jmartpr

Sounds right....my car with a valve-less exhaust still exhibit this cold start behavior.....and as noted neighbors "love" it when I get up early for a Sunday drive! Personally is like music to my ears....

d00d

My S8 uses a (failing) secondary air injection pump the size of a pumpkin for Catalyst warmup, thankfully Porsche does it this way to save weight.

Accel Junky

This is within spitting distance of 450 crank hp assuming 15% loss. With 3000lbs, this would be real-world 991 GT3 RS power-to-weight territory.

Jamie@dundonmotorsports

When performance is the goal, then there is some room to go after especially if designed correctly!

Porsche has a number of factors to consider in the engine mapping including emissions, mileage, noise regulations etc...

Jamie@dundonmotorsports

We're at 14% loss on our dyno, so 435hp... By the time all is said and done, I think some GT3RS owners will be giving point by's...

krell

Jamie was kind enough to spend almost an hour talking to me yesterday about the forthcoming BBS wheels, and headers and tune. I came away more than impressed and confident Dundon knows what they're doing and, will provide an OUTSTANDING solution to those wanting more power. I'm pretty excited to see the final package.

Jamie, many thanks again for your time and your assistance to the community.

Jamie@dundonmotorsports

It was my pleasure, excited to help you get your GT4 setup for Road America!!

Buteo

I'm in for catted headers/full exhaust integrated system as soon as it's available.

Jamie@dundonmotorsports

Took the GT4 out for a little road test and it sounds so good! Quiet when off the throttle and angry when you're on it. Sinister off throttle overrun crackle and gobs of torque even for the tall GT4 gears!

Will get videos tomorrow on track!

Alan C.

Looking forward to hearing and seeing the results.

jslee225

Thanks for supporting the gt4 community. Quick question for those of us that live in places that reach 100+ degrees (ie texas) and only track the gt4. How will the gt4 react with the protune in these types of conditions? I ask bc recently a few members on the board had Cobb protunes at COTA and had to go back to stock settings for the car to operate properly without "limp mode". This is the only thing that is holding me back from tuning my car. Can you guarantee no such issues with running up to 4hrs/100+ heat "***** to the wall" track time at a demanding track in a single day, bc I would jump on this if so? I know from personal experience the GT4 can handle these conditions in stock form even with aftermarket headers. Sorry if this has already been addressed in the thread. Thanks

Jamie@dundonmotorsports

We're testing tomorrow and working with Cobb to open up a few more maps to ensure it's happy. Can you share what the mods were and what tune they were using? Most time limp mode is multiple misfires or the like.

We haven't had issues with pulling timing with our tune and headers and it will 90 here tomorrow, so we're headed to the track to see what happens! Gotta test everything!

Jamie

jslee225

I believe 1 car was stock and the other had exhaust/headers/ipd/TB.

I'll let them decide to chime in if they want to with further details.

d00d

A tune issue was discussed recently in this thread;
https://rennlist.com/forums/gt4/8822...potential.html

Jamie@dundonmotorsports

97 degrees at the track yesterday and the car performed flawlessly! No CEL with the tune and headers on the car. 1:40minutes of track time at 137 degree track temps.

We do have some fueling to correct and Cobb is opening the map in the GT4 to do that. Just means the car is making more power on the road than on the dyno which is good news!

Still working on the track videos, for now here's a preview...