gruppe m initial impressions

[r4gs]

so, got a gruppe m in from a fellow zposter today and found a bit of time to install it. bought a k&n recharge kit from the local advanced auto parts store and dusted, cleaned and oiled the filter prior to the install. recharging the filter took about two hours (really only two minutes to dust and spray the cleaner on, soak for 10 minutes, wash under cool water for about 5 minutes, let dry for an hour, spray generous amounts of oil both on the inside and the outside of the filter material, let wick, respray areas which were still dry, let wick further for about 20 minutes).

the actual install required some trial and error figuring out how the various parts fit together, but was otherwise a straightforward loosen and tighten screws, nuts and bolts kind-of-deal. clocked in about an hour start to finish, a lot of which was spent adjusting and readjusting to get the entire assembly to fit.

got the engine warmed up, asked my old roommate out for some supper, nice 15 minute drives to and from on a short stretch of highway and some inner city roads, got into the mid to upper rev range and...feeling somewhat letdown. perhaps it's the expectations of a remarkable world of difference in sound, but it's definitely not as pronounced as i had imagined it to be. below 3k rpm, an almost negligible, if any, difference in sound amplitude or tone. get the s54 up above 3k rpm into the mid rev band, very slight suction noise followed by a noticeably throatier growl. the high rev band - more pronounced roar that is louder and has more bass than stock.

still, i feel as if i'm wanting more!? absurd? maybe i need to give the dme a bit more time to adapt, but i'm certain tt isn't changing the sound any. as for butt dyno, really didn't notice any difference (gains or losses). hoping fuel economy improves as a plus point at the very least.

[mousitch]

Worth it if it was $400 or so but IMHO not worth the high price. Sounds decent but thats all. I would have put that money in my supercharger fund instead. But I have it in the car and that's where she will stay till someone has to have one and then maybe I will sell for a premium...

[r4gs]

^mousitch, curious if u get a lot of leaves, bugs, dirt etc with the rpi scoop and the open-design gruppe m? i realize having to pull, clean and re-oil the filter is pretty much going to require removing the entire gruppe m setup, so am somewhat happy that the stock scoop is designed the way it is.

[mousitch]

Originally Posted by r4gs

^mousitch, curious if u get a lot of leaves, bugs, dirt etc with the rpi scoop and the open-design gruppe m? i realize having to pull, clean and re-oil the filter is pretty much going to require removing the entire gruppe m setup, so am somewhat happy that the stock scoop is designed the way it is.

I have been pretty diligent in checking the filter by eyeballing it weekly. Looks pretty clean so far...

[NickyC]

Intakes are a waste on our cars.

[mousitch]

Originally Posted by NickyC

Intakes are a waste on our cars.

Too each their own. I wouldn't have bought it other than i got a helluva deal from a fellow St.Louisan who sold their z for a C63 AMG.

[johanness]

Originally Posted by mousitch

Too each their own.

Exactly

[gatorfast]

Sounds about right for an intake. Wont make much difference in sound in the low rpm's but should add a decent growl when you get it up there. You arent going to get a full fledged aural experience throughout the rev band like you would with an exhaust.

[pokeybritches]

Intakes make a big difference when the engine is under load. Otherwise they sound pretty close to stock levels, which is good because they are only louder when you want them to be (unlike an aftermarket exhaust). I'd rate the aFe as about a 50% increase in volume under load, and I'd imagine the Gruppe M is about the same. I agree an intake is not worth $1000, but picking up a lightly used aFe for $300 is definitely a worthy investment if you want to improve the sound of the car. I say go with an intake+exhaust if you want more.

How is the car's cold start behavior now? I didn't realize how bad mine was until I added the AA tune and everything smoothed out.

[r4gs]

pokeybritches - cold start behavior is unchanged as far as i've noticed. engine cranks immediately to about 1500rpm, then dips to about 1000rpm momentarily before stabilizing at about 1200rpm. temps in the morning here average in the 40s. the afe was always a consideration at less than half the price of the gruppe m (brand new costs us$1246 shipped direct from japan now due to the strengthening yen). reckon both would sound extremely similar. gains/losses and fuel efficiency benefits are left for debate, however.

shift@red - ur exact combination on ur m coupe u had before, and i'm sure they complement very well. have sat in a friend's s2000 with cai and straight pipe and the drone was excessive to the point of driving one crazy! tt's my principle consideration when looking at aftermarket exhausts. and unless there's a magical way to transform the z4m's exhaust note into something more f1-esque like capristos on 360 challenge stradales, i'm not so sure the day-to-day increase in boomy bass and drone is worth the trouble right now. maybe i'll succumb eventually....

gatorfast - tt was my exact intention - to have an increase in volume, bass and growl as the revs climbed while keeping things stock at highway speeds where i can actually listen to my music.

mousitch - good to know. i was under the impression the scoop would introduce tons of excess dirt, bugs and what-have-you cos of the open-mouthed design.

nickyc - performance gains wise the gruppe m, or afe for tt matter, are definitely questionable. i'm going to need an extended period of time to really notice any change in fuel efficiency. right now the aural character of the car is enhanced, but nothing more than just tt. i was hoping for 'transformed'.

[r4gs]

update - took the m out through some hill country passes this weekend and really got to unwind the gruppe m. definitely beginning to get tt insatiable desire to just drag the gears out and power through the throttle into the deep, resonating roar. as many have put it before, the sound is absolutely intoxicating! starting to feel like it's money well spent for the renewed aural experience tt's really enhanced the overall feel and drive of the car. it's a complete stab-in-the-dark, but i'm noticing better throttle response and a little bit more torque down low between 3000 and 4000 rpms, especially in 1st and 2nd. fuel economy improvement seems minimal thus far though.

[VinnieAces]

damn it...i was really excited to pick up a Gruppe M, just been waiting for the opportune moment although now it sounds like i'll be hugely let down as well

[Starscream]

It did take a while for my DME to adapt to my GruppeM,
It ran a little rough for about 50 miles, then after it adapted it felt great,
Very smooth and awesome sound, I have it mated to a RPI scoop,

Love the sound and looks

[r4gs]

Originally Posted by VinnieAces

damn it...i was really excited to pick up a Gruppe M, just been waiting for the opportune moment although now it sounds like i'll be hugely let down as well

those were my initial sentiments as well, although maybe not a huge let down, more of just an unimpressed + wanting more feeling. however, after putting on about 200 miles since the install, it is significantly more pronounced now and has become somewhat addictive! i've had to take the m coupe out for silly short drives around base and various stop signs just to have some excuse to hear that sumptuous growl.