Exhaust Options Index

G’day David
I’m not interested in a valve controller but I am interested in the 3rd cat delete. Can you confirm which one you installed and that there are no issues for us in Oz re warranty if we fit this?
Cheers
Hi mate. I bought the miltek decat. The GRP decat is much the same but slightly cheaper. Prob best go that way as they deliver much quicker and cheaper. I had the lotus guys fit it, and they were surprised at how much it improved the performance and sound. No probs so far. Doubt there will be. Make sure u buy the “o” gasket if u buy it from GRP. I didn’t bother with the valve controller. I don’t see any problems with it without it. It’s not that noisy, and I don’t give a shit about the neighbours.
While u are at it, it’s probably worth u buying the GRP cold air filter in the same order to save on the expensive postage. I’ve just ordered one.
 
Hi mate. I bought the miltek decat. The GRP decat is much the same but slightly cheaper. Prob best go that way as they deliver much quicker and cheaper. I had the lotus guys fit it, and they were surprised at how much it improved the performance and sound. No probs so far. Doubt there will be. Make sure u buy the “o” gasket if u buy it from GRP. I didn’t bother with the valve controller. I don’t see any problems with it without it. It’s not that noisy, and I don’t give a shit about the neighbours.
While u are at it, it’s probably worth u buying the GRP cold air filter in the same order to save on the expensive postage. I’ve just ordered one.
That’s interesting, thanks.
I’m pleasantly surprised that the dealer was happy to install the parts, presumably with no effect on the warranty (unlike what I’m reading about other exhaust installations).
I take it you mean the “high flow dry media drop in” air filter?
Again I take it there is no warranty issue with that?
As you can tell I’m a little paranoid about doing anything that may void the power train warranty.
My old Ferrari had many aftermarket parts on it (several installed by the dealer) but that was way out of warranty so no one seemed to care!
With the Emira I really don’t want to risk it.
 
That’s interesting, thanks.
I’m pleasantly surprised that the dealer was happy to install the parts, presumably with no effect on the warranty (unlike what I’m reading about other exhaust installations).
I take it you mean the “high flow dry media drop in” air filter?
Again I take it there is no warranty issue with that?
As you can tell I’m a little paranoid about doing anything that may void the power train warranty.
My old Ferrari had many aftermarket parts on it (several installed by the dealer) but that was way out of warranty so no one seemed to care!
With the Emira I really don’t want to risk it.
Fair enough. I guess I’m not too worried about warrenty issues. I doubt minor changes i do with the emira would cause any problems to the engine. I’ve had 4 lotus from new, and never had a day problem with engine or gbox/drivetrain. I’ve had some pretty serious engine and suspension mods done on a couple of them and had zero clutch/drivetrain/gbox problems. I sometime snigger a bit when I read some of the comments with regards to these parts failing at 500 bhp or whatever bullshit figure they choose. Yet, in the large lotus community I belong to, no one has had such problems. I think these types of problems occur more due to driving styles rather than mods. But fair enough. If won’t sit right with u, its best to leave it alone. Otherwise you will tend to leave it in the garage too much.
You’ve probably not experienced Lotus before by the sounds. They are much more robust than what you’ve probably read. Don’t fall for that BS either.
 
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  • #125
I have already done the Milltek GPF/OPF Bypass and now I was wondering if changing the rest of the exhaust system will make any difference, I am comparing between two options for the exhaust system, shall I go for the Milltek or the Larini ?

Milltek exhaust: https://milltekshop.com/particulate...ation-emira-3-5l-v6-supercharged-2022-ssxlo5/

Larini exhaust: https://www.blackwatchracing.com/product-p/la-emira-clubsport.htm
I like Milleks' Valve Controller, but I feel like Lanari's exhaust system has more of a super car sound.
 
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I have already done the Milltek GPF/OPF Bypass and now I was wondering if changing the rest of the exhaust system will make any difference, I am comparing between two options for the exhaust system, shall I go for the Milltek or the Larini ?

Milltek exhaust: https://milltekshop.com/particulate...ation-emira-3-5l-v6-supercharged-2022-ssxlo5/

Larini exhaust: https://www.blackwatchracing.com/product-p/la-emira-clubsport.htm
It would be good if you could hear both in person because I have the Miltek and it sounds different to the installers video.
 
Different how?
Firstly it can only sound as good as the device it is recorded on and played back on. The the sound when they are first fitted seems to change after it has settled down. Mine is louder and a bit more race car sounding than first fitted. Sounds lame saying more race car but I can't think how else to describe it.
Hopefully one of the forum owners will be meeting me in the next week or so and we can check them side by side.
 
Here's a DeCat vs Full System pros and cons list from chatgpt. 💡
**De Cat System:**

Pros:
1. **Increased Power:** Removing the catalytic converter can improve exhaust flow, potentially leading to increased horsepower.
2. **Enhanced Sound:** De Cat systems often result in a more aggressive and louder exhaust note, appealing to those who enjoy a sportier sound.
3. **Simplified Design:** Since you're removing a component (catalytic converter), the exhaust system becomes simpler and lighter.

Cons:
1. **Emissions Impact:** Removing the catalytic converter may result in increased emissions, making it illegal in some areas or affecting your ability to pass emissions tests.
2. **Potential for Check Engine Light:**-NON ISSUE FOR EMIRA
"Doing a third cat delete will 100% NOT cause a check engine light.
It is an un-monitored catalyst."


3. **Legal Issues:** In some regions, it's illegal to remove the catalytic converter due to environmental and emissions regulations.

**Full Exhaust System:**

Pros:
1. **Comprehensive Performance Improvement:** A full exhaust system includes various components like headers, mid-pipes, and mufflers, providing a more comprehensive performance upgrade.
2. **Balanced Performance:** Full exhaust systems are designed to provide a balance between improved performance and maintaining compliance with emissions regulations.
3. **Tuned Sound:** Some full exhaust systems are designed to provide an enhanced exhaust note without being overly loud, catering to enthusiasts who prefer a specific tone.

Cons:
1. **Cost:** Full exhaust systems are typically more expensive than De Cat systems due to the inclusion of multiple components.
2. **Installation Complexity:** Installing a full exhaust system might be more complex than just removing the catalytic converter, requiring professional installation in some cases.
3. **Less Aggressive Sound:** For enthusiasts seeking an extremely aggressive exhaust note, a full system might not deliver the same level of raw sound as a De Cat setup.

Ultimately, the choice between a De Cat system and a Full Exhaust system depends on your preferences, local regulations, and the specific goals you have for your car modifications.
How can a full system have less aggressive sound? Im planning to change to race headers and y-pipe because I want more (screaming) sound.. So this is a myth? I was in the understanding that a (straight) pipe eg race headers vs stock gives better performance (icm ecu tune) and also better/louder sound? Please advice..
 
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  • #130
GRP titanium exhaust
 
OMG @GRP, more views of the install, KILL THE STUPID MUSIC so we can hear the exhaust! What's the weight difference between your exhaust (no 3rd cat delete, just the exhaust) and the factory exhaust?

Okay nevermind. I just went to their website and there's videos of it with valve closed and open. HOWEVER, both still have the 3rd cat delete. Can we get a sound check with the 3rd cat installed? Especially with the valve open?

They also list the weight: 13.2 lbs versus 30 lbs for the stock muffler. That's a fairly decent reduction; 16.8 lbs. If you combine that with the reduction from an Antigravity battery, that's about 46.5 lbs. It'll cost ya about $3,500 but it is what it is.

Now we need some dyno charts.
 
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omg i want GRP to make a full video so bad. its been MONTHS

we need

1. fly bys
2. inside audio
3. startup
4. stationary revs
5. before and after clips

lets goooooooooo
 
Hey guys, I'm looking at a car with the Milltek exhaust already installed by the dealer. This is a $2,300 exhaust system from GRP but the line item on the sticker is $5,000. The explanation is that installation is labor intensive. Hard to imagine this job could taker longer than 2.5 to 3 hours for any experienced tech, right?
 
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Skip to 2:00 for the Emira content.

Stradman is going to add GRP decat+titanium exhaust

 
Hi mate. I bought the miltek decat. The GRP decat is much the same but slightly cheaper. Prob best go that way as they deliver much quicker and cheaper. I had the lotus guys fit it, and they were surprised at how much it improved the performance and sound. No probs so far. Doubt there will be. Make sure u buy the “o” gasket if u buy it from GRP. I didn’t bother with the valve controller. I don’t see any problems with it without it. It’s not that noisy, and I don’t give a shit about the neighbours.
While u are at it, it’s probably worth u buying the GRP cold air filter in the same order to save on the expensive postage. I’ve just ordered one.
What pat number is the O gasket or where can it be found? Thanks
 
Hey guys, I'm looking at a car with the Milltek exhaust already installed by the dealer. This is a $2,300 exhaust system from GRP but the line item on the sticker is $5,000. The explanation is that installation is labor intensive. Hard to imagine this job could taker longer than 2.5 to 3 hours for any experienced tech, right?

$2,700?!?! That’s absurdly overpriced for installation of an exhaust.

Are you buying from a Lotus dealer?

I would have signed and dated, in writing from the dealership manager and service department manager, that the exhaust in no way changes warranty coverage in the car. Heck, I’d probably want something in writing from Lotus themselves.
 
$2,700?!?! That’s absurdly overpriced for installation of an exhaust.

Are you buying from a Lotus dealer?

I would have signed and dated, in writing from the dealership manager and service department manager, that the exhaust in no way changes warranty coverage in the car. Heck, I’d probably want something in writing from Lotus themselves.

$2,700?!?! That’s absurdly overpriced for installation of an exhaust.

Are you buying from a Lotus dealer?

I would have signed and dated, in writing from the dealership manager and service department manager, that the exhaust in no way changes warranty coverage in the car. Heck, I’d probably want something in writing from Lotus themselves.
Yeah, this was installed by the dealer on a new car. They definitely applied the "Lotus tax" and that was more than I was willing to pay for the convenience of having it done from the start. I couldn't make a deal on that car but ended up finding one closer to my spec at MSRP so it all worked out. I'll likely go with the GRP titanium exhaust when I get around to it.
 
Even if you figure 3 hours at $250, you’re still well under $1,000.

Looking at installation instructions, there just ain’t that much to changing the exhaust. What’s more, it’s not like there’s a bunch of one time use expensive fasteners and gaskets that are needed.

I guess if you can get someone to pull the trigger, ok, but that seems like a stupid way to do business.
 

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