I bought a 2008 c4s with an Evoms intake and stage 1 tune. Its obvious how to return the intake to stock, any idea how to return the tune to stock?

 

You dont like the tune?

 

The tuner (or one of their authorized locations) or Porsche dealer should be able to flash you back to stock.

 

I just think one is better off with the engine close to stock. And based on dyno tests, it seems most mods actually decrease power. That plus changing may put your engine at higher risk, and lower your resale. Why do it? I'm more worried about bore scoring, or losing my engine on the track, than how it sounds or chasing a few hp, that may or may not be there.

 

If you could find a dealer, that would be the easiest. I have yet to find a Porsche dealer who will flash an ECU back to stock due to liability reasons. I have friends that just resorted back to buying another stock ECU.

 

After market airboxes make less power than stock oem air box.
Thats why they are reffered to as "cash flow" devices for those companies.
Altough correct dyno tuning/headers/x-pipes make lots more power.

 

My 911 Turbo came flashed with Revo and it wouldn't pass emissions. I took it off and noticed zero performance difference. I had an "authorized" Revo shop reflash the ECU back to stock (read: I had to pay an hour labor to show a clueless 18 year old how to use a laptop and flash ROM file). The Porsche dealer here would have done it for me too with their PIWIS but it would have been more expensive.

 

By themselves, true. Combined with other mods and/or a tune, I disagree, and before you send me the link to the video of the flawed stationary test everyone refers to, I've seen it. Flawed because they never reset the DME for it to learn and adjust for the new increased airflow, so was likely running lean in their next pull, can't simulate real word airflow on a stationary Dyno no matter how many fans you blow on the car, etc.

OP, I would track your fuel trims with the tune and see if there are any issues with it before risking removal, as you may eliminate 30 HP or so if 8t is a proper tune, and EVOMS is a good company.

 

I have an EVOMs tune on my car with a Sharkwerks X-pipe. It's a nice little bump in torque and rock solid. Tune has been on the car for 2 years, many track days and daily driving, approx. 30K+ miles.

But, since you didn't ask for my opinion on the tune itself, I'd contact EVOMs for advice. The problem would be you don't have the software controller that plugs into the OBDII port. The original owner would have the stock tune stored on his, btw. Also, if you have Sport Chrono on your car, that's an example of a tune. Nothing scary about it if the company is reputable.

Here's an excerpt from an email exchange with Sam the owner describing to me what the tune delivers on my base Carrera. He says it best-

"Rated performance is 366hp / 298lb-ft, with arguably the greatest improvement over stock coming in the form of a nice boost in mid range torque.
Our tune does maintain use of the Sport setting and the differences in throttle response that come with it. With the tune, non-sport feels a bit more like OE Sport mode, while tuned Sport mode gets slightly more aggressive. Both changes feel natural, and the differences compared to stock regarding throttle response are suitable compared to what we did on the older cars as Porsche made big improvements out of the box on the 997.2."

 

Butzi 997, have you put your car on a dyno? Have you done a bore scope?

 

fireman, I haven't dynoed the car, before or after. The tune was obvious when first installed, now it's "normal." Having tuned STIs in the past, my expectations were measured, as they should be tuning any NA car, but I was pleasantly surprised.

I understand bore scoring is a real thing, but my car- owned since 50K miles, now at 93K- has only ever used oil on track, even then it was as little as 6 oz, never more than 12 oz. None in town, and since I started using LiquiMoly oil I haven't used any on track either. Blackstone UOAs are very good, last interval they recommended I go 6K or 700 track miles between changes. I didn't quite have the nerve for that, so I just sent a sample with 5300K on it.

So do I know I don't have bore scoring? I do not. But my method of using the car within a range of use I believe Porsche designed it for (daily and track events) and over-maintaining it, if something goes wrong, I'll have it fixed. No intention of ever selling it. It's the 6th car I've used for daily and track event use and it's better by miles than anything I've owned before.

 

You can send us the ECU to have it flashed back to stock. I used to recommend people go to their dealer to avoid the removal/shipping process, but the newer PIWIS tools seem to refuse to flash a DME if it detects something isn't stock so doing it through a tuner is the best way to go. Email me at sstone@evoms.com for more information on how to arrange that.

On a healthy car, the tune and intake should be worth a fairly noticeable amount of power; ~20hp or so over stock. The devil is in the details though, these cars are getting to the age that a worn sensor (MAF or O2 sensors) or a vacuum leak can throw things off to the point where the car goes into limp mode. At that point, it doesn't matter if the car is tuned or stock, it will run flat and not make power.

The intake design definitely matters--it's easy to outperform the stock intake in terms of flow, but of all the intakes I've tested on these cars our V-Flow is the only system that realizes that flow improvement while maintaining near-stock intake temperatures AND an accurate MAF reading. On the other intakes I've tested, high intake temperatures or inaccuracies in MAF reading due to flow issues through the housing (due to proximity of the filter or a bend just upstream of it) cause engine management issues that result in a loss of performance greater than what is gained by increased airflow. Essentially, the ECU pulls a bunch of ignition timing, either due to knock (because it isn't measuring airflow into the engine correctly and thus can't accurately operate the engine) or safety because it sees extremely high intake temps. In testing, the V-Flow maintains intake temperatures close to stock (within 5-10F in any given situation), maintains consistently near-stock fuel trims under a variety of conditions signifying the MAF reading is accurate, and shows 8-10% higher load (load is air mass ingested per stroke--so all things equal, more air into the cylinder = more fuel into the cylinder = more energy = more torque = more power) on an otherwise stock engine.

Sam

 

Yep, and if you want a scientific study about how some of these CAI systems flow more air which mixed with more fuel and makes more power, here's a realmworld test done by another member in real driving situations instead of on a stationary Dyno.

https://rennlist.com/forums/997-foru...surements.html