12secSS

iTrader: (30)

I have had one of those. I worked it hard and was only able to get 5rwhp at the top (re-adjusting timing, along with fuel), customer was very disappointed ... until he drove it and part throttle/response was much improved.

SSpdDmon

iTrader: (10)

Lean to the point of KR is not good.

Rich will allow/require higher, or more advanced timing because the denser fuel mixture has a slower burn rate. Therefore, finding the optimal point of ignition will require the spark to fire sooner. So, in a sense you're retarding the timing indirectly by running a richer mixture.

The truth is, you want the optimal mixture and the optimal timing together. To get there, you need a WBO2 and a dyno...plain and simple.

NHRAMAN

iTrader: (1)

From one end to the other. [good question]

rickssz

Edcmat
I thought afr in 11's was rich and 13/14 headed toward lean?

rickssz

SSpdDmon
Thats what my guy was doing he kept dropping AFR 14 to 13 to 12 etc which I thought was getting richer. I could see the AFR on the dyno screen but he wouldnt give me any timing specs. He said WOT timing didnt actually show on the screen but he could figure it out or calculate it. He was using HPtuners.

rickssz

So how do you recalibrate a MAF?

SSpdDmon

iTrader: (10)

Ideally, you want to be between 12.5:1 and 13.0:1. Yes, lower ratios are richer and higher are leaner. Do you remember where you ended up? Did he change the timing at all? Or would he completely not say a word? Either way, it sounds slightly shady. If he's working on my car and I ask what he's doing to the timing, he best be telling me or he's not getting my money, I'm taking the keys, and I'm out.

edcmat-l1

iTrader: (10)

Thats right. What I was talking about was sometimes you see a car thats around 12.8/13:1 already. These are not normal. On these cars you dont ever get a sizable increase from tuning. MOST factory tunes are around 11.5:1. Leaning them out a little, (because they're actually still rich at 13:1) is where you get the chunk of HP. After you get the fuel right then you tweak the ignition.
Your tuner should be willing to show you what he has done. At least show you something like the timing table.

rickssz

SSpd
Dyno says he started at 13.0 to 13.7 low to high rpm.
Finished with 12.4 to 12.9 low to high rpm.
He said he made some timing changes but didnt reveal any timing specs. He did say it didnt knock anymore but I dont know if the increased richness stopped the knock or if he just retarded total timing???

SSpdDmon

iTrader: (10)

AFR is in a 'respectable' range. Ideally, a slightly richer AFR (in theory) makes for better torque numbers. I've never had the opportunity to play around with this on a dyno though. I'm most curious about the timing. For example, I could bump my '02 A4 up to ~22* prior to peak torque, but could only run 18* at peak torque before ending up around 23* at peak power. The pre-'01 cars are quite a bit different though as they come with anywhere from 23*~29* of WOT timing above 2200rpm from the factory. Really, the only sure way to tell is to make a couple different pulls on the dyno to see what the car likes. If he just adjusted AFR and then said, "Hmmm...no KR - I can call it quits," then there may be some left. If he said, I wonder how it likes 22* vs 24* vs 26* at this AFR, then I'd say you're not going to find any more HP hiding in there.

rickssz

Dmon
Thanks for the feedback it def helps. Hey your 02 timing question was that with torque management active or deleted?

SSpdDmon

iTrader: (10)

I'm confused. Was it a question in another thread?

I only ran 50% torque management on that car because of the stall. But, that shouldn't matter during WOT...just during WOT upshifts.

rickssz

Sorry I was referring to your 02 Z28. I thought TM may have pulled some timing at peak torque.

TLUZLS1

iTrader: (6)

I hate to dig up this thread but....... Im about to get my car re-tuned friday and need to verify a few things. I originaly got tuned about 3-4 weeks ago. The car baselined 326/338 SAE (cutout open w/ all mods in sig). The AFR was at 13.5-13.6. He lowered it to 13.0-13.1 and found 6 more peak hp and 13 more peak tq (332/351). He said, if i remember correctly, the timing looks ok and there is no knock retard. He felt pretty sure that was all he was gonna get. The numbers after the tune were significantly higher in the lower rpms, and not so much up top. The next day I realized I had a loose spark plug, so loose it was ticking like an exhaust leak (you could grab it and move it around in the hole, really wobbly). I then read on here that if your AFR is higher than 13.0 you probably have a dirty maf. So i cleaned that as well. After all this i decided I should get tuned again. I want to go in there a little more educated this time.

Ok, so from what i've gathered so far in this thread, I shouldn't gain much from the tune since I was already pretty lean. However, my maf might have been throwing off the afr, correct? If I go in and dyno the same ~332 with the same 13.05 afr, what should i do to find more power? With all my mods I should be making atleast 340, I think we can all agree on that.

Thanks guys...

SSpdDmon

iTrader: (10)

There should be a little room to be had in the timing. Not much....but some.

slow

iTrader: (7)

I have gained between 4fwhp and 150 rwhp on stock vehicles with a tune.

All depends on the vehicle.

Stock focus picked up 4 fwhp, and a stock 6.0 diesel, will pick up 150 rwhp.

most lsx gain about 10-15 rwhp on average, some only pickup 5-7

Ryan

TLUZLS1

iTrader: (6)

How would the dirty MAF and loose spark plug come into play? If my AFR was ~13.55 then that was because of the MAF right? Was I loosing any hp from the loose spark plug?

TLUZLS1

iTrader: (6)

Anyone? I need to understand all of this a little better before I get my tune tomorrow...