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      11-30-2012, 07:38 AM   #23
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Originally Posted by RPiM5 View Post
Yes I would definitely be willing to do a dyno run on anyones machine. I can pretty much guarantee that any random dyno test will show the vehicles horsepower much higher than what dyno data RPi states. That is because RPi does dyno tests extremely conservatively. However this should be irrelavent since power gains from stock to aftermarket should still be the same.

Name a time and place and I'll work with anybody to dyno my car (for free that is :P).
Let's set it up with Tom at EAS. We just need to find a stock F10 M5 to do the before and after runs. The iND M5 is still in CA but I want to use a 100% unbiased beast so no RPi M5 car or RPi customer car.
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      11-30-2012, 09:50 AM   #24
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I agree ... this will help people looking for a exhaust system make their decision easier
It would also probably make some people think about switching their exhaust system too

As for the title I think it should be for ANY F10 M5 in the US to brag about ... lol

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Originally Posted by star21 View Post
+1

A friendly business competition will certainly help the customer in the long run. I think it'd be interesting to see the RPi exhaust on a DynoJet versus a Dyno Dynamics unit.

Since the RPi exhaust claims the most significant expected gain of 20-30 HP, I think it'd be great to independently verify it. The 3" piping and VERY straight through design (so much so that it includes a new support brace!) will definitely help to reach that goal. The straight through design also goes in a completely different direction from all other exhausts on the market.

The exhaust system you can tell is a tuner shop product as the weld joints appear to be done by a skilled hand. It looks well built and again shows contrast to the other big names on the market who probably have robotic welded joints, pressed muffler sections, etc. I'm not a fan of the muffler look/design and the support brace but if it works then one doesn't have much to complain about.
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On another note, is there a purpose to having "the most powerful F10 M5 in the U.S." or just merely bragging rights? Private party or tuner shop?

Not to complicate things but just plain out raw power is one thing but having usable power that won't prematurely detonate the power train is entirely different. Power that can be used throughout the RPM range (without significant lag or power delivery abruptness) instead of only a top RPM sweet spot. No offense but I just find this kind of thread talk a bit ridiculous. I can totally understand it though as many consumers will be drawn or tricked simply by focusing on peak horsepower gains.

If you're just talking about raw numbers, I'm sure if someone was brave enough (or stupid depending on your outlook) they'd just increase the boost and add power adders to get BIG peak numbers.
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      11-30-2012, 10:06 AM   #25
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Originally Posted by RPiM5 View Post
Actually I'm not a fan of the muffler design that much either. In fact I'm highly considering having RPi design me a one off Y-Pipe design for a complete muffler delete on the system. Coming from a Full RPi Stage 2 E60 M5, the straight piped exhaust system for the V10 produced a crazy insane amount of drone and no other drone in the world will ever be worse than that car was. Therefore doing a muffler delete in an turbo muffled F10 M5 wouldn't bother me at all. Just remember that I am a little crazy when it comes to the decibal level on M5's. LOL!

But yes everything you pointed out is very observant and accurate. A lot of what you said has exactly to do with the generation of so much power. That design came out of hundreds of hours of Research & Development and hundreds of dyno tests.

When you want your exhaust system to look pretty, you call Akropovic.

When you want proven power for your M5, you call RPi.
Who did BMW call

http://www.akrapovic.com/en/Automoti...ing-Teams.aspx

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      11-30-2012, 10:06 AM   #26
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I'd like to see dyno numbers but would LOVE to see real world action ...

(I had RPi air scoops for my E60 M5 too .. amazing)

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Originally Posted by RPiM5 View Post
Dude, you should have been around when RPi first came out with their air scoops for the E60 M5, a time tested and proven simple mod that make genuine power. There were many doubters and naysayers, but I was winning races left and right. Lol!

I'm not absolutely saying that it is or isn't the most powerful system out there. I'm saying that it is the most powerful that has been published so far. I haven't seen any other manufacterer claim or achieve these kind of power gains from just an exhaust system. If I did see another, then I would definitely mention them.

But seriously, I really don't care about dyno numbers. I'm all about real world results, hence the reference with air scoops and races.

The way that RPi tests its products is extremely rigorous. Hundreds of tests are run to look for the best power output combined with functionality, while form comes last, but always manages to be very aesthetic and a aurally good product as far as exhausts go. RPi also dyno's their vehicles on the low side. Their numbers are always the lowest out of any tuning shop as far as stock vehicle wheel horsepower goes.

I'm confident that I will win against anyone willing to play a little bit in the real world and not in the dyno world.
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      11-30-2012, 12:52 PM   #27
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Here's my review of the RPi GT Exhaust System.

Quote:
Dudes,

BMWDave here from Sunny San Diego. As the title suggests, I have recently installed my new Full RPi GT Catless Exhaust on my F10 M5.
I got it installed last Tuesday and have been driving with it now for two days. I am a long time RPi customer but nevertheless I will offer an unbiased complete review.

First off we'll go over the data.

BMW rates the stock F10 M5 with the following ratings: 560chp & 502ctq

However independent dyno tests of the stock F10 M5 have shown these disparities of horsepower to the crank:
The lowest I've seen is about: 580chp
The highest I've seen is about: 610chp

The RPi Full GT & GTS Exhaust System: RPi states that a gain of 20-30hp is present with both their GT and GTS system as well as a 40tq gain. So we'll go ahead and assume an average gain of 25hp and about 40tq. The RPi exhaust system completely eliminates the secondary cats and the GT system has no resonators where as the GTS includes the resonators but the resonators have no effect on horsepower gain.

With that here is the projected low and high theoretical F10 M5 horsepower ratings with RPi GT/GTS Exhaust System installed:

By adding an average of 25chp to each low and high rating we get:
1. Low Range: 605chp
2. High Range: 635chp
3. Torque is probably between 520ctq - 550ctq with the exhaust system installed.

Real world experience:

The truth is that I don't have a vbox, and I have never owned one. So I'm thinking about investing in one in the near future. No matter though, after I got the exhaust installed a couple of days ago, I was told to drive the M5 hard for a little while so that the ECU can make its automatic adjustments to the increased airflow that the RPi exhaust system offers. After the first night, to be honest I couldn't tell any difference in power or performance according to my butt dyno. Then came the second night, which was last night. I went to a local car meet last night and on the way there I didn't really push it, but on the way back home, I pushed the car pretty hard. It was late at night, about after 10:30pm and the roads and freeways we're pretty devoid of traffic. It turns out that the ECU does need a couple of days in order to adjust to the new exhaust. With RPi's stated gains, one would think that an addition of about 40tq would definitely be noticable in the car. Afterall, it was highly noticable with RPi's catless GT Headers giving the E60 M5 a gain of about 31tq. So yeah, last night when I was pushing the M5 hard I felt a very noticable difference in the performance of the M5. It was one of those experiences where I was thinking that there was no way that the F10 M5 could get any faster than it is stock, but with the RPi GT exhaust system it definitely is!!! When I was at full throttle, I was like GOOD GOD, this thing is insane!

Concerning the exhaust note and drone. Yes the GT exhaust is absolutely louder than stock. And yes there is a little drone that does occur with the GT system. With the GTS system there is no drone, however with the GT the drone only occurs in a very acute rpm range. The range for drone is exactly between 1,500 and 2,000 rpm. At exactly 1,700rpm the drone is the loudest. In my own opinion though the drone sounds SO good! The little bit of extra sound at that low rpm range is just what the doctor ordered on the F10 M5. With the stock system, the car is so quiet and is the reason why they introduced the artificial engine induction sound throug the speakers. With the RPi GT system, the M5 comes more alive during everyday driving at those low rpm's. Now at higher rpm's the decibel level of the exhaust is much louder than the stock system but there is zero drone at those high rpm's. I revved the engine at a few stop lights and while at the car meet last night, and everyone said that it sounds much much better. I even had some dude tell me not to rev my car at the car meet because it was too loud. Lol! When cruising on the highway at 70mph the drone might bother some people because the rpms are right under 2,000 at 70mph in 7th gear, which is right in the drone range. However, cruising at 80mph in 7th gear there is zero drone because the rpm's are at about 2,100 - 2,200rpms. Even such a slight change in rpms makes a big difference.

So in conclusion, in my personal opinion the F10 M5 needs an aftermarket exhaust, it doesn't matter which kind, only to give it more life, especially at low rpm's. If you want an exhaust system that just sits there and looks pretty, then call Akropovic, but if you want an exhaust system that makes real power, performance and sound, then call Race Precision Inc.

I haven't gotten a chance to take any picture of my exhaust in the daytime because I've been working alot, but here are a couple of pictures and video of my M5 when it was still stock compared to another F10 M5 which has the RPi GT system installed. Mine is the one with the Euro Plates on it. I will be doing a photoshoot of my M5 in the near future when I finish all of my mods. All I have left is my Clear-Bra installation this Saturday then I'm good to go.

Hope you enjoyed the review and have a great day!

One last thing. Don't let the YouTube video fool you. The RPi Exhaust is pretty loud. Lol!






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I think you missed the point of the M5. I can transport 5 people comfortably 200mph at 35,000ft.
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      11-30-2012, 12:52 PM   #28
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Haha nice! I love that car!
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      11-30-2012, 12:53 PM   #29
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Originally Posted by Nate@IND View Post
Let's set it up with Tom at EAS. We just need to find a stock F10 M5 to do the before and after runs. The iND M5 is still in CA but I want to use a 100% unbiased beast so no RPi M5 car or RPi customer car.
Yes as soon as you find a stock M5, we can work out a plan according to our schedules.
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      11-30-2012, 01:06 PM   #30
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Quote:
Originally Posted by Nate@IND View Post
Let's set it up with Tom at EAS. We just need to find a stock F10 M5 to do the before and after runs. The iND M5 is still in CA but I want to use a 100% unbiased beast so no RPi M5 car or RPi customer car.
I've got a stock M5 and am happy to help
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      11-30-2012, 01:07 PM   #31
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Originally Posted by RPiM5 View Post
Yes as soon as you find a stock M5, we can work out a plan according to our schedules.
Cool! Again not trying to start a anything here. I have respect for Rpi and we both even use the same tuner (ESS) so I know they only work with the best.

I did find out that another vendor on this site (not Rpi) ran a stock dyno and then installed a tune with the full exhaust but did not disclose that they beast was running a custom file. They are claiming that all of the power came from the exhaust system
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      11-30-2012, 01:15 PM   #32
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Cool! Again not trying to start a anything here. I have respect for Rpi and we both even use the same tuner (ESS) so I know they only work with the best.

I did find out that another vendor on this site (not Rpi) ran a stock dyno and then installed a tune with the full exhaust but did not disclose that they beast was running a custom file. They are claiming that all of the power came from the exhaust system
Dang, that's shady. Lol!

I know Rob///M5, we could prolly roll up together and do some dynoing.
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      11-30-2012, 03:23 PM   #33
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Pardon my ignorance but where is the GT system available for the F10 on the RPI website? Is it there or do I need a cup of joe and my reading glasses, many thanks
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      11-30-2012, 03:39 PM   #34
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Quote:
Originally Posted by Nate@IND View Post
Cool! Again not trying to start a anything here. I have respect for Rpi and we both even use the same tuner (ESS) so I know they only work with the best.

I did find out that another vendor on this site (not Rpi) ran a stock dyno and then installed a tune with the full exhaust but did not disclose that they beast was running a custom file. They are claiming that all of the power came from the exhaust system
Was this vendor also claiming around 30HP? If that's the case it is now off of my short list. PM me please Nate.
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      11-30-2012, 04:04 PM   #35
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Was this vendor also claiming around 30HP? If that's the case it is now off of my short list. PM me please Nate.
Correct same one.
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      11-30-2012, 04:05 PM   #36
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I agree w/ RPiM5 .. that's super shady that a company would do that.
Nate@IND Which company is trying to pull a fast one?

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Originally Posted by Nate@IND View Post
Cool! Again not trying to start a anything here. I have respect for Rpi and we both even use the same tuner (ESS) so I know they only work with the best.

I did find out that another vendor on this site (not Rpi) ran a stock dyno and then installed a tune with the full exhaust but did not disclose that they beast was running a custom file. They are claiming that all of the power came from the exhaust system
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      11-30-2012, 04:29 PM   #37
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Here's my review of the RPi GT Exhaust System.

I know this contrary to what most want but does the GTS sound stock but give the same gains?

I like the stock sound and don't want a louder car, would like the extra power though.

Any other exhaust systems to consider for max gain without noise. I know you can do valve control but not sure I want that either.


Sound like this

Drive like this

thx

D
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      11-30-2012, 04:56 PM   #38
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I know this contrary to what most want but does the GTS sound stock but give the same gains?

I like the stock sound and don't want a louder car, would like the extra power though.

Any other exhaust systems to consider for max gain without noise. I know you can do valve control but not sure I want that either.


Sound like this

Drive like this

thx

D
I've heard the GTS system in person. It is ever so slightly louder than stock. But the all of the power gains are still included. I will be making some of my own videos of the GT system like these this weekend.

Check these out.







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      11-30-2012, 05:10 PM   #39
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Nice. Very Nice.
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      11-30-2012, 07:42 PM   #40
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I'm looking forward to the results of the comparison ...
What would be more amazing is along with the dyno tests we find a runway or track to see the F10 M5's in action ...
I bet myself and members of M5POST would want to see that too!!

Anybody know of a safe and controlled place this could happen at?


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Originally Posted by Nate@IND View Post
Let's set it up with Tom at EAS. We just need to find a stock F10 M5 to do the before and after runs. The iND M5 is still in CA but I want to use a 100% unbiased beast so no RPi M5 car or RPi customer car.
Quote:
Originally Posted by RPiM5 View Post
Yes as soon as you find a stock M5, we can work out a plan according to our schedules.
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      11-30-2012, 08:44 PM   #41
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When you want your exhaust system to look pretty, you call Akropovic.

When you want proven power for your M5, you call RPi.
I don't really think I'd take it THAT far but I think the reason why there are a few against Akrapovic is because frankly they're the most popular (some could even say trendy) at the moment. Sure some might not be satisfied with the sound or power but I do really think there are some against it mainly because it has grown so popular.

Yes, power and sound may a bit conservative for the F10 M5 but that might've been the one of the many reasons why BMW decided to run Akrapovic on their safety car and do a subconscious endorsement of the brand. Clearly the quality is there if they're in the higher end of motorsports like DTM and FIA LMP1 racing.

People may balk at the price of the Akrapovic but let's not forget it's made out of titanium and not stainless steel so there will of course be a price increase in material and manufacturing costs. In that price sense, wouldn't the Eisenmann (as an example) be a tad overpriced since it's made out of stainless steel and priced close to the Akrapovic? People find it easy to find power numbers are down on the Akrapovic from others but forget about the performance benefits of less weight.

Are RPi's products corrosion resistant painted or even possibly ceramic coated for heat insulation? I've only seen several examples of the system unpainted/coated.
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      11-30-2012, 10:08 PM   #42
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I've only seen the Akrapovic exhaust on posts and heard what it sounds like in video clips ..
But based on the posts it certainly look's like a high quality product and the fact that BMW co-signed it is just the cherry on top.
Are there any dyno numbers showing how much HP increase the Akrapovic exhaust produces on the F10 M5?

Nevertheless Star21 has some great points ... TITANIUM baby!!


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I don't really think I'd take it THAT far but I think the reason why there are a few against Akrapovic is because frankly they're the most popular (some could even say trendy) at the moment. Sure some might not be satisfied with the sound or power but I do really think there are some against it mainly because it has grown so popular.

Yes, power and sound may a bit conservative for the F10 M5 but that might've been the one of the many reasons why BMW decided to run Akrapovic on their safety car and do a subconscious endorsement of the brand. Clearly the quality is there if they're in the higher end of motorsports like DTM and FIA LMP1 racing.

People may balk at the price of the Akrapovic but let's not forget it's made out of titanium and not stainless steel so there will of course be a price increase in material and manufacturing costs. In that price sense, wouldn't the Eisenmann (as an example) be a tad overpriced since it's made out of stainless steel and priced close to the Akrapovic? People find it easy to find power numbers are down on the Akrapovic from others but forget about the performance benefits of less weight.

Are RPi's products corrosion resistant painted or even possibly ceramic coated for heat insulation? I've only seen several examples of the system unpainted/coated.
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      11-30-2012, 10:12 PM   #43
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I think joe at trinity has some upcoming installs of rpi exhaust systems ...you guys might want to ping him to coordinate.
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      11-30-2012, 10:16 PM   #44
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*EDIT**

Moved ours to the last page so more people will see
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