DC640

CG race headers - do u need to flash ecu?

johnsopa

In theory you should get a CEL. The race headers use the pre-cat O2 sensor but not the post-cat O2 sensor. I left my post-cat sensor connected but zip tied them up against the firewall. No CEL at least for 10-15 mins of driving. I'm going to the track tomorrow so I will report back.

I do have an FVD tune that I will install at some point which will prevent the CEL from showing up. I wanted to see what would happen first.

ShakeNBake

Installed a VBOX Lite in a friends car:

TRAKCAR

I have my old VBOX shipped back and after 4.0 -> 964 -> old racecar -> back into 991RS.
I'll upgrade it if the HD is avail..

Rallyeporsche

Not doing this today but next Sunday (8/7) my car will be on display at the Carlsen Concours in Redwood City. If you show up lunch is on Carlsen.

GTautoDesign

scanned the GT4 yesterday, prepping for CFD analysis

ML///

Curious to see the high pressure areas

blackmist27

Today i decided to drive up to Alice's and over to La Honda. this is the first time i actually drove the car hard-ish... my impressions?? holy crap! this car is amazing!!!! it has so much grip and it is so well balanced i could not believe it. just wanted to keep going. it knew my movements before i actually executed them. this is by far the most fun car i have ever owned... cant wait to do more!

ShakeNBake

Jesus, how long before I need to talk to a doctor....4 hours?

Yargk

There was more than one blue GT4 driving out that way today.

John@Fabspeed

Any race headers that delete the primary catalytic converters monitored by the ECU is going to throw a CEL, it is just a matter of time. However, we can protune the car to shut off the CEL. I can also set you up with a pair of our catted O2 spacers to compliment our race headers. Although no guarantees as ECU's vary in emissions sensitivity, they should sufficiently desensitize the rear O2 sensor readings enough to minimize/eliminate a CEL occurance. It is the best chance outside of running a protune with the headers, but boy are our race headers worth it haha. Also, with a protune you'll get a nice additional jump in performance and throttle response

Now that is some good fun! Looking forward to seeing it in action

blackmist27

would have been cool to see you up there!

C5driver

Whoa! How it's done!

Dr. Ferdinand

Sold it!

Oh yeah, and got another one

okie981

Not today, but last weekend....

First oil and filter change at 603 miles, oil sample sent to Blackstone, old filter sliced open and inspected for debris. Added 8 quarts of Driven DT40 oil (5w-40), a magnetic drain plug from LN Engineering, and a new Porsche OEM filter. Next oil change planned at 2,000 miles of run time. I'll report what I find on this oil analysis and again at 2,000 when the DT40 is drained.

While under the car changing the oil, I noticed my driver's side rear tire had a screw in it, and yes, when I pulled the screw out, air escaped. I pulled the wheel off and inserted a plug, added 3 psi of air and drove it today with no issues. The screw shown in the photo was just barely long enough to puncture. Plug was more than an inch over from the edge of the tread.

Side note, the Liftbars jack system I have only required driving the GT4 up on 3/8" of old floor tiles to get the car high enough to get my low profile jack under the Liftbars. Very slight difference in clearance compared to my BS. Makes me wonder if the ride height of the GT4 is set correctly. Or if the wheel/tire profile provides a rolling radius on the GT4 that is longer than the BS rolling radius (19" BS wheels), thereby offsetting somewhat the supposed 30mm lowered suspension of the GT4 PASM?

Also found all lug bolts to be under-torqued, so the PDI tech either needed a recalibrated torque wrench or never checked them. I had to turn all bolts about 40 additional degrees to get 118 lb-ft. using a torque wrench I know to be accurate.