Tuner Shop Suggestions

[bigrobwoot]

Sorry if this is kind of derailing your thread, but what is wrong with a road tune over a dyno tune? I don't have a preference, since I've never been tuned, just wondering what everyone seems to have against it

[Dean]

Originally Posted by bigrobwoot

Sorry if this is kind of derailing your thread, but what is wrong with a road tune over a dyno tune? I don't have a preference, since I've never been tuned, just wondering what everyone seems to have against it

There has been much discussion in the past, search if you want to read more, but the short answer is...

A dyno is a controlled environment where different things can be reliably reproduced, and worked on. They do however lack air flow consistent with the speeds being simulated which can be an issue.

Road tuning is not as controlled or reproducible and speeds required may be in excess of the legal limits, but obviously does not have the airflow issue.

[cody]

Originally Posted by Lawrence_P

Hey everyone, thank you very much for all the replies. They helped. I called COBB and they found a map that matched my car pretty well and it's driving fine now. I still plan on going to DB Tuned, although Ed at EQ may be a good tuner, he does not have an AWD Dyno like DB does. He just has the open source/road tune, which I don't feel comfortable with.

Thanks again

I realize how easily this point may have been lost in the unfortunate bickering in this thread, but Ed can and does tune with Cobb's Protuner software, not just open source. I totally understand you not being comfortable with road tuning, though I personally prefer it to dyno tuning.

Actually, in a perfect world, as I understand it, you'd dyno tune the car and then data log it on the road and make any necessary tweaks.

And, yes, welcome to the forum and the area.

[k-dogg39]

Originally Posted by cody

The car most likely has issues due to being on the stock map at elevation.

Many, many people live in Tahoe and Truckee with aftermarket turbos and were tuned at sea level. They drive hard at elevation and yet their car survives. Let's hear from Kevin Weiss and some of the other guys who were tuned at sea level but live in Tahoe/Truckee. I'm not aware of anyone having elevation issues except maybe Sperry, but that's not a daily driver situation.

You, (Dean), on the otherhand, blew your new motor because you tuned it up here and then drove it hard at a track at sea level without data logging to make sure it was safe.

In my opinion, the OP would be best served by getting tuned by a reputable tuner at sea level and maybe shooting a couple logs from elevation to the tuner to be safe.

Welcome Lawrence! Post up some pics. Come out to an auto-x or a track day as well, they are fun!

As for my being tuned at sea level and living at elevation, I have not had any issues (knocks on wood), aside from the normal loss of boost/power due to elevation. I have had tunes from both GST (normal stage two), and now from DB after doing the VF34 swap. Both shops are excellent and very trustworthy IMO.

I do not know much about the tables yet, but now that I have the V2 accessport I am looking forward to doing some logging and learning much more!

[MikeK]

Originally Posted by k-dogg39

after doing the VF34 swap.

Woah, when did this happen?

[sperry]

Originally Posted by Dean

A dyno is a controlled environment where different things can be reliably reproduced, and worked on. They do however lack air flow consistent with the speeds being simulated which can be an issue.

That's only true on a dyno w/o a proper fan. Have you seen GST's dyno? They've got a 3' squirrel cage 240V fan that puts out a 100mph breeze. It's basically a wind tunnel in there.

[Dean]

Originally Posted by sperry

That's only true on a dyno w/o a proper fan. Have you seen GST's dyno? They've got a 3' squirrel cage 240V fan that puts out a 100mph breeze. It's basically a wind tunnel in there.

That is new since I was last there.

[k-dogg39]

Originally Posted by MikeK

Woah, when did this happen?

I am pretty sure you knew about this... It was done March 2008, you tried to recruit me into the Capt turbo army , called me Lt. Turbo.

[MikeK]

Originally Posted by k-dogg39

I am pretty sure you knew about this... It was done March 2008, you tried to recruit me into the Capt turbo army , called me Lt. Turbo.

I'm old now, and cannot be expected to remember things.

[DUB]

This was a great thread, thanks guys.

My future plans include some mods that will require a protune. I have always wondered about the issue of tuning at sea level when the car is daily driven a mile higher. Now I know.

[Kevin M]

Originally Posted by sperry

That's only true on a dyno w/o a proper fan. Have you seen GST's dyno? They've got a 3' squirrel cage 240V fan that puts out a 100mph breeze. It's basically a wind tunnel in there.

Well, true- but that airflow isn't actually a force applied against the acceleration against the car.

The way dynos account for the missing air resistance is through simple physics. If you know the drag coefficient of the car reasonably closely (and dyno software comes with presets for nearly every commonly tuned car) it's just a matter of subtracting the function of air resistance vs. speed for that car from the power read by the rollers. Road tuning, on the other hand, has no way to account for varying winds, varying slopes in the road, and therefore have a higher margin of error than shop dynos.

[sperry]

Originally Posted by Kevin M

Well, true- but that airflow isn't actually a force applied against the acceleration against the car.

The way dynos account for the missing air resistance is through simple physics. If you know the drag coefficient of the car reasonably closely (and dyno software comes with presets for nearly every commonly tuned car) it's just a matter of subtracting the function of air resistance vs. speed for that car from the power read by the rollers. Road tuning, on the other hand, has no way to account for varying winds, varying slopes in the road, and therefore have a higher margin of error than shop dynos.

All a dyno has to do is provide repeatable load on the motor as it pulls through the power band for tuning. Good airflow is just for proper cooling.

All that other mumbo-jumbo about cd and drag computation is to generate some horsepower number to brag about and has no real bearing on the tuning of the car.

[Kevin M]

Originally Posted by sperry

All a dyno has to do is provide repeatable load on the motor as it pulls through the power band for tuning. Good airflow is just for proper cooling.

All that other mumbo-jumbo about cd and drag computation is to generate some horsepower number to brag about and has no real bearing on the tuning of the car.

Correct, provided the rollers alone can create enough load for the engine, which all decent dynos can.

[100_Percent_Juice]

Originally Posted by sperry

That's only true on a dyno w/o a proper fan. Have you seen GST's dyno? They've got a 3' squirrel cage 240V fan that puts out a 100mph breeze. It's basically a wind tunnel in there.

I wonder if they will let you stand naked in front of that fan.

[bigrobwoot]

If you show up naked, who are they to say no?