The WORKS "Dr. Jekyll" Valved Catback Exhaust
 

We are proud to formally introduce the WORKS "Dr. Jekyll" Valved Catback Exhaust!

[ame]https://www.youtube.com/watch?v=C2d2HWtvnDU[/ame]

This active style exhaust is the first of its kind for the 86 platform! By utilizing a vacuum/boost operated valve; the driver is able to control the volume and tone of the exhaust on the fly. This is the perfect solution for your daily driver or dual purpose weekend track toy!

When closed; the exhaust gasses pass through a straight through muffled section keeping the volume minimal (while also free flowing).

In the absence of vacuum (for NA vehicles) or 5+ psi of boost (for boosted vehicles) The valve will open allowing for maximum flow!

This is perfect for those of you who constantly get complaints from your neighbors for early morning cold-starts. Driving down the highway is no longer loud and drone-y! Just step on the throttle and hear the valve open to produce a nice throaty tone! :party0030:

- WORKS Team

https://store.worksmotorsports.com/B...148.216-fi.htm

Very cool! Can this be done for an axleback at well?

I'd prefer manual operation though. After all, what operation will be auto-selected but what might be wished in cases of eg. high-speed cruising on autobahns? Or driver may have wish different mode at different moods. Even for track use, there might be tracks with strict local restrictions on noise. Manual mode switch also might be more failure-safe and make product cheaper.

This looks fantastic -- I've been waiting for this for a long time.

Unfortunately, from the looks of it, the muffler is a bit small. There's a good chance those with uncatted headers will still see a slight amount of drone on the highway, even with the valve closed. We really need this sort of system with the stock muffler in some ways.

Curious to see videos!

The ND miata has a similar exhaust available with same vacuum assist from a different company. As an add on you can tie it into the can-bus system and give it power to be controlled by either the wiper stalk or via remote. I don't see why an add on wouldn't be available for this either in the future and would simply tie into the vacuum line, pretty sure they all default to fully open without a vacuum anyway.

While it can be done; the factory exhaust system pre-catback is relatively quiet. We have found that the most dramatic change is when paired with a non-resonated midpipe.

This has been a topic of debate. We personally love the idea of a manually operated valve as it carries many benefits. The dilemma comes with the reliability of aftermarket electric valves after repeated heat cycles. By utilizing a vacuum operated valve; reliability is drastically increased. Additionally, this is great for those daily drivers who want the varied sound; without having to throw switches back and forth!

I like the idea of a similar system being implemented in a factory muffler. Stay tuned!

We'll do some research on integrated vacuum pump solutions! Unfortunately our Engineers aren't very satisfied with my proposition of using a Mityvac brake bleed pump routed through the cabin... :bonk:

Apart from electric valve exhaust cutouts there are also manually operated ones. Imho their reliability should be high enough (routing wiring for electrical cutout to inside of saloon is simpler though, as electric wire can be much longer, and can bend much better. Though if one doesn't make as goal for manual operation switch or lever placement in saloon near driver, but allowed elsewhere, eg. underside of wheel arch, behind bumper, or in boot or wherever there are existing technological holes not requiring drilling new ones, it may simplify much construction/production/mounting at expense of more tedious switching between modes). Apart from reliability, those manual/cable operated cutout valves imho also should cheapen whole exhaust, no?
For example if that cable can be routed through front of saloon - one might reuse sound tube hole in firewall. Maybe there are also other better fit/placed technological holes for use.

Speaking of simple "light set" usable with stock exhaust i see in way of such:
midpipe that allows fitting most of axlebacks (something should be done for it to be usable on both Kouki and Zenki due flange differences IIRC though (hmm, some "flange/mount adapters" on end of midpipe?)) with prefitted manual cutout with cable long enough to be routed through soundpipe hole, some mounting clamps for cable to underside of car, some switch/lever for mount in saloon. And here you go - relatively simple/cheap/light set that can be used with both stock & aftermarket axlebacks, maybe with some catbacks too if replacing their midpipe and if they reuse stock flange shape/position. BTW, product should also be relatively small/light (just midpipe vs complete catback/axleback), that should cheapen logistics (eg. shipping overseas).
No welding required to mount, just replacing one exhaust bit, reliable enough, cheap enough (including shipping).

I am sure you could put some sort of electronic valve in the vacuum line that either held the vacuum or opened the line up to the air so you could manually override the exhaust valve.