My first engine swap build thread

[festivaWES]

I may have one but unsure. I'll check my inventory for you.

[freshtiva]

"The B6 VAF should yield slightly better fuel economy and a little better idle and tip-in throttle performance. "

Guess I better dig one up somewhere. I want all I can get out of it.

[FB71]

They may meter the air flow differently, Since the B6 has a greater displacement, it would suck more air than a B3, therefore the VAF would need to meter the air differently

just to clarify;

The VAF doesn't actually "meter" (control delivery of) the air. It IS a meter, measuring the airflow. The throttle plate actually meters the air.

[FB71]

but besides a hot start issue mine's been running fine and getting mediocre mpgs.

there's your answer; mediocre mileage.

There's not a great amount of difference between the two VAFs. The B3 VAF has a slightly smaller passage and door than the B6 VAF. That will cause the B3 VAF door to open a little more than the B6 VAF door, because of the slightly higher airflow volume of the B6 engine. That gives the ECU a higher airflow reading than actual flow. In order to maintain proper A/F ratio, the ECU will add more fuel, causing it to run rich. The O2 sensor sees that rich condition, and will tell the ECU. The ECU then takes that info, and reduces the fuel trim just a little. Remember, the O2's information is only used for very small changes in A/F ratio trim. The ECU can't fully correct a rich condition based on the O2s feedback. It (the ECU) relys primarily on the VAF value to determine fuel delivery. The B6 VAF should yield slightly better fuel economy and a little better idle and tip-in throttle performance.

[skeeters_keeper]

I've been running the B3 VAF and others have as well.... I was under the impression that they were the same deal, but I just looked up the part #'s, and early B6, later B6, and B3 VAF's have different part #'s with both B6 units costing twice what the B3 costs.

Now I'm wondering what the difference is... but besides a hot start issue mine's been running fine and getting mediocre mpgs.

[Damkid]

They may meter the air flow differently, Since the B6 has a greater displacement, it would suck more air than a B3, therefore the VAF would need to meter the air differently

The B6 VAF should bolt directly to the B3 VAF housing to keep the factory look

[freshtiva]

Really ? Its running great now. How come the B6 VAF matters ? I believe you, Im just curious.

[FB71]

Marcus, I think his point is that you need the B6 VAF. It looks just like the B3 VAF, and will bolt right to the stock filter box. That may be part of your running issues.

[freshtiva]

did you use the festiva vaf? cause that looks like a stock festiva VAF to me...

Yes its the stock festiva airbox and VAF. Wanted to keep it as stock looking as possible plus Im not big on cone filters.

Thanks for the congrats everyone !

[Damkid]

Congrats!!! sounds like it runs pretty good!!

[geezerstiva]

did you use the festiva vaf? cause that looks like a stock festiva VAF to me...

[freshtiva]

WOW, that intake has alot of right angles in it. Are you planning on leaving it that way?

Yes, until I can find something better. Hopefully air will be able to make the turns.

[lanemeyer14]

Congrats Fresh! I'm jealous!

[sasquatch]

that sounds great it getting me all pumped up to get mine in only i think mine will be a bit louder :wink:

[nonamekid]

WOW, that intake has alot of right angles in it. Are you planning on leaving it that way? It has been 22 pages and I haven't been following all that closely.

Looks like you got a good swap and it is about time you got a motor swapped into one of those festiva.