Landshark92

So I guess the basic long block is identical. Are the exhaust manifolds/headers on the 981 worse than the 991's?

ledbette

From what I've read, changing the intake manifold makes negligible performance difference on the 981 3.4L. I think it's more the exhaust path issue.

txbdan

Cool, I just installed FVD Sport headers and have the base Cobb Stage 2 tune installed. I'm currently working with BGB on the Pro Tune. It feels awesome right now, I can't wait for more! haha

michaelscain

err ..Why did;nt you ask FVD for the ECU tune? they also provide a free additional Tune when add the FVD sports headers, which takes advantage of the new headers modification.

ekam

With the engine hanging at the back, it also gets better cooling.

txbdan

Two reasons. 1. I wanted BGB on the job. If its good enough for their race cars its good enough for me.

2. I like the fact that a Cobb ProTune is "closed loop". I log data for my car, they tune to my car, repeat. I can also log data afterwards for diagnostic purposes, etc. All the other tunes are "open loop" and assume your car is the same as the rest with no feedback mechanism to account for any variances.

Kernel Klink

I went for BGB as well, for these as well as their ability to allow for 100% opening of the TB.

txbdan

The other tuners can't do that?

Kernel Klink

Uncertain. I scoured both rennlist and planet-9 looking for the best option, and from what I found, John led the way with finding the solution. Given his race pedigree, I figured BGB as the best option to get the most out of my S without harm. I can say that with his base tune, it's a noticeable difference between it and the Cobb Stage two 93. I can't wait to see how the custom map plays out.

josbmw

Currently testing the FVD tune on my '16 Boxster GTS, PDK, PTV.

Drove the car for many years stock, and really enjoyed it.
I don't track my car, only public road use.

The car is already plenty fast for driving on public roads without tune if you rev it and keep it above 4.500 RPM.
I mostly drive it in Sport mode and PDK in manual. Even in auto the PDK keeps the car in a good rev range.
But the chassis could use some more power, especially in the mid range. Nice for quickly passing other cars without flooring it all the time.
And I'm intrigued by the fact the base 911 uses the same engine and has more power.

Read everything I could find about the different tunes and contacted Softronic, Ehresmann and FVD.
Ehresmann was the most informative and honest about his tune and has well documented dyno runs, but he is also the most expensive. He told me if you don't drive the car much over 4.500 RPM (which unfortunately is the reality in normal traffic over here), spending money on a tune is useless, and it's better to buy a car with another engine characteristic.

Anyway, I decided to go with the FVD tune due to their large Porsche background to see what difference it would make. They told me they could improve the mid power a little more.

To be honest: I really can't feel much difference on the street. Maybe a little more power in the top end, but I'm not really sure.
And I'm not talking about the low rev range here, but second and third gear above 4.500 RPM, which means highly illegal speeds on our public roads.
Luckily there are some small backroads with almost no traffic in my neighborhood to run some tests. Nothing really curved unfortunately . If you want nice roads where I live, that's at least a 2-3 hour drive.
The current Covid-19 situation in Europe makes it impossible anyway to go out for a day driving on nice roads in another country.

Car has no other engine mods. Recently installed the X73 rear swaybar, something I can really recommend to get sharper steering.
Don't want to go the road of 200 CEL headers plus tune. This would increase the exhaust sound about 25% with PSE enabled. I find the PSE already more than loud enough.
Exhaust sound regulations keep getting stricter over here, and I want to keep the exhaust sound stock, not louder.

Good to know: if you flash the car, a lot of error codes are stored in many other control units. All error codes are CAN-bus related.
The Genius flash tools only seems to clear the ECU errors.
Not an issue if you have a separate diagnostics tool (I use PoCOM, a really good and cheap tool). Just clear all the errors in the rest of the modules and you're good to go.

Went forth and back between the stock file and the tune.
Since I don't have a second stock GTS to do an immediate back to back comparison, I have to reflash the car to test (hook up external PSU, flash, clear error codes), and probably the ECU needs some time to re-adapt since the adaptations are reset after every flash. So it's not: jump in the car for an half our ride, 5 minute flash, retest and compare.
After the flash I really think the ECU needs some time to adapt. This makes it very difficult to immediately compare the tune with the stock file.

Did not do dyno runs, and don't intend to. I don't expect they will show great power and torque gains either.
I know the car is NA and tuning is much more difficult then a turbo engine, but I at least hoped to notice some improvement.
IMO when you want really more (noticeable) power and solve the torque dip around 3.500 RPM, you just have to throw a lot of money at it and make a lot more modifications to the engine.
Only a software tune is just not enough.
These kinds of mods is something I'm not prepared to do, since I want to keep the car as close to stock as possible.

A GTS 4.0 was on my list, but I don't think I will buy one. The OPF really muffles the flat six sound, and you can forget removing the OPF in Western Europe.
You really have to rev that engine to get a good sound. And due to the long gearing and the OPF, you're even driving at higher speeds then the 3.4.
Also the 3.4 dates from a period with much less stringent exhaust and sound level legislation.

I'm a real flat six fan, but I think I'll keep my eyes open for a 718 2.5 turbo GTS. I leave out the sound discussion, there are enough threads about the sound of the four pot.
In normal traffic, the turbo engine has much more boost in the lower RPM range used on public roads, and more the sensation of being a fast car. There of course are disadvantages to the turbo engine, but you can't have it all.

I already let a 718 2.5 GTS pass what was fully specked the way I wanted it. But I wasn't ready then to make the decision to let the flat six go for a four pot.
That's what you get when emotions and ratio start to play. Still love driving the 981, but the car has over 52.000 km's now, and I just want something different with another engine characteristic.
That's when the tune idea popped up by the way.

A 911 (991.2 or 992) is out of the question anyway. To impractical for me and especially too large on small roads. Plus I want a mid-engine car, not a car with the engine sitting behind the rear axle.
There just aren't many (no) other options in the market besides the 718 with the requirements I have (cabrio, mid engine, PDK, same price range, practical).
Before somebody mentions a Corvette C8: much more expensive in Europe then a 718 and the large engine is taxed heavily. The car is also much larger.

Feel free to comment with your own experiences with software tuning of your 3.4 engine.

Jos

Busta Rib

Well stated. I considered a software tune for my 981 GTS but decided against because the gains seem relatively negligible, unless you throw some serious money at the solution. If you want more noticeable power, consider getting a 718 S or GTS. Exhaust sound notwithstanding, these cars have more torque and can really scoot. You can really feel the diiference in the butt dyno too due to the turbo engine.

The sound of the 981 was more important than pure performance for me so I opted for a 981. Plus, 981 GTS power is still plenty for my purposes. But if you can live with the 4-cylinder sound, which isn't bad, just different IMO, get a 718. It's a fantastic car.

isthar

Thanks Jos for the time to write all that up! Great read, very sound arguments indeed. Good info.
I enjoyed the FVD on my base Boxster, but I do realize that tune *alone* once at a GTS probably won't be felt the same.

josbmw

Since I still had the chance to send the FVD tune back, I decided to have it dynoed on a SuperFlow four-wheel dyno to make sure I was not imagining things and before I made a decision (keep or return).
The company who did the runs on the dyno is specialized in building custom engines and tunes race cars, but always with their own ECU controllers. They don't do normal ECU chip tunes.

The car was warmed up with a 30 km drive on the road, setup on the dyno and al runs were done by the same person. The only thing what changed in between was the flash. While flashing, the car was connected to a dedicated power supply.
I always fuel the car with RON 98.
No other mods to the car, full stock. Only the ECU file was changed.

Diagram DATA9726 (black) is the original software, DATA9724 (red) was the first file I got from FVD and DATA9723 (blue) the second.
The first one (DATA9724) I got back in less then 15 minutes after sending my original file, the second (DATA9723) took some more time.

My car had the second flash (DATA9723) on board for the first run, then we flashed the first FVD file (DATA9724) and then back to stock (DATA9726).
Stock power of my car is already a healthy 344 HP and 372 Nm of torque (sorry guys, metric over here).

Decide for yourself.

As I already noticed when driving, the difference in the lower end below 4.700 RPM is minimal (and for me not noticeable). This is confirmed by the measurements.
The guy who did the runs and has a lot of experience with engine building, said his customers would not be happy with this result. Especially the torque curve is an issue with the dip around 3.800 RPM.
I hoped a tune of a specialized Porsche tuner would improve this, but that's not the case.

So I've send the MyGenius back to FVD and they paid me back immediately. Cudos for them.
Their comment was I was the first customer who wasn't satisfied with one of their tunes (which costs 1.422,05 EUR plus shipping over here including taxes, I got a 5% discount, so about USD 1.665).
If it had cost half of that price, I maybe had kept it. But this is just way to expensive compared to the improvements (and yes, I know it's an atmospheric engine).

Oh and by the way, after flashing the car, the exhaust sound changed. Most of the burbles and bangs were gone.
Even after flashing it back to stock, the exhaust sound isn't the same anymore. FVD says: different adaptions values need time to be adapted and maybe first after that is all OK.
Maybe, but the car doesn't sound the same anymore after a few hundred kilometers.
I just hope the exhaust sound gets back the way it was, but that currently is not the case.

And another thing: after you flash the car (tune or stock), all control units have errors, except the ECU. I have diagnostics software, so I cleared all the errors in the other CU's myself. They are all CAN related, which is logical.
Don't know if you took the car to a dealer for a warranty issue after flashing it back to stock what would happen.

I also asked FVD for more info what I should experience with the tune and the difference between the files they send me.
The answer I got was:
As you know we change various maps, multiplicators, factors, deltas values etc. but please understand that we don't practice writing details about and because of a lack of time I can't answer customer questions.

So my experience with FVD it not exactly the one I read on forums. But anyway, they paid me back without discussion and for me the case is closed.

Combined charts





Stock


Tune 1


Tune 2

michaelscain

here is my 2 cents...

A FVD tune will give you a claimed 352hp car in your 981 S or GTS.

You will find that the Cayman GTS has a power output of 340hp while a Boxster S has only 315hp.

Therefore there will be a lot bigger gains for a BS owner who would get a much more noticeable power increase to 352hp from the FVD tune.

If I had a Cayman GTS i would also not notice the 12 hp increase.

ledbette

I've not seen any tunes take this dip out of the torque curve. I've seen a few reduce it, but it seems to be an inherent characteristic of the engine.