I have a 98 firebird and I made a few mods and I was wondering which is best a mail order tune or dyno? I was told both are good. Just looking for some insight from someone who did this.

 

The dyno tune will be better, but many people with mail order tunes are very close to what a dyno tune can do. I ordered a madz28 tune and should have it on by this weekend. For $120 it's hard to beat plus you get 3 months of free tunes and only $50 for a tune after that period.

Jason

 

Let me make a quick analogy here.
Call your doctor and describe your symptoms get a diagnosis and treatment.
Or
Go to the doctors, get some labs done, maybe some x-rays, then a diagnosis and treatment.
Which is most likely to get the best results?

 

Totally untrue and a cyberspace myth

The only time this is close to true is if the person doing the tuning via mail is a slob, lazy or just knows nothing about what they are doing.

Using a static, non load bearing dyno is a joke.

1. Your car NEVER is driven the way its used on a dyno.
2. a dyno pull is less then 1 minute in length when the PCM is timed based so it never even gets a chance to make its adjustments. The PCM uses Adaptive Strategy software and so tuning only in non realworld driving conditions does not allow PCM to do its job and you get a unreal tune.

3. Dyno shops in many cases do not even have a weather station, if it does it may not be calibrated correctly or the operator does not even assure station is functional so what it reports is invalid. Its a laugh that they will take a flithy wideband O2, stick it in ONE muffler tip where temps are less then 200 degrees and from that think they are getting valid AFR, no - way.

4. dyno drums are 100's of lbs less then car/driver and again reports incorrectly and for tuning puposes gives incorrect tuning information

5. Chassis dyno tuning cannot tune for hot/cold starts, idle, shifting, braking, lifting off gas pedal or even driving on hilly roads.

6. dyno tuning only forces the PCM to use only 5 of the 24 fuel trim cells so after a dyno tune just driving home can delute the dyno tune.

7. lots of dyno shops like to market by claiming high tuning performance gains,

I have even seen them put the weather station on top of engine so the corrected values were bloated by 75 HP.

Example read this thread, its common I see all the time :
Bloated dyno tune results

Here they not only claim a 340 to 420 HP gain just installing a mild cam but after the dyno tune the car now has problems, PLUS the shop drilled a hole in the TB plate which is a nono for a C5.

Tuning engines today requires experience and knowledge, those not having this spread the myth that blowing $75 for use of a dynojet is the only way to go when in fact in 100's of F and Y bodies I have tuned, almost all of them 1st had a dyno tune and then end up coming to me for a true overall custom tune and the results are always my way of tuning is better.

We have tuned cars using a dyno, taken the same cars and hand tuned them and in all cases a hand tune wins.

The part missing is for bext case MAIL tune, the car owner needs to use a decent OBD-II scanner, go for a testdrive for about 10 miles while scanner is recording all engine and and PCM functions, this run includes all engine conditions, loads, RPMs and the way that driver likes to drive.
That recording is emailed to me and now I know a lot more about that car then doing a few pulls on a dyno ever will so my tuning is true custom tune for real world driving and performance gains.

If car owner has LS1edit or Hptuners they do not even need to mail the PCM, its all done via email but again the PCM scanner recording data being analzyed properly will give a far better tune then some dinky dyno queen tune.

EPA testing over the years states an engine only sees WOT less then 1% of the powertrains life and why WOT is not part of EPA smog rules, so also a dyno tune is seeing a condition most engines rarely see ( true WOT is 100% engine load you rarely even do on a dyno since the drum weighs less then car/driver) so why tune for only 1% when PCM averages and adjusts to what engine does over the 100% engine load/conditions.

A dyno is only useful if the person does not want to use high loads on the street to gain PCM data, and only after a hand tune was 1st done to calibrate all the other conditions you cannot do on a dyno.
Even then the PCM is a dyno and performance values for HP and Tq can be read from it and they are real world values

My view is not liked but is a fact.

 

I agree with all that you said except that many shops use eddy current dynos now which gives a proper steady load. but dynojets are great for bragging numbers.

 

Thanks for the very helpful information. I will continue doing my research.

 

I don't know how much is often gained by a mail order tune but I gained 17 rear wheel horsies by a *mini* dyno tune. Consisted of 3 full runs, tuning in between each. The guy said he could get me 10-20 more hp with a full day dyno tune

 

if your tuning for all out hp then a dyno tune but if you are wanting to tune drivability then and mail order tune will do.

 

A static dyno tune cannot tune for part throttle and thus your only tuning for fuel trim cells 15 and 22 (if OBD-II).
To get best performance part throttle has to be well tuned for its what either quickly or poorly gets engine to WOT.
WOT itself is effected in how well or poor engine is acting as it goes into WOT and reason why people think they have a great tune on a dyno but a week later car is not performing well.
There is no way on a static dyno to tune for best power enrichment conditions which is more important then WOT itself is.

Tuning between dyno pulls is useless since the PCM

A. Requires at least 40 minutes of relearn drive time and
B. Long term fuel trims are only acted on once every 10 minutes and O2s are only read once a second so multi tunes without allowing PCM to relearn/re-cal will gve false values as what values will be one hour or 1 day from then.

Any time the PCM is flashed and/or battery is removed the PCM is back to learn mode ( and internal EPA smog tests have to run until completed) , making judgements from a 30 second dyno pull will not even be close to what the PCM will be like once it is fully calibrated in.
Adaptive Strategy in PCM will force that dyno tune to be changed since PCM will relearn after real world driving is done and fuel trims have been averaged out in fact when on the dyno the 1st couple of pulls are really running on the long term fuel trims from the last 10 minutes before the pull so if there was a lot of idle time where engine was leaning out from it and increased heat then what looked like being too lean was false and that the tuner assumes as tunes richer when it really was not and why people doing dyno tunes later complain about surging issues.

On the other hand a tune done via using street or track PCM scanner data assures a correct tune not only for good daily driving but also maximum performance since your seeing
A. a fully calibrated PCM
B. All engine conditions that effect total calibration
C allows a full layered tune so that ALL fuel trims cells are balanced for best AFR and timing plus allows any knock or misfire to be seen and tuned out which you cannot do on a dyno simply using 1 gear for less then 30 seconds.

 

Team ZR1-
Could you please clarify what ecm/pcm's you're referring to?

 

Early this year I did a dyno day for the speeddensity guys.

Quite a few of them had one of my mail order chips and out of all of those guys I think the biggest gain I got over my mail order stuff vs. dyno tuning was about 7rwhp. On cars that are making 340-370rwhp thats lesst than 2% off! Thats something you can take to the bank..

I mean not everyone has access to 1. A dyno and 2. a person whose actually able to tune thier car.

Recently I was asked.. Do you tune by heart or by computer.. I asked, what the hell do you mean by heart.. well he said a buisness here in town dialed in his AFR for every possible hp with a fuel regulator. guy got charged around $500 for a "by heart" tune. Thats the type of dyno tuners you deal with all over the country.

 

Not sure what your asking but ECMs would be before 1994, anything newer is PCM based as to F and Y body ( vette solely had PCMs since 1994, except the ZR-1 which used a ECM even for 1995 model)

 

Let me just add,

If you have a 396 244/252 T-trim aftercooled 55lbs injectors car or something else exotic your not a good canadate for any mail order tuning. Unless the guys who are doing it can do it via email with WB feedback etc..

But if your like 99% of the people out who have common 350-396 setups or just anything NA really chances are if the mail order company has thier sh*t together they can nail it.

 

So it seems to me the best route to go would be a street tune rather than dyno. I want by car to be tune to gain the most out of my Mods for HP. so, I will look into it.

 

I understand the reasoning behind real time tuning. In fact I just bought all my chip burning equipment for my 85Z28 and my 95Z28. However, I had a chip burned for my 85 back in march of 03. It has been nothing short of a disaster. Had it burned here locally in AZ from a speed shop. Once I got the chip back the car wouldnt run right from 1200 to 2000 rpm under WOT in first gear (AT). It would spit and sputter real bad until I shifted into second. Anyway, when I would call the chip people back and tell them, they would say that my intake was the problem and wanted to sell me another one. After some time (4 mos) I decided maybe they were right (had modified tpi) and bought HSR system for my 406 SBC. Well that didnt work either. Recently had someone read my chip only to find out that the VE tables were messed up in both 1600 lines (I have 7730 ecm and using $8D mask). They didnt match.There were several other things wrong as well. I told them about it about six weeks ago and they burned me another one. Took them 5 weeks to get it back to me. The chip guy had to get help from his retired GM calibrator buddy. So, after I got my chip back about a week ago my cam went flat. Its not a roller cam. I was at my friends house that built my motor and thats what he told me based on the symptoms. It is due to fuel wash. I am blaming it on the chip that wasnt burned right. The chip people dont agree. So here I am with my new burning equipment and no way to do anything because my cam is shot. I can see I am going to have to pursue this in court but I need some help. I have both bins from the chip burnings in my tunerpro program and was needing someone who does this for a living (business) to read them and tell me what they think. After my cam is changed out (hopefully thats all thats wrong) I am going to burn my own with real time tuning form my autoprom setup. Can anyone help give me advice on the chips to help prove my case? Thanks...