Opinions on why my Roush went Rich..

[1BAD360R]

I recently came back from another dyno session where we installed a SCT tuner to bring my 360R back to the hp and torque it had last year.. The car had lost 50 hp and 20 ft/lbs. The a/f was also sitting at 10:1 ( very rich ).. Now, the car could have been richer because the computer set up at the facility didn't start reading the a/f until it reached 10:1..All is well now, the hp is at 380rw and the torque is at 413rw. The a/f is at 11.9:1 at the top of the tach..

So, the question is, why did the car go really rich and lose 50hp.. Does it have to do with the battery going dead over the winter twice? Understand that this car has already been reflashed by the previous owner ( with dyno results similar ), the Roush tune is gone, but last year, it ran strong, like now..No codes, nothing out of place, all seems well.. Car has 21000 miles.. Whats your Opinions? Thanks....

[GotKick]

Hopefully you don't mind me piggy-backing this conversation a little.

I will be interested to see what folks say to this. Now that all my drivetrain mods are done and the car is running well, I went ahead and swapped to the 2.8 pulley this afternoon. I just got back from two 5-mile runs and my wideband A/F gauge was reading low 10:1 at full throttle running the following:

CAI
Ported M90
2.8 Pulley
Ported Heads flowing almost 35% more on intake (223 vs 165)
JBA 1 5/8" headers
High flow H-pipe

The dyno run with the Patriot heads was showing 12.8:1 with the 2.8 pulley. I expected to be real lean with this setup. Maybe the higher flowing Cobra fuel assembly is keeping up on the Roush ECU. Obviously, I also want to see it move back to high 11s, but at least that is possible rather than expecting 12.8 to come down to 11.8. If it settles in over a few more drives, I am really wondering if I need to dyno-tune. I wish I had a boost gauge to see what that is pushing. Streetability is perfect and I hate to dump the Roush tune. Any tuning knowledge out there would be great to hear.

[RickRoush03]

once you flash a tune to the car it doesnt get lost by a dead battery. but if you reflash a new tune over a previous tune then you lost the old and are stuck with the new. why your car went backwards i don't know, maybe something went hay wire with the MAF??? maybe something was wrong with the new tune??

gotkick, your on the original tune with all that work done? and your only running a 10af also at wot, i'd say the same with you with a MAF not able to keep up so the car is going into a "safe" mode?? the 03-04 cobra pumps and the S3 pumps are almost identical, in fact the S3's would've used the cobra pumps if they were ready in time, but they obviously weren't.

[GotKick]

Originally Posted by RickRoush03

gotkick, your on the original tune with all that work done? and your only running a 10af also at wot, i'd say the same with you with a MAF not able to keep up so the car is going into a "safe" mode??

Very possible, I had not thought of that. I have a Lightning 90mm ready to go in with the new tune. I have an AutoTap setup. I should go WOT and capture on that and see if it maxes. I've never used it for any of the advanced diagnostics before. I guess I need to do a little reading up.

[HighDensity007]

If you're nearing 400rwhp I'd def say you're pegging out the stock MAF, mine was pegging out at 380rwhp, an extender will take care of that. Also, I wouldn't call it a "safe" mode, but, the maf just doesn't have the brains (at that power level pegging out) to allow more air to mix with the fuel, which his why I think you're showing a rich A/F, similar to the other theory posted above.

[Star Driver]

I've found that the 360 tune is set up so when the car gets hot, it runs richer to try to cool the car down, I'm guessing it probably pulls a little timing out of it also. I saw this when I dynoed mine. It lost about 15-20 hp on the second run as the engine had warmed up. The 380 tune does this to a lesser amount and keeps the a/f up where it should be.

In other words, get a 380 computer, I did.

[smokin-ponies]

Have you checked you O2 sensors? A bad sensor could make the A/F go rich but would most likely throw a check engine light. If your gonna go with a new MAF go with the SCT 2400. You'll never max that thing out.

[GotKick]

Originally Posted by smokin-ponies

Have you checked you O2 sensors? A bad sensor could make the A/F go rich but would most likely throw a check engine light. If your gonna go with a new MAF go with the SCT 2400. You'll never max that thing out.

Well, the A/F is at 11.0-11.2 today, be interesting to see how it settles in over the next few days. I still need to hook up the autotap and see if I am maxing the MAF - hopefully tonight. I have the SCT 2400 as well as the Lightning 90mm sitting brand new, but will go with the Lightning because the bright blue sticker on the SCT screams "AFTERMARKET!" We all know how California feels about that. Besides, the Lightning MAF is good to 450rwhp and I do not expect to break that barrier.

[1BAD360R]

Well, if there is a possibility that its the MAF, then how would I be able to bring the A/F back to the safe range? The MAF on our S3's is the same 80mm unit on the lightning ( the older models ) and there are several out there over 400rwhp not to mention that I believe the lightning uses the Eaton 112 supercharger. Now, its possible our M90 units may be more efficient, but isn't it safe to assume that the 80mm should be more than able to handle the flow demands?

The thing that stumps me on this is that the dyno results from before I bought the car and the most recent ones are damn near identical. Now how do you lose the tune in between? Also, if the MAF was pegging out, It should show up on the dyno results, true?

GotKick, what type of Wideband do you use and have you ever compared it with an actual A/f from a dyno?

[GotKick]

Originally Posted by 1BAD360R

Well, if there is a possibility that its the MAF, then how would I be able to bring the A/F back to the safe range? The MAF on our S3's is the same 80mm unit on the lightning ( the older models ) and there are several out there over 400rwhp not to mention that I believe the lightning uses the Eaton 112 supercharger. Now, its possible our M90 units may be more efficient, but isn't it safe to assume that the 80mm should be more than able to handle the flow demands?

The thing that stumps me on this is that the dyno results from before I bought the car and the most recent ones are damn near identical. Now how do you lose the tune in between? Also, if the MAF was pegging out, It should show up on the dyno results, true?

GotKick, what type of Wideband do you use and have you ever compared it with an actual A/f from a dyno?

I use the AEM wideband gauge which includes a digital readout. Since it is wideband, I would expect it to read as fast as any dyno. However, I am scheduled for a dyno tune next Wednesday. First thing I will have them do is take a set of pulls with the current setup. I will know then if it is anywhere close.

As for the S3 MAF, it is the same as the GT, but Roush has "extended it". I do not know exactly what they have done, but most likely it just does not peg as soon. However, looking at the numbers of the different MAFs, it looks like the S3 stock setup can't be far from pegging this MAF. I will go run mine in the next day or so on the computer and see if I hit full voltage on the stock MAF. If so, it pegged, and I will also know at what RPM. Here is a great overview of Ford MAFs as well as what RWHP each is good til. I'll post up what I find on my setup next Thursday.

[1BAD360R]

GotKick, the info on the MAF was given to me by one of Roush's techs when I called them. From what they told me they are of the 80mm variety and are calibrated for 36lb injectors.

Great info on the Lasota site about the MAF's..Now, they confirmed what I was previously thinking, if the MAF is pegged, the car goes lean, not rich, so I'm thinking along the lines like RickRoush said. Perhaps the shop that tuned on the car before pulled back some % of the tune after the last pull to make the car safe...

Thanks for the info and good luck next thursday. I'll be looking foward to what you find out....

[GotKick]

OK, I went out with the AutoTap this evening. I did 2 runs, the first is kinda rough in the beginning because I was coming off a stoplight and doing a cloverleaf onto the freeway. I took that one most of the way through 4th gear. The second is a U-turn at a light on the highway and up through 3rd. Looking at the MAF voltage (pegged at 4.7 volts) it looks like I am pegging out somewhere between 5500 and 6000 rpms. In the first pull, I pegged briefly in 4th around 5600 rpm. In the second pull, you can see where it pegs in 3rd and plateaus about 5700 rpm. However, in neither case did I see the A/F sensor go lean - probably because I was so near the end of the RPMs I was pushing. However, it looks like I definitely need to move up to a bigger MAF, especially since I am going to extend the rev limiter to 7000 rpm which Coast High Performance says is safe on this forged motor.

[1BAD360R]

GotKick, great info, are you going to try to extend the voltage range on your MAF before you buy a new one?

[GotKick]

Originally Posted by 1BAD360R

GotKick, great info, are you going to try to extend the voltage range on your MAF before you buy a new one?

No, I already have a Lightning 90mm in my hands. The 80mm narrows down a little before going into the 100mm intake pipe that I have, so the 90mm will reduce any swirl caused by that, if it is even an issue. I have this thing high flow and ported/port matched from intake to exhaust so I will go 90mm just to be consistent. I also have a SCT BA2400 brand new in box (which I was originally going to use), but will probably be selling that off in the coming weeks since it is obviously aftermarket for the CA smog nazis.

[02GT]

That AutoTap stuff is nice. What else does it do? I have a scrap laptop at home... what price was that?

[GotKick]

Originally Posted by 02GT

That AutoTap stuff is nice. What else does it do? I have a scrap laptop at home... what price was that?

I bought the original version somewhere around 5-6 years ago. A scrap laptop is perfect. It reads any sensor the ECU does (somewhere around 6000 parameters). I originally bought it to read my 97 Explorer and they are expensive. I paid $500 for the version that reads all codes for all domestics '97 or later (OBDII). I paid half price for an upgrade to the newest model last summer because the new hardware reads much faster and supports better software. You can get just the Ford reader for much less (about 50% I think). I have made my money back on both pieces and then some by being able to not only read trouble codes, but set it to log and graph any (or multiple) sensors against the others. It supposedly reads basic import data, but I don't have one so I have not done it. My favorite was when the Explorer was running rough and that car lets you read which cylinder is misfiring as it happens. Turned out that the #6 spark plug wire is so close to the exhaust manifold, the wire gets brittle and starts arcing. One short drive and I knew exactly where to look (and the fact that it was specific to just 1 cylinder). Obviously, the above graphs show I need a MAF with wider range. It's nice to be able to find these things out without paying for shop time. If more than one person is interested in getting a setup, I would be willing to call as an existing repeat customer and see if they will give folks on this board an extra discount.

[HORSE]

Originally Posted by 1BAD360R

Well, if there is a possibility that its the MAF, then how would I be able to bring the A/F back to the safe range? The MAF on our S3's is the same 80mm unit on the lightning ( the older models ) and there are several out there over 400rwhp not to mention that I believe the lightning uses the Eaton 112 supercharger. Now, its possible our M90 units may be more efficient, but isn't it safe to assume that the 80mm should be more than able to handle the flow demands?

The thing that stumps me on this is that the dyno results from before I bought the car and the most recent ones are damn near identical. Now how do you lose the tune in between? Also, if the MAF was pegging out, It should show up on the dyno results, true?

GotKick, what type of Wideband do you use and have you ever compared it with an actual A/f from a dyno?

I believe I read an article on the Home Page of this website about the stage 3/360R/380R supercharged engines stating the MAF is really 85mm and the injectors read 36lb but Roush worked them to 39LB. Just FYI