GRP Emira Decat Pipes Now Available!

[R35_J]

This might be an odd question but does anyone know what's quieter: GRP cat delete with valve closed or Miltek exhaust with valve closed?
Looking to increase sound when valve is open but keep the car quiet when valve is closed for road trips. Essentially looking to have the best of both worlds lol.

 

[Six Speed Stephen]

Installed the GRP decat and Milltek valve controller. It really brings the car alive. The sound difference is VERY noticeable in a positive way. Much more aggressive and deeper tone and louder in general.

It could be a mental thing, but the throttle response feels a bit sharper and the car definitely seems slightly quicker. I'm sure it's not a huge gain in power but the sound in and of itself is worth every penny.

Also, it takes 30 seconds to program/map the mirror Homelink buttons to the Milltek controller buttons so I just stowed the fobs away in my glovebox with the manuals after doing so. Now i just press the middle button for loud/fully open and the 3rd button for quiet (which is basically only for long highway hauls or entering neighborhoods at sensitive times).

What a fantastic pair of upgrades for relatively low cost. If you're not in a state that does CARB testing, I HIGHLY recommend you delete that third cat ASAP! Thanks @GRP. The pipe fit great. It was a bit snug and we had to use some channel locks to clamp it onto the midpipe but overall it was a smooth process (we were using a lift so that helped a ton!).

How much did it cost?

 

[K_Squared]

How much did it cost?

My brother owns the shop so the installation was free. A competent shop should be able to do the install of both in less than 2 hours total from start to finish so I don't think it should cost more than ~$300 if you don't want to do it yourself. Of course that all depends on cost of labor in your area.

Parts from GRP:

 

[K_Squared]

This might be an odd question but does anyone know what's quieter: GRP cat delete with valve closed or Miltek exhaust with valve closed?
Looking to increase sound when valve is open but keep the car quiet when valve is closed for road trips. Essentially looking to have the best of both worlds lol.

I can't speak for the Milltek exhaust, but I just drove ~150 miles on mostly highways with the full closed setting on the controller with the GRP delete it was very pleasant at around 75mph. A very slight drone but it's quiet and not at all tiring.

 

[GRP]

Just finished a write up/how-to for the the decat install.
Im no writer or journalist so its basic but serves the purpose.
Give it a look below!
Few take aways --

• Install took about 45 minutes on our shop car. Now I have done a lot of these on prior Evora's so know a few tricks but overall it wasnt very difficult and learned a few new tricks along the way.
• The muffler and other items 100% DO NOT need to be removed. See the pictures in the install doc.
• You may need a new gasket, ours was fine but we have had a couple others who had crumbly ones when swapping. We are working on getting stock of some oem replacements as well as investigating some off the shelf options from Napa/Oreilly's etc.
• The decat pipe alone sounds great and is a really nice improvement but when coupled with the Milltek valve controller its like a whole different car! The exhaust valve doesnt open 100% at idle and low rpms but instead gradually opens/fluctuates depending on load/rpms. The Milltek controller keeps it 100% open or closed with the press of a button and also remembers the mode you had it in when you shut the car off. So next time you cold start it and you had the valve open prior it sounds pretty killer! You no longer are funbling to get it into sport mode to get some sound out of it.

GRP EMIRA DECAT INSTALL DOC

 

[GRP]

Here are a few rough preliminary videos.
Dont mind the wind noise.
We will be posting some better quality in the next few days.


Decat installed
Milltek controller installed
#3 mode - Factory mode

 

[GRP]

Decat installed
Milltek controller installed
#2 - Valve closed mode

 

[GRP]

Decat installed
Milltek controller installed
#1 - Valve open Mode

 

[tnbuilder]

Looks like a mod I would like to do...but I was told it would void the warranty (by the salesperson). I plan on taking my car to the dealer for service. I am sure they would notice and doubt people are just swapping these back and forth...so how are people handling this situation?

 

[GRP]

FWIW -- I have never heard of someone getting warranty work refusal due to having a decat pipe or rear section exhaust installed on an Evora which is the same setup.
Take that with a grain of salt though as every situation is different and can vary from dealer to dealer. Some dealers even install these though.

 

[KJD]

FWIW -- I have never heard of someone getting warranty work refusal due to having a decat pipe or rear section exhaust installed on an Evora which is the same setup.
Take that with a grain of salt though as every situation is different and can vary from dealer to dealer. Some dealers even install these though.

I’d be more worried about the valve controller.

The ability to close the valve at high revs when the car would normally force it open might be an issue.

BTW, thanks for the install hints Greg.
I thought my bumper-off method was way harder than it should have been.
I hadn’t thought to undo the y-pipe mountings. That might have made it possible for me in my lying-on-my-back-on-the-driveway situation.

 

[scarzie]

I’d be more worried about the valve controller.

The ability to close the valve at high revs when the car would normally force it open might be an issue.

BTW, thanks for the install hints Greg.
I thought my bumper-off method was way harder than it should have been.
I hadn’t thought to undo the y-pipe mountings. That might have made it possible for me in my lying-on-my-back-on-the-driveway situation.

It would be nice if there was a 3rd option that reverts back to stock settings

 

[GRP]

It would be nice if there was a 3rd option that reverts back to stock settings

On the valve controller? There is!
The 3 buttons do the following:
1- Valve open 100%
2- Valve closed 100%
3- Factory valve contol.

 

[scarzie]

On the valve controller? There is!
The 3 buttons do the following:
1- Valve open 100%
2- Valve closed 100%
3- Factory valve contol.

I stand corrected, thanks!!!

 

[Rapture]

On the valve controller? There is!
The 3 buttons do the following:
1- Valve open 100%
2- Valve closed 100%
3- Factory valve contol.

In your first video above, what driving mode were you in, Touring, Sport, or Track?

I'm hoping that the sound in Tour mode with the Decat pipe is less than Track mode in stock form. I'd like to be able to keep some lower level of volume. More than stock in Touring mode is fine, just keep it lower on a highway cruise, etc.

Would you say it is quieter than Sport when driving in touring mode with the controller set to Stock? (man, that's a confusing question).

Also, can you program 1 HomeLink button to toggle through the controllers 3 modes? I already use 2 of the HomeLink buttons.

Thanks,

 

[GRP]

In your first video above, what driving mode were you in, Touring, Sport, or Track?

I'm hoping that the sound in Tour mode with the Decat pipe is less than Track mode in stock form. I'd like to be able to keep some lower level of volume. More than stock in Touring mode is fine, just keep it lower on a highway cruise, etc.

Would you say it is quieter than Sport when driving in touring mode with the controller set to Stock? (man, that's a confusing question).

Also, can you program 1 HomeLink button to toggle through the controllers 3 modes? I already use 2 of the HomeLink buttons.

Thanks,

That one was in sport mode.
I believe with the decat installed and the car in tour mode it is still quieter than track mode is with stock cat in place.
Either mode 2 or 3 on the controller keeps the car VERY civil and quiet. Obviously if you are ripping around about 4500 rpms the valve will open (in mode 3) and you will get the full decat effect but for a road trip, sneaking out of the house early etc the car is still very quiet with the valve closed and decat installed. Just need to remember which mode you had it in when you shut the car off because it will remain there the next time its started.

Each button transmits a different signal so I dont see a way to have one homelink button do multiple modes unfortunately.

 

[scarzie]

OK one more for ya, the controller only works once the battery is running, correct?

Say it's in stock mode when I shut the car off, and I want to start up with them open, do I hit the ignition once without trying to start, switch the mode, then start up?

 

[GRP]

OK one more for ya, the controller only works once the battery is running, correct?

Say it's in stock mode when I shut the car off, and I want to start up with them open, do I hit the ignition once without trying to start, switch the mode, then start up?

Unfortunately the valve only operates when the car is actually running so you cant make any changes until its fired up.

 

[FeelsWheels]

My brother owns the shop so the installation was free. A competent shop should be able to do the install of both in less than 2 hours total from start to finish so I don't think it should cost more than ~$300 if you don't want to do it yourself. Of course that all depends on cost of labor in your area.

Parts from GRP:

View attachment 39282

Where is your brothers shop?

 

[K_Squared]

Where is your brothers shop?

Lynchburg, Virginia.