Kevin

Jeff, everything in the Motronic 7.XX series ECU is handled thru a torque model and torque request. The input from the throttle is constant from non Sport to Sport mode. The difference is the requested load that changes. The ECU will increase boost and timing to meet that demand of the requested load. And yes, the throttle is the input source. But when you look at the datalogs you will see that your pedal is at 100% WOT on both modes.

The power levels between each mode is changed, it has to or you wouldn't pay for the Sport mode. The PEAK numbers don't change however the power or duration of torque is increased during the "time" in the Sport mode. Power under the curve is increased in that "time" frame/duration.

Edit.. For those that are interested, I will email datalogs from my car and other 997TT customers to see what is monitored and what the ECU is doing.

4ocious

This is really an important and informative thread that should be read by anyone considering an ECU reflash. Many thanks to all!!! Based upon your posts and recommendations I've ruled out the plenum and will proceed with a Europipe exhaust, Softronic ECU reflash, and OEM plugs. That combo when combined with my Pilot Super Sports and updated Pioneer Nav shoud turn my TT into a very enjoyable car to drive.

BTW, I tracked my 500 hp 08 MB AMG Black Series at the Virginia International Raceway (VIR). And you're right, it really does come down to driver skill. I remember staying with a modified 800 hp twin turbo Audi R8. He pulled me on the straights but his 800 hp actually hurt his performance on the twisties where I easily handled him. It ultimately came down to driver experience and a properly set-up track car.

I'm also going to reflash my Cayenne GTS's ECU and will probably also go with a Fabspeed secondary cat bypass. Net result should be approximatley 20+/- bhp and tq accompanied by better throttle response. I don't want to go too wild as my GTS is a limited edition and I intend to occasionally show it.

aa909

That sounds like a great combination of options and I think you'll be happy.

However let me clarify the following, since you are going to do your plugs due to their age anyway, then consider the cooler plugs since they should last longer than the stock plugs with the new tune.

If your stock plugs were new or very recently changed then I wouldn't necessarily spend the money to change to cooler plugs right away

Just something to consider
Art

eurotom

Yup a boxster last weekend at Laguna laid down a 1:41 lap, almost 7-10 seconds fast than cars with +200hp.

eurotom

+1

phillipj

Have the cooler Denso's that Todd recommended in mine. It runs beautifully..

TWTURBO

Some people keep there cars stock till the day they sell it ,but some of us just can't leave them alone ,i think the latter hang out here & on other boards as long as your happy with it thats all that matters ,myself i get used to the extra 50 hp & new wheels & want another 50 hp & new wheels

lic265

Reading with interest; as i am considering the same mods as 4ocious.
Question: Does all this extra HP cause significant wear and tear on other parts of the car? ie; are there other expenses to expect down the line( sans tires)?
Thanks

Silver997TT

I think the clutch is the first thing to replace after tuned power.

lic265

Makes sense- do folks upgrade the clutch or just wait until it needs replacing?
What does that cost?

eurotom

With a tune and exhaust your approaching the limits of the OEM clutch. Depending on the condition of your clutch you may or may not see slippage. Several guys are still running OEM clutches w/o issues. When the clutch does slip or go most will upgrade to a Sachs 2.5 kit. This runs anywhere from 1600-2500 depending on whether or not you want a new flywheel, labor not included.

aa909

btw here is the dyno chart that Vivid uses to market the softronic tune



From my calculations I get:
Base case assumption: Stock ECU (480 hp) + Free Flowing Exhaust (+20hp) = 500 hp at the crank
Dyno shows max 425 hp. Adjustment ratio for dyno loss: 500/425 = 1.176

Dyno for Softronic Tune + Exhaust produces max 491 hp: apply the dyno loss ratio calculated above (491 hp X 1.176) = 577 hp at the crank

570 hp is much more in line with what others expect to see with a tune + exhaust. As Phillip has pointed out his tuner has said ~550 hp is realistic to expect

so...

how does Vivid get to 615 hp? why would the stock set up have a 15% dyno loss but the tuned dyno run have a 20%+ dyno loss?
what am I missing?

aa909

^^^^^^^^ BTW I also posted this on Vivid's "Softronic March Sale" post on 6spd.
Hopefully Dan has a good answer

I love the real power gains with the Softronic Tune + EP exhaust, and believe me 570hp is waaaaaaaay more than you need on the street to enjoy these cars. I just want to clearly understand how they go from the 570 hp I calculated to the 615 hp they claim (I assume the dyno chart is real)

eurotom

^^^Details on website contrdict the dyno chart. They claim 80hp gains to the crank with tune alone, so lets just say with exhaust you're at 580 crank. I'm okay with that number, however I was told the 615 was based on a 93 tune. The dyno chart above has 93 scribbled in. Either way I don't believe you can gain ~35hp from 91 to 93. Hopefully we get some details and as I've said before APR/FVD/Softronic etc and Europipe,Tubi,GMG etc need to have a shoot out using the same car under the same conditions.

aa909

agree 100%. I think this is again one of those things where a claim is made that doesn't add up somehow.

At the end of the day It's really not important to me whether I've got 550hp or 570hp with this tune as I'm perfectly happy with the real world "feel" of the car given what I paid for the tune. It's more about understanding why the claim is 615hp, and if this claim is incorrect why it is it allowed to be perpetuated

- Art