I recently bought my MY00 PPP back after selling it 9 months ago, couldn't be without it any longer. My problem is the exhaust was changed for a H&S which is nice but too loud for the neighbours. So I bought a PPP backbox which is now fitted. But it just doesn't sound the as good as the one I used to have. The old PPP backbox would scream above 5000 rpm and the new one doesn't. Nothing else has been changed on the car except the panel airfilter to an sti one. Were there more than one type of PPP backbox made? Any other ideas? (except buying an aftermarket job)

 

I have exactly the same thing mate - I had a fulle Decat with a Scoobysport - sounded fantastic albeit very loud I have refitted the cat and the PPP exhaust centre and tail and its silent - I mean I don't think I can even hear the burble - I know however that when I originally bought the car you could hear it ? I did sell the original PPP pipework and have since re-purchased the prodrive pipes......one thing I will say is that the new Prodrive Exhaust is in far better condition than the one that came off so I am thinking that it might just need a bit of sooting up or something ?

 

eclipse - i know where you are coming from - you are referring to the almighty jet fighter whoosh that a PPP emits on a MY00 when you are caning it.

I am running a K&N panel filter and a straight through centre (MY99 PPP), i still have the original catted downpipe. I had a scoobysport on mine and i found that the car needed an ECU reset to adapt back to the PPP exhaust. Also I found that by adding preload to the wastegate actuator the almighty whoosh wasnt just back it was amplified with more low down torque.

First off you need to reset the ECU, secondly you need to let the ecu learn again and hopefully gradually the noise will come back. It is possible that your MAF or Lamda are on the way out due to the age of the car and that the mixture may not be correct, apart from that I cant think of any other reason.

 

Thanks Beastie, how do you reset the ECU is it just a case of disconneting the battery for 5 minutes? And whats adding preload on the wastegate actuator mean?

 

I usually disconnect the ecu overnight to ensure reset although there are other ways to do it.
The wastegate actuator is under the turbo heatshield. Take the heatshield off, disconnect one end of the rod and shorten it by tightening the thread, this applies preload to the wastegate and gives you more low down torque. Shorten the rod and try the car in stages so that you can check you dont hit overboost. If you hit overboost slacken the rod. A rule of thumb is shorten rod by 5mm max and 4mm should not give any problems.

I assume that you have the round tailed backbox with prodrive written on it which is identical to the Sti one same era?

 

Just FYI after going to my local dealership for some work I saw another classic with a Prodrive exhaust but the inside looked different to mine.

So a phone call was in order to Prodrive themselves. I found out that although Prodrive only made 1 round pipe exhaust for the classic in 98 maybe 99 they changed the internal dimensions from 2 1/2 inches to 2 inches for a linmited run, when it was decided they didn't sound loud enough. So they returned to the 2 1/2 inch internal. This explains why my exhaust doesn't sound like it did before as I have a different backbox.

Prodrive made it even more difficult to tell them apart by giving them the same part number.

So now the hunt begins for the 2 1/2 internal.