6ta1

Yep...

I am trying to learn about ECU tuning and especially how do "catalog" tunes work - some of the guys listed are "legit" meaning that they probably actually tuned a Porsche on a dyno but a lot of the cheaper tuners will sell you a tune for any car on the road.

I am thinking they play with the K-constant or similar so that all maps get modified at once by a certain %. But I have no data to prove this.

In the end I do not really care... all I want is to load the ROW tune on my car but no one around here will do it!

Capt. Obvious

If you can get the file for the tune, I can walk you through how to do it.

jrgordonsenior

If you want some specific benefits you really should have it tuned on a dyno. Many tuners work with different operators around the country via wireless connections and can tune your car on the fly. This is beneficial if the tuner you like is in Bosnia or Phoenix....

alpine003

This is the best but the most expensive and I would say it's worth it on a highly customized NA or FI motor. But for normal bolt ons that most of us will do, the rewards start diminishing pretty fast.

I would normally watch out for the "catalog" tunes you talk about but in regards to the 996, there's only a handful a good ones that were made and these are the ones that are recycling around the various companies. It's not like a Honda where there are several bad catalog tunes out there made by anyone, primarily because the electronics are more sophisticated and only a handful can get their hands on them.

Couldn't you just get a ROW BIN file and load it via PIWIS?

MiamiC70

Very interested in dyno sheets for x51 engines as they already have most of the options from factory (intake, larger plenum, head work, headers, cam, etc). Eveyone talke x more HP but in reality that is usually at the expense of torque or by moving that peak power even higher up the rpm band.

6ta1

I don't even need to "get" the file as my understanding is that all the maps are in PIWIS.

All I need is access to PIWIS, and none of the indies around here want to hear about it.

By the way for an assessment of the Porsche indies in DFW:
- there's a german specialist in Plano (off of K ave), I don't think they have seen a Porsche in years - had no idea about what I was asking for
- Louden motorcars seem to be very competent, but didn't want to deal with emissions
- I was not convinced by Zim's, the guy was quite rude and acted like he didn't know what I was talking about.
- the guys at Mayo performance are great but didn't want to deal with emissions

I guess I need to go pay a visit to RAC or Autoscope.

EVOMS

Going to headers and getting rid of the cats and mufflers (which tanks backpressure) is really the only thing we see that commonly kills low end power.

Often times gains to be had with a tune and intake are even across the board, due to how Porsche tunes the stock cars for federal emissions and fuel quality standards (conservative timing so nothing blows up on poor gas). Once you start playing with the throttle body, plenum, or headers, you get into things that are harmonically tuned for a given engine that can move the powerband or gain/lose power depending on RPM. The parts worth buying are engineered and tested to give minimal losses if any, even if they only give you an improvement in certain parts of the powerband.

An optimized tune can go a long ways towards helping this. Below is a dyno of a 2004 C4S with our intake, then our tune. See the big dip in power that the stock package has, that is somewhat amplified when installing the intake. With the tune, the dip is smoothed out. That mark aside, the car picks up 10-20ft-lb of torque at the wheels throughout the entire powerband.


Here's another chart from a Cayman S that shows similar features, this one with our intake and then our tune. No losses anywhere here as well.


This one is applicable to the current discussion. The black baseline is a Cayman S with a catback system. The blue is with an intake, IPD plenum, and GT3 throttle body installed, which is similar to what you see on a 996. The red is the same hardware with our tune. This chart starts at 3000rpm, with the untuned setup down about 5 ft-lb. The tune gets you nearly back to stock. The charts with the induction mods and tune get rid of the nasty dip in torque that the baseline displays from 3400-3800rpm, and the tune gets another 8-10whp starting at about 4600rpm. There may be some losses below 3000rpm, but aside from cruising around town, the 5ft-lb that might be lost below that are more than made up for with the 20ft-lb+ increase that develops over 3500.


I'll dig through some of our older files and see if we have an x51 dyno. But broadly speaking, the charts given above do a good job of showing the trends we typically see with hardware and software modifications on this family of naturally aspirated engines.

6ta1

I have to say, kudos to EVOMS for posting actual useful data!