I'm still running the 165 ECM mafless on my 305 t/a (after 4 years and aprox 160,000 miles). some background to the story... http://www.thirdgen.org/techboard/di...le-i-mean.html (MAFless in seattle(I mean st. louis)) http://www.thirdgen.org/techboard/di...g-mafless.html (still running mafless...) Really it's just a stock TBI motor (w/ ported swirl port heads, Ex energy cam, stock tpi intake and long tube headers). The peak numbers are...... 220rwhp 282rwtq What do you guys think? IMO it would have been closer to 230hp/300tq if the engine wasn't heat soaked. I'll post the dyno sheet soon. There is 3 pulls and I did some tuning. Once the sheet is posted, feel free to contact me for the calibration files.... ---------- Hope to upgrade the heads, rocker arms and intake soon. The next dyno session will include a 100hp shot of N2O. I have been working with that power adder alot in the past few years. It's amazing that GM computers can control everything so well.

Tim, have you thought about doing a dyno run with & without the MAF for a comparison?

Not really. The dyno testing was done w/o an intake tract. I feel like any comparisons would be within the margin of error (due to the hp level).

...I was impressed with the numbers. Seems to be good, compared to other TBI motors here at TGO...

I just saw these threads for the first time yesterday.

Have you done any tuning of the default airflow calculation, or are you really running the "defaults"?

In my experience the 4 gm/sec base offset is too low, and the IAC scale factor is also bit too high to represent the real IAC flow. I find 0.0547 gm/sec/count give a good fit.

I was involved in another "Mafless" tune project about a year ago with good results.

The car in question originally made 270 RWHP in the first configuration (350) and later on close to 400 RWHP in the second configuration (383) with only minimal tuning (mostly via fuel pressure adjustment) between engine configurations.

I used my own MAF equipped car to dial in the default calculation to closely match my MAF behavior, then adapted this to fit the other cars needs.

I know this approach can work pretty well.

I have totally tweeked the default table. The tune is not complete but decent. I thought that getting rid of closed loop would kill the ecm's ability to control fuel. Come to find out, alpha-n works just as well w/o an O2 sensor.


I really think it's possible to get 260-270rwhp out of this 305. This is w/ the stock swirl port heads. Future plans are,
1.6 Roller Rockers
CAI
StealthRam OR SuperRam
EGR delete
no P/S belt
mill heads (eventually get flat top pistons)


Should be good for low 13's, easy. Maybe high 11's on the bottle. I'm thinking with my friend's vette L98 heads, it will be over 300rwhp N/A.....

Hey i Am very interested in running without a MAF sensor. Search my post on Blank chip and you will see wat i am trying to Do Thanks