Review of high flow cat, resonator, and Borla exhaust
 

Welp, got my "CZMid-4" installed today. For those of you who haven't been following this, the unit is a high-flow, high-temp catalytic convertor by Random Technologies with a resonator. It's a legal replacement and CARB & EPA certified, as long as you have a good reason for replacing your stock cat - like damage or plugging. I figure if I need to, I'll pull it off when my car starts getting emissions test in 3 more years.

This unit replaces the stock cat, and while CanZoomer also sells just the HF/HT cat and midpipe, I wanted the unit with the resonator because the cat alone reputedly greatly increases the noise, especially with an aftermarket exhaust. I was concerned about this because I also have the Borla cat-back exhaust, which sounds beeeyoootiful :D by itself.

So is it louder? Most definitely. Is it too loud? Dunno, jury is still out on that. I've only put about 20 miles on the car since I got it on, and it is definitely louder when accelerating - but interestingly enough, not when at interstate-level speeds. Anyway, I'm hoping it will "mellow" with a few miles on it just like my Borla did. Time will tell if it does, and if not, whether the additional noise is enough to bug me.

How's it feel? MUCH better. The car feels smoother throughout the rev range, and seems to pull stronger. My butt-dyno tells me it's good for at least another 10 HP.

So there's the update, campers. :D

Does the Borla by itself with the stock cat and resonator sound good???

Is it loud enough to set off car alarms if you rev it in a crowded parking lot? My old flowmastered 57 chevy used to do that. If not, then it's not too loud. ;)

Also, have you replaced your flywheel/clutch yet? Personally, I'm thinking I might go with Borla/Random cat/ECU mod/flywheel.

Yep... really, really good. :D

Dunno, I'll have to try it. Probably. ;)

Not yet on the clutch/flywheel. Probably down the road a piece.

I was wondering how you would like it Omicron. It is definitely louder isn't it! I think it does mellow a little -- I have about 300 miles on it now including a full day at the track. It felt really nice at the track with all the very high reving -- really does smooth it out. For me it is right on the edge of being too loud -- the younger crowd seems to really enjoy the sound -- getting lots of approving looks and at the track the feedback I got was awesome. I think I may put some of the sound dampening material under the carpet in the trunk -- that will probably reduce the sound just enough for me.

Encouraging words about the mellowing... I hope you're right. And the sound deadener is a good idea too. Hmmm...

BYW, please drop me a PM with your email, I've got a lot of info for ya about the upcoming meet. Also posted in the Mountain forum, and on our website.

Are either of you guys considering going back to the stock exhaust with the Canzoomer midpipe?

That might tone things done enough for you. (plus you can sell your Borla for extra spending money.)

-Mr. Wigggles

That's a thought actually... that's what CanZoomer himself did. He had the MidP-4 and the Greddy cat back, and decided it was too loud.

If I were going to do this though, I'd have to replace the tips on the stock exhaust with something along the size of the Borla. I've really grown to like the way they look, and at this point think the stock tips look too small.

The other thing is that I don't know that I'd want to give up the deep, beautiful tone of the Borla. I'd have to hear the stock exhaust + MidP-4 first before I could make that call. I was also wondering (if I decide it's too loud still after ~500 miles or so) if I could put another resonator in place, somewhere along the length of the Borla's pipe before it gets to the muffler.

But I dunno. The car definitely runs and pulls more strongly, and the sound already seems to be mellowing a bit. Plus it got the Mrs. Omi stamp of approval this morning. :

Omi: So, how's it sound? Is it too loud?
Mrs. Omi: Sounds the same to me honey, it was a bit too loud before with just the Borla, and I don't notice any difference with the new cat. And that's ok because it sounds hot-sports car loud, and that's a good thing.
Omi: :D

Omicron,

Go to NOPI.com, you'll find plenty of tips there. I don't know if you'll find any less than 5" wide though. :)

-Mr. Wigggles

Actually, they've got 2.5" OEM style and up. Quite a bit of clicking but quite a selection too. Thanks!

what size ARE the 8's stock pipes inlets?

I don't think I'm gonna' rework an already good exhaust,but I really want some larger tips,imo the stock ARE too small in proportion.....

Great to hear! I can't wait to get mine. I'm keeping the stock exhaust though. I also really have to work on getting the Mrs. approval:D

hey Omicron, if you ever decide to sell your borla. I will be interested

You will have to pry my Borla out of my cold dead fingers :D

Dunno about inlets, but I think the tips are 2 inch or possibly 2.5 inch. Actually, I believe the cat back pipe is 2.5 inch stock.

The NOPI site listed above does indeed have some pretty nice tips that could be welded onto the stock exhaust in lieu of the stock tips, like this 3.5 inch one:

Or this one:

Or even this Borla one:

That's about how I feel about it. :D

From MIB "your offer is acceptable" ;) .

Maurice's car is nice and quiet now. Pretty much back to stock noise levels. The way he drives that's a good thing :) . The highflow/resonator and Greddy combination shouted "Look at me!" It's also a lot easier for me to test the CZ units. I can hear the injectors again.

where can i get the cz-mid pipe??

http://www.canzoomer.com

I too just installed the CZ Mid-pipe with resonator along with the high flow cat. Personally I do think it’s too loud. If you’re not looking for attention stick with the stock exhaust with the mid-pipe and high flow cat.

FYI, I’ve only had it on a few days and it does seem to be toning down a little. However that may just be me getting used to the sound. Time will tell, but usually mufflers get a little louder—hopefully this one just gets deeper.

Ben

Ben,
What cat-back system do you have? Borla?