educate me on handheld tuners VS dyno tune

[kalvick]

Hey All,

I was always under the assumption that whenever you did something to your car's computer, it was highly advisable to get tune done while your car was on the dyno. I was also under the assumption that when you start playing with the computer in the car, you where required to buy a 3rd party chip.

Now when I took my car to the shop to get gears installed. I also asked for the dyno tune because thats what I thought would be the correct thing to do. ( i have other mods too that where never tuned for) when the mechanic installed the gears, he asked me what kind of fuel I had in the car and I told him it was mid grade gas and not 93. he told me he wouldnt put the car on the dyno to tune it and really open her up because it would basically rip me off to have a half assed tune. I agreed. He did say he would program the computer in my car to have the correct calibration for it. he never added a 3rd party chip. he modified my current computer which I didnt think was possible.

It got me thinking so my question(s) is this..... if i get a tuner like sct x3 or live wire, and email the company I buy the tuner from and tell them all my mods so i can get a custom tune. is that really safe? or should i just not spend ~$400 on the tuner and instead spend $400 on someone to professionally tune my car on a dyno?

Here is my thinking.... if i get a dyno and tune by a mechanic I am stuck with those settings. If i get a tuner with a custom tune installed i can always make minor modifications my self..... such as programming it to take 87 gas instead of 93. or if i ask for a really tight shift points (i have an auto) and the shift points are way too tight or i just dont like them i can use the tuner and adjust those accordingly.


obviously i wont play with things like A/F, spark settings, etc... things like that
but the idea of being able to change between fuels, depending on my budget. and setting the car for valet so it caps the speed limit and stuff really interests me.

what do you recommend I do, dyno + tune? order a mail order tune and get a programmer? get a professional tune + dyno + the sct tuner? if I do go the sct tuner route, do i need to buy anything else besides the tuner?

finally I think I need some sort of switch to go from normal mode to something like valet mode. does that mean i have to get a 4 bank chip? so i can have normal mode, and valet mode, and 2 blank slots? I also assume I need some sort of dial or switch to change between modes?

can you backup computer updates on your computer. in case the tuner gets lost, broken or stolen?

anyways... lets discuss tuners, and anything else one would need to know to enter the world of screwing up car computers.

 

[darkside03gt]

there is really no need for a dyno tune with your mods. the tunes that come with your handheld will be just fine for what you have. getting the car dyno'd with your mods will be a waste of money. you will gain 1-5hp with a dyno tune over a canned tune. also have you looked into snipertuning? there are some of us on this forum using it and love it.

the only thing i can think of for valete mode is a sct switch chip. someone should be able to build you a tune to take care of that.

 

[BurningRubber]

I can answer some, but not all of those questions accuratley for you.


Chips are really a thing of the past, unless you like having a flip chip, or multi-tune chip that you can switch between tunes. However, now most handheld (flash) tuners have the same ability plus many more.

Dyno tunes are a very good idea for someone with something more than all bolt ons. Once you get into cams, nitrous, turbo, supercharging, or a serious N/A motor build it is almost a nececcity to dyno tune. One of the main reasons is so that the air/fuel ratio can be kept in check.

A good tuner can make you a tune, and you can load it yourself through a flash tuner, but you cannot be 100% sure that tune is REALLY dead on.

A competent tuner that will dyno tune a car can tune every aspect that needs attention. Hand held tuners only allow a certain degree of tuning over a certain range.

For a mostly bolt on car, a dyno tune will squeeze every last bit of power out of what you have. Overall, it may not be much and not worth the price of a custom flash tune.

I have a Diablosport Predator and I gained 6.9 rwhp and 13 lbft of tourqe OVER their "canned" (generic) tune by messing with my timing and air/fuel ratio.

I put my car on the dyno to check my air/fuel ratio and it was too lean. I added some fuel to make it better.


For now, if you bought say an SCT X-CAL 3 or something... You can buy it from a very reputable tuner, and he can burn a custom mail-order tune that has been proven through running it on multiple cars with good results.

You can upload that tune, and adjust certain user end features such as shift points, gear ratio's, fuel, timing, so on (I beleive SCT offers those user end adjustments).

In the future, you should be able to take YOUR tuner to an SCT certified tuner, and they can custom tune your car for the price that they would normally charge for a custom dyno tune, since you are brining them your tuner.


I hope that helped a little bit, it took me a while to catch on to the tuning aspect of a car also, but once it clicks its pretty smooth going.

 

[kalvick]

Here is another question....

On the sct website it says the flasher is for off road use only. Is that because it can tune cars with out cats? lets say i get it and apply a tune to my car. would i fail Connecticut state emisions for any reason? would the guy doing the test be able to know i flashed my computer?

 

[BurningRubber]

I'd hope they don't check for computer modifications when you do emissions testing.

I am not sure, as my state doesn't require or even give them.

However... There is no reason the car shouldn't pass emissions with a tune on it as long as it is a good tune. You COULD make the car run like crap with a tune, but that would defeat the purpose very much so.

Yes, you can tune a car with or without catalytic converters with the tuner. Some tuners allow you to shut off the rear o2 sensors so when you swap to a catless mid pipe you wont get a CEL for that code.

 

[COramprat]

A handheld can be loaded with a dyno tune so it is upgradeable. Because a purely stock car has been somewhat restricted from the factory a tune can help a little with a few mods but not much. I think you would be disappointed if you had a dyno or road tune at this point. You can buy a tuner with a canned tune and be happy with it as well as the little manipulations you can do yourself. Once you make more upgrades it can be changed as you go along.

 

[blubullett]

The emmissions places cant tell what tune is in the computer, but they might see a chip sticking out the side of it so stick with the tuner. Also when you do need a dyno tune someday they just use your tuner to tune it.