Gelignite

I am doing my first track day of the year in a few weeks and also the first since having a cat bypass fitted. Does anyone think I will have any problems meeting the 101db limit? Exhaust is stock apart from that with no leaks (now!).

Also I need to change my front pads for the track day. I have done many searches but still not sure if I should go for original porsche or thinking about pagid blue? If I go with the pagid blue I'll probably swap them back out afterwards to finish off the exsiting ones on the road. It will only be my 4th track day so I'm still pretty useless - although the instructor did commend my braking on the last one (just a shame about everything else). One other reason for erring on the blues is the scary break in procedure on the pagid site - 110-50mph. Where exactly do you do that without attracting every blue flashing light in the area

Any advice gratefully received
Steve

joey bagadonuts

You can give them a preliminary break in on the street (so that you'll have some grip) and then finish it off at the track. Take it easy during the first session--they might be slick--and keep building speed. They probably won't be right until after they're given a rest but should be great for the rest of the day.

No need to change out the Blues in between track days. Use them as your everyday pads. Changing compounds is not advisable because your braking force is due in part to the material transferred to the rotors (adherent friction). Changing pads means you'll lose grip and have to bed in the new compound each time you switch.

Stock exhaust with cat bypass should meet most any track's sound requirement.

boxsey911

Steve, I guess it's Bedford because of the 101 db limit?

Mine was 102 db with cat, cup pipe, standard final. I've recently changed to de-cat, standard primary and standard final and I would say the car is now a bit quieter. So, I think you will be OK on the static test. However, if you just fail it they will let you out to see if you trip the drivebys. Even though these are lower, 964s are usually fine on driveby.

gchristofi

Sounds like you're off to Bedford. I went for preliminary sound static sound check there with normal cat, standard primary and g-pipe. It clocked 104 db so failed. If you want to be sure, you can call the track and arrange a free test before the day.

I have since returned for 2 trackdays with a cat bypass and the rest or the exhaust as stock (as you have). 1st day was 100.5 db static, next was 99.5 db. so you should have no problems.

The marshalls advised that I was close to static limit and I might want to consider short shifting if they later advised I was near the drive by limits. This however never happened and I have it on good advice that NA 911s rarely fail drive by noise limits once they have passed the static test.

Enjoy, and be kind to your brakes at the end of that straight!

Jamie Summers

I have a two stage final silencer tip which allows me to get my 107db, de-catted, cup piped and cone air filtered 964 RS down to about 100db to get past the static test at Bedford. I can put you in touch with the guy who supplies them if you have trouble at Bedford.
To give yourself the best chance of passing the static test make sure the engine is good and hot and push the clutch pedal in to reduce drive-line chatter, and be a little "conservative" with how many revs you give them !
As others have said the drive-by test is a non-issue for 964s.
I'm actually doing a trackday at Bedford on Saturday, so will report back if anything significant has changed ref the noise testing.

Jamie

RonCT

If your exhaust is stock with the only exception being the cat bypass, then you should be absolutely fine. My 964 had the bypass and the primary delete (G pipe) and it had no problem passing the 94 db limit at Lime Rock Park here in CT.

For pads, I'd not mix stock rears with race fronts - that's going to really change the bias. I'd get some new pads and match front to rear and I would change them between (only took me about 30 minutes to change all 4).

Pesty

When I installed my cat bypas it seemed not to change the volume at all. IIRC it almost seemed quieter.

Mine was the bypass type that looked like the original rather than a straight pipe.

Now quite a bot noisier with a Cup 1 bypass.

Gelignite

Thanks for all the feedback, extremely helpful as always.
Steve

madmoog

Decat, 3.8 and not had issues at Bedford, a little close static, but they didn't seem concerned and no short shifting required

bedding in the pads shouldn't be too difficult, try repeated 70-30 on some quite lightly trafficked roads (the lanes near me suit this well). 8 to 10 1g stops should get them warm (or whatever pagid says) but remember not to stop and hold the car on the brakes or hand brake until they have fully cooled!!