. I picked up a 98gt maf for like $20-30 and an adapter for $40 at the ford dealership (get parts at cost WOOT). I think you need to log your Mafv, rpm, and load and see were your at.

Keep the dizzy at 10* as it is far better to tune it with the QH/tweecer. For one you can tune to have all your timing in by 2500-3k and doing it globally is like buying a barret .50 to go deer hunting...overkill and a waste. For one your EGR will be 4* higher and it hits mid 40's* when at cruise so you just bumped it and it will skew your logs as the eec will not know you bumped it at the dizzy. This "unseen" timing can cause issues if you run into any idle/load/ping issues or simply using logs to tune safely at WOT and everywhere else.