Godzilla

100 Cell cats do not meet ADR's. There are 200 cell cats that do meet adr's and are therefore EPA legal. You could pass a EPA test with a 100 cell if your engine tune is spot on. 200 Cell is as good as you can get and thump it to the testers at the same time, if you want to go 100 cell, why bother, just put a straight pipe for max flow, its just as illegal or do as I have on my GTR and run a 5" cat body with all the guts removed for max flow. Coppers look and they see a cat, if they ask for a EPA test, a cheap 400 cell one gets bolted in for a few hours. Both my fake cat (straight pipe) and legal cat have identical flanges made up, just undo a few bolts, pull the sensor off and bolt the other one on, less than 5 minutes work. Edit; forgot to mention, no cat, 100 cell or 200 cell makes no/very little difference in sound, cats dont muffle the sound, they have no sound absorbing properties.

I run 255 Continental Sport contact 2 V max tyres on my GTR and they are best as a warm weather tyre. In the cold theres a lack of traction.

Make sure the lip of the pipe goes deep enough into the hose so when the clamp is tightened there is no way the lip can slip though the clamp. Many people tighten clamps onto the lip/flange of the pipe rather than behind it by mistake. Having said that, plastic piping will always have give in it, ive even blown my GTR 4inch metal intake piping with lips and silicon joiners off twice on hard deceleration with a tightly wound up BOV. Why? Clamp was a little on the lip/flange by accident.

Pinging sounds like timing or running lean. You turned up the boost, did you check your fuel map on a dyno? Id be getting it checked out before melting a piston or taking out a headgasket.

Some basic info on gutting cats or running decats. If your pulled over and served a EPA test notice you have time to correct your setup before forwarding your car for testing. It quite cheap to but a stock front pipe with cat and drop it in. Dont do anything and let them notice your running no cat or a NON ADR APPROVED cat and its a $10,000 fine. How many have asked if their 100cpi cat meets Aussie design rules before they fitted it? Fail the test and a retest costs you $, serious $. Lets not forget they also check you Db and exhaust gasses, its when the exhaust gas part fails that they begin to look at your cat, ecu and injectors. The last horror story I heard from a mate that went though was he got the car back as a non runner, the ecu kick panel removed, they even opened his ECU looking for the aftermarket chip on his Jap import. Being served a EPA notice is not something you want to take lightly Id just run a gutted cat that has the same dia flanges as the exhaust pipe, get ordered to take a test and just bolt in a stock front pipe with cat.

Try ebay I have Redbacks up new for less than that with all new gaskets and mounts. Just the delivery would jack it up higher. A good system that you could install yourself in an afternoon over a few beers.

The Redback system flows well, all mandrel bent, straight through mufflers without baffles whether its the twin 2 1/2inch or quad outlet system however if I was serious about producing some serious power id go single 4 inch with straight through mufflers and a 100cpi high flow cat. Even on my GTR with a single 3 inch and going to a 4 inch with a high flow cat or even better still with a decat pipe, the top end power difference in really noticeable when running over 400awKw. Its all about flow from the exhaust to the head to the intake.

Yes these systems are from Redback and are all mandrel bent with straight through high flow mufflers but as mentioned by Bensxr6t, one pipe on one side for the rear is a little squashed to clear around the spare wheel well.