TheMegalodon

Hey guys, as a few of you know I have the Greddy Evo II on my TL-S and while it's a great sounding exhaust it's terrible for drone. To eliminate this I purchased a Car Chemistry 2.5" 3 disk exhaust insert that was recommended by a couple 3G members. Here's the thread: https://acurazine.com/forums/showthr...=exhaust+drone


Stainless steel packing that goes inbetween disks:

Now, the insert works amazing and completely rid my exhaust of its drone at all times, especially on the highway. However, I feel as though the extra bit of restriction has robbed me of more than just the minimal gains from having a straight flow exhaust. I had it installed right after the cat before the Greddy's first resonator (best spot acc. to manufacturer). My only other performance mod is a UR crank pulley, and from what I remember my car would do 0-60 in roughly 7 seconds or so.

This is with a quarter tank of gas, properly inflated tires (18s), newer spark plugs, clean air filter, engine running well and I'm about 170lbs.

After installing the insert, it feels as though my engine does not rev as quickly as it used to, more so in the upper powerband (4000+ rpm).

Yesterday and today I did a few runs and the TL is consistently taking 9 seconds to reach 60mph (100km/h). Yes, 9 bloody seconds. VIDEOS BELOW

Do you guys think it's the insert that's really affecting the exhaust flow enough to rob my engine of power?

First dead stop run


Second dead stop run


Short rolling start

TheMegalodon

Anyone want to chime in?

fourthmeal

well it is a bigger restriction than stock, so it makes sense...you're choking the engine. I've always heard that the stock exhaust is quite good as long as the headers are dealt with.

hANDYcaptd

iTrader: (5)

I think it's definitely restricting the flow. It looks like barely a 1" opening...super bottleneck.

'03TL-S

iTrader: (10)

It is definitely holding back power as 2nd gear takes awfully long. It is usually one of the best gears to pick up speed for the TL-S.

RUF87

I don't have any real world experience with them, but let's try a take a stab at it anyway.

First, how many disks did you install, and where within your exhaust system did you install it? If all three, reduce it to 2 or even 1. Also, as I understand this device it was originally designed for use in open header applications, but can be used with a full exhaust. So the further you install this type of device from the header the more restriction it can be. Reason it that the exhaust gas pressure is higher in the headers and gets lower as it moves to the mufflers. So when used in open header applications there is sufficient pressure to 'more easily' pass through the device, and when placed where pressure is lower it will become much more restrictive. So my suggestion is to reduce the number of disks to 1 and hopefully the drone is acceptable to you, if not try 2. If that doesn't work I'm assuming you can move it closer to the headers.

Note, the picture of your device looks different than the one I'm familar with as noted below. I'm assuming you do have the type that fits in to the exhaust pipe.



Ruf

TheMegalodon

Thanks for the comments guys, Ruf I outlined which piece of installed at the top of my post (2.5" 3 disk insert in the pipe) and also mentioned that I installed it right after the cat, which is exactly where it's supposed to be. I also wrapped this stainless steel mesh from the manufacturer (looks like steel wool) around the disks for extra sound reduction (probably a bad idea).

I'm wondering if I should spend more money to have them cut open the pipe again, bang this thing out, take off the SS packing and cut a disk off.

I knew there would be some restriction, but I was so annoyed by the drone that I didn't consider just how badly I was restricting the exhaust flow at higher rpms. As you can see by the videos, my car is crippled in second gear at full throttle. It's kind of depressing because my exhaust sounds perfect now, but my car is slower than a civic.

I should've stayed stock. Should've done more reading before swapping exhausts with a guy.

RUF87

Not laughing at you . . . I've dealing with the same major drone issue right now. I'm actually considering the inserts as a last step solution. I'm still waiting on a new resonator that I hope will fix it . . it's amazing how bad the drone can be and yet it sounds so good from the outside. Like you, I've got enough in it that it'll be more expensive to go back stock than get it fixed . . . I hope.

The one mistake I made was not watching them install the new exhaust . . they welded everything up . . pissed me off. I'm like how am I supposed to work on different parts with it welded verses flange connects at key points . . Cat, resonator, muffler, etc. Anyway, I'll get that fixed when they have to install the new resonator (there's none on there right now . . long story). That way I can swap out parts and play with the insert . . . if it comes to that.

Anyway, good luck and let us know what works, and I'll do the same.

Ruf

TheMegalodon

Sounds like you have more issues than I do Ruf. No flange connections?! That's ridiculous (minus not worrying about gaskets)..See I have two resonators between the cat and the mufflers that are part of the Greddy setup. Unfortunately the straight flow design and the shape of the mufflers is bad for drone. All other aftermarket performance exhausts (comptech, tanabe, apexi) have offset inlets/center outlets on the mufflers. That's probably why they have less problems with drone than this damn Greddy setup of mine.

I may have to seriously consider dropping more coin to cut a disk off the insert and rid myself of that packing because I'm not willing to sacrifice that much performance for a quieter ride. Our cars make their best power at 4000+ rpms, and by restricting my exhaust flow so much I've basically cut a leg off my car if it were a man.

I should have tried out a Vibrant ultra quiet resonator. I hear those things are great. The funny thing is, they look the same as the stock mid muffler that everyone chops off their exhaust.

Hindsight...

I'll let you know what I do.

RUF87

I've actually got the ultra quiet resonator on order . . it was back ordered so I'm hoping to get it next week sometime . . . will let you know when and how it works out.

Yeah, hindsight . . . I just wasn't thinking. I was planning on keeping at least a resonator in the flow, but when I had it removed at the last second. When my cat destroyed itself . . junk got in to the resonator and mid muffler . . they rattled with junk so I had them removed. So I'm really hoping the ultra quiet resonator does the trick.

Ruf