Since there are a few 991 TT-S owners here- my thread about the GIAC tune

[Vic55]

This was my post at 6speedonline. My tune is on 91 octane so my car starts with a lower dyno read out and ends with a lower number post tune but the gains are similar so here is the 93 octane dyno. Remember a few things, this is AWD hp and tq gains not RWHP and its sweet spot gains (usable rpm ranges). The car is a stock monster but I know you guys; you want more and this is what I call MORE!!!!! GIAC was very very deliberate with this tune to ensure safety. You can always tune and get more but at what risk; I trust GIAC.

Stock 991TT-S's trap mid to high 120's (octane and ecu dependant- the ecu hurts up top with the 91 fuel) in the quarter so while the stock hp might seem low to some its the performance of the car on the street and the way the power hits the ground that matters to me.

First off Id like to thank Eric at SupremePower in Placentia and Austin at GIAC for being so accommodating. If you are in SoCal I recommend calling Eric for your tuning and modding needs. Austin took my car in and had it done in less than one hour; simple OBDII updates and baaaaaaam the car was done.

Impressions (all with less than 50 miles on post tune):

I probably drive my car in Sport Plus 95% of the time and the other 5% is Sport so my thoughts are almost all about the tune with Sport Plus.

Throttle:

The car jumps- the response is greatly improved. I'd guess its around 30-40% more responsive. Sport Plus like Sport Plus Plus now and my few miles in Sport made me think I was in Sport Plus. When rolling the car is just aggressive- turbo boost delay is reduced and I feel like I'm in a NA car moreso than before. Some here have felt the throttle on the Turbo S to be a bit lacking in feel or mushy and the tune alleviates that feel.


Power:

The gains are easily felt- I mean easily. From a dig the car is even more scary and triple digits come faster and the pull to 160 mph (I was able to reach 162 on the speedo about 10 miles into the tune). The AWD drag to tends to pull the Turbo back is gone. Whats great is for us Cali guys on 91 octane- we get the power that the car should be making to trap in the high 120's. Most mags have tested the Turbo S in Cali on crap 91 and the ECU was holding it back up top. The tune makes this much less of an issue. As the dynos dictate (GIAC thread) the gains are circa 40 AWHP and 50 AWTQ. I didn't dyno the car due to timing issues on my part but my butt dyno says I got all the hp if not more. And the TQ- whoa- the car is a mad beast now and the way it should have come out of the box!! What I like is the usable gains in the sweet spot rpms; this is very noticeable during street driving where speeds of 30-70 are mainly achieved.


I really am glad I did this mod and I have always tuned my Turbos (this is my 4th)- this tune could very well be the best of the lot. I still need more seat time for true adaptations but this is my initial review.

Thanks again GIAC and SupremePower!!

[Tom C]

Nice! But I am jealous that the car is out for a few months and real tunes are available.. Grrr

[Vic55]

Originally Posted by Tom C

Nice! But I am jealous that the car is out for a few months and real tunes are available.. Grrr

And a simple OBDII tune...

[lasquintanas]

Good info Vic. Saw this over on 6speed.

Just picked up my '14 TTS and am thinking about doing a tune based on your info. You've been a great source online.

Weird that I use mpost more than 6speed or rennlist. Seems to be a bit livelier here.

[Vic55]

Originally Posted by lasquintanas

Good info Vic. Saw this over on 6speed.

Just picked up my '14 TTS and am thinking about doing a tune based on your info. You've been a great source online.

Weird that I use mpost more than 6speed or rennlist. Seems to be a bit livelier here.

Thanks for the kind words....

I think for the most part, the M5 owners are enthusiasts of other great cars and this section was only recently created maybe 8 months ago. But lately a lot of the M5 guys (or members here) have been interested in Pcars or have actually purchased the 991's/997's so the traffic and posts are fairly relevant.

You should check out the dark side thread below LOL.

[RPiM5]

Originally Posted by Vic55

Nice! But I am jealous that the car is out for a few months and real tunes are available.. Grrr

And a simple OBDII tune...

Jesus! Why is Porsche basically giving tuners open source code while BMW is creating a fortress of security with their encryption? Almost make me want to jump ship to Porsche. Lol! Beautiful gains by the way. I'm envious of such accessibility to the Turbo's ECU code.

[Vic55]

Originally Posted by RPiM5

Jesus! Why is Porsche basically giving tuners open source code while BMW is creating a fortress of security with their encryption? Almost make me want to jump ship to Porsche. Lol! Beautiful gains by the way. I'm envious of such accessibility to the Turbo's ECU code.

Yo Dave you need a pcar already LOLOLOL

Assumptions is all I see here sometimes... GIAC has been working on this for months (since Oct at least) and maybe their focus is more intense than that of lesser tuners in the industry for BMW. Or maybe you are right and the Porsche DME is easy to break but if that was the case there would be other tunes out which there is not (I haven't heard of).

[stealth.pilot]

Originally Posted by RPiM5

Jesus! Why is Porsche basically giving tuners open source code while BMW is creating a fortress of security with their encryption? Almost make me want to jump ship to Porsche. Lol! Beautiful gains by the way. I'm envious of such accessibility to the Turbo's ECU code.

Probably because Porsche likes the idea of people voiding warranties as a cost avoidance measure for them.

[avlnch]

I agree, the throttle pedal is a bit mushy in the beginning. Which maybe my #1 reason for considering a tune.

Does the tune adjust idle rpm? I ask because in sport/+ it increases.

I am about to do some more research into this tune. Hopefully they ship you a unit to upload and remove the tune yourself.

[avlnch]

Originally Posted by stealth.pilot

Probably because Porsche likes the idea of people voiding warranties as a cost avoidance measure for them.

Porsche just expects you to maintain the vehicle at a higher level.. when tracking it. They even tell you what to do.. running a cool down lap before stopping the car, checking the rotors/pads/cooling ducts, not to run slicks, checking chassis/suspension alignment, checking aero parts.. keeping oil level 3 marks above minimum when tracking, changing the oil after 4,500mi of tracking, etc.

They give you a whole checklist, and tell you that if it's ignored and you don't keep up on the increased maintenance that is needed when tracking the car, warranty can be voided. Which IMO is common sense.. I think their OEM maintenance intervals are way too long for street driving. They expect first oil change at 10k. I'll be getting my first change from Indy shop at just before 2k.

It seems like Porsche understands owners will be tracking the car. I agree with you, they could of easily encrypted their ECU's. So there's some kind of reason they didn't. I think it's sort of against the image of the brand.

Champion is very cool with modding.. I believe so is Braman WPB.

[FLOMACKS]

Originally Posted by lasquintanas

Good info Vic. Saw this over on 6speed.

Just picked up my '14 TTS and am thinking about doing a tune based on your info. You've been a great source online.

Weird that I use mpost more than 6speed or rennlist. Seems to be a bit livelier here.

Agreed. Better crowd here for sure.