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Me: I’ve had terrible experience with GIAC and personally feel they are the Walmart of tuners. Again, no experience with a 911 but on 2 past personal cars and known issues with several people I’m close to with non Porsche 3.0tt.
Others: There have been a handful that have had good things to say but not bought for this particular car.
YMMV - you’re asking on the internet so weigh any response (mine included) accordingly!
Always fun when this guy pokes his nose into 991.2 topics adding absolutely nothing of value...
GIAC had the first tune on the platform with a very, VERY difficult ECU to crack. They deserve tremendous respect for being to market a year ahead of everyone else.
The quickest and fastest 991.2's in the 1/4 mile are all running a GIAC tune at this time.
Now that the ECU is cracked more results are getting out there. A base 991.2 with a Gintani tune recently made 420 whp and 440 lb-ft of wtq tune only on 91 octane. Just absolutely monster gains. Just google: http://lmgtfy.com/?q=gintani+991.2+tune
991.2 tuning is taking that next big step right now. Turbo upgrades are being tuned as we speak!
Thanks sticky for your peanut gallery comments. I posted my real world experience and qualified it. Your information is something you read online somewhere. Your comment is LESS useful.
I’m glad people are pushing these limits. Same comments apply that I made to the 3.8 supercharged thread... same I’d make for a turbo upgrade on the 3.0 thread. Not for me but I enjoy hearing about what others are capable of. I just don’t have the stomach to push the limits outside of warranty anymore.... and I’ve done just that on many cars in the past.
OP, do lots of research and personally talk to a couple people that have had it done first is my advice... which you may not find useful and that is okay too.
You keep calling everyone who disagrees with you some other username and just continue to push people off this forum.
You have literally zero experience with 991.2 tuning so why are you talking? I pointed the OP to 991.2 tuning results. That is what he is asking about. He isn't asking for you to justify your 991.1 purchase in yet another 991.2 thread.
If you don't have the stomach to tune or experience with the paltform then let the people who do talk. Kthxbye
you have a lot of anger for someone with less than a month in on the forum.... and parot the same BS verbatim that you did as sticky and the other screen names that got banned post getting banned as sticky...getting banned multiple times under different names is a lot different than “pushing people off the forum.”
anyone considering voiding the warranty on a 6 figure car should have a mild amount of healthy skepticism IMO when considering something like this. Not sure why you are so adverse to someone pointing to doing research and not take face value blind claims made over the internet with no history on longevity with this platform.
In S plus, the up shift from 2nd to 3rd drops back to ~5300rpm and likewise from 3rd to 4th. Thus, from a performance perspective you've gained about 50 ft lbs at the top end ~ roughly in line with the .2 S.
Giac tune is awesome, makes the base car just as fast, if not faster, than a GTS
.
Not based on those curves your peak is at about 6500rpm and you are down about 22 ft lbs at peak HP (roughly) and the HP gap is maintained through to the redline. Looks very close to the S to me with the exception of a little extra around 3000rpm.
The GTS traps @ 125mph and the S 11.3s to 11.4s @ 123mph and has a nice linear power "curve" e.g. not lumpy. You'll have to purchase those GTS turbos Suncoast have them on special.
Base C4 with a Giac tune and Fabspeed bypass pipes.
11.3@118
Can probably go faster with better tires and track conditions.
Giac tune is awesome, makes the base car just as fast, if not faster, than a GTS
How is the drivability and refinement?
Is the throttle response just as smooth?
Does it pull all the way to the redline?
Does it accept full throttle at 1500 rpm without coughing?
Do you feel any difference in turbo lag?
Carrera S 11.5s @ 120.5mph - Motortrend, California, WGDR 6.
Both dynos show a peak HP gain of around 50HP from the base - thus the stock base with tune has the approximate performance of the S.
Also the base does not make 347RWHP or 364RWHP (1st dyno and 2nd dyno plots), its more like 300-310RWHP.
The delta in both, at peak is ~50HP. (Moreover, look at the shape of the curves - after tune the power delivery looks lumpy - something Porsche took great effort to get away from).
The drag strip slip shows 11.38 @ 118.27mph.
I can only conclude based on the material you have presented that you have a real gain of around 50HP and that the power delivery is no longer linear. The tunes have delivered the performance of the S but at the cost of linearity.
If you want GTS performance and linearity you have to add GTS turbos.
The only argument here is on the method of measuring the cars outputs both stock and when tuned. Why waste time arguing points that really can't really be proven without a real world test? Line up a tuned base and a tuned S roll them.
I do agree that the linear power band seen with these cars currently will be somewhat lost when tuned to extract more out of the turbo's capacity. Realistically, IMO, its not that big of a tradeoff as they will just pull harder at the higher rpms. The 991.2 is a turbo motor, its not terrible in my mind that it behaves like one. Especially if you're tuning it do exactly that.
You can really feel that there's more power in the motor when you spin them up. They should just keep pulling but they definitely have a power plateau as they climb in rpms that feels "artificial" to me knowing that they car is FI. Don't get me wrong, the power band is nice and linear, offering excellent acceleration, but theres more there to be had!
(1) . Put two identical cars, with identical engines, with identical redlines and identical tires on the same dyno but one has a different state of tune by 50HP and you will find the losses are the same. Thus in this instance because the losses cancel out in near identical amounts the difference at the wheel and the fly wheel will be near identical e.g 50HP
(2) The stock 991.2 does not make a true 364HP at the wheels (given it makes only 370 at the crank) thus your tuned car does not make a true 419HP at the wheels (see dyno plot 2). The delta between the plots on the same dyno is ~ 50HP, given this was run on the same dyno at around the same time the delta of 50HP is likely real.
(3) . Given the base makes 370HP at the crank and given point (1) and (2) above - the tuned car is making the equivalent of 370HP + 50HP = 420HP
(4) . 420HP is what the 991.2 S makes at the crank
(5) Ergo the tuned car will have the peak performance of the S.
(6) There is no reason to believe that Porsche understate their engines (in fact they are renowed for having very tight tolerances in this regard) and where tested on dynos that show towing/run down losses it has been repeatedly demonstrated the cars deliver what Porsche quote in their documentation.
11-27-2017, 05:22 PM
GIAC tune for 991.2 Base Carrera
