I installed a new K&N filter in my modded stock airbox. When I drove home from work yesterday I thought the L was running better than ever. I just assumed that the weather conditions were perfect for a blown motor. Well this morning on the way to work I tried getting on it several times and it's a f'ing rocket ship! There is no way an air filter change should make this much difference. I replaced the stock filter (14,000 miles) and the fresh air hose in the bottom of the box has been installed for months. The old filter really looked good. It did not look all that dirty at all. Shurly either something in the weather is causing this or the truck is about to blow up (racers always talk about how a motor will really feel strong right before it blows). The thing that is amazing is that I'm running on the towing setting on my chip because I need to get it back to Sal because ever since the weather turned cool (in December) it's pinging on any other position on my four position chip. I flipped over to position 2 (street performance) and made one run and the rear broke loose in a turn at the 2-3 shift. The puckker factor was high! The thing that really shocked me was it did not ping even one time during that one run.

This is the strongest my truck has EVER pulled! Common since tells me the K&N could not be responsible for this much of a difference.

Any thoughts!


Jerry

 

Jerry, I've had issues in the past with customers having detonation issues that just didn't make sense for their combos, when they had a 4 or 6 lb pulley. I'd detune the chip some, make changes here and there, and even set stuff less aggressive than STOCK settings and it was still there. The common thing between those trucks was that they still had the stock airbox, whether it was the "modded" type with a hole in the bottom, or just with a drop in K&N. In every case, switching to our PSP filter setup solved the detonation and we were able to put their normal tune back in. We've also seen drop offs in high rpm power when still using the stock box setup with a 4 or larger pulley. I don't feel the K&N panel flows enough. No matter how many holes you have in the bottom of the box, it still has to draw air through the same size filter. We have been working on your issues for a while now, but I did not realize you didn't have a filter setup. That could be your whole problem.

 

I would definitely have to agree with Sal on this issue (as if anyone would doubt his knowledge). I had the exact same issue until I switch to the PSP filter setup. I was getting detonation in colder weather with the drop in filter, but it all went away once I installed the conical filter. I have since never had a problem.

 

Thanks for the info Sal. As you know you are my tuner and I trust you completely. That said I still don't understand what you are saying. I could take this off line but I thought someone else may have the same situation. How could letting more air in cause the truck to stop pinging? Wouldn't letting more air in cause a more lean mixture and make the pinging worse? Also what would this have to do with cooler temps? My truck NEVER pings at any temp over 70 degrees! I',m also sure I read several time where you said that up to 12 lbs. of boost that the stock box with holes in the bottom would flow plenty of air. My last question is don't you think it's possible that people can't hear pinging as well with an open filter? I personally hate the sound of the supercharger. I used to like it but now I like hearing the exhaust and being able to hear any other noises the motor makes. I'm going to try to run it like this (my stock box has a 3" tube that goes right next to the inner cooler radiator opening) it should get plenty of cool air. If it does not ping then great. If it still does then I hope your right and I'll purchase a filter kit from you. My feeble mind just can't see how more air could cure detonation. Remember my truck dynoed at 405/512 with the stock paper filter. That should be about right for the mods I have.

Chip, underdrive pulleys, long tube headers and high flow cats BR7's, and e-fan



Jerry

 

Well, I'm not saying 100% that the air box is your problem. BUT, I have had this similar issue with quite a few other customers, with the same results. With anything over a 4lb, the stock airbox caused this same problem you are having on certain trucks. And I HAVE done testing on the dyno that showed even a modded airbox with a K&N, hurt power up top over even a standard cone filter.

As to WHY, my guess is that the lack of flow through the panel size filter, is causing the air to "stall" as it goes through the MAF, throwing everything off to the PCM. So timing and load values change, and things don't run right. When it gets cold, timing is added back in, so that's why you're only seeing it there.

I don't want to see you buy something you really don't want, but it COULD very well be the problem.

 

I have a 5lb pulley, etc. and a PSP Fast Air kit installed. These mods have been on for some 50,000 miles with no pinging and it's gotten into the 20's in the morning on the way to work.

Dan

 

Dan, Thanks for the input but I am on my second Lightning and have been with Sal all the way. I had about the same mods on my 99 and never had a moment of detonation. The 03 is a whole different story. Nothing has been easy on this truck. I think Murphy must have built it because every time I do I mod if something can go wrong it will go wrong. I don't know how many times I've heard "I've never had the problem with this mod before"....exhasut, e-fan, lowering kit, anti sway bars, underdrive pulleys, chip. Missing wrist pins....the list goes on and on.



Jerry