F10 M5 RPi GTM Exhaust: With Fully Catless Downpipes Now! - (I went Full Retard)

[mwlmd]

Very cool. To bad you can't drive it on public roads anymore. It would be nice to have this type of setup available at the push of a button so the M5 could be truly dual purpose.

I am guessing you had to buy a Fiat because your M5 while very cool in limited doses is just too obnoxious for you to drive to work daily?

[dhirm5]

Originally Posted by RPiM5

As for racing my friends Lambo, this is an older video I shot when I only had the RPi GT Exhaust system installed. He has the Superleggera with the 523hp version, but he's still about 1,000lbs lighter than me. Lol!

Nice - you walked him before, you'd crush him now. Impressive!

[bmellion]

Wow...

[RPiM5]

Originally Posted by mwlmd

Very cool. To bad you can't drive it on public roads anymore. It would be nice to have this type of setup available at the push of a button so the M5 could be truly dual purpose.

I am guessing you had to buy a Fiat because your M5 while very cool in limited doses is just too obnoxious for you to drive to work daily?

Nope, absolutely wrong on both counts.

Even with the straightpipes, the F10 M5 can easily still be as quiet as stock. Driving around in D1 or D2 is totally fine. Not loud at all. The only thing that's really loud in the neighborhood is the Cold Start. I haven't had anyone in my neighborhood complain to me about driving around in the neighborhood.

People need to understand that this Twin Turbo V8 does not share many of the same characteristics as the E60 V10. When I used to drive my straightpiped V10 all around town and I wanted to keep it quiet, it was so essential to keep the revs under 3,500rpm. Above that the V10 would just start to scream no matter if you were hard on the throttle or not. With the F10's V8, it's ONLY loud when you are hard on the throttle. If you are light on it, and drive it around like most peoples wive's, it's pretty much the same level as the stock exhaust. Therefore there is absolutely no need for valves with this system. With the V10 there was a need for valves, as it is hard to keep it low rpms all the time, unless you were driving around in the clunky D-modes on the SMG, but who ever did that?!

I have my Fiat Abarth because it's better on gas mileage for my commute to work (still 35mpg on the highway) and I work by the ocean where there is a lot of dust and salt spray in the air and I don't like my M5 sitting all day, everyday in that environment. Plus the Abarth is just as much fun as the M5 is, but at a lower speed. I never got the Fiat Abarth because my M5 was too loud or obnoxious driving around daily. It's that I'd rather keep the M5 in the garage all week, staying clean and not being exposed to door dings and scratches every day. I used to drive my straightpiped E60 V10 to work everyday and I loved the sound of the loud V10 driving to work everyday, but to be honest I made the suspension too stiff on it, and it became very uncomfortable as a daily driver.

I'm thinking that my next video should be driving the F10 M5 around town in normal mode to show just how quiet it can still be, even with the Straightpipes. I'll call it: "F10 M5 RPi GTM Exhaust: See how you can have your cake and eat it too, even with 100% Straightpipes."

[Boss330]

Sounds mean and loud!

At 01:10-01:15 - Revving the car and then killing the engine - You are not treating your turbos nice. It's adviced to let the engine sit at idle for up to 1 minute before switching off the engine. The turbos need time to spool down and cool before loosing lubrication (when you stop the engine the oil pump shuts down, but the turbos are still spinning without lubrication...)

Even though the exhaust note is loud and mean, it's not quite F1 high pitch... Just came home from the Monaco GP and there is not much that can compare with a F1 engine at full song. Those engines are the loudest thing I have experienced, ever!!! And those cracks and bangs while downshifting/upshifting are just insane (and does not come through on TV at all). You could feel the pressure wave from the explosions when you where close to the track. It was like gunshots or top end fireworks bangs!!!

[info@trinityautosport]

awesome stuff Dave

[RPiM5]

Originally Posted by Boss330

Even though the exhaust note is loud and mean, it's not quite F1 high pitch... And those cracks and bangs while downshifting/upshifting are just insane (and does not come through on TV at all). You could feel the pressure wave from the explosions when you where close to the track. It was like gunshots or top end fireworks bangs!!!

You are right it's not quite F1 high pitch, I think if the S63tu was a higher revving engine we could achieve that though. My girlfriend was the one who helped me film some of the footage. She said that when I would pass by her and upshift/downshift she could feel the sound pressure wave of the crack of my exhaust move through her body. It's something that you just have to be there to experience like you said. The upshifts/downshifts sound just like gunshots or as I used to describe like loud bullwhip cracks on my exhaust also. You can ask any of the guys that were driving their M5's behind me last weekend on our little run through "Mexico," M54ccibo, Grayblack, MindlessMark07.

[mwlmd]

Originally Posted by RPiM5

Nope, absolutely wrong on both counts.

Even with the straightpipes, the F10 M5 can easily still be as quiet as stock. Driving around in D1 or D2 is totally fine. Not loud at all. The only thing that's really loud in the neighborhood is the Cold Start. I haven't had anyone in my neighborhood complain to me about driving around in the neighborhood.

People need to understand that this Twin Turbo V8 does not share many of the same characteristics as the E60 V10. When I used to drive my straightpiped V10 all around town and I wanted to keep it quiet, it was so essential to keep the revs under 3,500rpm. Above that the V10 would just start to scream no matter if you were hard on the throttle or not. With the F10's V8, it's ONLY loud when you are hard on the throttle. If you are light on it, and drive it around like most peoples wive's, it's pretty much the same level as the stock exhaust. Therefore there is absolutely no need for valves with this system. With the V10 there was a need for valves, as it is hard to keep it low rpms all the time, unless you were driving around in the clunky D-modes on the SMG, but who ever did that?!

I have my Fiat Abarth because it's better on gas mileage for my commute to work (still 35mpg on the highway) and I work by the ocean where there is a lot of dust and salt spray in the air and I don't like my M5 sitting all day, everyday in that environment. Plus the Abarth is just as much fun as the M5 is, but at a lower speed. I never got the Fiat Abarth because my M5 was too loud or obnoxious driving around daily. It's that I'd rather keep the M5 in the garage all week, staying clean and not being exposed to door dings and scratches every day. I used to drive my straightpiped E60 V10 to work everyday and I loved the sound of the loud V10 driving to work everyday, but to be honest I made the suspension too stiff on it, and it became very uncomfortable as a daily driver.

I'm thinking that my next video should be driving the F10 M5 around town in normal mode to show just how quiet it can still be, even with the Straightpipes. I'll call it: "F10 M5 RPi GTM Exhaust: See how you can have your cake and eat it too, even with 100% Straightpipes."

That is very interesting. It would be good to hear how quiet your setup can be. I suppose the low end torque if this engine makes low rpm stealth cruising not just possible but practical. Very cool!

What do you do when renewing DEQ TAGS? Just put cats back on?

[RPiM5]

Originally Posted by mwlmd

What do you do when renewing DEQ TAGS? Just put cats back on?

Yup, didn't you read the original post? Install only took about 2 1/2 hours. Supereasy, and shouldn't cost anymore than a few hundred sheckles for the job.

[Boss330]

Originally Posted by RPiM5

You are right it's not quite F1 high pitch, I think if the S63tu was a higher revving engine we could achieve that though. My girlfriend was the one who helped me film some of the footage. She said that when I would pass by her and upshift/downshift she could feel the sound pressure wave of the crack of my exhaust move through her body. It's something that you just have to be there to experience like you said. The upshifts/downshifts sound just like gunshots or as I used to describe like loud bullwhip cracks on my exhaust also. You can ask any of the guys that were driving their M5's behind me last weekend on our little run through "Mexico," M54ccibo, Grayblack, MindlessMark07.

Amazing

(I wasn't trying to be negative to the sound of your car, but maybe my wording was a bit blunt )

[Tom C]

RPiM5:

Very nice write-ups and videos!

I assume that your dyno pulls were done with 91 octane gas...is that true?

[RPiM5]

Originally Posted by Tom C

RPiM5:

Very nice write-ups and videos!

I assume that your dyno pulls were done with 91 octane gas...is that true?

Yes, good ole' crappy California 91 octane gas.

[dhirm5]

Originally Posted by RPiM5

Yup, didn't you read the original post? Install only took about 2 1/2 hours. Supereasy, and shouldn't cost anymore than a few hundred sheckles for the job.

Do they read smog directly from your tailpipe in CA or do they get the reading off OBDII? If OBD you may be ok..

[h4nh]

Sounds really good! Do you daily it? lol

[jbomb]

Here is a question for you all.
How about a stock exhaust but with the catless downpipes? I had this on my last car, TTRS, and it sounded perfect. No problems with drone etc but much more aggressive sound.
Would love to hear that, plus that's a much cheaper option than changing the rear cans isn't it? Understand you will have an issue with removing cats.

[mwlmd]

Originally Posted by dhirm5

Do they read smog directly from your tailpipe in CA or do they get the reading off OBDII? If OBD you may be ok..

Even if its obd2 won't the smell be somewhat obvious?

[dhirm5]

Originally Posted by mwlmd

Even if its obd2 won't the smell be somewhat obvious?

Fair enough.. Though a friend of mine has a fully decatted E60 M5 and I have to say, I didn't smell anything driving it nor standing next to it.

[wisesoul]

Originally Posted by Boss330

Sounds mean and loud!

At 01:10-01:15 - Revving the car and then killing the engine - You are not treating your turbos nice. It's adviced to let the engine sit at idle for up to 1 minute before switching off the engine. The turbos need time to spool down and cool before loosing lubrication (when you stop the engine the oil pump shuts down, but the turbos are still spinning without lubrication...)

Even though the exhaust note is loud and mean, it's not quite F1 high pitch... Just came home from the Monaco GP and there is not much that can compare with a F1 engine at full song. Those engines are the loudest thing I have experienced, ever!!! And those cracks and bangs while downshifting/upshifting are just insane (and does not come through on TV at all). You could feel the pressure wave from the explosions when you where close to the track. It was like gunshots or top end fireworks bangs!!!

Regarding the revving, our turbos are water cooled and very efficient, I wouldn't be concerned about damaging the turbos at all.

[Scott_in_FL]

I like this idea. Given that the stock system flows so well, the only real restriction is at the downpipes/cats. Freeing those up should give us the majority of the hp gains with manageable sound levels (at a fraction of the price of a full system swap).

Originally Posted by jbomb

Here is a question for you all.
How about a stock exhaust but with the catless downpipes? I had this on my last car, TTRS, and it sounded perfect. No problems with drone etc but much more aggressive sound.
Would love to hear that, plus that's a much cheaper option than changing the rear cans isn't it? Understand you will have an issue with removing cats.

[Boss330]

Originally Posted by wisesoul

Regarding the revving, our turbos are water cooled and very efficient, I wouldn't be concerned about damaging the turbos at all.

Turbos have been watercooled since the dark ages... Even my 1988 Sierra RS Cosworth has a watercooled turbo.

Obviously bearing- and turbine shaft materials have improved since the '80ies. But it's still recommendable to let the turbos spool down and cool before shutting off the engine. Especially after a spirited drive.

But, coming to think off it I also realize that the "Start/Stop" function actually stops the engine as well. This means that there either is some sort of oil pressure/lubrication even when the engine is stopped or that the bearing materials are super long life. Not as crucial as I thought then, but I'd still let the engine sit at idle for a few moments before killing it.

[wisesoul]

Originally Posted by Boss330

Turbos have been watercooled since the dark ages... Even my 1988 Sierra RS Cosworth has a watercooled turbo.

Obviously bearing- and turbine shaft materials have improved since the '80ies. But it's still recommendable to let the turbos spool down and cool before shutting off the engine. Especially after a spirited drive.

But, coming to think off it I also realize that the "Start/Stop" function actually stops the engine as well. This means that there either is some sort of oil pressure/lubrication even when the engine is stopped or that the bearing materials are super long life. Not as crucial as I thought then, but I'd still let the engine sit at idle for a few moments before killing it.

Yeah, well just put it out there, not new tech by any means lol. RPI was only revving it a few times, not really enough load on the engine to produce extended periods of boost or make the exhaust really hot (like after a spirited drive) Unless he drove it like he stole, then that's a different story!

[greentrbo95gst]

Originally Posted by Boss330

Turbos have been watercooled since the dark ages... Even my 1988 Sierra RS Cosworth has a watercooled turbo.

Obviously bearing- and turbine shaft materials have improved since the '80ies. But it's still recommendable to let the turbos spool down and cool before shutting off the engine. Especially after a spirited drive.

But, coming to think off it I also realize that the "Start/Stop" function actually stops the engine as well. This means that there either is some sort of oil pressure/lubrication even when the engine is stopped or that the bearing materials are super long life. Not as crucial as I thought then, but I'd still let the engine sit at idle for a few moments before killing it.

Many turbos out there are not water cooled. They are oil cooled and we used to have some air cooled ones.
There is really no need to water cool it, but manufactures added it for longevity. I have used many turbos that were oil cooled only in the last 10 years and they were great. In the late 90's we used turbo timers to cool it off after driving. Nowadays there has to be something else to cool them after the engine is shut off.