Help me understand tunes better

[Drunktank]

Along the same lines, is a tune the only mod for our trucks to get firmer shifting? I hate how lazy the shifts are in this truck but I don't want to put a tune on yet since its obvious to dealers.

I am used to older cars where you can just throw a shift kit in or a line pressure booster but I'm betting with an electronically controlled tranny you can't do that right?

IM along the same lines... Id LOVE firmer shifting but dont wanna mess with the tunes for the engine either. Is there a separate computer for the tranny???

 

[TurboEd]

Good question. Probably one of those yes and no answer. From what I understand. The TCM (trans control module) and ECM (engine control module) are controlled by the PCM (powertrain control module) where all the information is written. This is so any code coming from any of the different systems can be logged and relayed through the ODB port. So, all this information probably lives on the same file in the PCM. It has many different tables or sets of instructions for almost all the systems, all interrelated. I do not believe you can flash the transmission control module (TCM) on a different, independent computer on it's own independent file like you can on other vehicles. Even if it did, the dealer could probably be able to tell anyway. They would rather void warranties than pay for "unnecessary" repairs.

We need an expert Ford tuner here.

 

[ZBoater]

Tune related: what does "firmer" shifting mean?

There's stuff the tunes do to the engine outside of the transmission to give a little more pep. I was reading the 5Star website for some explanations, but the point was driven home (pardon the pun) today when I switched from the SCT 93 canned tune to the 5Star 93 performance tune modified with a softer shift strategy.

Even without taking into account the shifting, the engine felt peppier or "gruntier". I like it. It's like the gas was spiked with extra octane or something. It's not something wild (I hope) but enough to be noticed.

I am not an expert but these 6.2 engines seem to be leaving a lot of "grunt" on the table out of the factory. These tunes bring that animal out, but it doesn't seem to be obnoxious or crazy. It's subtle but noticeable. I don't know of many people who'd buy a Raptor because it's a "sedate" truck. I'd get a Lariat for that...

 

[TurboEd]

My last LS7 got a Killerbee intake installed. Bone stock. Got it on the Dynojet. Dynoed 430. Immediately uned on 93 went from 430 to 480. A 50 whp gain. So yes. Tuning will yield more power than most bolt ons on these big NA engines than simple bolt ons. 50whp on a 3100lb car it's a huge difference compared to maybe 30whp on a 6100lb truck.

That 5star 93oct "soft trans" performance tune should be fun.

 

[Agent 00 L]

Good question. Probably one of those yes and no answer. From what I understand. The TCM (trans control module) and ECM (engine control module) are controlled by the PCM (powertrain control module) where all the information is written. This is so any code coming from any of the different systems can be logged and relayed through the ODB port. So, all this information probably lives on the same file in the PCM. It has many different tables or sets of instructions for almost all the systems, all interrelated. I do not believe you can flash the transmission control module (TCM) on a different, independent computer on it's own independent file like you can on other vehicles. Even if it did, the dealer could probably be able to tell anyway. They would rather void warranties than pay for "unnecessary" repairs.

We need an expert Ford tuner here.

It all really lives in the same place on the PCM. There are lots of different files and functions in there that control every thing from spark and fuel to when the fans stop and start.

Softer shifting might feel nice but keep in mind it will wear your transmission more. During a soft shift the clutches fill slowly and until there is enough pressure to fully engage the clutch it is slipping. When the clutches slip they are wearing out.

Your truck should have firm shifts if you have added power or are towing. It doesn't have to be all the time but when you are getting on it for some "spirited" driving the firmer shifts will help the trans last longer. The beauty of electronics is that you can have soft shifts for cruising too.

 

[ZBoater]

I've been blogging my experience with tunes here

http://www.fordraptorforum.com/f24/my-initial-tune-thoughts-35000/

But I wanted to start a different topic. For those who understand what tunes do, can you share a little "under the hood" knowledge?

I understand the differences between performance, economy and tow tunes as far as shift strategies go. Some tunes hold on to certain gears longer. I'm still not 100 % clear on the "faster" or "firmer" shifts, but that's ok.

What else differentiates an "economy" and a "performance" tune? What impact does the fuel air ratios have on performance and how are they tuned?

In other words, what is the difference between a 87 performance tune and a 93 economy tune outside of shift strategy? What other tweaks are made?

I'm not looking for tuner "secret sauce". Just to understand a little mire as I try to decide what tune to stick with.

 

[onesickpuppy]

There are subtile changes to parameters. Some are as simple as making the intake air appear to be cooler than it really is, Old school racer tricks....

 

[Stepside]

Fuel tables and shift points are altered and/or coordinated by way of
timing; throttle position; octane; speed; load; barometric pressure; temperature; etc
to establish a 'performance tune', 'load tune', 'economy tune'.
A thorough understanding of the vehicle and its dynamics yields --> 5 Star Tunes.
Its over my head.

 

[pat247]

^^^ What Stepside said. ^^^

 

[ZBoater]

Ok, but how would a 87 performance tune compare with a 93 economy tune in terms other than shifting? Should I expect the same "power" from both being that the lower octane has a "performance" tune? Should I expect better mileage from the higher octane or the economy tune even though it's lower octane?