sc and cutout question's
Thread Starter
Registered User
Joined: Oct 2008
Posts: 652
Likes: 0
sc and cutout question's
Im going to be getting my vt kit installed soon and it will be at 10psi. I want to get all the power i can out of it by getting some sort of exhaust but I want to be able to controll when I want it loud or not. So I have decided to get a cutout.
The only problem is that I want to keep the stock cat and have the cutout before the cat. Is there enough room for this? its not a turbo setup or else I would have just put it on the dp. what if I get after market headers, will that leave me with enough room for one?
I will be using an EMU for tuning. Will there be tuning issues if one second theres a cat and the next second its gone? (open/close valve)
thanks guys!
The only problem is that I want to keep the stock cat and have the cutout before the cat. Is there enough room for this? its not a turbo setup or else I would have just put it on the dp. what if I get after market headers, will that leave me with enough room for one?
I will be using an EMU for tuning. Will there be tuning issues if one second theres a cat and the next second its gone? (open/close valve)
thanks guys!
Community Organizer
Joined: Jun 2007
Posts: 31,070
Likes: 566
There is probably a way you could cut into your factory header to install this and leave your cat, there may be enough room, however there is going to be quite a bit of an extreme between an open header and a catted exhaust system, so I don’t know how that will work. The only thing that would seem possible to me is to have it boost actuated so that it would open automatically at a pre determined boost level and you could tune around this. Otherwise you will likely run way to lean on the same tune. Maybe someone else can chime in who has played with one of these.
Registered User
Joined: Apr 2007
Posts: 1,677
Likes: 0
i am planning on welding on a 3inch cut out Tuesday but its going where the test pipe is and i'm gonna run it by psi. So it will fully open at like 7psi. I'm still a noob at this and don't know about different maps.
Thread Starter
Registered User
Joined: Oct 2008
Posts: 652
Likes: 0
Originally Posted by Sideways,Oct 23 2009, 11:33 AM
Get the supercharger in first.
Thats why im trying to get info.
Do you have a solution for me?
Joined: Oct 2002
Posts: 8,044
Likes: 6
From: South Florida
most likely car will need to be tuned with it open and closed. closed will be super restrictive exhaust and car will prolly make more boost for less power.
your best bet is having it open in boost and then one tune does it all.
otherwise, two maps to get best performance. or tune with it open and then close it and make sure its still ok. but leave it with tune for when its open.
your best bet is having it open in boost and then one tune does it all.
otherwise, two maps to get best performance. or tune with it open and then close it and make sure its still ok. but leave it with tune for when its open.
Trending Topics
Joined: Jan 2007
Posts: 373
Likes: 1
Im a huge proponent of cutouts, i've had one in multiple locations for a couple years now on my turbo setups.
a cutout will not fit before the cat with the factory header. end of story.
to successfully accomplish an install of a cutout with a stock N/A header, you will have to remove the cat and put the cutout in place of it. I had this on my first setup. Doing it this way, you will need to do some exhaust fab work to get the Y pipe in place properly and mate with the flanges, but you can keep your factory cat back exhaust and factory header, with the cutout in between. Just like a test pipe, but much better...see this (with pictures)
for non-turbo and a cutout you will go insane from the noise if you leave it open for more than a few mins.
for turbo applications, its not nearly as loud due to the turbine adsorbing the sound.
as far as how to opening it (on the fly), you need something better than boost activated, which sucks.
you'll have to (micro)electronically open it depending on throttle/load, otherwise just use a switch. read
what i did...
I created a custom circuit, microchip and software to open the cutout via a switch or with a push of the throttle (as in going full throttle).
The micro switches on the extra fuel map (nitrous) in the AEMEMS when the cutout is open to supply the extra fuel that is required due to the increased air flow. It turns off the map when the cutout is closed.
This is IMPORTANT if you don't have some way to change the fuel map, tune for numbers with the cutout open and simply run rich when it is closed. this is better than running lean with it open.
read the part about the cutout here for more info
a cutout will not fit before the cat with the factory header. end of story.
to successfully accomplish an install of a cutout with a stock N/A header, you will have to remove the cat and put the cutout in place of it. I had this on my first setup. Doing it this way, you will need to do some exhaust fab work to get the Y pipe in place properly and mate with the flanges, but you can keep your factory cat back exhaust and factory header, with the cutout in between. Just like a test pipe, but much better...see this (with pictures)
for non-turbo and a cutout you will go insane from the noise if you leave it open for more than a few mins.
for turbo applications, its not nearly as loud due to the turbine adsorbing the sound.
as far as how to opening it (on the fly), you need something better than boost activated, which sucks.
you'll have to (micro)electronically open it depending on throttle/load, otherwise just use a switch. read
what i did...
I created a custom circuit, microchip and software to open the cutout via a switch or with a push of the throttle (as in going full throttle).
The micro switches on the extra fuel map (nitrous) in the AEMEMS when the cutout is open to supply the extra fuel that is required due to the increased air flow. It turns off the map when the cutout is closed.
This is IMPORTANT if you don't have some way to change the fuel map, tune for numbers with the cutout open and simply run rich when it is closed. this is better than running lean with it open.
read the part about the cutout here for more info
Thread Starter
Registered User
Joined: Oct 2008
Posts: 652
Likes: 0
Originally Posted by averageJoe,Oct 24 2009, 01:20 AM
Im a huge proponent of cutouts, i've had one in multiple locations for a couple years now on my turbo setups.
a cutout will not fit before the cat with the factory header. end of story.
to successfully accomplish an install of a cutout with a stock N/A header, you will have to remove the cat and put the cutout in place of it. I had this on my first setup. Doing it this way, you will need to do some exhaust fab work to get the Y pipe in place properly and mate with the flanges, but you can keep your factory cat back exhaust and factory header, with the cutout in between. Just like a test pipe, but much better...see this (with pictures)
for non-turbo and a cutout you will go insane from the noise if you leave it open for more than a few mins.
for turbo applications, its not nearly as loud due to the turbine adsorbing the sound.
as far as how to opening it (on the fly), you need something better than boost activated, which sucks.
you'll have to (micro)electronically open it depending on throttle/load, otherwise just use a switch. read
what i did...
I created a custom circuit, microchip and software to open the cutout via a switch or with a push of the throttle (as in going full throttle).
The micro switches on the extra fuel map (nitrous) in the AEMEMS when the cutout is open to supply the extra fuel that is required due to the increased air flow. It turns off the map when the cutout is closed.
This is IMPORTANT if you don't have some way to change the fuel map, tune for numbers with the cutout open and simply run rich when it is closed. this is better than running lean with it open.
read the part about the cutout here for more info
a cutout will not fit before the cat with the factory header. end of story.
to successfully accomplish an install of a cutout with a stock N/A header, you will have to remove the cat and put the cutout in place of it. I had this on my first setup. Doing it this way, you will need to do some exhaust fab work to get the Y pipe in place properly and mate with the flanges, but you can keep your factory cat back exhaust and factory header, with the cutout in between. Just like a test pipe, but much better...see this (with pictures)
for non-turbo and a cutout you will go insane from the noise if you leave it open for more than a few mins.
for turbo applications, its not nearly as loud due to the turbine adsorbing the sound.
as far as how to opening it (on the fly), you need something better than boost activated, which sucks.
you'll have to (micro)electronically open it depending on throttle/load, otherwise just use a switch. read
what i did...
I created a custom circuit, microchip and software to open the cutout via a switch or with a push of the throttle (as in going full throttle).
The micro switches on the extra fuel map (nitrous) in the AEMEMS when the cutout is open to supply the extra fuel that is required due to the increased air flow. It turns off the map when the cutout is closed.
This is IMPORTANT if you don't have some way to change the fuel map, tune for numbers with the cutout open and simply run rich when it is closed. this is better than running lean with it open.
read the part about the cutout here for more info
Ill probably go with tuning with the flap open and the manual swich for whenever I want to get on it. Will there be any problems daily driving with the flap closed and running slightly rich? maybe long term problems?
So there is absolutely no way to swich between 2 maps on a EMU? Later on I plan on running 14psi and meth. I want to also have 2 maps for that. One with valve closed and no meth for dd and the other for valve open and meth spraying at full throttle and above a certain psi (5-6)
Registered User
Joined: Mar 2008
Posts: 1,327
Likes: 0
From: seminole, Fla
just tune the car with the cutout open and then drive on that tune with it closed, it wont be that far off.
QTP makes good cutouts, Ive had them in the past. they have a toggle switch that you hold for 3 seconds to open the cutout.
QTP makes good cutouts, Ive had them in the past. they have a toggle switch that you hold for 3 seconds to open the cutout.