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      01-14-2011, 03:42 PM   #23
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Originally Posted by Dubbedown View Post
Aside from weight savings, I doubt the Stebro muffler gave you any gains. I don't even claim that my Bastuck midpipe & muffler yielded any gains. At most, you shaved few pounds and it increased sound. Thats why if OP is serious about hitting any hp #s, he shouldn't even bother with the exhaust and just go straight for the headers and cats, which is where most of the restriction lies.
i didnt think so either but like i said i compared it to a friends car before and after and it was faster than previous runs. that and the throttle response is undeniably better. doubt its anything more than about 2 or 3 hp but its something.
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      01-14-2011, 03:51 PM   #24
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The only way you will get the gains you desire is by swapping out the final drive. I don't even think you can get 30 hp by running the car catless, so there's no way on this earth you will get 30 hp with a tune, intake, and exhaust that leave the cats in place. The Euro headers are already catless (and I believe hydroformed), so the OEM quality is good. It is just not possible to get 30 hp. The ones who say it is are probably trying to sell you something.

Spend $3k (US) and get a Performance Gearing limited slip differential with a 3.64 final drive. That way you improve your handling and ability to power out of turns at the same time. Someone correct me if I'm wrong, but:

3.64 (new ratio) / 3.23 (stock ratio) ~ 1.12693

265 hp (stock hp) * 1.12693 ~ 298.63 hp (new equivalent hp)

Your RPM will increase by about 12.7% in each gear so you will have to shift slightly more often, and thus you won't be able to hold each gear as long. Regardless, it will give you the equivalent of the 30 hp gain you desire. If you want more, you can even go with a 3.91 final drive.

This isn't guesswork or claimed gains. It's a mathematical fact that if you swap out the final drive, you WILL put more torque to the ground, and the precise number CAN be calculated. And, the handling benefits of having a limited slip in the back are even more useful than the extra grunt.
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      01-14-2011, 03:57 PM   #25
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Originally Posted by pokeybritches View Post
The only way you will get the gains you desire is by swapping out the final drive. I don't even think you can get 30 hp by running the car catless, so there's no way on this earth you will get 30 hp with a tune, intake, and exhaust that leave the cats in place. The Euro headers are already catless (and I believe hydroformed), so the OEM quality is good. It is just not possible to get 30 hp. The ones who say it is are probably trying to sell you something.

Spend $3k (US) and get a Performance Gearing limited slip differential with a 3.64 final drive. That way you improve your handling and ability to power out of turns at the same time. Someone correct me if I'm wrong, but:

3.64 (new ratio) / 3.23 (stock ratio) ~ 1.12693

265 hp (stock hp) * 1.12693 ~ 298.63 hp (new equivalent hp)

Your RPM will increase by about 12.7% in each gear so you will have to shift slightly more often, and thus you won't be able to hold each gear as long. Regardless, it will give you the equivalent of the 30 hp gain you desire. If you want more, you can even go with a 3.91 final drive.

This isn't guesswork or claimed gains. It's a mathematical fact that if you swap out the final drive, you WILL put more torque to the ground, and the precise number CAN be calculated. And, the handling benefits of having a limited slip in the back are even more useful than the extra grunt.
Agreed on taller gearing... might as well throw in a limited slip while you're at it. For the 3.0si coupe, 3.64 is stock for auto, but manual is 3.46 - not sure what OP has, or if it's totally different for roadster. I ended up doing the opposite by going with the limited slip but kept stock gearing. I'm content with the shift points, but it was really a money thing... $500 on top of what I was already paying for the lsd was out of my budget. But 3.73 for auto-x was awfully tempting...
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      01-14-2011, 04:54 PM   #26
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You have been busy while I was gone I am thinking that I will leave the final drive swap for now, I am not even sure I want to consider that option at all.

OK, so to sum up for now, I am definitely getting the RPi Intake Scoop, as for the air filter, I will have to do some more digging. I am still open to suggestions on that. Normally, price is not an issue, but 1200 USD for an air filter sounds a bit harsh.

I have a question about the cats though. For instance, if I order the full Supersprint system, do I have to buy cats separately, or do high flow cats come with the system, and if they do NOT come with the system, what high flow cats should I get that could be fitted on the Supersprint.

I have one more question, has anyone actually gotten a full Supersprint or KKS system (I have been on the site and I know for sure that they have a full system with an electronic switch), and would be able to give some information on the headers, etc. Now, the Supersprint system will set me back a good 3500 euros, while the KSS costs around 2400 euro for the 3.0 (it does not say whether it is for the 3.0 only or it also fits the 3.0si), I am wondering which one sounds better to you guys, if you have heard the second one in action?

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      01-14-2011, 05:01 PM   #27
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Update:

I also found this, can someone look at it and give his opinion: http://www.turnermotorsport.com/html...CT_ID=54-11942

I am referring to the dry version ofc.

And this is the item on the manufacturer's website: http://afepower.com/shop/details_new...L6&&brandID=53

Notice the difference in the HP gain in the description of both sites .

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      01-14-2011, 07:13 PM   #28
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OK, so I've done some more digging on the air filter issue, and I did find the GruppeM RAM AIR SYSTEM. It would cost me around 500 euros, which is OK if it provides the modest HP improvement when coupled with the RPi scoop and also a better engine sound.

If I understand correctly the GruppeM RAM AIR SYSTEM replaces the OEM air filter and box, and RPi scoop forces more air to the RAM AIR SYSTEM. Are these assumptions correct? (I am not an expert, YET )
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      01-14-2011, 09:10 PM   #29
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honestly, just call up whichever vendor or company and they'll answer all your questions, including the ones you've already posted here. me personally, i'd stay away from the afe just b/c i've read so many negative reviews, and functionally it makes sense as to why you'd lose hp.

in terms of the supersprint system, nothing is ever included with these guys. you have to order each part individually. also, supersprint designed their headers such that for a true plug-n-play fit, you have to also purchase the high flow cats, which is stupid in my opinion. sure, any competent shop can weld an adapter for you, but for $1600, you'd expect something that mates up to the oem piping. or to your point, why else list cats separately from the headers knowing you'd have to purchase both for a seamless fit?

for what it's worth though, like i said if money is no object by all means go for it. i'm sure there will be "some gains" but i do find it weird that supersprint will give advertise specific hp gains on some of their headers (with a dyno chart), but nothing for this one. so i'm sure there are gains, just a question of how much are you really getting...
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      01-14-2011, 09:29 PM   #30
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kudos to dubbedown, some tremendously useful info in this thread for 3.0si owners. the euro headers are already catless and are oem quality, so i wouldn't bother swapping them out. if u're concerned about emissions, then race cats in section 1 and a revised section 2 are really the only other alternatives. mufflers add hardly any power and are just means to vastly changing exhaust sound, whether for better or worse. tune is really the only way to go for noticeable and appreciable gains in addition to swapping ur final drive.
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      01-14-2011, 10:47 PM   #31
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Quote:
Originally Posted by r4gs View Post
kudos to dubbedown, some tremendously useful info in this thread for 3.0si owners. the euro headers are already catless and are oem quality, so i wouldn't bother swapping them out. if u're concerned about emissions, then race cats in section 1 and a revised section 2 are really the only other alternatives. mufflers add hardly any power and are just means to vastly changing exhaust sound, whether for better or worse. tune is really the only way to go for noticeable and appreciable gains in addition to swapping ur final drive.
Thanks man, I guess this is the amount of knowledge you acquire when you're the guinea pig and have gone through many trial and error exercise.

OP - I know you said money is not a huge constraint here, but even as a fellow Si owner, I hate to say it but it's pretty much the same conclusion others have drawn when going down this path. For the amount you're willing to spend on a filter, exhaust, headers - you're looking at around $3000 before labor. This doesn't even include some of the other cosmetic things you were considering (dual exhaust conversion which means new bumper, paint, etc.). For all this, say $4000 total you could get the same performance and looks buying a M coupe.

Now don't get me wrong, I love my Si coupe and have spent a good amount of money modifying it, but I spent money on mods that I believe offered "better value" in my opinion. But like other Si owners, we were content with the overall performance the card has to offer in stock form. But if 300hp or whatever is a hard target, you'd seriously get that plus more just purchasing a m coupe / roadster, which essentially could be had for given the cost of your car + the money you're willing to spend on mods. Not to mention that car will also include better suspension, brakes, limited-slip, etc.

Either way, hope you get what you're looking for... I just thought I'd throw this out there b/c last thing I want to see is someone spend a lot of money and not be happy with their return on investment.
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      01-15-2011, 02:06 AM   #32
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Quote:
Originally Posted by Dubbedown View Post
Now don't get me wrong, I love my Si coupe and have spent a good amount of money modifying it, but I spent money on mods that I believe offered "better value" in my opinion. But like other Si owners, we were content with the overall performance the card has to offer in stock form. But if 300hp or whatever is a hard target, you'd seriously get that plus more just purchasing a m coupe / roadster, which essentially could be had for given the cost of your car + the money you're willing to spend on mods. Not to mention that car will also include better suspension, brakes, limited-slip, etc.

Either way, hope you get what you're looking for... I just thought I'd throw this out there b/c last thing I want to see is someone spend a lot of money and not be happy with their return on investment.
Hi, well as I explained earlier, getting and M is not an option for me because I do not want to drive a manual any more. In any case, if there is an improvement to sound or power, even if modest I will be happy with the upgrade and the money spent.

Can you also tell me if these assumptions that I posted late last night (late last night for me at least) are correct: "If I understand correctly the GruppeM RAM AIR SYSTEM replaces the OEM air filter and box, and the RPi scoop forces more air to the RAM AIR SYSTEM."
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      01-15-2011, 08:09 AM   #33
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i have a gruppe m intake on my m coupe and it completely replaces the oem airbox and filter. i am going to presume this is the same in the 3.0si as well. i do not, however, have the rpi scoop and cannot comment on its benefits. of course, just by virtue of its design, without a doubt it forces more air through the intake, and this effect increases with speed.

one thing i should add about a gruppe m, it frees up a lot more engine growl and the sound is absolutely intoxicating! at least on the s54 in the m coupe's....

did capristo get back with u?
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      01-15-2011, 11:48 AM   #34
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Quote:
Originally Posted by r4gs View Post
i have a gruppe m intake on my m coupe and it completely replaces the oem airbox and filter. i am going to presume this is the same in the 3.0si as well. i do not, however, have the rpi scoop and cannot comment on its benefits. of course, just by virtue of its design, without a doubt it forces more air through the intake, and this effect increases with speed.

one thing i should add about a gruppe m, it frees up a lot more engine growl and the sound is absolutely intoxicating! at least on the s54 in the m coupe's....

did capristo get back with u?
No, Capristo have not yet answered, however, I will update this thread when they do.

I went through youtube in an attempt to find a 3.0si or at least a 3.0i with a Gruppe M Ram Air System, but there wasn't much there really. If anyone has it on without a lot of other mods, it would be appreciated if they could record the sound and post it here so we can hear it .

I have a question about the Gruppe M system though. Is the system's air filter replaceable or can I just clean it? And also on the Gruppe M website there is something called a Super Cleaner [Carbon Duct]: http://gruppem.co.jp/en/product/sc/index.html
Does anyone have any idea what this is used for? Is it an alternative for the Ram System?
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      01-15-2011, 12:24 PM   #35
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gruppe m systems use k&n oiled filters, which are completely replaceable or alternatively, rechargeable using a k&n oil recharge kit. the kit includes cleaning and re-oiling the filters for optimal air flow. usually every 5,000 miles or so. since the filters must be oiled to function optimally, they cannot simply be washed under running water and air-dried.
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      01-15-2011, 12:35 PM   #36
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im almost positive that they dont make a gruppe m for our car. the k&N filter is a great mod but was only $50 for me. maybe just look on any big atuo supplier website to find one. its just a panel filter that fits in the stock location.

for what it sounds like your looking for i would get someone to just swap the cats with a highflow instead of wasting the money on a complete setup. your headers are already catless and not of bad design either so i wouldnt be in any rush to replace those. like the others have said, the diff swap is going to be your best bet, with the tune as a close second. I really dont think there would be ANY problem running the tune wihtout more cooling. I live in Texas and i cant say that im all that worried for when summer comes.
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      01-15-2011, 01:13 PM   #37
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So basically what you are saying is that I can just buy spare K&N filters for the Gruppe M Ram Air System and just change them every 5000 miles or so?

I also wanted to ask about the high flow cats. I've been searching around the web and the ones that popped up most often were some Magnaflow universal ones. I am not sure whether they are any good. Any suggestions and some info on the Magnaflow ones will be much appreciated.

Spark plugs are another area that I am thinking about. Is there anything better than the stock ones that I could put on, and if there is, what are the advantages?
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      01-15-2011, 01:54 PM   #38
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gruppe m does indeed make a specific intake for the 06-08 3.0si z4's with the n52 engines. i'm not sure who the distributor is in europe, but if u buy direct from gruppe m, it's going to cost an arm and a leg.

u do not need to buy spare k&n filters. all u need is a k&n oil recharge kit and follow the instructions to clean and re-oil ur k&n filter every 5,000 miles or so.
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      01-15-2011, 02:59 PM   #39
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Quote:
Originally Posted by r4gs View Post
gruppe m does indeed make a specific intake for the 06-08 3.0si z4's with the n52 engines. i'm not sure who the distributor is in europe, but if u buy direct from gruppe m, it's going to cost an arm and a leg.

u do not need to buy spare k&n filters. all u need is a k&n oil recharge kit and follow the instructions to clean and re-oil ur k&n filter every 5,000 miles or so.
OK, I will check out the oil recharge kit, how about the spark plugs, and the high flow cats? Any ideas on that?

Also, has anyone heard of POGEA RACING CHIP TUNING?

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      01-15-2011, 06:09 PM   #40
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Gruppe M does make an intake for the 3.0si, check our sponsored vendors. If you can't find any videos online then try looking up 328/330i e90, cabin noise will be different but noise from outside should be similar.


Quote:
Originally Posted by Arxangel View Post
OK, I will check out the oil recharge kit, how about the spark plugs, and the high flow cats? Any ideas on that?

Also, has anyone heard of POGEA RACING CHIP TUNING?
Why would you want to change spark plugs? Unless you're going forced induction there's no reason to go colder. Cats should net you few hp but nobody here has done it. If you don't want SS, then get generic ones from Magnaflow and have a shop weld them in.

Aside from the brands I already mentioned (AA, OE Tuning / Gintani), I doubt others can comment on any other. The only other tune I can think of is Wetterauer. They're not big in the states but popular in European Audi / VW scene. Even if you find other "tuners," stick to the reputable ones. I would not chance my motor with anyone new or relatively unknown.
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      01-15-2011, 06:24 PM   #41
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By the way seeing how serious you are about this you should contact Craven328, he's done extensive modification to his 328, from headers to custom exhaust and tuning. He won't know specific questions regarding parts for the Z4 but he'll know everything there is to maximizing the N52. For the most part, nobody here has done anything beyond an exhaust on the 3.0si so most of your questions will go beyond our level of expertise (or experience).
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      01-15-2011, 06:31 PM   #42
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Isn't he the one designing the supercharger kit?
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      01-15-2011, 06:32 PM   #43
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Quote:
Originally Posted by Dubbedown View Post
Gruppe M does make an intake for the 3.0si, check our sponsored vendors. If you can't find any videos online then try looking up 328/330i e90, cabin noise will be different but noise from outside should be similar.




Why would you want to change spark plugs? Unless you're going forced induction there's no reason to go colder. Cats should net you few hp but nobody here has done it. If you don't want SS, then get generic ones from Magnaflow and have a shop weld them in.

Aside from the brands I already mentioned (AA, OE Tuning / Gintani), I doubt others can comment on any other. The only other tune I can think of is Wetterauer. They're not big in the states but popular in European Audi / VW scene. Even if you find other "tuners," stick to the reputable ones. I would not chance my motor with anyone new or relatively unknown.
Right, well I guess I will stick with AA then, but this is going to be the final stage, I would like to go through the other mods before that so that the re-mapping can be done to my specific configuration.

I am guessing now there is only one final question left, and then I would be able to summarize everything.

If I decide to get only the SS Y-pipe and muffler, is the Y-pipe compatible to the OEM system or is the OEM pipe a straight one?

Can I get the Magnaflow cats and replace mine and put the SS Y-pipe and muffler right after that? Should I buy 1 or 2 units of the Magnaflow cats for the 3.0si?
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      01-15-2011, 06:33 PM   #44
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Quote:
Originally Posted by Dubbedown View Post
By the way seeing how serious you are about this you should contact Craven328, he's done extensive modification to his 328, from headers to custom exhaust and tuning. He won't know specific questions regarding parts for the Z4 but he'll know everything there is to maximizing the N52. For the most part, nobody here has done anything beyond an exhaust on the 3.0si so most of your questions will go beyond our level of expertise (or experience).
Will do, thanks .
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