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Gruppe M ver 3 exhaust installed on my 02!

Joined
9 January 2004
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217
Location
San Francisco
Gruppe M ver 3 exhaust installed on my 02 + DYNO!

The exhaust has been on the car since wednesday late afternoon and this is my impression:

Ever since I got my NSX, I've heard rumors about this Gruppe M exhaust and how wonderful it sounds. After all these years, I have yet to see or hear one. So several weeks ago, I bought.

It was a bit tricky since the Gruppe M exhaust was made for the 3.0 liter (I think the main difference between the 3.0 and the 3.2 is that the headers come out as a 3-hole flange on the 3.0 while the 3.2 come out as 2-hole flange; along with a couple of inches in lenght.)

THE SOUND
I got the exhaust because I thought it sounds good but I am neutral on the sound of this exhaust. I don't hate it but not upto my expectations. I think it was too hyped-up for me. Sorry but I don't have any device to record a sound clip.

POWER?
The power and feel from this exhaust however is AWESOME! More than what I expected from any exhaust. I noticed the 2-1-2 design and expected more low-mid range gain but it keeps climbing all the way to 8K faster than ever before.

Is it worth the price tag? Well that's all a matter of an opinion but I spent over $2K on my used one and I have no regrets.


Happy NSX-ing!
Sung
 
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I am a little hyped too about the noise it makes, I sure don't hope I waste 2700 $$$ when I'm gonna buy one :(

The other choise is to save 1700 $ and buy Taitec GT Lightweight exhaust...


Anyways, too bad you didn't have a recording device because I am curious :D
 
Look forward to comapring against my single tip Tubi Sung!

Curious - how did you get around removing the cats on your OBDII? Did you have to install spoof devices? i.e. O2 simulator
 
D'Ecosse said:
Look forward to comapring against my single tip Tubi Sung!

Curious - how did you get around removing the cats on your OBDII? Did you have to install spoof devices? i.e. O2 simulator

Went to Kragen, bought 2 spark plug defoulers, little bit of drilling, attached to the sensor then to the pipe. Better than any electronical device that I have used.

Of course I only do this setup at the track:wink:
 
My suggestion is to let someone else drive your car and just drive next to it and listen to it from the outside. During spirited driving, you'll hear that the exhaust has a very complex tone. It almost sounds like it is talking to you.

I am running GM v2 now and it is not as loud as v3 and has a fuller sound. The v3 does have more HP gain. A broken in GM v3 is piercing loud. You can tell when driving through tunnels and fwy underpasses. Rev'ing the car doesn't do justice to the exhaust.

We have a v2 and a v3 in my neighborhood and when we ride together, I always drive a half car length behind their cars just so that I can hear them sing.

I hope to see some pics of the setup. I never thought that it is an easy task to fit one in an OBDII car.
 
sycosho said:
Went to Kragen, bought 2 spark plug defoulers, little bit of drilling, attached to the sensor then to the pipe. Better than any electronical device that I have used.

Of course I only do this setup at the track:wink:

CDub said:
I hope to see some pics of the setup. I never thought that it is an easy task to fit one in an OBDII car.

I have a Gruppe M Ver 3 and Ver 2 sitting in my garage right now. However I have not fitted either becuase both are for the NA1 and I have a NA2 now.

I am hoping to do back to back comparisons between the Gruppe M Ver 2 and Ver 3 for both sound and power gains on my 98 3.2 but am yet to find a way to fit a NA1 exhaust to an NA2 NSX

I thought it may be possible to make it work but sycosho you are the first I have heard to do this.

I would really appreciate details (with photos if possible) of how you accomplished this!

Thanks.
 
CDub said:
My suggestion is to let someone else drive your car and just drive next to it and listen to it from the outside. During spirited driving, you'll hear that the exhaust has a very complex tone. It almost sounds like it is talking to you.

From talking car alarms to talking exhausts. I guess I got ripped off on that Taitec :biggrin:
 
John@Microsoft said:
From talking car alarms to talking exhausts. I guess I got ripped off on that Taitec :biggrin:

John, if you have the GTLW, you should have have no regrets. It is still a very nice sounding exhaust.
 
AU_NSX said:
I have a Gruppe M Ver 3 and Ver 2 sitting in my garage right now. However I have not fitted either becuase both are for the NA1 and I have a NA2 now.

I am hoping to do back to back comparisons between the Gruppe M Ver 2 and Ver 3 for both sound and power gains on my 98 3.2 but am yet to find a way to fit a NA1 exhaust to an NA2 NSX

I had a v3 before I switched back to v2. I can tell you that they both tuned with very similar sound. The v2 has smaller pippings, as you may know already and it is a lot heavier (28lbs if I remember correctly) than the 19 lb v3. It does have a fuller sound and much quieter from the outside comparing to a well broken in v3.
 
AU_NSX said:
I have a Gruppe M Ver 3 and Ver 2 sitting in my garage right now. However I have not fitted either becuase both are for the NA1 and I have a NA2 now.

I am hoping to do back to back comparisons between the Gruppe M Ver 2 and Ver 3 for both sound and power gains on my 98 3.2 but am yet to find a way to fit a NA1 exhaust to an NA2 NSX

I thought it may be possible to make it work but sycosho you are the first I have heard to do this.

I would really appreciate details (with photos if possible) of how you accomplished this!

Thanks.

When I get some pics, I'll give you a full detail as well.
But for starters, you either have to get a matching flange for gruppe m exhaust (very hard to find) or hack that flanges off the gruppe m ehaust (which is what I did). Decision was very hard to make, which was one of the reasons why this project took so long.

Oh yeh, I forgot about the weight... it is so light for an exhaust this size!
I had a comptech before.

Sung
 
CDub said:
A broken in GM v3 is piercing loud. You can tell when driving through tunnels and fwy underpasses. Rev'ing the car doesn't do justice to the exhaust.

Hey CDub, your inputs as well as SilverOne's inputs on the GruppeM exhausts are excellent, thanks.

To anyone who owns a broken-in GM v3, is it "nice" loud, or "get pulled over and cited" loud? :biggrin:
 
drewdeezee said:
To anyone who owns a broken-in GM v3, is it "nice" loud, or "get pulled over and cited" loud? :biggrin:

My v3 was broken-in with over 2k miles. At cruising speed, the exhaust is not unbearably loud. I have never been pulled over for that. At WOT, it is excellent inside the car, but it is ears piercing loud from the outside. The tone is very high pitch and very addictive. It's just a bit too loud for me to not feel embarrassed driving in local traffics.
 
Sorry it took so long but here are the pics:

Here you can see the general layout and the extra lenght needed for the upper and lower piping:

9406full.jpg


You can kind of see the "S" shaped pipe used for the Upper piping. This would be the hardest piece to find or make without sacrificing the mandrel bend.

9406nsxs_010.jpg


Another angle of the upper piping (from the right rear wheel):

9406top1.jpg



Another look at the upper piping.
So the Gruppe M connects with a 3 hole flange so we cut-off-ed the lower flange of the Gruppe M and reused it for the upper flange.
(ugly weld but I was a bit unpatient).

9406close.jpg



A closer look at the bend of the upper piping. It does touch and rattle the car sometimes but I'll get some cushion in there soon.

9406close_2.jpg



A look at the lower piping:

9406bottom.jpg



A straight pipe was used to extend the Gruppe M all the way to the DC Header:

9406lower.jpg
 
I didn't know it had bungs for the O2 sensors. Nice! I just assumed since there were no cats the sensors would be left hanging.

And I see you're using the old anti-fouler trick to aviod the CEL. :D
 
dave22 said:
I didn't know it had bungs for the O2 sensors. Nice! I just assumed since there were no cats the sensors would be left hanging.

And I see you're using the old anti-fouler trick to aviod the CEL. :D

We had to add one of the bungs for the O2 and the other one was available from the test pipe.

The anti-fouler's the only way to go!
 
last night Sung gave me a ride in his NSX to poker night with the NSX elitist and I liked the sound of the exhaust and his car is definitely faster than mine(or perhaps its his Need4Speed driving technique).

I didn't even notice the rattleing noise until Sung pointed it out

:redface:
 
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Sycosho,

Thanks for taking the time to share with use your project! It is a very daring operation you did to an expensive exhaust.

After all that work, I sure hope that you like the result, I do.
 
<B>sycosho</B>: whatever doubts you have now, time will erode them i'm sure. You got the right exhaust. At NSXPO I experienced lots of great exhausts, but my own personal favourite that continually stood out of the crowd was the GM... v2 and v3 are pretty much the same to me. ;) Gruppe M is just too much fun. :D


The thing I noticed most about the GM was it's not so loud inside the cabin... it's when you're behind someone with a GM exhaust that you clutch your ears. :D :D :D Also, like CDub said a GM3 is piercing through tunnels and overpasses... that where most exhausts shine. :)

Where's <B>SilverOne</B> and <B>NSXBOX</B>? ...i'm sure they'll have some advice to contribute.
 
Inside the cabin, my GruppeM intake almost totally drowns out the sound of my GruppeM v2 exhaust under WOT. However with the windows rolled down it is the opposite-- the exhaust sound drowns out the intake.

The exhaust is nearly always quiet inside the cabin. The exception is a very low-pitched drone that is frequently present (especially when cruising or idling at lower rpms). The drone is one of those omni-present type sounds that feels like it's everywhere and there's no escape. I kind of like it!

I have never heard what the exhaust sounds like from behind, but I know it must be loud because sometimes during normal driving with moderate acceleration, it will cause other drivers to look over at you (this is especially true going thru freeway underpasses where it sounds more like a high revving motor bike than a car.)
 
sycosho said:
We had to add one of the bungs for the O2 and the other one was available from the test pipe.

The anti-fouler's the only way to go!

I want to thank you sycsho for this write-up! It has answered a lot of my questions!

I was wondering, looking at the extension you have welded onto the Y pipe and the extension pipe fabricated so that the 3-hole flange will bolt up to the 2-hole flange of the 97+headers...

I do not have access to a welder myself so would these adapter pipes from SOS esentially do the same job?http://www.scienceofspeed.com/products/exhaust_airflow_products/NSX/ScienceofSpeed/factory_header_adaptors/

If so, then it would essentially be a bolt-on modification except that then I would just have to add the extra bungs for the anti-fouler mounting of the after CAT O2 sensors.
 

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I have all comptech exhaust and headers w/ test pipes. i will post pics as soon as i get them but, i have had no problem w/ the o2 sensor. the check engine light came on and i took it to acrura and they replaced the o2 sensor for free because it was under warranty.
 
The exhaust really must have had only a few hundred miles because I can hear the exhaust note changing as the days go by. I guess it's finally breaking in :biggrin:

AU_NSX

I don't know if you can use those adaptors. My Comptech had similar adaptors on the exhaust but the 3-hole flange was almost a perfect triangle and if you notice on your Gruppe M, one of the holes is a lot further than the other two. I can't tell from the angle of that picture.

Also realize that you are going to hack those up so I don't know if it's worth paying over $200 when all you really need is the flange.

If you use the route that I took, You won't need to buy any flange. But I know it's hard hacking up a perfectly good exhaust.

rasir_x

I think your car is odb I that's why the test pipe doesn't affect your car. Maybe another member can confirm my thought.
 
CDUB described everything very well. I don't need to add anything on top of it. I love my v3, it's great tool also in traffic to tell the other drivers to keep their instance by blipping the throttle to 4k rpm ;)

I think I have ~2k miles on my GM v3 currently, and it still does not sound 'broken in'. It's still very tight with the sound, and from 4k-7k rpm, it'is just piercing. From within the cabin, I can only hear the pleasing tone, its not loud at all. But from the outside, your eardrums will hurt! I know as I have followed behind others that drove my car.

Neo experienced GM v3 in a looong tunnel during NSXPO, and I am anxiously waiting for the full "Get away in Phoenix" video. :)



NeoNSX said:
<B>sycosho</B>: whatever doubts you have now, time will erode them i'm sure. You got the right exhaust. At NSXPO I experienced lots of great exhausts, but my own personal favourite that continually stood out of the crowd was the GM... v2 and v3 are pretty much the same to me. ;) Gruppe M is just too much fun. :D


The thing I noticed most about the GM was it's not so loud inside the cabin... it's when you're behind someone with a GM exhaust that you clutch your ears. :D :D :D Also, like CDub said a GM3 is piercing through tunnels and overpasses... that where most exhausts shine. :)

Where's <B>SilverOne</B> and <B>NSXBOX</B>? ...i'm sure they'll have some advice to contribute.
 
sycosho said:
I don't know if you can use those adaptors. My Comptech had similar adaptors on the exhaust but the 3-hole flange was almost a perfect triangle and if you notice on your Gruppe M, one of the holes is a lot further than the other two. I can't tell from the angle of that picture.

sycosho you are correct. the Gruppe M flange does in fact have one hole a lot further away than the other two. However, I think if you look at your CATS, you will see that the bolt patterns at each end are different. The end closest to the headers is like the Gruppe M with 1 bolt further away from the other two and the other end closest to the muffler is almost a perfect triangle.

So, I have emailed Chris at SOS about the adapter pipes and he has said that they are meant to exactly this (but usually for people wanting to put the OEM 97+ headers on their 91-94 cars and bolt onto their existing CATS and exhaust.

The other method he suggests is to buy the 91-94 extractors to bolt onto the later 97+ car and then the Gruppe M will of course bolt directly onto that without the need for the adapter pipes.

sycosho said:
Also realize that you are going to hack those up so I don't know if it's worth paying over $200 when all you really need is the flange.

If you use the route that I took, You won't need to buy any flange. But I know it's hard hacking up a perfectly good exhaust.


The one modification that will have to be done which ever path I take will be the additional O2 sensor lugs have to be welded on. So it looks like I can fit the Gruppe M without having to hack up a perfectly good exhaust but I cannot avoid having to add in the additional O2 sensor holes/lugs.


sycosho said:
rasir_x

I think your car is odb I that's why the test pipe doesn't affect your car. Maybe another member can confirm my thought.
yes exactly!
 
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