328 Hyperflow cat - increased noise?

Why not just replace the OEM cat with an aftermarket replacement? That's
what I did - can't recall the brand, but it was about $400 as opposed to the
$1200 that Ferarri charges. Works great - passed smog - and sounds the same
as the old cat (which was rattling - but that's a whole other story).

Jedi

 

I replaced my cat with the Hyperflow. It seems to be a little deeper, but not really any louder.

 

I have been running a Hyperflow for over 5 years on my 328, a test pipe for about 4 years prior to that and stock cat prior to the test pipe. You will notice a significant power increase over a factory cat and a noticable db increase as well. At idle it will have a deeper rumble but I can't say what it will be like at higher RPM's because I run an aftermarket muffler that is much louder than stock. The tubi competion muffler is quiet compared to what I have, I tried a tubi for a couple of months and then went back to my old one. I don't know who made it because there is no markings on it, but it is stainless steel and lighter than the tubi. I have had no problems with my hyperflow and it passes California emissions everytime it's tested.

 

No noticable difference for me on my Mondial 3.2. Maybe a touch more growl, but no resonance or anything annoying to worry about. Bad experience with resonnance with two name brand exhausts, I gave up and decided the stock exhaust with hyperflow is best for frequent use, although to each his own...

 

toss me $400 & you can have my original Ferrari cat that is in perfect shape with no blockage.
Chris

 

Buy two of these: http://www.hottexhaust.com/detail.asp?PRODUCT_ID=59954 = $250 shipped

Take them to a skilled local exhaust wizard and have him weld them in - mine quoted me $200 for the job and that is California prices.

Now you have high flow metal substrate catalysts that will last and last and you still have enough money for dinner.

 

Sorry, I have a Mondial t - same as a 348 that has two cats. If your car has one, you only need one, but maybe with bigger diameter inlets and outlets - they have them all at about the same price. Another big advantage of the metal cat is the size - they are tiny compared to the factory item. I think the hyperflows are as big as they are more for looks than anything.

Where are you located?

 

measure the diameter of the tube that feeds your cat - should be 2.5 to 3 inches I would guess. Then I would go ahead and order one of those cats with the same size opening. It is unlikely they will stay this cheap for long. Supposedly the retail price on these is around $300. I couldn't find them anywhere else for as near cheap. Then when you have a chance and have located a good and fairly priced exhaust man, you will have the goody ready to go. (I have a guy, but Northen Cal. is a bit far to drive. )

 

I would agree with Randy, buy a metal catalyst core, and have your factory cat cut open, and have the new core tack welded in place. Less costly, and should flow as well or better than factory, yet retain a factory appearance....well except for the cut and weld on the factory cat outer case.

 

I have a Hyperflow with the stock muffler on my 328. It is indeed louder, and noticeably so, but not overpowering.

This combination is much quieter than a Tubi, but does have a very nice rumble at idle, and a more pronounced growl at speed than the stock configuration. Also sailed through California emissions without batting an eye. I think it also gave me a power boost, but I have no dyno numbers to verify it, and it may just be my imagination given the increased snarl coming from behind me... In any case, I like it.