killerbee

We typically get about 24 mpg with UMW flash and can not say we are working in a gas saving mode. Low rpm torque with the flash is excellent and minimizes swapping gears in traffic which surely contributes to fuel economy. However, at the track it seems to get in the low 4 mpg

pewter82: The computer can be a bit wonky its far more reliable to do what Miklley suggests.

1AS

I found myself wondering, how is it that Kevin knows more than Porsche, when it comes to ECU tuning? It would be hard to believe that Porsche doesn't know how to tune the car for better power and better mileage. Rather, I wonder if Porsche keeps the info suppressed, as they sell it for a bunch of money as "improvements" in later years.
The surprising thing about the retune is that the car is better all-around. Of course, if Porsche had released it this way, it would have been much harder to sell later upgrades, like Sports Chrono. If they had sold a car with over 550 hp in 2002, what could they sell in 2010?
My view of the current performance is that it takes away all motivation to buy a new 997tt. I'd have to add $100,000 to get similar power and add a paddle shifter(I never thought the earlier 997tt's were significantly better than my X50). I have 3 other cars that have over 515 hp, and I am confident the new tune yields well over that figure. I have driven a new ZR1, which seems quicker (tho lighter), but that's about all that can stay ahead of my re-mapped X50. AS

dantzig

Porsche tunes their cars for their entire market, whereas Kevin works with people who are looking for a particular type of performance. Just as a simple example, Porsche can't be sure that every owner will always run 93 octane. Better to have a car that makes "only" 425 hp and doesn't risk detonation on lower octane fuel, than one that makes a bit more, but runs closer to the limits for problems.

That said, I really like my UMW setup. I also get great fuel economy on the highway. Depends a bit on the weather, but I have seen 27 mpg on all highway driving, starting with the engine already warm. It's more like 6 mpg on the track.

I like working with Kevin because he knows what he is talking about, and because he is data-driven. Durametric doesn't lie, as he says. When we installed the upgraded turbos, he sent me his baseline file for that configuration, had me log some data, then tweaked the program for what my car was doing. That is why his tunes work so well.

Jon

prche951

Porsche does know how to tune, but they do not know who is going to be driving their cars. In many cases it is some 80 year old Lady who just got it because it looks good. You cannot have a hairy beast right out of the dealer. A custom tune will gain lots of power. And Kevin is one of the best at this. A K16 996tt with just a flash, lwfw and exhaust ran 7.6x 60-130 which is impressive.

by the way, Kevin is the guy that has rebuilt turbos for 959's and many other high end p-cars for porsche, so in some cases he knows at least as much if not more than porsche. He is an engineer, not just a mechanic who learned in a mom/pop shop. Most tuners are just code guys. Kevin actually knows the mechanics of these cars as well as the tuning.

1AS

I understand the point about "who will drive it", but that ignores the fact that the 2010 997tt is lightning fast, right out of the box. Clearly, the same grandmother could buy that. I may be stupid, but I think Porsche kept the easy horsepower gains under wraps, so they could be sequentially unveiled as benefits of the newer models. AS

z99

OK, so now I am starting to understand why my car behaves the way it does. I went with Fabspeed headers, exhaust, cats and intake. Then I added a GAIC flash, diverter valves and wastegate adjustment. The Dyno showed 517 at the wheels. But, it does not feel that strong. A few weeks ago I flashed back to stock and got a higher top speed at the NJMP lightening track straight. Someone told me that the flash does not work with the PSM. I went with GAIC due to dealer warranty. So what I am hearing is that those Dyno numbers were optimistic? Or, is the PSM going nuts under full throttle coming onto straight? Thereby retarding car? Once I reflashed to stock, I actually starting passing cars that I could not keep up with. I became much smoother and faster on every part of the track. One other strange thing was that the non flashed numbers on Dyno were only 35 hp less then flashed numbers. That seems like high numbers for just an exhaust and intake.

Is this PSM or the car not producing the claimed horsepower?

Mikelly

Couple of questions here...

What type of dyno?

Rear wheel drive or all wheel drive 517HP?

I've found that turning PSM off actually has helped smooth out my driving. I'm more able to slide the car where I want to on places like T4 at VIR. It's actually increased my speed thru that part of the track according to my traqmate data.

Mike

z99

All wheel drive dyno.

Agree with being faster with PSM off. But, I am talking anywhere between 15 to 20 mph slower at end of straight. I feed throttle very gently coming on to straight and I do not see PSM light go on. But car feels like it is holding back. There was a very knowledgable instructor there that told me that most flashes do not work with PSM electronics on this car. Basically, feels good at the red light, but on the track it starts showing problems. He asked me to try going out with flash off. What I noticed was going over the hump on the back straight, the car continued to pull hard. With flash it seemed the car cut back as it unloaded, even though PSM light would not go on.

dantzig

Was there a significant difference in ambient air temperatures on the days in comparison?

Kevin

z99 in order to see the entire picture you really need to buy a Durametric system. Datalog your engine parameters. Feel free to email them to me.

TT Surgeon

I've actually seen that in a giac car (996tt0, where the stock ecu just overrides the 'flash' by retarding the timing to save the motor, resulting in terrible track performance.

1AS

I happened to do the modification in 3 stages:
1. Flash back to stock X50(I couldn't feel it as any slower than with GIAC)
2. Diverters/waste gate kit (very obvious improvement in immediacy of throttle response, rate of boost build-up)
3. UMW re-flash (Dramatic improvement over step2, and absolutely no comparison to the GIAC flash. The GIAC "improvement" in not detectable from the driver's seat. The UMW improvement is remarkable and very obvious.
In my opinion, it is most likely that GIAC primarily reset the redline with minimal other changes. As I had to send my ECU away, it is even possible that I did not get my original back, as there was a discrepancy in the security codes.
If you don't want to reflash, you do owe yourself the diverter and wastegate changes. It is eady to do things way more expensive for less instant benefit. AS

z99

Similar experience. Do not feel much faster with tune. Also, inconsistent speeds on the straights. I do have DVs, but the wastegate was only "adjusted". Not sure what that means. Adjustment required with X50 according to dealer.

I feel the comment that ecu is overriding flash may be correct. My times are lower without the flash. $2500 wasted?

To previous question, temps were in the 70s in all situations.

I do not know enough to be confident it is the flash. Maybe something is wrong with car. But, I am not getting 1 to 1.1 bars until I hit redline on the street. Before very upper range of rpm, not much happening..

jcb-memphis

Mike, I only get 24...with the big wing..... I will have to try DE with PSM off....thanks guys.





Jeff

1AS

As an aside, I decided to answer my question regarding accuracy of calculated MPG after reflash. Turns out, the calculated gas mileage is accurate (within 2% of measured). When I saw higher mpg numbers, I thought it might be a built-in error. On my last tank it's accurate Computer showed 18.0. When miles were divided by gallons, it was 17.8)-close enough. (There was a lot of city driving, and some spirited acceleration runs on that tank)AS