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MAF data bench-racing?


marc_w

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Me of all people should be starting this... :rolleyes::D

 

What kind of numbers are you guys seeing through your MAF?

 

I was just looking at some current logs, and trying to reference back to some older ones to see what kind of improvements I've made. Still haven't found any data I can directly compare to. It's a serious PITA for me to get to the track or dyno, so I'm working with what I got.

 

Me... 38.X

 

Of course the stroker and FI guys will have their own numbers... I figured it'd be interesting to compare some bolt-on trucks, cammed trucks, etc. etc.

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I've seen peaks of 40.0 lbs/min twice (one was 39.97). Seen 39.x quite a few times.

 

For a while I played around with trying to tune for maximum MAF reading, as opposed to using the delivered torque reading. Didn't seem to make much difference. Probably because the MAF reading is used to calculate the delivered torque value. Nitrous (wet shot) also has little effect on MAF reading, because the extra oxidizer is being added after the sensor and not measured.

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No, no porting. I've REALLY been thinking about it though. Maybe I'll have some time to pull things apart on Monday.

 

I think my exhaust is a bit of a restriction... I can't say for sure, but I know the muffler isn't a 'straight through' design.

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  • 3 months later...

I don't know squat about tuning. I just logg data and email it to the tuning professionals...lol

 

After reading this post I look at a log i made this morning and have a MAF 62.31 lb/min peak reading.

 

I don't have a clue what this means but heres mine..... :crackup:

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Whar elevation are you guys at?

 

Elevation: 6500'

Temp: 50 f

RPM 5192

Boost 7.6 psi

MAF: 330 gm/sec 43.5 lb/m

 

For those that have a dyno run, what kind of correlation are you seeing between MAF gm/sec and RWHP?

 

Michael

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  • 1 month later...

We did a couple runs on my H2 yesterday and got the AFR tuned into the 11.2 AFR range throghout 1st and 2nd gears. As we did we found that the truck seems to like 11.2 more than 11.5 and it's sucking in a pretty good quantity of air. At the top of 1st (6000 rpm) it's pulling 58.94 lbs/min (446.59 gms/s) and the top of second (5700 rpm) was pulling 56.64 lb/min (430.71 gms/s).

 

We've adjusted the programming to shift 50 rpm earlier on the 1-2 and 100 rpm later on the 2-3. I'll lose some flow on the 1st gear but will gain on the second gear MAF flow. Factory springs are kinda scary even when they only have 4000 miles on them.

 

Now I'm waiting on the 2.9 pulley so I can do the final tune and leave things alone.

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In late 2003 when I was modding my truck for N/A use, I often saw peaks of 47 pounds MAF flow.

 

Now with my Radix and cold weather, I've maxed out the MAF table by 4800 rpms.

 

 

After reading this post I look at a log i made this morning and have a MAF 62.31 lb/min peak reading.

I find that hard to believe. The stock PCM/MAF only reads flow up to 59.9 lb/min or 454 grams/sec.

 

 

MAF:            330 gm/sec  43.5 lb/m

 

For those that have a dyno run,  what kind of correlation are you seeing between MAF gm/sec and RWHP?

Wow, that elevation must really be keeping your power down. I'd be expecting more MAF flow than that. A typical estimate is 10 flywheel HP per pound of MAF flow.

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