When I went lean with the 181, I installed a SL55 fuel pump and corrected the problem. FYI, tuning didn't help, as I tried.

A while back I added a smaller SC pulley (stacked) and the lean issue came back. After a few retunes the problem persisted. Subsequently I installed TTM injectors and resolved the problem. I've also installed the TTM fuel rail with front crossover for good measure.

Don't ask for track times, as I exploded my differential at the track a few days ago. Track times aren't the most important thing with fueling though, it's the Air/Fuel ratio. As you'll see in the image below, my air/fuel is right on the money. A big shout-out to Bruce at TTM for telling me to stop being stubborn and to give the setup a shot. A big thanks to Steve for introducing me to Bruce and hooking me up.

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FYI, the newest version hides the braided line completely.

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Here's a few pics of my poor XF after the abuse. I really appreciate all the assistance from my great friend Steve Rivet (32krazy!), for all the help.

Here's my baby caching a ride back on Steve's trailer:

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Here's a few from my garage after Steve and I (Steve mostly) pulled the carrier:

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Thanks for posting about the TTM injectors (55 AMG as far as I know) and results. One observation, where is your spark advance? I'm at 24º! Well, at least with 104 in the tank.

Les

 

Steve and I are working on the right now. I'm working my way up from 6 degrees and I'm currently at around 17. My tunes are getting more aggressive on each revision. This tuner is new to this engine, so we're taking our time at getting the tune perfected.

 

I would see around 16º (cold) when I first started logging. After a few tunes around 19º cold. Then I got nervous about running lean and put 104 in the tank and what do you know, 24º no matter the ECT's or IAT's. I really don't want to run 104 though. 245 ECT's with 180 IAT's with 13 AFR's and 24º spark advance. The more you know the more you wonder.

Les

 

That's a heavy resonator and muffler to be carring down the track. Squirrel Crusher

 

True, but they are necessary due to the way I daily drive the XF. I love to get on the throttle in town quite a bit, so I don't want to draw any unnecessary attention. Therefore, the stock (quiet) exhaust is the way to go for me. FWIW, I did remove the rear cats.

 

I don't know if I missed it but did you dyno after the latest fuel mod? Have you taken the diff apart yet? any pics of the internal explosion?

 

There will hopefully be a lot of pictures of the new/finalized setup as of Sunday. key word being hopefully, I left my camera with Bruce and it had a SD card that could take upwards of 5000 pictures...so hopefully he documents everything done to the car this week.

I heard a 15 minute lecture from Bruce last weekend about how I need to change my exhaust. He made some good points, and I definitely agree...unfortunately, my wallet isn't agreeing with anything else right now. Right now I only have the secondary cats removed as well...

 

What other mods did u have when the 181 went lean. I think im having the same issue up top. Mods are in my sig. I was leaning towards just getting the fuel pump but have been told it would not solve the problem. Theres a wideband on the way and im pretty sure as soon as its installed my wot joyrides will be over until i richen it up a bit. What afr was it before and after the pump?

 

I would love to hear Bruce's thoughts on the exhaust...

 

Cliff notes version is, specifically for my car, I have a ton of intake side work done. I am getting all sorts of air in the engine (except he hates the throttle body, he refers to it as a "straw"), but I am not pinching off the exhaust side by keeping the stock primaries..

I equate it to trying to trying to fit a gallon of water down a qt funnel...it will go through, but it won't flow as fast as it should...

Therefore, by opening up the primaries and making a better exhaust manifold/header type situation you can really create more potential for the engine...especially on a highly modified engine like mine.


...turns out those notes weren't quite cliff...

 

The SL55 pump solved my lean issue until I added more boost. At that point I ran out of fuel again and ordered the injectors. I suspect the injectors would have done the trick for just the 181, but it wasn't an option at the time. Before the pump I was seeing 14-15 A/F and afterwards 11's.

 

I haven't dyno'd the car and probably won't. To me, trap speed tells the tale.

I pulled the cover off the differential and there was no mess inside whatsoever. The pin had a little play in it and there were some small metal shards. Other than that, everything looked nice and tidy.

 

did the pin just shear?? that would really be different... you're making too much power! HA!

 

I don't get to the 1/4 mile often but hit the dyno whenever I make a change. I'm not a magnate, I've been going to this dyno since they opened so they treat me like family. ($25.00 or $30.00 for 3 pulls) I was tuned for 11.8 AFR's at the top of 3rd. My car was tuned on the dyno. Very important! After switching out the Code3 for a 178 ASP pulley and adding Needswings manifolds I did a dyno. After a retune I had another dyno done. Here's the results. The red is the dyno tune after the parts changes and the blue is the retune to add fuel. Looking at the AFR's before the retune you can see the sudden upturn nearing redline. My local tuners say it's lack of fuel pressure or the limit of the injectors has been reached. After the retune and next retune, which is better, I'm still leaner than before any retune. People, do what I say and not what I did, get a tune on the dyno. That's what I'll be coordinating this week. I wanted to post this for comment and also as a lesson in what to look for. Frankly, I'm not a tuner or experienced in this area so any comment I might make is of an apprentice and preoccupied SRT owner.

Les

 

les the issue with dyno tunes is that you are at the mercy of the guy running the dyno. how hard he straps the car down, the force of the drum , the way he sets the dyno, the amount of air being pushed into the engine up all have an effect on the tune. a dyno shop can make you think your making huge power when in fact your not. also theres no way to know if the wideband 02 sensor is worn out or calibrated properly.
imo the best way to tune a car is to do real time driving , log the results be it track or roadcourse and send them to your tuner. he adjusts according to the info he receives and back to the logs we go. this can go on for many weeks or it can be done in a single day if he is in the car next to you tuning on the fly.
i believe the biggest issue tuners have to deal with is many guys want to mod the car with the biggest baddest parts they can find and will spare no cost but wont buy a simple wideband and boost gauge. it stands to reason the butt dyno is worthless but a dashdaq or innovate can tell the tuner all he needs to effectivly tune a car. this isnt directed at anyone specific but as a generalization that i see time and time again. then when the car blows up the guy blames a reckless tune or engine builder.

just my .02! that and 5$ gets you a latte!!

 

I'm not a big advocate of dyno tuning, but it's certainly very beneficial. Too many people spend money on mods and have no idea they are running lean. Some may never know.

I'm very careful and have a solid regimen I follow to ensure I'm not running lean. When I get a new tune or add mods that may lean the A/F out, I do a quick 2nd gear pull, dataloging the A/F. If the A/F is good, I do a 3rd gear pull. If I see 13's or higher on the gauge during either pull, it's aborted until more fuel is added.

I've also read of lean issues not surfacing on the dyno, but at the track.

 

I can agree with a lot of what your saying. In my case I data log on the street but can't (won't) go WOT in 3rd to redline anywhere but the track or dyno. I do some WOT pulls in 2nd. Then I hit the dyno to confirm and see what's happening in 3rd. My AFR's are perfect in first and second gear. The recent problem is only at the top of third. Perhaps at the top of 4th as well but I rarely pass 140. I agree that before getting a tune you should have a wideband. I did! I'm a dyno tune guy from experience. After having a few canned tunes that IMO were way off I got a dyno tune that I think was perfect. So, from the graph do you think I'm out of fuel pressure or near the duty cycle limits or something else?

Les

 

les i dont think its a fuel pressure or a idc issue. the 178 doesnt have a history of going static at wot. if the pulls that the tune was built for were 2nd gear pulls theres part of the problem. the biggest engine load is during 3rd gear and of course 4th gear. the workhorse is 3rd and sees high rpm for extended periods. so the tune has to take that into consideration. if it were me and take this with a grain of salt. i would do a pull from 30mph in 3rd gear to redline or until the afr goes lean. send that to your tuner and have him tune for the lean issue. once tuned lather rinse repeat! each time the lean issue should move farther up the rpm band until its gone. until i had a proper afr for the range i race the car in i wouldnt abuse it. may cost you the season but will save your engine.

 

More fuel pressure and more duty cycle will make it richer, unless fuel demands are exceeding pump supply (monitoring fuel pressure at WOT will tell this) or duty cycle is maxed out (monitoring injector duty cycle will tell you this).