MrSandman

So, I go to a car show held by a local car dealer. They have a dyno setup each year.

Last year my car made 389 hp.

Went again this year.. and the car made 389 hp.

Problem is, I had some spark knock while on the dyno this year. You can see it in the video. Clank.. then a puff of smoke. Very apparent twice in the video.

My problem? Last year i was not running the Procal FRPP tune. This year I was. The HP numbers were exactly the same with and without the tune. I realize there is variation between dynos, weather, etc, but it looks like all the tune got me was detonation. I've always run 93 octane in this car.

Damn...

vid:

drewsky

you need a brenspeed or bama tune!

MrSandman

I'm done with mail-order tunes. Returned it back to stock... If I decide to get it tuned, I'm gonna do it right and take it to a tuner. Disappointed to think I could have taken some life off the engine. The spark knock happened on both runs just after 5000 rpms.. been there many times since I've had the tune.

I got the FRPP tune because I thought it would be safe and i really just wanted to get rid skip shift.

Nuke

I was never a fan of the FRPP tune on the 4.6 and you've convinced me that the FRPP tune is a waste on the 5.0, too. Sorry to hear your dilemna.

AzPete

Unplug the harness from the tranny and no more skip shift. Rear passenger side up high on the tranny. Still shows on the dash but does not interfere with the selection of gears. I did mine and have had no issues for 17,000+ miles. I test the high speed shifting every time I drive it.

808muscle

Ford racing tune..... that would **** me off too.

Derf00

How long have you had the tune?

Your issue could be from bad gas or a bad tune. Only way to tell for sure is to dyno it with both the stock tune and FRPP tune on the same tank of gas.

MrSandman

Could be bad gas.. but I had just filled up at a BP that does a lot of volume. The tune is for 91 and I fill with 93. Also, the car dynoed the same HP without the tune. Again, it was a year apart between runs, but the fact that it was the exact same number, and the conditions last weekend were perfect (75 F, 29.32 in-Hg, Humidity 29%) with the tune, and not so perfect without (was in 90's and very humid), makes me not so impressed even without the detonation.

I put it back to stock yesterday evening. Its hard to explain, but the car just feels better with the stock tune. It revs so much smoother. Since I couldnt hear the detonation from inside the car, the only way for me to be 100% it wasnt the gas would be to run it on a dyno again. Even then, if I still have detonation, I would still have to wonder about the gas. Its safer to stick with the stock tune, especially since there was no appreciable gain from the FRPP tune.

Also, ive searched about this over the last few days and did not like what I found. Apparently, this tune runs lean. For people who have documented detonation, Fords response is "its normal" and "the knock sensors are doing their job".. WTH! Detonation is never normal! If the tune was done the right way, the knock sensors wouldnt have to go nuts after 5000rpm! Ford is more concerned about the cats and emissions than engine life. They have the tune lean on purpose.

moosestang

I've read the 5.0 has detonation with the stock tune. I've always wondered how they can claim you can use any octane. So basically the computer advances timing until it senses detonation then it pulls it back.

flash gordon

It's a shame to hear your problem with Ford tune. I was seriously considering it at one time, but now, after hearing your experience with it, I will keep mine stock.