Hello Folks,

I own a 2006 A6 (C6). I just recently had the following installed,
a D1 procharger, ported/polished heads, cam, headers, fuel boost pump, 60lbs fuel injectors, and full exhaust.

The shop that did the install, did a real nice job and I would recommend them. However, these guys are really Ford Mustang guys and cant tune vettes (I didn't find this out until the job was done and got a nice discount off the install price).

After the install, I drove to Nevada and had some outfit out there do a tune. I was told that I was running out of fuel above 5000 RPM, although I was still getting 542 RWHP, after they tuned it.

The shop then suggested that I have them install a fuel boost pump, which I agreed to.

Well, they installed the pump, but didnt re-tune the car? I was told that the original tune would be fine (which I later found out was BS). I didn't know any better and decided to take their word for it. Pressed for time, I had to get back home.

That evening, I took my car and drove home. However, while enroute, I noticed that the car ran sluggish and didnt feel like the 542RWHP I was told it had?

Upon returning, I had the original install shop throw my car up on their mustang dyno. This time the car only made 385 RWHP??? I was then told that I'm running 9.7 Fuel/Air mixture across the board, through all RPM's, and that this was too rich?

So my questions is this... Where should my fuel/Air mixture be? And can anyone help me find an honest tuner near El Paso Texas? I dont feel like driving all the way back up to Nevada to have these knuckle heads screw it up any more than it is.

However, I'm willing to drive 4-6 hours, in any direction from El Paso, Texas, provided I dont screw up my car. I just want to put this thing to bed and finally enjoy all my mods, without the car running like crap and bogging down, every time I accelerate.

 

Was it running 9.7 even at part throttle? Do you have a check engine light? If it is running closed loop at 14.6 air fuel ratio at light load and running around 10 at wide open throttle only, you now have plenty of fuel pump and the car can be tuned now to lean it out and get the power back.

Most wide bands peg out at 10 air fuel ratio so you may be running richer than the 9.7 you indicate. Not good.

Texas Speed in Lubbock first. Call me as a last resort!

Joe

 

If what they added was a fuel boost pump, then it should increase the fuel pressure when the boost reaches a predetermined point. This prevents the engine from going lean at high boost levels, and damaging the engine. It sounds as if the boost switch is not working correctly, so that the fuel pressure boost occurs all the time, thus richening the A/F mixture too much.

 

around 12-13:1

 

Did they add a Kenne Bell Boost-A-Pump and boost switch or an in-line "fuel boost pump". If they added a pump downstream of the stock pump, hitman99 is probably right, its running unregulated, fuel pressure is now too high, not good.

Joe

 

Thanks for all the great info guys, I really appreciate all the feedback. They installed an in-line fuel boost pump. They even srewed that up somehow. When my car hits a quarter tank, the fuel guage goes to "E" and the computer says, "service fuel system". Then, when I re-fill the tank, past a quarter tank of fuel, everything is normal. The shop got away with this, because they told me that this was normal and that the computer had to re-learn everything. They stated that it would take some time, which at this point, I realize was BS. They knew I was heading back to El Paso and knew I wouldn't make that crazy drive again to take it back to them.

Anyways, the car idols at 14, but when you gun it, the car hovers around 9.7. The car feels really heavy, boggs down and feels like it wants to shut off between 1000-2000 RPM and again above 5000 RPM.

Also, it burned about a quart of oil from Utah to El Paso, which was about 800 miles. I'm pretty much scared to drive it now, but this is my daily driver, so I'm kinda in a bad spot.

 

When the car is being driven and is in using the O2 sensors to set A/F, you should be at 14.7 A/F

When you got WOT (PE) mode, the A/F should be 12.2 for your blower or richer.

Getting crazy **** like A/Fs in the 9s is too pig rich, period.

Setting the PE table to 12.0 or 12.2 will be more than adequate BUT BEFORE you can get any true readings there are things that must be taken into consideration.

First LTFTs MUST be negative BEFORE and AS you go to PE. If the LTFTs are positive, the PCM sees the car running lean and will add fuel to the PE mode and thus fatten up the A/F. Your LTFTs showing a negative number means that the PCM sees the car as running rich and will NOT add extra fuel during PE mode.

Next, you need to take COT into consideration and raise the settings a little to keep the COT from also splashing in fuel if it sees the CATs going too lean and adds fuel to cool them.

Without those two things, setting A/F is impossible.

So, get that done and get the car retuned so you can get all the power our of it.

Elmer

 

And check how they are getting the A/F ratios. There is a difference between a wide band O2 sensor reading and a tailpipe sniffer reading. I've heard that 13.0 with a tailpipe sniffer is equal to 12.4 to 12.6 with a wide band.

 

put a catch can on it so it will stop burning oil, you'll be capturing it instead.

find a reputable tuner in your area, i'm afraid, but it sounds like they/you screwed up. it's probably gonna cost you some money to get it fixed but in the end it will be worth it.

 

Shoulda left it alone. Quit paying people to screw up your car.

 

If I were you I would contact Charlie Williams @ RPM motors. He tunes for Andy Green @ A&A corvette. These people are the experts on Supercharged LS2 set ups. Charlie is the guru for tunning these motors. Stop screwing around on the forum. Go to the best source possible for help. A&A # 805-278-4107.

 

Supercharged LS2, I usually aim for 12.0-12.2 AFR at WOT taken right after the collector and before the cats (if any).

I'm just perplexed as to why they would finish the tune knowing that they were running out of fuel. As soon as something like that comes up, they should stop what they're doing, let you know what's happening, give you a few options, then finish tuning with the options you authorized. I constantly stop tuning when injectors run out, or fuel pressure drops to far, only to have to put it back on the dyno a few days later.

I'm sorry you got burnt by two shops, that's some bad luck, hope you get everything sorted out and working for you. I'd offer my services, but I'm kind of out of your area. As for A&A, Andy and his staff know their stuff.

 

A catch can is a good idea in general, but will do nothing to help the oil burning problem, which is a result of running pig rich. The A/F mix is so rich that fuel is washing down the cylinder walls, contaminating the oil, causing ring sealing problems.

 

one of the reasons i suggested the catch can was to find out where the oil is going/being burnt. is it coming out the pcv system (due to the additional boost) or via the rings, etc. if with a can he continues to burn/go through oil but doesn't capture much then it would lead me to believe there are other issues.

thanks for the dialogue.

 

Good point about the extra crankcase pressure from the boost.