Handheld tuner vs. Mail tune vs. Dyno tune

DocG

5th graders > me. They're not bant
Sep 25, 2005
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Could someone explain the difference between adjusting tune settings with a handheld (e.g. SCT), using the tune they send you by mail on the SCT, and having a car actually dyno tuned. I understand on the dyno that they will monitor A/F and adjust accordingly to keep it safe, but what is actually adjusted....and is the same parameters adjustable by the handheld only, or do you need the actual Pro Racer pack to make the same adjustments? With the tunes that are sent with the SCT from wherever you buy it, can you make the same adjustments yourself using the SCT? Finally...if you get a tuner with included mail-order tunes, and say...add gears so you use the SCT to make those changes, will the mail-order tune still be the same and it just adds that change, or does it reset things?

Just trying to understand some of the differences. Thanks!
 
A dynotune is (should be) much more than adjusting A/F ratio. There are a lot of parameters that are changed. A dynotune is the best solution - and if you want adjustability, get a dynotune with an XCal 2. On a mostly stock car a mail order tune will work pretty good. The End user adjustability with an XCal 2 is VERY limited compared to a Pro Racer package where you get full control over the processor. If you have a mail order tune, and an XCal 2 and add gears and change it in the XCal 2 you do not lose the rest of the tune. Hope this helps.
Don
 
DocG2828 said:
Could someone explain the difference between adjusting tune settings with a handheld (e.g. SCT), using the tune they send you by mail on the SCT, and having a car actually dyno tuned. I understand on the dyno that they will monitor A/F and adjust accordingly to keep it safe, but what is actually adjusted....and is the same parameters adjustable by the handheld only, or do you need the actual Pro Racer pack to make the same adjustments? With the tunes that are sent with the SCT from wherever you buy it, can you make the same adjustments yourself using the SCT? Finally...if you get a tuner with included mail-order tunes, and say...add gears so you use the SCT to make those changes, will the mail-order tune still be the same and it just adds that change, or does it reset things?

Just trying to understand some of the differences. Thanks!

Only coarse adjustments across relatively broad rpm ranges can be made on a handheld tuner, while dyno tuning software (and the SCT Pro Racer Package) allow adjustments across much finer increments. For instance, my car had slight rise in A/F ratio from 3,000 to 3,500 rpm. The handheld tuner I use does not allow me to adjust the fuel table for just that specific range of rpm, rather I could only adjust within two ranges; from 2,000 to 4,000 rpm and 4,000 - 7,000 rpm. The XCal 2 may have different ranges, but they still will not be narrow enough to allow pinpoint adjustments.
Note that custom tuning and dyno tuning can mean the same thing, if the the custom tune (which can be delivered by e-mail) is developed for your specific vehicle based on your dyno and datalogging results. The tune(s) pre-loaded on a XCal 2 when you buy it are not true custom tunes. Although they may be based on your vehicle's ECU code and mods, they are not yet adjusted for performance data that you, yourself, have obtained on a dyno. The tune(s) pre-loaded on an XCal 2 should be somewhat better than the one-size-fits-all performance tune preloaded on a Diablo Predator however, since they are at least based on vehicles very similar to yours.
When you make adjustments for gear changes, tire sizes, etc. the performance settings of your tune(s) remain unchanged.
 
blackfang said:
Just so you know, the SCT Xcals(hald held programmers) are mail order tunes. They come blank and the place you get them from tunes them before they ship them to you.

Yeah, I know. I'm just trying to distinguish between the tune they send you (mail order tunes) and the things that you can tune yourself using the handheld. Does the mail order tune include more tuned parameters than you can just tune yourself with the tuner. I know a dyno tune includes more parameters, just didn't know if the mail order ones do too.
 
Don 95Vert said:
A dynotune is (should be) much more than adjusting A/F ratio. There are a lot of parameters that are changed. A dynotune is the best solution - and if you want adjustability, get a dynotune with an XCal 2. On a mostly stock car a mail order tune will work pretty good. The End user adjustability with an XCal 2 is VERY limited compared to a Pro Racer package where you get full control over the processor. If you have a mail order tune, and an XCal 2 and add gears and change it in the XCal 2 you do not lose the rest of the tune. Hope this helps.
Don

^^ This is the man you want to listen to on the subject ^^

But I would add that while a dyno tune is the best solution of the three listed, road tuning is the best overall, just not practical for most people unless you want to learn to do it yourself.
 
True, adjusting A/F via MAF transfer is the best way way to go, and this will not be an option when using the handheld tuner directly. Even with road tuning, which I agree is the best way to go, it's still worthwhile to follow up with a dyno session in my opinion to check your HP and TQ numbers.
 
Cool, makes more sense now. I knew with the SCT, you could adjust spark and a few things, but now it makes sense that its only in wide rpm ranges vs. the fine tuning of a dyno or Pro Racer.

I planned to do a dyno tune down the road after more mods, probably when I get cams installed for sure (and probably LT's at that time). But will likely get an SCT before that to do the gears, 02's, etc....but wasn't sure if I should hold out until I do some of the exhaust and simple mods to have those mods as a part of the mail order tune. Just didn't know all the details, but now it makes more sense.

Either way, Modular Depot is in my backyard and is who will do my dyno tuning when the time comes, so maybe I'll just order my SCT from them and have them do the "mail order" tune also.

Thanks guys!
 
DocG2828 said:
Yeah, I know. I'm just trying to distinguish between the tune they send you (mail order tunes) and the things that you can tune yourself using the handheld. Does the mail order tune include more tuned parameters than you can just tune yourself with the tuner. I know a dyno tune includes more parameters, just didn't know if the mail order ones do too.

The mail order tune they send you has been written with with SCT software which is (or should be) identical to current SCT software used by a dyno shop, so yes, the mail order tune has been written by adjustments to more parameters than you can adjust with the handheld. The main difference is the mail order tune is not yet adjusted for your specific vehicle, rather it is adjusted for all Mustangs with your ECU code and mods.
 
Give Me TP said:
The mail order tune they send you has been written with with SCT software which is (or should be) identical to current SCT software used by a dyno shop, so yes, the mail order tune has been written by adjustments to more parameters than you can adjust with the handheld. The main difference is the mail order tune is not yet adjusted for your specific vehicle, rather it is adjusted for all Mustangs with your ECU code and mods.

Ok...so I guess I'll really just have to make a decision as to between which mods it makes sense to have it mail-order tuned and buying the SCT. Probably do it when I buy a mid-pipe....to do the 02's...and have the SCT tuned for the midpipe and catback I'll hopefully have by then. If that will even matter any.

On a side note - which of the bolt-ons would really even benefit from custom tunings (mail order or dyno). Intakes, plenums, TB's, cat-backs, midpipes, window stickers, fuzzy dice, etc. I know cams and LT's...really would go dyno.
 
Give Me TP said:
it's still worthwhile to follow up with a dyno session in my opinion to check your HP and TQ numbers.

True, but you can also guage your progress at the track on the test & tune nights, which is a little more fun than paying $75 an hour for dyno time. Or something that is really cool, is PLX now has an analog g-meter (accelerometer) that can be mounted in the car and datalogged with whatever software you are using. Dont know how well it works, but the idea is pretty cool if you are into geek stuff like me.
 
DocG2828 said:
Ok...so I guess I'll really just have to make a decision as to between which mods it makes sense to have it mail-order tuned and buying the SCT. Probably do it when I buy a mid-pipe....to do the 02's...and have the SCT tuned for the midpipe and catback I'll hopefully have by then. If that will even matter any.

On a side note - which of the bolt-ons would really even benefit from custom tunings (mail order or dyno). Intakes, plenums, TB's, cat-backs, midpipes, window stickers, fuzzy dice, etc. I know cams and LT's...really would go dyno.

Intake and exhaust mods tend to lean out your A/F ratio, or at least in my case they did so significantly even with the factory tune.