I decided to throw my car on the dyno because A: I wanted to maximize my setup on the dyno and B: I was curious what my car was making in order to run a 5.9 60-130. I guessed around 630 whp based on what other 997TTs have made on this dyno and what their 60-130 times were showing. I also wanted to correct a few drivability issues I've had since swapping over to the ID1k injectors about a year ago. Dzenno and Mitch @ Cobb have been exemplary to work with, but a good buddy of mine Rob Harper of robtuned.com who happens to do all of the high end GTR tuning for Topspeed (a local tuning shop and GTR mecca), as well as multiple other well known GT-R shops, recently bought another good friend's 997 with Proto 63.5mm turbos and ID1300s. Rob is responsible for all the tuning on this car as well, and on E85 it makes 700 whp and 680 wtq (torque is intentionally limited, roughly 19 psi climbing to 24 by redline). He's spent over 20 hours in drivability calibration on this car since making it his, and I was hoping that his effort in this area would translate over to my car. In addition, I've driven this car and it is a damn BULLET...it makes my car feel slow.

Before starting the new tuning, I swapped in a new Bosch 3 bar MAP sensor, so I could actually see what peak boost was. We started street tuning with an E85 base map that had all of his drivability changes as well as appropriately scaled for the 3 bar map sensor. Immediately I noticed a huge improvement in the drivability. There was always a subtle hesitation when going from idle or decel fuel cut back into load. This is totally resolved. Lean backfires into the intake while warm was also history. Finally, it was faster and smoother. We made a couple more small revisions, and then decided to call it it a day and throw it on the dyno the next morning.

To get a baseline, and to see what it actually takes to push a 997 coupe to a 5.9, we loaded the old map in. As you can see, the car is well tuned and puts down great numbers with very smooth curves. This map is not pushing the car at all on E85. Timing and boost are very conservative and torque is well within the limitations of the rods. The power plateau is very, very broad as well with excellent area under the curve and confirms my butt dyno that power did not fall off any significant amount as redline approached.



Next we loaded up Rob's new street tuned map, and made a few more pulls making small changes to both timing and boost. Fueling was cleaned up a touch as well. As you can see, the car was picking up great power while keeping things safe (peak of 23 psi or so). I wanted to limit torque to around 680 wtq or so, but even with another 3-4 deg pulled out in peak torque regions versus the map I was running earlier, the car continued to make nearly 700 wtq...oh well Final numbers as you can see are 656 whp / 693 wtq! It actually made over 660 whp, but the additional boost pressure wasn't worth the power, so we backed it back down.



One more small change was made, and then this happened. The car became very laggy, and power fell off hard there-after. This was literally one pull after everything looked so beautiful. Other than the power, the car ran and idled completely normal. No noises or smoke. We tried flashing back to older maps and a lot of other tricks....nothing changed



The car felt gutless until it finally spooled up, then it hit hard and fell right back down again. WTH. We thought about boost leaks, smoke tested fine. Thought about cat failure at these flow rates, pulled the exhaust and it was fine. The whole time in the back of my mind I was wondering if the dreaded Variocam collar slip had reared it's ugly head. The car had no CEL and idled fine, zero misfires either. We didn't think to log cam deviation during the pulls, but decided to hook up the durametric for potential codes anyway. There it was, bank 2 intake cam deviation, but no CEL yet.
This is looking like it is going to be roughly a $5k fix. You no longer have to buy new intake cams (at $2k a pop!) as Topspeed (and I'm sure others) have a machine shop that can correct and pin your spun cam shafts, which brings the price from $8-10k down to about half.

The warning is that this appears to be an up and coming "common failure" as the 07s (most prone to this) continue to end up in the mileage range where this occurs most commonly (35-50k). Cars making a lot of torque are also prone to it. TopSpeed as well as multiple other regional shops have seen an uptick in the number of stock and modified cars coming in with this issue.

Anyway, you pay to play, and that's fine. I'm looking forward to getting the car back soon and setting some new 60-130 records

Oh, and one final pic of the 997 with my new toy and my brother's TA viper.

 

Nice numbers.

Variocam problem is not uncommon. I am swapping in some Schrick cams, would roughly be same price to pull and pin my cam. I had a laggy cam as well, rears it's ugly head on the proefi moreso than factory DME.

 

Yep, not uncommon but apparently becoming a much bigger deal than many people think (myself included).

 

You can see here where my cam lags

It happens every once in awhile, but the ECU triggers a cut while it catches, so it can get annoying.

 

Rob is the man!!! The tune is always about the tuner.

 

Your GT3 is just beautiful. I wish the turbo could be ordered to look exactly like that but with the turbo and turbo parts. Oh well, dare to dream. FrankenPorsche is probably not going to happen, lol.

 

Yes he is! This hardware issue is completely unrelated to the tune.

Thank you, and I agree. That is called a GT2, btw

 

Parts failure is part of playing with cars and pushing the envelope. At least it didn't happen to me on a stock car, that would be the most irritating of all

I feel I'm in excellent hands with the car at TopSpeed.

 

Great write up. Sucks that everything was going so well and this happened. I agree you are in some good hands. Can't wait to see how you do once everything is buttoned up. Good luck

 

Sorry to hear about this unfortunate repair.


Your car is making some serious power, all on stock snails!


To do 5.9 with your set up is beyond impressive, let alone better!


I am staying tuned to this channel!

 

07's dont have map sensors from the factory? Never knew that. Where did u end up installing it?

 

No, they do. That's what that sensor is that's in the Y pipe just before the throttle body. It's a 2.5 bar absolute sensor though, so it saturates at 22.5 psi. Just slightly lower than the maximum my car runs.

 

these numbers are insane for stock turbos. good job on the tuning. sorry about the cam situation, sucks u didnt get to enjoy the new files on the street. throw some upgraded cams in it and see what you can do stock turbos with cams... since you gonna be paying for labor anyway.

 

Thanks man! You were actually going to be who I was going to reach out to next if we didn't figure out the problem. I'm bummed I couldn't get it on the street after the new calibration, but that's ok. It'll make it that much better once I get it back. After the cams are pinned, every semi-common problem on a 997.1 turbo will be repaired or preemptively fixed on this car. I guess I'm keeping it forever

 

Sorry about the hardware issue (had one myself recently).


Insane numbers...just goes to show that e85 is amazing stuff. Going to experiment with it soon on the 3.8 DI.