someone explain to me why dyno tuning is worthless

[skipztt]

ive been reading alot of posts about tuning, cause i starting to head in that direction. in some of the posts ive read, a couple of u guys (i cant remember who, cause ive read so many) said the a dyno tune is worthless. because its tuning a WOT only. now remember im new to this. im not bashing on anyones theory or whatever.

so my question really comes down to this.....why is WOT or chassis dyno not the way to tune? isnt really WOT the only way we race. (if that makes sence :squint: ). should the tune really be best for WOT?

remember... im all "ears" here...i want to learn. im just asking questions to learn the way you guys do this.


explain everything....oh yeah keep it in terms i can understand...just pretend like im 10yo. :rotf:

thanks

 

[2kwik4u]

Re: someone explain to me why dyno tuning is worthless

Where do you spend most of your time driving? Part Throttle......So why would you spend an exorbitant amount of money doing something you're only going to use a small percentage of the time??

If it's a true race only vehicle then WOT/Dyno tuning is great, otherwise it's a ton of money to make some pretty numbers, and have a truck you still can't drive around all that well.

NOW....If you find an eddy current dyno, you can do all your tuning there, both part throttle, and WOT and get a great tune without the dangers of tuning on the street.

 

[skipztt]

Re: someone explain to me why dyno tuning is worthless

why should you just tune for part throttle or 3/4 throttle or whatever? wouldnt it be better to tune just for WOT? even on the street?

remember im just asking here. i just want to learn

 

[The Devils Own Chariot]

Re: someone explain to me why dyno tuning is worthless

That makes no sense to me. How do you know what tune is making your max amount of power if your not on a dyno? You can go for feel but there is just no numbers associated with it. How do eddy current dynos tune at part throttle? If your good at WOT why would you not be good at part throttle? WOT is the harshest state you engine endures. Im not following either. I must have much to lean as well.

 

[jslezak83]

Re: someone explain to me why dyno tuning is worthless

If your good at WOT why would you not be good at part throttle? WOT is the harshest state you engine endures...

im guessing for the same reason my 350 runs good part throttle, but sucks at WOT. different fueling needs for different conditions. if you're only tuning WOT, its gonna drink gas on the street, and be a rich pig.

 

[dgoodhue]

Re: someone explain to me why dyno tuning is worthless

Their are few reason, one is that you want to tune the whole rpm band as mention about. The further you away from stock usually the worse the engine drive in part throttle. This is particularly true with Cam/Head/Inejctor changes. Another would also be that the upper portion of the part throttle table affects the WOT section. Beleive it or not the WOT tuning is actually the easiest part of tuning a vehicle its probably only 5% of the time tuning a vehicle. Lastly I have heard &read that Dyno don't alway load Turbo engine properly. I know of one person who ran thier Truck at the track, had it Dyno tuned (gain like 20hp) and ran it again the track only to lose a couple MPH. He put back the old tune and MPH reappeared.

 

[cloneman315]

Re: someone explain to me why dyno tuning is worthless

the dyno we dialed mine in u can load the dyno,which i believe got it real close .then the track u can fine tune it in.

 

[NOJIMMY]

Re: someone explain to me why dyno tuning is worthless

....Im just guessing, but it would seem that dyno tuning (which in itself differs from
shop to shop, and dyno to dyno):
1. Is only as good as the shop, type of dyno, tuner/ability, and goal
(ie approximate hp/tq figures, or breaking in an engine, or comparing changes/mods)
2. Is only an approximate to real live conditions, whether its wot, idling, handling, throttle response
or engine response (like brake torquing, trans-braking, etc)
3. Can in itself, cause engine problems

One probably should realize that with today`s "lack of unpopulated roads anymore"
there simply isnt a lot of places one can experiment/tune without creating issues
(especially if you have personalized plates, which make it easy to record/notify the police).

Im sure test-n-tune nights help with racers, but for street driven/combo builds
dialing in boost levels, settings, tire pressures, suspension, rpm shift points,
and ecm tables takes "lots" of time and patience, with dyno tuning expensive
and for some, not the best bang for the buck. But if your buying a pre-built motor
its sometimes good to know that there are no leaks, broken parts, or issues with
the long block (and that you get mods that work together to produce a certain hp/torque).


So its useful for some applications but certainly not all...but the above is just a theory.

-Larry

 

[SCWolverine]

Re: someone explain to me why dyno tuning is worthless

My $.02 (for what it's worth): Tuning is a LOT more than making a big number at one spot (wot), unless you trailer in, do your thing, then load up and go home. By the time you pay for a couple of dyno sessions you could be the better part of the way to being set up to do it all yourself (WBO2, laptop, ostrich...) AND be ready to adjust when you make your next mod.

I'd rather know what's gonna happen in the real world, and no dyno is gonna accurately reproduce ALL the scenarios. Read some of the posts by the guys that have been tuning for a long time (turbodig, JS Manufacturing, and sytyguy come to mind, but there are more), such a small portion of their time is spent tuning wot. Say you get the "max hp dyno tune", my $$ says one of the above (or others) could spend a few DAYS with the truck, and get some more out of it, and at LEAST 5 mpg to boot.

Code 59 (with autotune as a guide) has made it so much more simple (and easy), there's almost no excuse. I agree with NOJIMMY regarding tuning extremes on public roads, but then again, they're the conditions that require the least amount of attention.

Like I said, my $.02, ymmv.

 

[cloneman315]

Re: someone explain to me why dyno tuning is worthless

when me and turbo 6 did mine i think it took 6 pulls to get it perfect,but we need to do some track time a lil more,but i will say the dyno tune has got my truck dead nuts perfect,cruising ,idle,cruising etc,but that was just my experience

 

[skipztt]

Re: someone explain to me why dyno tuning is worthless

thanks everyone for the responces.

i understand tuning the whole rpm range..ect...just not WOT. ive also read/heard that the dyno doesnt really accurately measure "road conditions". such a s the load on the motor when it drivin fon the road, compared to the rollers.

though cloneman315 has had good experiences with dyno tuning. maybe thats the way to do it dyno it then take it to the streets to fine tune it????

i plan on tuning myself with a laptop, ostrich and wideband 02. and ill be posting alot more on code59..ha.

im just really trying to figure out a good way to start tuning. i know some guys who have a chassis dyno and i can probably get some free passes on it if i want. i just want to hear everyones thoughts on this.

 

[ashman]

Re: someone explain to me why dyno tuning is worthless

i believe there is some good that could come from a AWD "LOAD CELL" dyno (dyno capable of variable loading, i think Mustang Dynos do this) and some good tuning software (aka 'code59' and 'autotune'). you could log your truck in loads that would be impossible to find in a real world conditions and it would be able to hold those loads for tuning (fueling/timing) in specific areas.

obviously, the shop would have to be capable of providing enough cooling for the truck for extended runs.

first you'd have to decide where your truck made the most power via AFR and timing for each cell of autotune (this would be the most time consuming part) and then you'd enter those numbers into autotunes 'desired AFR' table and let autotune 'spit out' the proper corrections to the F29x table.

easier said than done

 

[turbodig]

Re: someone explain to me why dyno tuning is worthless

I'll summarize it this way:

no tuning < inertial dyno tuning < eddy current (loadable) dyno tuning < real world tuning.

The quality of tune you get on a dyno has a lot to do with how willing the dyno operator is willing to go into the details, and the skill of the tuner.

Bottom line... nobody races on a dyno. A good tune takes into account normal air conditions, the behavior of the intercooler (which a dyno can't simulate), and launch characteristics. The only way to see those is a real world test.

A dyno can get you *closer*, but it can never replace the effects of the real world.

 

[TYTILIDIE]

Re: someone explain to me why dyno tuning is worthless

Ill jump in here and just say that my truck is a perfect example of why you need to tune everywhere instead of just on a dyno. While I certainlly couldve left the truck stock and went with a plug and play chip(which I actually did), I decided that since I was going to mod the truck I had better do something in the way of tuning. I slapped on the 20g and knew a stock chip wouldnt cut so I got me an ultimate chip. It was nice and functioned ok but it ran awfully rich at idle and lean up top. Now keep in mind IM at 6000' and the chip made for far less alititude than that. So I got into tuning with the ostrich and Tuner Pro. I basically have to start from scratch, not literally. In certain conditions, my truck would run just awful. For example, taking off from a light at a normal speed, it would hiccup or bog but being able to tune on the fly so to speak I was able to tune around that and get it to where I needed it to be. Then, I had my tune almost dead on and we got a cold front that moved in, guess what, my AFR's were as much 2 points off, still havent got around to figuring that one out yet, I know theres a correction table I have to sue just havent had time to figure out which one it is. So basically, being able to hav full control is the ultimate IMO and a hell of a lot cheaper.

 

[2kwik4u]

Re: someone explain to me why dyno tuning is worthless

It should also be mentioned that there is alot more to a good tune than higher WOT hp numbers. Just because WOT is where most people measure their performance doesn't mean it's the best place to measure. There are also other factors of performance to consider. Gas mileage, drivability, and throttle response are a couple that nobodys talked about. Those you simply cannot replicate on a dyno.

 

[JSM]

Re: someone explain to me why dyno tuning is worthless

It should also be mentioned that there is alot more to a good tune than higher WOT hp numbers. Just because WOT is where most people measure their performance doesn't mean it's the best place to measure. There are also other factors of performance to consider. Gas mileage, drivability, and throttle response are a couple that nobodys talked about. Those you simply cannot replicate on a dyno.

And these "other" things take 97% of the time to tune.

Here is another thing, if you have the old code stuff (not code59), if you do WOT first, then go fix drivability, you will have lost your WOT.

 

[UR50SLO]

Re: someone explain to me why dyno tuning is worthless

Exactly what T-Dig,JS and Dob said.

The Dyno can't account for launches,wind drag,real world acts of force on the vehicle ect.

Why pay to tune in a place that you'll never "drive" the truck? If you want to pay a few hundered dollars to say I made X amount of power that's fine.

I've never been on a engine dyno or Chassis dyno. I do feel it's totaly pointless. I get asked all the time how much HP my Camaro makes. It frustrates people that I don't have a number for them all I have is a 1/4mi et and MPH. Of which I normaly only look at the MPH. If your making the MPH for a given ET and your time is slower then you've got a tuning problem/traction problem/combo problem and you need to repair one of those things before MPH and ET can match.

I'm with Jeff Dob and Dig on this one. Why are we one of the few that think this way? I've not even done any WOT tuning on Heather's truck yet. It's safe up there on timing and fuel but it's no where near what it should be. Heck... I've spent hours driving around getting all the part throttle stuff close! I've not even gotten to the big end yet!
~Scott

 

[Vertigo]

Re: someone explain to me why dyno tuning is worthless

I guess for me it comes down to how extensive your mods are, what engine management you're running and how flexible it is.

Prior to the AEM EMS, I've tuned/logged countless hours on deserted streets and made adjustments from there. My car was running pretty damned good and since I had factory knock control if I was a little off it didn't bother me any.

Now with the complete standalone and a crapload of new mods I wouldn't trust 'driving' the car on the street even to set a base tune. On a good dyno you can start right from a stop, load it up and tune until you're completely happy with throttle tip-in, fuel trim adjustments and the whole works well before you even think about going WOT.

Additionally (and again this probably doesn't totally apply here unless $59 has control over knock sensitivity) I can turn the knock control off, target an AFR and watch the torque numbers to see where it's knocking. Then I can set the parameters to give me a precise and effective KR control. I couldn't imagine doing this on the street.

However I must say this - once it's through wrecking the dyno, I will tweak things for the real-world conditions the car will see.

 

[ed hess]

Re: someone explain to me why dyno tuning is worthless

well fwiw we never used a dyno to tune my truck, last time on highway while doing boosted pulls which really suck up fuel and still got 15 mpg. this is with 160 injectors.

that should pretty well take care of the question.

ed

 

[JSM]

Re: someone explain to me why dyno tuning is worthless

The times I have been on a dyno I have noticed they do NOT load the truck the same as the street. Even Mustang dyno's. Boost control is off, etc.