jmartpr

I just met a GT4 owner with the Fabspeed GT450 package (sport headers) and he has been trouble/CEL free for the past 2 months. His GT4 is a daily use car but no track time so far......

COBB Tuning

Hope everyone had an excellent Holiday weekend and I'll be happy to "chime in" regarding the recent issues Shake and Bailey had with their cars going into limp mode at COTA. The OTS maps are optimized for street use and though we've had plenty of track miles racked up with them, we believe the combination of extremely high ambient temperatures, the overall punishing ground that COTA is, and the 93 map, pushed the cars past their limitations. Obviously this wasn't optimal and we weren't able to reach either of the effected cars in time to have datalogs taken to 100% confirm suspicions as to the official cause of the limp modes. However, since both cars ran fine when returned to the stock tune then logic obviously points to the aggressiveness of the tuning.

With that said, we do our absolute best to be available to everyone, even on weekends, and especially in emergency situations where the car is shutting down, to try and resolve situations such as these. Part of what makes COBB an industry leader is our customer service and we strive to live up to that reputation all of the time. We've posted our personal emails, I've made posts of where to find me at COTA when I'm personally attending an event, etc. PLEASE reach out to us IMMEDIATELY should an issue like this occur, or even if there's no issue at all but you just want us to look at some logs to confirm everyone still looks good. Between Jon, Mitch, Joe, or myself, we almost always have someone available to respond to emails rapidly during non business hours. Unfortunately, forum posts after the fact mean we're unable to collect valuable data, confirm a failure, or offer a fix. Even a Facebook post or PM will more than likely be responded to and passed on to us in a timely manner.

One of the most powerful features of the Accessport is it's ability to datalog. With logs, we're able to review, adjust, confirm, etc. and it removes the guess work of wondering what is going on with the car. There shouldn't be a widespread fear of running a non factory tune on the track, as there are hundreds, if not thousands, of other cars tracked every year with COBB OTS and ProTunes on them. We do offer the 91, 93, and 100 Octane OTS maps and depending upon the temperature and the track, you may never have an issue with any of them. What we do suggest once ambient temperatures reach ~90 degrees and above is to DOWNGRADE your map one octane level to increase the safety margin and if in an extremely hot climate, also add a few gallons of 100+ unleaded race fuel or an effective octane booster to raise your relative in-tank octane level a few points. Every little bit helps and as Bailey pointed out, a couple of gallons mixed in to a regular tank will help. If you only have 91 pump available at your location, then plan to use the race fuel/octane booster technique.

For example, if you're going to be running COTA in September for the Chin event Labor Day weekend, we can presume temps will be fairly close to what they were for the June events. Change your map to the Stage 1 (or 2 if you have headers) 91 map with a quick 5 minute map reflash using the Accessport. Then let's use this calculator real quick:

http://www.bazellracefuels.com/Calcs/OC1.htm

If you're trying to get lets say 95ish Oct in the tank and you're using 93 pump, run the tank almost empty and fill with 10 gallons of 93. Then you should be able to get ~5 gallons of 100 Octane in the car and you'll be sitting somewhere in the 95-96 Oct range in the car. From there on, just keep a few 5 gallon jugs of 100 Octane available at the track and as you refill with 93 pump maintain your ratio to keep the in-tank octane roughly around the 95/96 mark. Is this extra work? Absolutely. Is it 100% necessary for every car? More than likely not. Most will probably be just fine with switching to the 91 map without needing the additional buffer room of the higher octane in tank. However, we strongly suggest everyone take a few logs of your sessions and email them to us so we can take a look and see how your particular car is doing. Each car/motor is different and though we do our absolute best to make sure an OTS map will work for everyone, all the time, under every possible scenario, there are going to be some limitations and that's where having data available is critical to fine tuning the calibrations.

And for reference again- here are the emails to contact us at:

porsche.experts@cobbtuning.com
mitch.mckee@cobbtuning.com
jon.hebbeln@cobbtuning.com
joe.graham@cobbtuning.com
jared.bronson@cobbtuning.com

We're here to help in any way we can and we're Porsche enthusiasts, just like all of you. With those emails you're talking directly to the engineers who wrote the code to communicate with your ECU, who performed the table discovery to control things like global timing, cam timing, injector duty cycle, who spend hours on dynos, and at tracks, in cars, adjusting calibrations. They're the same guys who are sitting in cars with laptops at the IMSA events and they're the same guys who will bend over backwards to make sure your car is running optimally. Please reach out to us with any questions or concerns!

Thanks!

~Jared

myBailey07

Thanks for "chiming" in. Great info. I have some more questions, but will pm them as we have hijacked John's thread enough for now...

COBB Tuning

Indeed! Good thing John likes Mitch- otherwise we'd be getting a bill for taking up his thread

~Jared

John@Fabspeed

I have no input on OTS maps, but we are having ZERO issues with the IPD Plenum/TB when coupled with a custom map from our in house protuner Steve. This includes several track-prepped GT4's running on Sebring in Florida.

BGB Motorsports

Today we wrapped up the tuning for the Stage II package and it's at a point where I am 100% happy with the drivability. Prior to this we had shown that the Stage II package can make over 410 rwhp on a Dynojet with a stock PSE muffler system, no ECU flash and about 1/3 of a tank of 98 octane mixed with mediocre 92 on a car with X51 heads, cams, manifold a lightweight flywheel and aftermarket air filters. That's what puts you guys on the edge of your chair but the release of it was hung up by the fact that i didn't think the drivability was perfect enough for any of you to sit comfortably in said chair. That was then...this is now.

I really want to say thank you to the entire Cobb staff, especially Mitch. While I have only sold a few APs and while i can't imagine i represent a ton of demand for them, those guys have bent over backwards to help me and our shop and even revised their actual software to do what my oddball needs require. We have been lucky enough to keep going as a retail shop building crazy cars for customers and i have needed this level of control for a long time. That control in now some of our customer race cars whose rules packages allow for mods and firmwares need revising; it is in a bunch of GT4s because we need control to keep customers happy that have extraordinary car configurations and have purchased aftermarket items. Having said all of this, I know how tight the Rennlist community is and we all are aware of a few cars that have had issues and i'm actively trying to help them so that Cobb can continue to deliver great customer service, despite the fact that theyre not even my customers.

While more power is awesome and now at my finger tips, what matters to me most is that i'm excited to drive the thing home tonight because it behaves once again like a totally stock car. It wasn't even far off and was probably perfect enough for most to leave alone but my OCD/ADD get the best of me at times as i try and perfect some impossible stuff.

I hope to have the 4.0 done just in time for another important 40 anniversary at the end of the month and since all of that R&D was done this winter, it should be rather smooth sailing. I just didn't want to go to Stage III officially until Stage II was adequate IMO. Thanks for the support here on the forum and most importantly, thanks to the folks at Cobb.

P.S. I just realized this thread is 1 year old today!

COBB Tuning

We appreciate the kind words John!

Also, if anyone is having issues with any maps, has questions on maps or logs or just wants to talk about stuff please feel free to reach out to me. I don't get on forums nearly as much as I like but I am always on email. I am happy to give out my cell phone as well.

We really strive to go to whatever end it takes to make sure that we have the best product on the market and any type of issue we generally try and handle ASAP.

With that being said please feel free to reach out to me if anyone has questions on anything. I am always available.

Thanks,

Mitch Mckee

mitch.mckee@cobbtuning.com

DuckieRS

Since it got mentioned in this thread: https://rennlist.com/forums/gt4/8959...l#post13463340 I'd like to add the video:

CAlexio

An interesting note in the YouTube video description "this vehicle got a short 8:36 gearbox ratio"... Who sells this?

jmartpr

I finally got around to do a custom COBB ProTune on my car with CG Sport headers and CG Cup Muffler exhaust. Car was running great and I wasn't expecting a lot of gains, but boy was I in for a surprise.


For some reason my car was VERY lean across the board. The tuner was a bit confused on this but he ended up fixing the fuel, timing and cam maps. After 3 hours trying stuff we made a pretty decent gain across the whole rev range. They have a theory that PAG did several version of the ECU with different tuning....mine is an earlier car so who know??? Also, my car had some bad gas problem some time ago and maybe this got stuck on the ECU after adjusting...but that was a long time ago.


Anyway, car does feel a lot stronger from the lower RPM range all the way to the top....you do feel the difference but this huge change in power could be that my car ECUs was not optimize for some reason so don't expect to make the same gains but if you do make at least half it's still a good mod. Can't wait to get the IPD + TB with filters on the car!


BTW...this is a Mustang dyno so numbers are lower than other dynos....

user1029

awesome gains

Accel Junky

Is that headers/exhaust no tune vs. with tune? Or stock vs. headers/exhaust/tune?

jmartpr

That's Header/exhaust vs header/exhaust/tune.....

Jimmy-D

Wow - tune accomplishes quite a bit.

I am still waiting for the Plenum and then will add tune to my headers and exhaust. The Tuner in Germany recommends I wait until I have all the hardware on before tuning. So far with just headers and exhaust there is a noticeable difference. Certainly liking the valveless exhaust though - no need for valves on this car

okie981

The more I drive the BS and GT4 with PSE, the way the valves operate on these cars, the more silly I think the whole valve concept is. It doesn't make the exhaust that much quieter in normal mode, because in normal mode when you have your foot in it above 3,500 RPM, the valves are open anyway. If the valves stayed closed all the time in normal mode, and open all the time in sport mode, then PSE with controllable valves would make more sense to me.