Philip in AL

If you remember last years posts, I tried one of the first new Unichip setups for my 2004 GT3; and had great HP but bad problems with rev limiter coming in too soon; stumbling etc.

This time they got it right. Base Dyno Run was 342 HP and 255 TQ. After the install, 370 HP and 284 TQ. Using map B (you flip a rocker that advances timing), I showed 377 HP (can't remember the TQ).

You can certainly tell a difference in the way the car runs! The only thing that concerns me, is that it now may be running too lean. I'm under what I'm told acceptable (not really higher than 13 to 13.1 or 13.2 A/F) to about 6,000 RPM's, then it starts to lean out to about mid 13's to redline.

I'm going to order a Digital Air/Fuel Ratio Meter and do some "real world", street driving test of the A/F vs the car sitting still on a dyno. Anyway, the car fly's!

Any comments on the A/F ratio would be appreciated?

Z06

Those numbers are fine for air fuel....can we see a dyno graph? Is it a computer flash?

Philip in AL

We finished on late Friday afternoon: I'll have to go back to the shop and print all of the graphs. It's not a flash, it is two black boxes (that attach to the ECU) and a twin wire setup that you can mount by the driver seat. One rocker is the A/B map setting (advances timing), the other rocker resets the ECU power AND backup power. Looks like this http://www.unichip.us/about_unichip.asp

So you think a A/F ratio of 13.59 to 13.38 is OK between at 7,000 and 7,500 rpm?

Z06

My LPE 383 Z06 had that kind of fuel ratio....So yes it's fine. How did they read the Air/feul ratio.
with my Z the used another 02 sensor.. in the exhaust header. If it was to lean you would lose power.

DCLee

So is this a piggyback satellite system that is not dealer detectable, or what? Kinda strange in these days of flash loaders to have a dual-box setup. Who did the tuning, and what's the approximate cost of the package (PM is OK... )

Lee in D.C.
'04 RS Clone

Philip in AL

It's a piggyback system that is not detectable. I know that the ECU reset does in fact work. Had mechanic hookup the OBD2 computer to it yesterday. Shows nothing in memory (accept of course the stuff that stays in flash, such as over revs etc). I was told that it's immpossible to ever remove those.

A/F ratio was determined using an O2 sensor in the tailpipe.

Tuning was done locally, by an independent with plenty of experience.

I don't know the cost, we started this project so long ago. I did pay the mechanic about $1,200 in the beginning. Call Tony or Jack at UniChip 866-864-2447

ArcticFox

Had a Unichip in my M3....worked wonders for tuning an OBD II car! Glad to hear this is now an option for our cars...I may have to do this... :-) Please continune to share any info! Thanks!

Philip in AL

Have the dyno sheets today; looking for a way to post to the net. Hopefully in the AM. Very impressive.

nmex

I had a unichip on my old Boxter and still have the unit could I get it reprogram and re install in my GT3. Also I been told many times that the computer in our cars re adapts all the time and eventualy the unichip is inefective. is these tru or not. On my boxter it was program by the racers group and I intall it my self. could I do here the same thing or is it car especific

Philip in AL

Here's the dyno sheets; if you keep clicking the photo's, they will get larger.

http://www.sendpix.com/albums/05100110/vb1o662m70/

I don't think the ecu will revert back; plus the unichip has a second switch that resets the ecu by disabling both the main and the backup power. Call them.

PogueMoHone

Beware the "software" changes to the ECU that you can't detect. You may not be able to see them, but Porsche will if they choose to look for them.

These days OEM Manufacturers put of sorts of little "gottchas" in their software to record tampering and they are often impossible to identify.

Just because you can't see doesn't mean a record isn't there.

Steve Weiner-Rennsport Systems

FWIW,......A/F readings taken AFTER the cat are not accurate.

One must install the wide-band sensor BEFORE the cat for any meaningful A/F values to be had.

Best HP is between 13:1 and 13.2:1 on these cars,....

Philip in AL

Steve, are you saying that if I enriched the mixture down to those levels, I could pick up even more HP?

Steve Weiner-Rennsport Systems

A little bit, yes.

Don't forget, every production engine is slightly different due to manufacturing tolerances.

Personally, I'd run it closer to 13:1 if you do any DE events.