LFA951

I installed the 951 MAX chips to replace the Autothority MAF 30C Calibration chips I had in there that were going lean upwards of 4,800 rpm in the dyno chart. Right away I noticed that I was running really rich, backfiring when shifting, stumbling and bucking in 4th and 5th gear when accelerating and deccelerating. I called Russ and he told me to set the FQS in the DME to position 2 which is -3.1% fuel, and instantly noticed the idle was smoother and it blew out less smoke when accelerating and overall ran much better, no more backfiring or sluggishness in higher gears, has anyone else had to adjust their FQS with these chips or is this a rare thing to do?

KuHL 951

I've had to play with the FQS with every chip I've owned. Are you sure that it's not 3.1% less timing to allow for octane and altitude variations? It's called a Fuel Quality Switch for a reason, not a Fuel Quantity Switch.

95ONE

Maybe you have a 3bar FPR and he thought it was a stock one?

LFA951

If you look at the 951 Racer X website, it shows what each of the settings are for, the first two are for more or less fuel and the higher ones are for more or less timing and fuel as well...

stock 0 0
1 +3.1% 0
2 -3.1% 0
3 +6.3% 0
4 0 -2.72°
5 +3.1% -2.72°
6 -3.1% -2.72°
7 +6.3% -2.72°

I do have a 3 bar, he said his chips required a 3 bar

95ONE

If you have stock injectors... to meet the higher horsepower requirements.

Do you have stock injectors?

KuHL 951

Thanks,
I never knew Danno had that on his old site

Acetylene

Very interesting. I am installing my 951MAX chips on Thursday.

95ONE

Or maybe you have the same problem I just found. If you have a tear or leak in the vacuum hose going to your regulator. It will read atmospheric instead of Vacuum at idle and push almost 10psi more pressure in there. But, when you're on boost, it will do the opposite and not compensate for the higher pressure an go lean. There are many reasons that could be causing problems before looking at the chips.

Definately worth a look.

Frank@Work

I also had to use the FQS switch with the 951MAX MAF chips to get it running good.

Portly

Potentially-ignorant question - What is the "FCS"?

_Jeff

rberry951

When I first started making chip I would set all FQS values the same, just because so many other vendors had used them for other things. I just wanted to be able to control who the car ran regardless of user adjustments in the past. Once I got into the MAF chips I decided to set the FQS to behave like the factory intended, to give you a bit of adjustability, sometimes you need it. Cars with bigger injectors have historically had idle issues, and top end richness issues. If you use the FQS switches for fuel injector sizing, then your adjustability is gone. This is the main reason I never use the FQS switch for this. I feel it is better to map the chip to the injector size and leave the FQS for some adjustability if needed.

I've also seen a bit of confusion on the boards about what 'true MAF' chips are. I've had chips in cars with MAFs since the beginning. They are not 'MAF' chips, they are AFM chips intended to be used with a piggyback. They worked much better than a lot of AFM chips because I took other steps within the chip to 'tame' some of the factory code. MAF units behave differently than AFM even when using a piggyback controller. So when someone orders a chip for a car with any kind of MAF in it, it is indeed slightly different than an AFM chip for that same car.

True MAF chips are where the AFM transfer function in the chip is changed to properly interpret the MAF voltage signal, where a piggyback would no longer be required. I've only done this for two of Lindsey Racing's MAFs. In doing so I came to the conclusion that I'm not real fond of MAFs! They are a pain. You can literally take 5 exact same units from the same manufacturer, put each on the same car without changing anything else, and get vastly different results. That's just how it is. So even vendors who have perfected the transfer function for a particular MAF still have to sell a piggyback for fine tuning, because they cannot know the exact behavior of your car. Again, that's just how it is. You can change the behavior of your MAF simply by clocking it differently in the pipe. If someone comes to me and says they are running rich/lean, that's the first thing I tell them is to try different clocking of the MAF. 80% of the time that will give them the change they are looking for to dial in their tune.

I got a box of Scivision MAFs in yesterday, and today several boxes are going to the post office. Last night my buddy came over with his track car and while I loaded up his chip file in a Maxtronic and installed Maxtune on his laptop he installed the Scivision. He was done before I was. And he took it for a drive too. Nothing else changed, car ran great! That is truly plug and play. Then we went out playing with Maxtune (on a closed course, of course). We didn't really get a lot accomplished because it was dark out, and at the moment he only has a narrow band O2 on the car, but it was fun none the less. Like setting his rev limiter to 2000 RPM when he's trying to pull out into traffic, etc... When I get back from vacation (8/28-9/4) we're going to get his car on a dyno and dial it in perfect. This will help me optimize the chip I pair with the Scivision to get the most performance I can out of the car with the unit installed. Lots of fun!

Regards,
Russell

rberry951

FQS? Fuel Quality Switch. If you look at the bottom of your DME computer in the frame, you'll see a little rubber plug. Take out that plug and you have access to a little rotary switch. This is the FQS. It has 8 positions which values are listed above in a previous post.

Regards,
Russell

LFA951

Which position did you put it on, 2?

LFA951

I have brand new Goodyear hoses on the vacuum lines and an updated venturi delete system, so no tears anywhere...

LFA951

I've tried "clocking" it like most threads have said, but I saw no difference in the idle and found no "sweet spot", so I put it at 10-11 o' clock like most with Autothority MAF's do...