N2338V

Hello everyone,

I spoke with a local shop regarding tuning a new 991TTS. The owner (mentioned on this site and others in a very positive manner mostly) said that they custom tune on a dyno nearby and get a superior outcome when compared to GIAC or other such tunes (or piggy-backs for that matter).

What experience do any of you have with a custom dyno tune versus other well-known providers of tunes (GIAC, Softronic, piggy-back, whatever)? Good or bad?

I realize that this is highly dependent upon the tuner and their experience, but on the whole, how likely are you to go for something like this rather than "off the shelf?"

Thanks in advance. Hope you all are having a great weekend!

Mike

PMNewton

As far as I know, right now GIAC is the only company that can actually rewrite the ECU. My suspicion is that the "guy up the street" is just going to slap a tuner box on it and call it good. There's nothing custom about that. It would help a lot if you shared the name of the shop. To answer the rest of your question, I have GIAC Stage II and a high flowing exhaust and my car is a monster. There are zero conditions in which I can catch it doing something squirrely. I have tried flooring it in 7th from 40 mph, run it hard at 12,000 feet altitude and LC launched it in 107 degree weather. Not a single sputter or puff.

- Patrick

FBA

I'm not sure what makes the GIAC tune and tuning so different from other vehicles out there, where the best tune is going to be one written by a really good Dyno operator with a load of experience with that particular platform, especially in light of the fact that they are generally accompanied by other aftermarket mods, making each situation/ vehicle unique.

I can't say as to whether GIAC is the only one able to write in the ECU or not, but I would chose to have my tune written by a qualified, experienced Porsche tuner over a canned tune. All of my vehicles have been done that way, and they are all running monster power, very safely.

N2338V

Thanks for the feedback, guys.

I wasn't sure about the etiquette when mentioning company names so I didn't want to go outside norms.

PMNewton

GIAC is the only company who can rewrite the ECU and they are by far the most prolific Porsche ECU tuner in the world.

OP, please post the name of the shop you are considering so that the forum can weigh in with any personal experiences.

- Patrick

N2338V

The shop I spoke with was Intersport in the Tysons Corner area.

proTUNING Freaks

We're expecting to have the 991 Cobb Accessport and tuner software ready by beginning of August and we'll have the custom tuning offering available just like we have for the 996, 997.1 and 997.2 Turbos. We're really excited about it and given the amount of success we've had compared to common off the shelf tunes we're really looking forward to seeing what we can do on the 991 as well.

Dzenno@PTF

ScottKelly911

I would find out how they are going about re-writing the ecu? Currently, I believe only GIAC and EVOMS have cracked the code and are able to do so. I do think Cobb is working on it also. But I'd be wary until they tell you which software they're using. If they say that they're not using anyone else's software, well, let's just say I doubt that they've cracked Porsche's code on the 991TT and would need to see dyno graphs from another car to prove that they have and if they did, how it's been delivered and if it's significantly improved over stock form.

N2338V

[QUOTE= let's just say I doubt that they've cracked Porsche's code on the 991TT and would need to see dyno graphs from another car to prove that they have and if they did, how it's been delivered and if it's significantly improved over stock form.[/QUOTE]

Good advice. Agreed...

PMNewton

Here's another thing to consider: GIAC and EVOMS don't give their tuning software to anyone. Another shop can't custom tune a car using GIAC or EVOMS software. All they can do is load an encrypted file that came from GIAC or EVOMS. In order to "custom tune" they would need a way of reading data out of the ECU (not too hard) then writing a new file (very hard without proprietary software) and finally breaking the encryption to write the file to the ECU (extremely, extremely hard). It is HIGHLY unlikely that some shop in Tyson's Corner - that nobody on the forum has ever heard of - has been able to do these three things as quickly as GIAC. Honestly, my best advice for you is to get a GIAC tune done and don't try to be too fancy. My GIAC Stage II 991 TT is a beast in any gear and has been absolutely infallible in daily driving.

- Patrick

hduffy

My experience with GIAC in the past has been Phenomenal. Also, I wouldn't want a surgeon who has done 6 heart transplants doing mine. I'd want somebody who does it on a daily basis. Same with my car. Not sure many tuners have the experience of GIAC.

N2338V

Thank you both for your thoughts. Agreed on all points made.

Guess it's time to look for a GIAC tuner nearby.

Have a great weekend everyone,

Mike

pasd18

I am considering Cobb also, I like the option of the accessport and the ability to install and update at my convenience.

sdg1871

I went with GIAC. GIAC has the most experience with flash tuning our cars. Flash tunes are superior to piggy backs because there is so much more you can do to enhance performance inside an ECU while still leaving the ECU's safeguards in place than simply fooling it like a piggyback does.

Also because GIAC sells so many their tunes are very protective of the drivetrain as they do not want engines/trannies they tuned grenading -- not good for business.

ecpchris

Really neat article about Cobb's development for the 991 turbo. http://www.cobbtuning.com/porsche-99...p-development/
Not only do they have custom dyno tuning and a handful of easily switchable OTS maps, but they have extremely quick logging of countless ecu parameters (that the end user can view and use at will). No one else has this capability on the 991
http://www.cobbtuning.com/porsche-99...esting-part-2/