NJ991

I had this post typed up and after I uploaded a picture from my phone it erased everything I typed. Annoying. Now you will get my condensed version. Lol
I had done my homework for a while about exhausts for the 991.1. I wanted an enhanced exhaust note and some power, of course. I knew that headers would be the route I take. I was confident that SOUL was going to be the one. I got a call from John Gaydos, from SOUL, and we had a lengthy conversation. Not so much about the headers, but gearhead stuff. John G. is a great guy and the rest of the staff at SOUL. The headers are a masterpiece and a one of a kind. The fitment and install was perfect. Anyways, John G, offered up to cover the costs to have my car on the dyno for pre/post install sessions. What an offer, right.
He puts me in touch with Apex MotorWerks in Clifton, NJ, who I highly recommend for work on our cars. John, the owner, is extremely knowledgeable and they work on Porsche’s extensively, and do lots of track prep work. We put the car on the dyno and run 4 sessions. Keep in mind, a Mustang dyno runs lower numbers than most. It was hot and humid today too. John said the 911 S will put down 320whp. Sure enough my car put down 321whp and 275ftlb. I was glad to see it put down healthy numbers, what it’s supposed to. Also, I did not get a tune done, which is highly recommended and will yield much more power. We let the car cool down, then the install went without a hitch. Like I mentioned previously, absolute perfect fitment. We get back on the dyno, and we run another 4 sessions. They were all about the same. Very consistent. I was pleasantly surprised. The peak numbers aren’t crazy, we put down 327whp and 281ftlb. Sure, that’s only 6whp and 6ftlb of TQ, but look at the dyno plot and look at the large gains at various spots. There was power made throughout the entire power band and I could feel it. I’m still surprised that I could feel the gains in a NA car, but it pulls harder throughout the entire power-band. Look at the TQ from 3-4.5k. Gains of 20-38ftlb at the wheels. HP is up around 10-15hp at the wheels. Then, from 4.7-5.5k TQ is up about 10-15ftlb and HP is up about 10HP. The car is making more power throughout the powerband, and it can be felt. John at Apex highly recommends tuning the car with headers. The peak HP and TQ numbers should be up around 20 more than stock, which are great gains. Me personally, I am extremely pleased with the results. Having gained that much power through out, even though not increasing peak HP and TQ that much, is one mod worth it. Can’t thank John G. at SOUL enough. This guy called me and talked to me about the headers, set this whole dyno session and install, and called me when I was home to follow up and see how I was liking it. The guy was there for the entire process. He didn’t have to be, but he truly wanted to make sure I was happy. Gotta love that type of customer service. Overall, couldn’t be happier all the way around. Great vendor and great install shop. Now, how long do I go before I got back to Apex for a tune lol!

Cyberbug

Thats great, what the dyno cost?
does apex tune?

NJ991

Thanks Cyberbug. I didn't ask how much the dyno costs, but Ill find out. Apex does tune. He does his own custom tune to however you like.

nstar8

Thanks for posting this up. Good to see some base runs prior to any mods, then the runs after the headers.
Questions:
1. Do you have the PSE?
2. Are these catless headers?
3. How much timing were you pulling? Peak and average

I just did similar with SOUL catless headers last weekend, and then dyno runs on Wed with tune. I wish I had done what you did, as I was only able to compare stock tunes, to Cobb Stage 1 tune, to my eventual custom tune...all with PSE and catless headers already installed. Yeah those SOUL headers are definitely a masterpiece, and fitment was perfect! Not to mention they have bronzed up really nicely and catch your eye from behind.
Nice post man.

NJ991

nstar8, yes I have PSE, and they are not catless, they are the sport headers with high flow cats. Not sure about timing, but that’s a good question. The shop installer pointed out some points in the dyno where the car would benefit from a tune. For me, I wanted to get a set much information as I could. So now I have my baseline, which we ran 4 or 5 times and the numbers were pretty much identical each time. Now having the headers numbers, will give me a good idea how much more the tune l(when I do get it) will actually get me. The tune will clean up and smooth out a lot of the jitter you see on the dyno. What did your dyno look like with everything installed ?

nstar8

We did about 10 runs and in pairs. The reason we did that was every first run of the car produced lower numbers than the consecutive run. The car seemed to like being warmer to produce more power. Never seen anything like that before. Maybe we were just in sweet spot temperature wise with the consecutive runs. The temp was about 71-75 degrees and nearly zero humidity here in the Denver area.
My final numbers were peak 367hp/305tq, but the vehicle just makes more power across the entire RPM range from about 4-7.8k. The car is tuned to produce more within that range vs. trying to get more lower rpm power. That is what I wanted. The curve did smooth a bit, but seemed to have the same overall "ripple shape" across the band, just more power, and slightly skewed to the right or upper end of the RPM band.
Check out my post below as I have posted the last dyno run and added a couple of zoomed in views of the dyno run to show the difference.
https://rennlist.com/forums/991/1146...-dyno-day.html
I'm very happy with the results as getting power from NA without opening the motor or forced induction is pretty tough here at altitude.

NJ991

Thanks for posting that up. I was reading your other post and you did great with the mods. For a NA engine, these cars make decent power. I think once I get the tune, my numbers should be close to what you have posted, but a little less. I think the catless pipes will yield more power than high flow cats. You’re right, it would’ve been good to get a baseline to compare the gains you got. But overall those are great gains. My baseline shows low because of the Mustang dyno, but that doesn’t matter, I just want to see the difference with mods. I think on most other dynos, our cars put down around 340whp. I’m trying to resist on getting the tune right away, I wanted to wait a bit. But it’s hard knowing that there is power to tap into. Lol

nstar8

I'm telling ya man...You must get the tune. The driveability is much much better IMO. To me in stock form, the accelerator seemed to have a sensation of giving alot of feedback in the form of pressure. Now that the tune is done, it seems to have lessened quite a bit and feels a little more free flowing. To be honest I haven't driven to red line since the dyno, but I have been above the 4K mark a few times and the car is very very smooth and pulls pretty good.
Also, I was a bit pressed for the tune as the catless headers throw a CEL, which I could reset with the Cobb, but wanted the correct timing A/F ratios, and wanted the car to run correctly.
To me, if you add the headers, a tune must be done to optimize the efficiency of the vehicles engine, with the side benefit of more power. For example my timing/fuel delivery was a bit out of whack before the tune. We actually richened the tune to achieve more power and got the timing into a more realistic area of operation.

spdracerut

My guess is the headers need some heat in them. On the 911, they are very exposed to ambient airflow. If the headers are cold, they suck the heat out of the exhaust flow which slows the flow down; I'm guessing that increases back pressure a bit. With the headers hot after the first pull, there's less heat transfer from the exhaust gas to the headers due to lower temperature difference. On most cars, the headers are nice and tucked into some engine bay and less exposed to airflow. Anyway, just a guess.

NJ991

You’re killing me, but you are right. Damn it lol

mikeearly

Very good to see you managed to get a before and after dyno run -- that is great and helps me have some idea of what happened to mine when I upgraded. (I had tried to get a before run but the business that tried to do the dyno did not know what they were doing and had strapped the front wheels -- by the time they figured out the problem I was out of time, both for that visit and prior to going up to Soul for the install.)

I took John's advice and went to Softronic for the tune --- John was pretty high on Scott at Softronic -- and after seeing Scott's background and expertise, it was a no-brainer for me. Love the tune and Scott is a great guy to talk to.....

NJ991

I called my dealer in NJ and they offer a GIAC tune. Spoke to the service manager, I leave the car when them and they tell GIAC what mods I have and send the tune over. The “dealer” will honor warranty and not give me a hassle. Good to know and the total with labor is around 2,000. The service manager was high on the SOUL headers, really likes their products. They wanted to schedule me, but I said I’ll let it sit for a bit and schedule in the future.

erko1905

Congrats - that's a sweet setup.

I had the catless version of those headers and John's tune on the C4S, the car was fantastic to drive. I could've given you a ride to show what a difference the tune makes if I still had it around. But I can tell you a custom tune on the dyno will for sure be better than a Softronic or GIAC off the shelf tune - having said that, it sounds like it might be more dealer friendly so there's definitely some value there.

You need to bring this car to the next NNJR PCA track event, come to either Mont Tremblant or Watkins Glen in July.

NJ991

John and George are a great group. They really know what they're doing. We actually briefly spoke about you, because I told him that I was late seeing your for sale post for the headers/tune, and would've jumped on that. But I had already ordered my set from SOUL. I really want a custom tune from John, but I spoke to my dealer about the GIAC, and it's a safe direction to take. I'm going to sit on it and wait a bit and decide later on.
Id love to go to one of the track events. I'm just getting into the whole track thing and learning to drive this car. Not sure I feel comfortable enough to track the car yet, but maybe go and watch one and learn, and meet some people there. I'll certainly try and get to one for sure.

Soul Performance

Thanks for the excellent review and feedback Eran! It was a pleasure working with you and we are quite thrilled at the results you saw on the dyno. We were sent the raw files and will be sure to post them up on our site and the appropriate threads such as this one so people can review the gains across the entire curve. It is also quite interesting where you can see the car either off or pulling timing, it wants to make more power but the software just isn't having it haha.

Regards,
John Gaydos