<ul><li><a href="http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&amp;ih=017&amp;sspagename=STRK%3AME WA%3AIT&amp;viewitem=&amp;item=270269833581&amp;rd=1">http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&amp;ih=017&amp;sspagename=STRK

Those are way too big.

Stock is around 170cc. Those are 380cc. Unless you're making a 12v on crack (turbo/nitrous), those aren't going to work.

Saw what you're up to on another forum.<ul><li><a href="http://forums.audiworld.com/other/msgs/8416578.phtml">Realized your that guy with the silly plans and rear mount turbo.</a></li></ul>

He's just going to bolt stuff on that engine until someone's impressed.

If you increase the MAF area with the same percentage as you increased your injectors capacity it will be just fine.

That can cause your ECM to never go into open-loop operation at WOT, and you will likely run lean at that point regardless of how big the injectors are, as the ECM will still be trying to regulate the A/F ratio via lamba control. Been there, done that.

These computers are more sophisticated than that. More than just the MAF signal is used to determine fueling, and the MAF signal is used for more than to just set injector duty cycle.

What can i say.. it works just fine for us.

Do you have a dyno plot with A/F readings? What is your exact setup? Which ECM do you have? Any pics of your MAF mods? Who is "us"?

equipped cars based on MAF internal diameter rather than brake specific fuel consumption, duty cycles, cc's per minute and/or horsepower numbers. MAF ID has NOTHING to do with injector sizing or flow ratings. MAF bore data, dimensions or flow specifications will simply NEVER come up on ANY injector worksheet, PERIOD! In fact MAF internal diameter has EXACTLY the same effect on injector selection/sizing as right front high beam has on left rear tire pressure!

You can flow 100, 200, 500 or 1,000HP thru a 3" ID MAF housing and I guarantee the injectors used on the 100HP model won't fly on the 1,000HP car or vise-versa!!

voltage ratio.

Sorry haven't been here in a while but just saw a link yesterday to this forum

In any case, I have a mustang MAF, 19lb Mustang injectors adjustable FPR and rising rate FPR when I did my turbo application. My dyno AFR was a rich 12:1 but that's because it was not fine tuned.

The only major issue with running larger injectors on a stock ECU is cold start and WOT. These are preprogrammed values that don't listen to MAF. In between (close loop), the MAF dictates the duty cycles. WOT is not a problem in fact it's the sole reason I chose 19 lbs because I can tune their delivery with fuel pressure. RPM and the fixed duty cycle takes care of the rest. That's how I ended up with 12:1

At close loop it doesn't matter because the 02 tells the ECU to reconfigure the STFT. And mine never went outside 12% so I never had a code.

In any case, I had put the A4 back to stock to get it smogged a long time ago. And I have since been tuning our TT while my wife daily drove the A4 for a while. Now that I am done with our TT (and it's track fast), and my wife has a C6 A6, I will go back and play with A4 to match our TT :)

when he says "If you increase the MAF area with the same percentage as you increased your injectors capacity it will be just fine"

Which we all know increasing "MAF airflow" by increasing the MAF ID actually "slows" the "metered/measured" air velocity across the sensor wires the same way widening the banks of a river slows the flow of water, ie; same volume of water but now traveling at a slower velocity.

When I matched airflow a long time ago, the two sources I used are a [blush] vacuum cleaner and my [uhrmm] ERAM. Both didn't pull as much as what the 12V can do at max RPM, but at least it gave me a voltage ratio between my stock MAF vs the replacement one when I placed them inline and applied 5V to each.

I've seen you have a lot of great development!!

I will revive my turbo project but first I just got my aluminum welder last week. I have a second manifold since last year that I will be hacking to create twin butterfly TB and split flow to cylinders 120 degrees apart. When done, I'd like to see if this made any dyno improvement over a stock setup. Although it will be facing front where the p/s pump is to ease plumbing for later (I/C and stuff).

I'm going to take a lot of ideas you posted if you don't mind - such as the injector opening since I will still be using the lower base of the manifold :)

BTW, the MAF trick is just that. The ECU thinks the car is getting very little air so it adjust duty cycle accordingly. The fuel volume delivered is compensated by the large injector sizing.