Just after a bit of exhaust advice for track

[Linus27]

My DC5 has AEM V2 induction, Spoon B Pipe, Spoon N1 and K100. It made 228bhp and I'm really happy with the power and sound. However, for track, I'm led to believe the Spoon system is going to be too loud so I'm looking at what my best options are.

I do have Fujisubo Power Getter cat back system in the loft which I believe is much quieter. However is it more restrictive? I believe the Spoon system is a very good free flowing system. I could get a decat which might free things up a bit more.

Another option is to keep the Spoon B pipe and change the back box but I tried this by trying to fit the Fujisubo Power Getter back box but it came up short and would not reach the mid pipe. Not sure what's going on there.

So I'm just open to ideas and suggestions really so any thoughts really appreciated.

 

[MrRy]

I swapped my n1 backbox for oem last week. Fits the Spoon B pipe perfectly. Really quiet now so perfect for track and I can't feel any power difference at all. it's just the Oem box is a good 3kg or so heavier.

 

[Rob R]

As above, just bung your OEM backbox on to save having to swap the whole cat back.

 

[Linus27]

Thanks guys. The car never came with the OEM backbox, only a Spoon cat back and a Fujisubo cat back.

Might try and get an OEM backbox and get a decat with map tweak whilst keeping the Spoon B pipe. Seems like a good plan

 

[Liam]

Completely depends on the track in my experience. If the place you're going isn't too strict on noise, you should be fine for a 105db day.

 

[hondazzz]

In my opinion , if the Fujitsubo rear muffler has the same bore and is totally straight through ( no built in silencer or chamber -oem style) you have not changed anything...

If you put the oem muffler..well the k100 map wont be optimum.

 

[Linus27]

Completely depends on the track in my experience. If the place you're going isn't too strict on noise, you should be fine for a 105db day.

I was kind of thinking of doing all of them, Brands, Croft, Silverstone, Donington and Bedford. I know Bedford is strict so I could skip that one.

 

[Linus27]

In my opinion , if the Fujitsubo rear muffler has the same bore and is totally straight through ( no built in silencer or chamber -oem style) you have not changed anything...

If you put the oem muffler..well the k100 map wont be optimum.

The Fujitsubo is noticeably quieter than the Spoon system which is known to be pretty loud. Changing to most other cat back systems will be quieter but the Spoon system is very good. As I say, if I just changed to an OEM back box and kept the Spoon mid pipe, then I would get a decat and a remap.

 

[hondazzz]

The Fujitsubo is noticeably quieter than the Spoon system which is known to be pretty loud. Changing to most other cat back systems will be quieter but the Spoon system is very good. As I say, if I just changed to an OEM back box and kept the Spoon mid pipe, then I would get a decat and a remap.

i thought you were doing the swap just for trackdays..my fault.. well if i were you i would put the fujitsubo..lighter than oem and even if it has a built in silencer i doubt if it would be worst than OEM in terms of power.. then again... dyno will tell you

 

[blueguy]

Of course the best thing would be to go down to your nearest track and get it noise tested, however if you're running the OEM header and cat I would've thought your noise levels would be fine (excluding Bedford).

 

[Linus27]

Of course the best thing would be to go down to your nearest track and get it noise tested, however if you're running the OEM header and cat I would've thought your noise levels would be fine (excluding Bedford).

I think this might be the sensible thing to do first. My only concern is I would only be able to do static and as we know, when we hit VTEC, all hell breaks loose in terms of noise

 

[Linus27]

I think I have decided to keep the Spoon B-Pipe, get an OEM back box and then get a DC Sports 4-2-1 manifold and map tweek.

This should be ok for track??

 

[El_Boomo]

For what it's worth I popped to Snetterton and had mine noise tested today. I'm running a Spoon N1 and a custom 2.5" B-pipe which was based on the Spoon B with a smaller silencer.

The tester wanted me to do 6000 RPM but I explained that the ECU wouldn't let me do over 5500 whilst static. They were fine with this and went ahead and tested it. It read 102dB, which he said would be fine despite not being revved to 3/4 of the redline like they normally ask.

With regards to all hell breaking loose whilst on the move, he told me it's highly unlikely to cause a problem on a 'noisy' day

 

[Linus27]

Thanks El_Boomo. I was going to pop to Brands on Wednesday to be noise tested so I might still pop along and see what they say. I have a K100 with launch control. I found out today that if I have the car in neutral and the foot on the brake, I can override the limiter and rev to what they want for the test.

 

[Mebz]

Thanks El_Boomo. I was going to pop to Brands on Wednesday to be noise tested so I might still pop along and see what they say. I have a K100 with launch control. I found out today that if I have the car in neutral and the foot on the brake, I can override the limiter and rev to what they want for the test.

I wouldn't do that.

The limiter is there to protect the engine, it's not really a launch control.

Not sure on the exact details on how the limiter does it but it's something to do with vtec engagement on idle.

 

[Linus27]

I wouldn't do that.
The limiter is there to protect the engine, it's not really a launch control.
Not sure on the exact details on how the limiter does it but it's something to do with vtec engagement on idle.

I think this is true on a standard ECU but I am sure the latest K100 software puts a launch control system in the ECU at 4k revs but can be over-ridden by keeping your foot on the brake and in neutral.

 

[Rob.]

I think this is true on a standard ECU but I am sure the latest K100 software puts a launch control system in the ECU at 4k revs but can be over-ridden by keeping your foot on the brake and in neutral.

Yep holding your foot on the brake pedal just takes the launch control off, won't hurt anything

 

[Linus27]

So, I fitted an OEM back box to the car and wow, it's a lot quieter. In some way, it's nicer like this. It has a much smoother, purer sound rather than that bit of boom you get from the Spoon N1. When you hit VTEC, you just get induction noise now which is also very clean sounding.

So, the next step is the decat. Not sure to go for a DC Sports 4-2-1 or just the Spoon 2-1 and mate it with my existing OEM 4-2 manifold. Again, the worry is noise. I believe the Spoon 2-1 will be a little quiter than a whole 4-2-1 race header and yet, will still make a few gains over the OEM 2-1 when remapped.

Anyone had any experience of this?

 

[Dan34]

So, I fitted an OEM back box to the car and wow, it's a lot quieter. In some way, it's nicer like this. It has a much smoother, purer sound rather than that bit of boom you get from the Spoon N1. When you hit VTEC, you just get induction noise now which is also very clean sounding.

So, the next step is the decat. Not sure to go for a DC Sports 4-2-1 or just the Spoon 2-1 and mate it with my existing OEM 4-2 manifold. Again, the worry is noise. I believe the Spoon 2-1 will be a little quiter than a whole 4-2-1 race header and yet, will still make a few gains over the OEM 2-1 when remapped.

Anyone had any experience of this?

I was very surprised how little the noise levels went up in mine when I went decat. I have a Toda backbox and static test at trackdays I am only 87db.

I have the tegiwa exhaust manifold.

 

[Linus27]

I was very surprised how little the noise levels went up in mine when I went decat. I have a Toda backbox and static test at trackdays I am only 87db.

I have the tegiwa exhaust manifold.

Now that's interesting as I think I would prefer a full race header as I've read the Spoon 2-1 is prone to rattles and cracking. Might just say sod it and get the DC Sports race header and go from there