c4_4ya

I have read posts on the net about the internals of cats breaking up and getting into the turbos. Seems to me it would make sense that this would be something to avoid like the plague. I am down on power and suspecting either a boost leak or clogged cat, just have had no time to troubleshoot due to being out of town constantly on biz.

I hate to replace parts without knowing exactly what the problem is, but if this is true and more than a rare freak occurrence then I would want to preempt the problem anyway.

So, for those of you with turbos remotely mounted after the cats, do you recommend:

A. Not to worry due to the rarity
B. Run completely gutted cats
C. Use free-flow cats

TracyRR

It may be rare that a cat would come apart but do you want to chance it destroying a turbo or two? When i was rear mounted, removing the cats made a nice difference in spool. It will make the car louder so keep that in mind. I didn't notice the "gas smell" at all, but i read several threads of guys who didn't like it. Peace of mind and quicker spool.....I say go for it!!! Best of luck

c4_4ya

So would it be fair to say that free flow is no better than oe cats regarding them breaking up and potentially destroying the turbos? I would think gutted would be the safest route but have read many posts of hating the smell and noise. I also assume all 4 cats should be gutted not just the two main ones.

This is not a track car, a small increase in noise would be acceptable but driving a stink bomb is not. I just wonder how common it is for the cats to disintegrate. Would love to hear first hand experiences either way!

venomws7

take it off..
made big diffrence in spool time in mine and you have the risk of losing one of the turbos.

c4_4ya

Pre and main cats? How's the sound for a street car?

TracyRR

All four cats! I ran the pup cats only for a while and yes with the pups removed it does improve spool and also make it a bit louder. Although i never ride around with the windows down i do not have the fuel smell at all. Maybe my sense of smell is bad but it works for me.

schnellTTZ06

I actually had my cats break up and shoot out the tail pipes in the form of white dust. It was from the meth kit when I first installed it. It didnt seem to affect the performance at all, but years later I had the turbos rebuilt and they said the turbine wheels were damaged.

2000BC

I have 30,000 miles on Random High Flow Metal Matrix cats with no problems. If anything acts up or I change the headers I'll just gut them.

CamminC5

If you don't want the gas smell keep your air on recirc.

Slow Z06

Jareck lost a turbo due to cats coming apart. IMHO I would ditch the cats. The expense to replace and repair out weighs the slight increase in odor or sound

0chris@sfcc

if you need a set of cats with nothing in them PM me, I might have a set in the garage.

undertaker

pretty loud with no cats, you might want to think of putting some bullet mufflers in their place up in the tunnel.

c4_4ya

I had an exhaust shop do a flow or backpressure test and they said the cats were flowing good. Of course that was only at 2500RPM and no boost. I would like to gut them just to avoid the potential turbo destruction.

While it was on the lift I noticed the precats weren't present. I have read that they were only installed on some Y2K vettes not all... or they were removed.

Thanks for the input all.

c4_4ya

2 Questions:

Which bullet muffler would work best for sound without sacrificing flow? I don't want it much if any louder than it is now.

Where exactly would they be mounted? I've got a Borla X-pipe on there now if that makes a difference.

Thanks!

undertaker

way back when I had STS on my car in like 06 or 07, the guys at ECS swapped my turbos out for GT35s and sent out my manifolds and midpipes for coating and wrapped them. I'm not entirely sure which bullet mufflers they wound up using, I only picked up the car and handed them a check. It was still very loud with the mufflers but doug said it was outright obnoxious with nothing other than the turbos. I was on a stock H-pipe other than the cats being swapped out for mufflers.

jbondfl

Why would a bullet muffler in front of the turbo be any less risky than a cat?
Is there room enough after the turbo to fit a really small muffler in, maybe sideways?

c4_4ya

My understanding is that mufflers (usually) are just Metal chambers where cats have ceramic and other "guts" that when old and/or heated too high break apart. I've seen mufflers rust apart though but rust isn't a problem in my area. Please correcte if I'm wrong.

Unless there is a muffler that is shorter than 4" I don't see how they could fit after the turbos.

c4_4ya

So bullet mufflers swapped in place of cats... That seems to make sense but would need to swap back to pass NC visual inspection. Hmmm...

bjsz06

I have undertakers old setup on my 01 z06 and I couldn't be happier with it. No smells and everyone that hears it loves the way it sounds.