School Me On Tuning

[rduchateau2954]

Right off the bat, does it make any sense to tune a basically stock truck?

I get the general idea that a tune changes mixtures and shift points and what not but that's about the extent of my knowledge.

So what's the story?

Also I was wondering hemi fevers site and saw tunes and tunes with a tuner. Are tunes something that are flashed and forget or are the tuners installed and constantly in the truck running?

Excuse the ignorance, this is my first obii vehicle I care about.

 

[Talon_66]

All factory tunes are very conservative.
Canned or custom tunes will pull even more power out of the engine.
Once the tune is flash, you can take the tuner out of the truck and forget about it. The tune will remain

 

[MADDOG]

OK...tuning 101:

Tuning can help a basically stock truck a lot.

With a tune you see higher HP and torque values lower in the RPM range. The torque is especially important as that is what moves the mass of the truck from a dead stop.

A tune helps maximize use of available air and fuel for a better burn which will help improve your fuel mileage by optimizing the air/fuel ratio.

Cars and trucks tend to be tuned to run lean for emissions but they are always on the verge of knock. The vehicle's computer senses knock and pulls fuel and timing, with a resultant loss of power. The tuner once again steps in to richen the mixture as fuel demands increase, avoiding knock and allowing the engine to work without the "knock nanny" interfering.

Shifts at normal throttle and WOT can also be optimized. In some cases you can set your shiftpoints under WOT to maximize power without falling over the torque and HP cliff where the powerband starts to drop off, wasting your time and fuel.

Programmers have "canned" tunes which are loaded by the manufacturers, such as DiabloSport. What HemiFever does is load the tuners he sells with one of his "canned" tunes for you to try on your vehicle. He'll ask you to log with the programmer and send him back some files. He'll do some work on his PC and churn out a tune made specifically for your truck. He can provide all the instructions you need to download the files from your tuner to your computer to send to him, then he will assist you with loading up the custom tune he sends you.

A tune is flashed to the vehicles computer via the programmer/tuner. You can remove the programmer/tuner from the OBD II port on your vehicle after the programmer/tuner finishes loading the tune and put it away until the next time you need to return to stock or want to get another custom tune made.

 

[Hemi450hp]

If you were to only add 1 mod to your truck, the tuner would be that mod. Even with everything else being stock, the tuner will give you more hp/dollar than any other mod you can buy.

When you purchase a tuner from Hemifever, he will send you a regular Diablo tuner. You will then load 1 of the Diablo tunes onto the truck. When you do this, it saves the stock tune file onto the tuner. Email him that stock "backup" file, the "last tune written", and your truck info, and he will then write your custom tune and email it back to you. Then save it from the email to the tuner, and plug it back into the truck. Its a fairly easy process, and he will email you loading instructions as well so that you aren't stuck trying to figure it out on your own.

 

[rduchateau2954]

You guys are awesome. So basically what I'm hearing is you do have to buy the tuner. Couple more questions for you all:

1: I wasn't planning on a throttle body or intake, but, would I it be dumb not to do them?
2: How does a tune work with the different summer and winter gas?
3. " " with summer and winter temps?
4. What gains could I be looking at (if I did the throttle body and intake) on my '11 RCSB 4x4 5.7 with a hemi fever tune?
5. " " with a canned tune?

 

[MADDOG]

1. I'd do the intake. A larger TB on the HEMI's is basically not worth it unless you plan on doing a cam, valve work, head work, etc...
2. The tune works with either although the ethanol based winter mixes will affect mileage but that's normal.
3. Tune works fine with all ambient temps. Colder is better (all colder air conditions are better for HP).
4. No comment
5. No comment

There are too many variables to nail down an exact gain.

One of the biggest improvements I saw with a canned tune was throttle response, better HP/torque lower in the RPM band and having the power levels elevated all the way to redline.

 

[rduchateau2954]

I get exact isn't possible. ballpark it for me. I won't come looking for you if they don't match up. With an intake and a cat back, would you go hemi fever or canned tune?

 

[Csanders1992]

A custom tune is always better than a canned one. Every engine runs a little different and the custom tune will account for that


Sent from my iPhone using Tapatalk

 

[MADDOG]

My 2007 MegaCab with the 5.7L HEMI and Diablosport canned 91 octane tune.

Air/Fuel ratio - Blue line is stock, green line with the tune.

In stock tune configuration (blue line) you'll note that the engine stays lean (above 14.0) almost the whole run in stock configuration, finally dipping down around 4300 RPM, which meant it was lean well past WOT. Then it got extremely fat beyond 4300 RPM really really fast. Basically, the PCM started over-fueling the engine.

Then, note that with the tune the fuel mixture (green line) gradually riches and the A/F number goes from around 14.5 at idle to around 12.4 when the run was stopped just above 5300 RPM. Also note that the A/F started to drop near the front of the WOT run. An A/F around 12.5 is considered the "sweet spot", i.e., the optimum A/F for a stock HEMI. Lean @ WOT is bad...

Now for HP & Torque: Blue line is stock, green line is with the canned 91 octane tune. There are no huge gains here but look at the 91 octane tune green line for HP and torque. See how they improve sooner in the RPM band? That makes for a much more responsive truck off the line. Also, you'll note that the gains are sustained all the way to the end of the run.

You will start with a "canned tune" when you get the programmer. Then you can do some logging with the programmer and send some files to Sean to get your custom tune built. He'll walk you through the process from beginning to end.

YMMV

 

[Quint]

Can Sean do custom tunes that are more geared for getting maximum fuel mileage as well as maximum hp and torque?

 

[cableguy_hd]

I never understood those graphs until now.... Thanks for the explanation

 

[MADDOG]

Can Sean do custom tunes that are more geared for getting maximum fuel mileage as well as maximum hp and torque?

Those two conditions will conflict a bit but ask him what he can do to optimize a tune for you.

 

[MADDOG]

I never understood those graphs until now.... Thanks for the explanation

You're welcome.

 

[rduchateau2954]

Those two conditions will conflict a bit but ask him what he can do to optimize a tune for you.

You talking about like a diesel tuner with different modes?

 

[MADDOG]

NO...gas tuner. It may be that multiple tunes would be the solution, one for say Towing for max HP / max torque, one for Daily Driving with max mileage (leaner burn), maybe a race tune! The DS units will hold more than one tune.

 

[rduchateau2954]

Can Sean do custom tunes that are more geared for getting maximum fuel mileage as well as maximum hp and torque?

That's who I meant to quote

 

[rduchateau2954]

NO...gas tuner. It may be that multiple tunes would be the solution, one for say Towing for max HP / max torque, one for Daily Driving with max mileage (leaner burn), maybe a race tune! The DS units will hold more than one tune.

Don't be telling me such things! I can't afford the tickets that having a race mode would cause. I can tell you right now that's the only "mode" I'd ever use.

 

[MADDOG]

Well, then maybe you only need "one" tune.

 

[NorthTexasHemi]

I had questions about this topic. What a great thread and the responses were great!! Thanks for enlightening newbies like me

So what about when getting service do you keep the tune in place or do you swap it back to stock configuration. Would the dealership know that it was changed around?

 

[SlowRoller]

So what about when getting service do you keep the tune in place or do you swap it back to stock configuration. Would the dealership know that it was changed around?

Unclear w/RAM, but some manufacturers ECU's / diagnostic tools can tell if you've changed tunes, even if you reload the OEM tune before you go to the Dealer.

Didn't used to be a problem years ago, but unclear what the exact status/capabilities are today.

I played around with a few basic SC tunes in my 09. Yep, more power, but not interested in those things today. I can see where others might enjoy it.

(Basically lost my lust for 'tuning/haulin ass' after I got pulled over while trying to beat my 'personal best' on a public road,,, Sold the tuner shortly thereafter,,,)