viperbob

After almost 4 weeks, I got my car back today. While it was in getting corner balanced and corner weighed after I installed PSS9s and TRG sway bars, I had a Unichip installed along with Porsche Motorsport turbos, FVD cat bypass, and an exhaust manifold update by Robert Holcombe. Results were very good.
<img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />

The car went from 374HP at the start to 507HP. The before run was done in the cool morning, and the after was in the afternoon (and now it is warm here) so under similar conditions, the car should have gained in excess of 150 HP. Even with the bigger turbos because I removed the cats, boost comes on about 2500-3000 rpms and builds to 1 bar (street setting for 91 octane. There will be a switch installed to cut over to mapping for 100+ octane on the track). Now with 315 Sport cups on the back with 6mm spacers, I can't wait to get to the track......

ZCAT3

Sounds great Bob - does the car basically feel the same under normal driving with a lot more kick when driving hard or did the engine characteristics change at all?

viperbob

Bill,

Car drivability is better than ever. The turbos knock you back in you seat VERY quickly even at low RPMs. Seems to have even better feel and acceleration even without the turbos, probably from the lack of cats. Overall, a successful upgrade, with only one small problem. The CEL did come on about an hour away from the shop. No doubt because of the lack of cats. Not sure why it took so long to come on. Checked it this morning and it was an O2 code. Turned it off. Hopefully a few cycles and it will stay off permanently for this code.

krish

<img border="0" alt="[jumper]" title="" src="graemlins/jumper.gif" /> Nice, very nice! 507 Hp conservative with switchable mapping for 100 octane at the track? The green eyed monster in me is rising!

Great results, try not to enjoy yourself too much, and keep us posted on your day to day experience with this setup!!!

cheers,
Kris
'97 993 tt
'89 964 C4

EricGT3

Bob,

What did it all cost if I may ask? Very envious. Enjoy that sweet ride!

Eric

HBdirtbag

sounds awesome man, glad to see you didn't waste much time

viperbob

Eric,

The Unichip set up was $3,500. Kind of expensive, but they do a lot of dyno tuning . I got the turbos for a steal on Ebay for $1,500, the cat bypass was $1,750 and the exhaust mod was $500. As they were tuning, it was evident that the car was WAY lean. So they also had to install 2 additional fuel injectors. They made a really cool adapter that splices into the tubes between the turbo and the intercooler. So when pressure is starting to build from the turbos, the ECU turns on the additional injectors
and the high pressure is already full of atomized fuel. The Unichip has the ability to control these additional injectors as a part of its mapping process. With these injectors, the A/F ratio stays in the upper 11:1 range (11.7 to 11.9) across the entire RPM range.

Alot of money, but the car is GREAT.

EricGT3

Bob,

Everyone seems very high on doing the cat bypass, with better response from the turbos. I wonder what the difference is without the new turbos you got. And it seems you got quite a deal. You spent maybe $7500-$8000 for 100+ hp gain. If you do a Ruf upgrade it would cost $20k. Something I would consider for my car.

"Alot of money, but the car is GREAT" I think you mean the car is even GREATER.

Arthur Del Mundo

Did you get your work done at TRG? I only have a Naturally Aspirated 993, but would love to know your impression of the Unichip process. I was debating doing the Unichip, getting a DME from a 97/98 N/A 993, or wait til GIAC USA (Garrett) makes an adapter for the 96 993, which I hear they are doing so the EPROM can be reprogrammed. Did they have to cut and splice your DME in order to do the UNICHIP?

Q

Interesting they chose to add extra injectors !

Who else has added K24s ?
Did you change injectors
or
change the fuel pressure regulator ?

viperbob

Arthur,

Yes the work was done at TRG. And no one only has a 993. The Unichip is MUCH cheaper if you do not have a turbo as the tuning takes a lot less time. Also, there is only so much that can be done without a turbo. The thing that I like about the Unichip over buying an ECU mod is that you KNOW that they have mapped the most out of YOUR car. Not some car done in a shop one time, in another part of the country that should work for your car.

Q, I forgot to mention that I also added the fuel regulator first. Still not enough fuel. Instead of going to bigger injectors which may make the car run too rich when not at full throttle, the additional injectors allow for true tuning (only turned on when the fuel is necessary). The two injectors added were larger than the stock injectors. So the additional fuel requirement was pretty large.

Anir

Bob,

Thanks for sharing your upgrade details with us. Did the TRG mechanics experience any fitment issues with the FVD cat bypass?

Also, please let us know if the CEL finally "learns" to put up with the lack of cats.

viperbob

Anir,

There were substantial fitment issues with both sides of the FVD cat bypass pipes. I will not say that it was totally the FVDs fault. I also had the mating flange of the exhaust manifold to the turbo reworked. So if this was off just a little bit, then the turbo would be moved slightly causing fit problems with the FVDs.

As for the CEL, I've cleared the fault code once already, and it has not come back on yet. When it appears that it is off for good, I will post the number of recycles to keep it off.

acastell

So Bob, when can we see this car in person...maybe we should organize a quick rednez vous tomorrow (Sunday am) at 92/35. We can talk cars and go for a quick loop- 35 to 84 to 1 to 92...

I am sure there are others that will join...

AC

EricGT3

Anthony,

Sunday AM let me know!