I’ve been hunting for a GT Silver / Bordeaux red 991.2 TTS coupe for a while. I finally found one through online consignment that is optioned EXACTLY as I would have from the factory. It also has all the modifications that I would have dreamed of doing but likely never would have been able to rationalize. It’s like the exact car I would have bought and built in a parallel universe, Lol. I’ve had a few Porsches in the past and have been itching to get back in to one for a while. I’m really looking forward to this one.

I’m not going to receive it for at least a week yet so I’m trying to do all the research I can in the mean time. I typically run FBO and tune on all my cars but this will be my first modified to this extent. I’d appreciate any insight and advice from others with 991.x Turbo S modified to this extent.

This build is probably overkill for my needs so I’m also curious about reliability at this level. I realize there is some inherent risk here. Modified cars are generally more reliable if you overbuild then turn down so I’m not above de-tuning this if needed. The car reportedly makes “a little below 900whp” but I’m not sure what map and how many maps there are and what the torque curve looks like. Does anyone know at what point the 991.2 PDK clutches start slipping at? I’ve heard they are stronger than 991.1 but not sure by how much. I have a friend with a 991.1 AIM 850R that has been rock solid but he has the Dodson clutches. I realize that Boost logic is not as big of a name in the Porsche world as AIM, but I’ve seen a lot of stellar Boost Logic builds in the GT-R world I come from (prior to my NC1 NSX) so I’m hoping their attention to detail carries over here. I’m eager to learn all I can about this car and the best way to maintain it for longevity. I’m going to chat with last owner later tonight and try and get more detailed information.

Pics and initial details below.

Highlights:

• Boost Logic 911 Turbo Widowmaker BL991 1100 Package
• G25-660 Turbos
• AMS Alpha Performance Intercooler System
• Boost Logic 4” intakes
• Boost Logic 991 Y-Pipe
• Tial Blow Off Valves
• 991 Turbo S Plenum
• Boost Logic Formula Series Titanium Exhaust
• Cobb Accessport with PDK Flashing
• HKS EVC 6 Boost Controller
• Water Methanol Injection Kit
• Custom Dyno Tuning
• H&R Lowering Springs and Alignment
• Signature Forged SV104 Center lock wheels wrapped in Michelin Pilot Sport Cup 2's

 

Funny, I was checking that one out a month or so ago.
As long as it is done right that power level should be ok.
It's really mostly in the tune and Boost Logic does build some nice cars.

 

Yes, easiest way to break a high HP car these days is with a keyboard. I feel somewhat better that it was tuned in person on a dyno and this build has a couple years and few thousand miles on it.

Why did you end up passing on this one if you don’t mind sharing?

 

At just below 900 wheel hp, you are probably at the limit for PDK. All depends on the torque curve and delivery.
Too early and too aggressive, especially with those Garretts, the PDK not gonna last long on stock clutches.
Don't think there is any difference in pdk between the 991.1 & 991.2

Also, this kit on the car is not an overbuild. Pretty sure the 1100 stands for crank hp, ie 900 wheel hp.
It build to the max of the stock engine and stock clutches. So regular oil changes and regular PDK service is definitely needed.

Weak point for this build would probably be the stock plastic intake manifold.

 

Super nice build, Has anything been done to the fuel system or is that 1100 hp achieved with the stock fuel system and the meth?

 

I had read elsewhere 991.2 TT S clutches hold more power but can’t find the thread now. Not sure if this information was accurate.

Yes, 1100 is crank potential which jives with the dyno from this stock motor upgraded clutch car here using the same kit:
https://www.6speedonline.com/forums/...ock-motor.html

I’m going to see if owner has a dyno for this car but I expect it was turned down to somewhere between 850-900whp. It could always be turned down further once I understand best limits for stock clutch. It’s the torque curve that kills the clutches really so I’m going to try and get a hold of a dyno chart from the owner. Also, once I have the car, I can datalog with the Cobb and review everything for safety.

 

Thank you. I think this car is tuned closer to 1000 crank HP but turbo kit supports more. Other than the methanol injection system, invoice above shows 6 fuel injectors but I didn’t’ think these were replaceable on 991s… didn’t see any mention of pumps or supplemental injection so I’m going to assume it’s leaning on meth. I’m going to be in touch with prior owner later tonight so I can ask him more about this then.

 

Just not the right time and I think I'm going in another direction with the next one.
Yours is a nice car, I know what they were asking when I saw it online and it was a fair price at that point.
Has the interior and exterior features I was looking for so it crossed my mind.

 

I think I saw something similar but can't remember where.
Figure stock rods are good for up to or around 700 wheel torque or so, but this is based on the comments of those much more knowledgable, the guys that actually build these cars and past threads I have read over time.
From what I understand, most of the stock rod cars are kept below 700wtq or so.
Still a very quick car.

 

Probably race gas/meth and flywheel estimate.
Those turbos will make the power.

 

definitely at the flywheel, probably 900 on kill at the tires.

 

I spoke with owner who built the car last night and got a little more info.

Boost logic initially tuned the car on the dyno to around 800 whp peak on 93 + m1 meth at 25 psi. Dyno was a RWD dyno and showed around 750 toque which is a bit higher than ideal.


He was told 750 torque in RWD dyno is a lot different than AWD on the street but owner was still concerned so he had Boost Logic street tune the car in conjunction with Kuwait tuner Faisal Dashti of Xtreme performance to limit the torque.

Faisal reportedly set the car up to run at two peak boost levels (25 and 28-29psi) via changing correction offset on boost controller (base:10 vs base:30).. Both use the same tune and both use 93 plus meth, no race gas. (Is no race gas normal at high boost?) At low boost, max torque setting at the clutch is limited to 650 lb ft. At high boost it’s limited to 750 lb ft and estimated HP is 900 whp +/-. At high setting, the car ran a 60-130 in 4.9 seconds in Texas 100 degree heat.

There are not any dynos after street tuning but logs were reviewed by Faisal. Faisal told him only run the high boost if temp outside is above 55F, otherwise keep it on low boost to be safe when weather is cool. Car will be on low boost when I receive it and it’s been near 100 degrees this summer in NC.

There is an AWD dyno near me in NC so I’m thinking it may be a good idea to dyno the car on booth boost settings to get a better look at the torque curve. Maybe run it on intermediate boost level as well to find configuration with just under 700 lb ft. I may even be able to book some time in conjunction with a tuner to review everything and adjust as needed to be sure it’s all safe.

Any advice or recommendations others may have is welcomed as well. I’m in uncharted territory here. Thanks.

 

Does your current tune also have a PDK tune to help with clutch life?
You will lose some HP/Torque at these NC temps simply due to heat soak. Even with meth. Cooler nights and humidity/rain will still result in a lot of Wheel spin though. I don't have bigger turbos or meth YET but I feel the loss even in my Stage 3 during hot summer days.
What part of NC?

 

700-750lbft is about the limit of most factory rods in these high end cars - somewhat anecdotal as I've seen ttrs and r35s survive more but its very much advised against by people who would warranty the work done right. If you go for rods then it usually turns into a "since were splitting the case..." logic and you find yourself in some 4L mountain towing thing in no time with a 2nd mortgage and the ability to run down the Flash .

Unless you live at a track, more than 900awhp tends to need bottom end work, fuel adjustment re e85/meth, and timing pulls enough to earn the car a seat on the short bus - power levels often not fully usable on the street with maintenance and operational considerations significantly more onerous than normal cars. Its also a bloody 911 - not the best candidate for learning the ins and outs of daily-ing builds IMO. NC is pretty populous and as I recall quite ticket-happy; your setup strikes me as well balanced between being faster than most things one can buy and supportable without a serious history owning built things while still passing for maybe stock/street legal in places that care about noise and emissions. Most people in a position to own these aren't street racing off stop lights for a few thousand bucks every night (clutches and braces if they are so inclined...) so on-street its more or less "pass 3 cars where normally its just 2" sort of advantage along with the ability to confuse sports bike riders (even more than they had to be to get on it :-p).

Congratulations, that is a gorgeous setup and should be gobs of fun. If the temperature thresholds thing are a bother (I've frozen my posterior a couple of times in the woods around lejeune), they can be addressed automatically through software (boost limits on temp, fuel, etc thresholds along w timing safety nets) but that may require a standalone which tend to upset OBD scanners at inspection stations (not end of days but a pita to play "match the pigtail"). Curious how the electronics are doing in there - I've seen a significant increase in owner complaints about digital components after the 991.2 refresh and wondering how all of yours are doing with the polite but nontrivial changes.

 

Yes, there is PDK tune as well and reportedly never any slippage observed.

I’m in Chapel hill in the Chatham county part so no emissions / OBD II testing. Just annual safety checks to make sure tires, wipers lights horn etc are good.