dillon410021

Which setting on the fqs switch should I choose and do I still need to add fuel to the map?
thanks


Below is from LINDSEY RACING (< I am giving credit to LR for this )!
http://www.lindseyracing.com/LR/Parts/DMEFQSSWITCH.html

The DME FQS Switch Adjustment is located in the DME computer box. The FQS switch has a triangular female socket in the end for a special tool. We use a 2.5mm Allen wrench to adjust the switch. It's a snug fit and you should insert it with care. Chip sets purchased after 02-10-09 will include the allen wrench.

When you rotate the switch all the way counter-clockwise until it stops, that's considered position 0. From there, the first click clock-wise from there is position 1, next click is position 2 and so on.

FQS Positions for 944 8v from '85/2 and 944 Turbo

Switch Position /Fuel Mixture /Ignition Timing
O stock 0% 0%
1 +3% 0º
2 -3% 0º
3 +6% 0º
4 0% -3º
5 +3% -3º
6 -3% -3º
7 +6% -3º

Rogue_Ant

Which position was it in during your last test?

dillon410021

I will have to check. I would assume stock

schip43

Well you know would they about "assuming"! I would "assume" it's not in the stock position!

Let us know.

dillon410021

I checked the fqs and it is in the stock position (position 0= turned all the way counter-clockwise). What position should I change it to to lower the nox?
Thanks Rennlist

Scott H

FQS 4 will leave the mixture unchanged while pulling 3* of timing from everywhere.

Tom M'Guinn

What chips, FPR, and injectors do you have, and do you have the factory AFM or an aftermarket MAF? And how old is your factory O2 sensor? If you have stock chips, FPR, injectors and AFM sitting around, and put in a new O2 sensor, I bet you will pass. As is, it looks like you are running leaner than needed -- your HC and CO levels are way below their limits while NOx is too high.

blown 944

I'd use pos 5

Rogue_Ant

Yep, use either position 4 or 5... Position 5 will lower NOx more, but will raise HC some.

dillon410021

ok, I will try position 5 on tuesday and reveal the results

schip43

I like FQS 4, FTW!

Tom M'Guinn

Does the FQS work the same on all aftermarket chips? I thought not. And, does it retard by the full x degrees across all rpm's and load ranges?

Rogue_Ant

The FQS is adjusted to whatever the tuner set it to...

That is a good point, if you don't know what the settings are, you are safer going to position 4, rather than position 5. Almost always tuners leave the ~3° timing retard alone, and only adjust the FQS fuel mapping.

And additionally, the FQS timing reduction is only in-effect above 1600rpm, IIRC.

Tom M'Guinn

ibkevin

Too bad you didn't do a search. New Magnaflow 3" sfr cat here for cheap.

Check the O2 for dithering and make sure there aren't any upstream leaks, even the smallest will kill a rolling dyno test.