Exhaust Options Index

[Jjrho]

I just installed the 3rd cat delete bypass n miltek valve controller.... was not too difficult.... grp had a good instruction sheet so.....
I did my 1st oil change too at 950 miles....oil looked almost new.... any way,definitely get the gasket.... mine was bad on removal of the cat....

On the miltek valve controller, I put some silicone on the box wiring area so that no moisture can get in there n also wrapped the wires with foil so it doesn't melt with exhaust heat..... I mounted it with dbl sided tape on the rear subframe ... that area will get moisture from driving in rain, etc so, I decided to water proof it.... here's some pics....

James R

 

[Jjrho]

I measured some sound levels....

On stock exh.... using SPL Meter set at dB C to account for low frequency sound, at about 10ft from exh tips....
Oem cold start 86dB C
Sport mode 93 dB C

After 3rd Cat Delete, with exh valves fully open, cold start 91dB
n upto 105 dB at 4k rev blip.

These are just relative figures for reference....

My huracan w fab speed exh hits 115 dB on cold start up. FYI.

There's definitely more decel pop now on fully open.... it is nice having a fully closed option now.... it's quite quiet despite the 3rd cat being gone....

I'd prefer louder if possible.... I may just put an electric Y valve on the 3rd cat delete pipe so that I also have an option for 'straight pipe' level of noise....

James R

 

[Jjrho]

Full open, idle

 

[Gprodigy]

Lotus Emira Valved Sport Exhaust System

Elevate Your Lotus Emira with the Ultimate Titanium Valved Exhaust System Experience the pinnacle of performance and precision engineering with our Titanium Valved Exhaust System, meticulously crafted for the exhilarating Lotus Emira. Building upon our success with the Lotus Evora platform...

valvetronic.com

(F1 sound) price $5k

 

[Blackthought_]

View attachment 49144
View attachment 49145

Lotus Emira Valved Sport Exhaust System

Elevate Your Lotus Emira with the Ultimate Titanium Valved Exhaust System Experience the pinnacle of performance and precision engineering with our Titanium Valved Exhaust System, meticulously crafted for the exhilarating Lotus Emira. Building upon our success with the Lotus Evora platform...

valvetronic.com

(F1 sound) price $5k

Wow what is the f1 noise!

 

[Gprodigy]

Wow what is the f1 noise!

Valvetronic Exhaust

Have you seen the valvetronic exhaust from Facebook? It seriously sounds like a F1. They have more videos in the cabin, with the Valve Controller switching (Via fb). But this is impressive...

www.emiraforum.com

Members are going more in depth here, looks like the race headers is the answer to your question.

 

[Jincook]

After reading through members comments on headers, it got me worried about installing headers and y pipe. Does anyone have recommendations on how to avoid check engine light with headers and y pipe ??

My car is currently equipped with

1. Eventuri Intake
2. Miltek valve control
3. 3rd cat delete

I thought my next step will be headers and y pipe but im worried reading through members comments about getting check engine lights and warranty void.

Anyone here installed the headers without getting a check engine light?

 

[seriously]

Headers and y pipe are more complex for proper tuning and smog. Cat delete is no problem.

 

[Tobiasz17azs]

After reading through members comments on headers, it got me worried about installing headers and y pipe. Does anyone have recommendations on how to avoid check engine light with headers and y pipe ??

My car is currently equipped with

1. Eventuri Intake
2. Miltek valve control
3. 3rd cat delete

I thought my next step will be headers and y pipe but im worried reading through members comments about getting check engine lights and warranty void.

Anyone here installed the headers without getting a check engine light?

I'm a big fan of how cars sound with a full exhaust. But a Lotus is a Lotus, and I don't want to mess with the headers while I still have my factory warranty. Maybe for now, less noise but also less headaches if it comes to any warranty work.

For now I’ll keep valve controller and 3rd cat delete . Maybe I’ll do eventuri intake

 

[crashprash]

Headers and y pipe are more complex for proper tuning and smog. Cat delete is no problem.

I've done y-pipe with exhaust, 3rd cat delete with no CEL. The O2 sensors are in the headers so only changing headers will require ECU mods. There isn't a cat in the stock y-pipe (has a sensor as well) so changing to aftermarket y-pipe shouldn't change anything (maybe a bit better flowing as a the stock one has a big dent in it)

 

[Jincook]

Thanks to everyone for inputting suggestions.. @crashprash does sound change after y pipe? Any power gain?? I currently have 3rd cat delete but adding y pipe would change sound and power??

 

[crashprash]

Thanks to everyone for inputting suggestions.. @crashprash does sound change after y pipe? Any power gain?? I currently have 3rd cat delete but adding y pipe would change sound and power??

Never did a dyno so no idea about power change. Also no idea about sound as everything was fitted at once.

 

[Gprodigy]

This may be helpful others.
V10 vs. V6 (open valve, 3rd Cat delete $500/600mod). They sound identical from idle Rev.

 

[FST]

This may be helpful others.
V10 vs. V6 (open valve, 3rd Cat delete $500/600mod). They sound identical from idle Rev.
View attachment 50912

so.. what is the trick? decat and milltek valve controller?

 

[NorCalEmira]

so.. what is the trick? decat and milltek valve controller?

That's all you need to get the sound. Jury is still out on whether there are any power gains to be had with a full cat back exhaust but I doubt it. If there were gains to be had, the manufacturers wouldn't be keeping the good news a secret. If you want power gains, you'd likely need headers and Y-pipe and then you have the smog / CEL implications.

It boils down to 3 options based on what I've seen on the forums:

1) Just want a more aggressive sound - Milltek valve controller + 3rd cat delete
2) Want to lose 20 lbs at a cost of $2,500 or more - Add a titanium cat back exhaust
3) Looking for power gains - Go all in with headers but be prepared for the tuning and smog ramifications

 

[Gprodigy]

so.. what is the trick? decat and milltek valve controller?

No trick, thats all you need. $600 for those two parts and it sounds like a v10 lambo respectfully.

NorCalEmira's response is spot on

 

[Blackthought_]

Has anyone had first hand experience with the GRP titanium exhaust? Curious on the sound it makes, especially with the decay and the controller installed. Videos unfortunately don’t do it justice

 

[John777]

That's all you need to get the sound. Jury is still out on whether there are any power gains to be had with a full cat back exhaust but I doubt it. If there were gains to be had, the manufacturers wouldn't be keeping the good news a secret. If you want power gains, you'd likely need headers and Y-pipe and then you have the smog / CEL implications.

It boils down to 3 options based on what I've seen on the forums:

1) Just want a more aggressive sound - Milltek valve controller + 3rd cat delete
2) Want to lose 20 lbs at a cost of $2,500 or more - Add a titanium cat back exhaust
3) Looking for power gains - Go all in with headers but be prepared for the tuning and smog ramifications

So 3rd cat delete and millitek does that sound almost or is it indentical to 3rd cat delete, millitek and a titanium exhaust?


I was looking at valvetronic one but crazy pricing then I saw stradmans GRP titanium with 3rd cat delete and sounded awesome..

But if its not much different then I'd rather save several thousand..and just get 3rd cat delete GRP and millitek controller.

 

[NorCalEmira]

So 3rd cat delete and millitek does that sound almost or is it indentical to 3rd cat delete, millitek and a titanium exhaust?


I was looking at valvetronic one but crazy pricing then I saw stradmans GRP titanium with 3rd cat delete and sounded awesome..

But if its not much different then I'd rather save several thousand..and just get 3rd cat delete GRP and millitek controller.

You’ll get a different tone if you add the full GRP exhaust and reduce weight as well. The 3rd cat delete with valve controller makes a huge difference at a minimal cost. Both good alternatives.

 

[Speedy Emira]

Never did a dyno so no idea about power change. Also no idea about sound as everything was fitted at once.

I can't see a y pipe will make any difference to the power on a standard tune because it is a forced air induction set up with more than enough air being supplied. Sure you will get some power gains from removing the main cat but even that isn't a gamechanger. I deleted the cat for the better and louder exhaust note.
It is like the gas flowed head work JUBU offer which is pointless on a standard car but works well with a larger supercharger or turbo conversion.
On a separate note I watched the YouTube video showing the best 5 Emira exhaust systems and it was a pointless exercise because they weren't all fitted with equal parts. Any of the systems would be better with a cat delete and even better with headers. To do a real comparison they need to be in the same setting (indoors/outdoors/going through a tunnel) and equal set-up. That doesn't even take into account what the sound was recorded on and where in relation to the exhausts.
The Emira exhaust being mid-engine is so short it is hard to make any big difference in design and the reason all of the aftermarket exhausts look nearly the same.