Noob custom tune question (06 SCREW 5.4)

Grabber523 · #1 Thu, February 5th, 2009, 03:59 PM

I have a custom DIDO with an X-pipe feeding 2 Magnaflow body mufflers. Stock manifolds and Cats and a K&N drop in filter. People rave about the custom tunes over the canned ones so I'm trying to decide what combination of octane, performance and tow to go with. I want to do an 89 tune for sure, but not sure whether to get tow or performance.

So I wonder:

Which would be a better all-around daily driver tune for best economy, the tow or performance? Either way I want to continue to run 89 octane. I'm also tossing around doing an 89 tow, 89 performance, then another performance or tow, either 91 or E85.

Which brings up another question:

E85 or 91? I know ultimately I should probably go with 91 and switch back to stock to run E85 since I want to feel the powaaaah! Any thoughts?

So to recap what I'm trying to decide:

1. 89 tow/performance
2. 89 performance/tow
3. 91/E85 performance/tow

What's everybody else usually run for DD?

Sorry I know this question is asked more than any other on this site, but I haven't really been able to find info specific to my possible tune choices.

Thanks a lot for your input!

Chris74 · #2 Fri, February 6th, 2009, 11:07 AM

I run 87 performance as my DD. Now I have been told that our gas up here in Canada performs very well......probably very similar to 89 in the U.S.

Anyway, it's an excellent "happy medium" of performance and economy for DD'ing!

Do not be scared of the 87 octane.........many good tuners will tell you that our 5.4's actually like the cheap gas pretty well and obviously can save you some cabbage!

Grabber523 · #3 Fri, February 6th, 2009, 11:13 AM

Cool, thanks man. Here in the "Corn Belt" our 89 is cheaper than 87 because of all the E10...even our "premium" (91) is an Ethanol blend. So Performance is the one to use DDing?

Chris74 · #4 Fri, February 6th, 2009, 11:21 AM

Yes......I recommend the performance tune as your DD'er!
Some guys like an economy tune though.

Grabber523 · #5 Fri, February 6th, 2009, 11:23 AM

Word! Thanks of the replies!

***Jackpine*** · #6 Fri, February 6th, 2009, 11:51 AM

Grabber, if you can stand it (I put a reply to this question in your "Hello" thread), I'm going to add to it here.

E85 has a high octane rating, but its available energy is lower than "real" gasoline. I don't know that you're going to feel "power" using it. (If I'm wrong here, everyone will be happy to tell me). :o And, E85 will give you much poorer gas mileage. If you find that it's cheaper though, things might balance out.

E10 has pretty much become the "standard". I imagine it might be difficult to find gas that doesn't have SOME ethanol in it through most of the country.

As I said in my other post, call Bill and discuss what you want with him. Ultimately, there will be some compromise. Find one you can live with.

- Jack

Grabber523 · #7 Fri, February 6th, 2009, 12:11 PM

I actually like running E85 when I can get it (usually back home in South Dakota). We've calcualted cost vs. mpg running 89 and E85 and depending on the market, even though the mpg number is lower it can be cheaper. But usually not by much. Plus it smells good!

Edit: There are more and more racers in my area converting to E85 for track use because of it's resistance to detonation. Not cheap to convert your fuel system because of the extra volume of E85 it takes versus gasoline to run stoich (9.7-1 vs 14.7-1 for gas)...by the time you're WOT, you're pushing a lot more fuel to maintain proper A/F, but the extra power you can make by upping boost/timing/compression makes it worthwhile...especailly since you're no longer paying $7 a gallon for race fuel.

***Jackpine*** · #8 Fri, February 6th, 2009, 12:38 PM

Looks like you've got your priorities all figured out and it's obvious you know what's going on. My previous posts really don't address your concerns do they?

Sorry if I possibly wasted your time.

Now it sounds like you DO want an E85 tune, as well as two others. I can't tell from your previous posts - do you actually tow? A towing tune is set up more to get things rolling from a stop or to bring things up to speed. You probably get a fall off in power at the higher speed end. And, if you tow, what is it that you tow? A big heavy horse trailer or a fishing boat?

If it's something lightweight, you probably don't want a tow tune at all.

- Jack

Grabber523 · #9 Fri, February 6th, 2009, 12:55 PM

Haha no you're not wasting my time!

I'm in the Air Force and supervise 90 people, so I'm all about getting feedback from as many people as possible, and you seem to be one of the most knowledgeable folks here. I haul my Mustang, boats and campers so definitely getting the tow tune. My SCrew is rated to pull 7500 pounds and I use a lot of that. It's just so hard to pick 3 tunes when I could use 4!

I think I'm going to have to narrow it down to the 89 perf, 89 tow, and 91 perf and switch back to stock to run E85 since, like I said, I mostly use it when I go visit the folks and that's usually once a month. The price point of E85 vs regular in North Dakota isn't quite as good as back home so it's something I can live without for the time being. After driving it for a while if I decide to scrap the 91 perf tune for E85 perf, I'll do that. It's nice having that option! Did I mention I'm really glad I found this site?!

Word of mouth is a powerful tool...