Exhaust —*Design vs. weight

[KAL]

Miata people! I'm looking at upgrading my exhaust and i'm torn between lightweightness (Enthuza) and a custom design.
The custom design will be a one-off and i've planned it with an exhaust-shop. The problem is that it will be a a tad heavy, if i'm to keep the price at a reasonable level. Looking at $748 (with install) and about 40 lbs.

The hp gains will probably be similar to an Enthuza exhaust. The Enthuza will cost about the same (after shipping and import tax to Norway *sigh*), but at under half of the weight. So — will the weight of an aftermarket exhaust give me "more" than the hp-gain? And is the NA Racer the lightest exhaust at the price?

[kung fu jesus]

It depends on your car. Are you force inducted? Naturally aspirated? Engine work?

If you are n/a, the gains between systems are minimal. The weight really depends on the materials and the components, which comes to the next question...
Are you restricted to decibal limitations, are you sensitive to resonance in the cabin?

A pure, lightweight system will use more expensive materials like stainless steel or even titanium. It will aslo use less or smaller components to save weight a the cost of noise comfort.

I have used both bolt-on and custom exhausts. Each was used for different applications. For n/a, I stuck with a well-known manufacturer that saved weight, but also wasn't too loud. When I was turbo charged, I had a custom, one-piece exhaust made at a specialty shop. I supplied the muffler, tip, and a 100mm diameter x 455mm L "bullet" muffler to be used in the midpipe as a resonator. I paid about the same, or a little less than a bolt-on system, but it was superior in quality (build and sound) and reliability (one flange, not multiples).

I sold that custom system because it wasn't suitable for n/a (too loud).

I think for the money of some exhausts, you're really just paying for styling or a noise maker. In terms of weight savings, you can work with the shop to get the weight down by supplying some parts yourself or asking them what is available with weight as a key factor.

[KAL]

Thanks for the reply! The miata completely stock, with the only planned upgrades beeing mild cams, a header, Megasquirt and the exhaust.
The reason for the custom exhaust for beeing that heavy is that it relies on the shop's stock inventory to keep the cost down, and it is in no way a "race shop".
Maybe i should take my plans to another shop, or ask if it possible to supply some of the parts myself. :bow:

[kung fu jesus]

You're welcome!

I found my exhaust shop by hanging out at a few car shows featuring mostly hotrods and muscle cars. I got a little bit of flak being there in a Miata, but when you start talking to the car owners, show genuine interest, they will share their knowledge of preferred shops readily. The shop I went to was in the sticks, and when I showed up, there was a mix of rat rods and psychobilly cars in the lot. The guys there were actually really cool when I told them what I wanted, what the car was, and what I do with it. They told me they liked the challenge and get tired of working on the same sort of cars all the time. They did a fantastic job and I let them test drive it when it was done. They tore up and down the street for about 15 minutes and loved it. :) I referred probably 5 or 6 other guys to them and have heard a number of SCCA guys now only have them do their custom work.

A similar story happened when I had my headwork done, but that's off-topic.

Car guys are car guys. When it all boils down, we all can appreciate a good product with performance in mind.

[fitftw]

I have Corksport Drift catback 2.5". It weighs 14 lbs. which I am pretty sure is lighter than Enthuza.

[etikoner]

From my experience, most of the gain you feel is from shedding weight.

I got one of the lightest( If not the lightest) off the shelf exhaust's made for the Miata and I love it. The fujitsubo RM01-A is around 17 lbs from the mid pipe to the tip and it sounds great!

I'd only switch it out for an ARC Cat back exhaust.. hah

Some custom made pieces should be able to keep the weight down as well. 40 lb's sounds insanely heavy, though.

[Thumper13]

I have Corksport Drift catback 2.5". It weighs 14 lbs. which I am pretty sure is lighter than Enthuza.

Unless they taught arithmetic different where you went to school................the Enthuza XR weighs 9.5 punds

[xjdesertfox]

If I recall, an enthuza XR doesnt include a midpipe...which a corksport drift does.

We're comparing apples to oranges.

[Slammedmx]

i like apples more that oranges.. :mrgreen: i went with a custom made and i dont have any complaints

[BoBo]

Its up to you, if your ocd about weight, then get the lighter setup. Specially if your going to keep your car all motor. But if you ask me, there is not much to gain in a lighter exhaust system other than looks. In addition, it might be more susceptible in cracking. A custom exhaust is cheaper and will probably give similar tiny hp gains. You can get away with $150-250 on a custom exhaust, you just gotta find a good exhaust shop. Lucky me there is a good shop near my place.

[Flyin 92]

To be honest, unless someone has an F/I system of some sort or making crazy power on an N/A build (Maruha, FM stroker, etc) then an exhaust is purely for sound and looks imho. Sure a lightweight exhaust is always plus so you can save weight, but outside of that there's no benefit.

[Blueiii]

Odd... This goes against everything I know from autocross, which says that in STS a 1.6L with headers, exhuast and RB CAI, once tuned, is as fast in the straights as a 1.8L. Wouldn't that lend some credence to the belief that an exhaust is part of the power gain, or do we think its just because of the tune?

[Flyin 92]

Odd... This goes against everything I know from autocross, which says that in STS a 1.6L with headers, exhuast and RB CAI, once tuned, is as fast in the straights as a 1.8L. Wouldn't that lend some credence to the belief that an exhaust is part of the power gain, or do we think its just because of the tune?

Everything I’ve read seems to suggest there are gains to be had, but nothing significant. There are a few 1.6s out there that made significant gains by removing the AFM and tuning the car properly. Adding a “high flow” intake, header and exhaust would help would improve throttle response no doubt. Even then, you’re looking at a 5-7hp gain at most; Possibly as much as 9hp depending on what intake, header and exhaust combo is used.

If I were a betting man, I'd say the tune probably netted a larger gain. Dyno sheets would go a long way in proving one way or another.

[Phatmiata]

Last time I checked Jason at Enthuza will make a custom exhaust for your car, and it would fit spot on! Just my .02 cents

[ShawnM]

this is helping a lot! I plan to do a custom exhaust also to and most of my questions are being answered. but just to add a little help to the poster, the shop doing my exhaust is ok with me supplying all the stuff needed to do my exhaust. the only question I have that didnt get brought up is , what diameter would be best for a all motor with a cold air intake header and advanced timing ?

[vindi49]

I have an ARC cat back exhaust... so you can guess which way I'd vote!! The difference in power is minimal to none as others have said, but the weight saving (assuming you're bothered to make similar savings throughout the car) will really change the way the car feels.

Edit - my previous exhaust was fabricated by a local shop and cost about £300 ($450?). It had a nice tone and weighed a lot less that the Racing Beat I had before it... so I'd suggest try another shop.

Russell.

[etikoner]

The things I'd do to get hold of an ARC catback for my car... :(