Congrats to 8legs/ScotcH

[craz azn]

LOL. Those Genesis' look so rough already. Especially that 'new' one that was supposedly just put together this year. What makes it look worse is the tape all over the car... like if your panels are gonna need all that tape to hold it together, I think you are doing something wrong.

[ecosse335]

Here are some BMW photos from Mosport.
https://www.facebook.com/media/set/?...7181884&type=1
The Muscle Milk car does indeed have an Aston Martin. Last year they ran the Porsche RS Spyders, that's probably where the confusion is.

[Darkness95m3]

Originally Posted by King Luis

here's 2 for you. large size.

Awsome pic...

Congrats on the win...

[exbmwtech]

Originally Posted by craz azn

LOL. Those Genesis' look so rough already. Especially that 'new' one that was supposedly just put together this year. What makes it look worse is the tape all over the car... like if your panels are gonna need all that tape to hold it together, I think you are doing something wrong.

The "new one " has had a "few incidents" this year which might explain the rough look. The Genesis are also favoured by the rules this year ,so it shows how well Arek can drive.

[exbmwtech]

Arek could you give us some specs/ more info on your car

[ScotcH]

Originally Posted by exbmwtech

Arek could you give us some specs/ more info on your car

Sure, what do you want to know? Here are the basics:

- e46 sedan BMW motorsport chassis #007 (built by BMW to FIA spec)
- Moton tripple adjustable dampers
- Spring rates vary, but at Mosport its 950# front, 500# rear (coil over rear)
- big ass anti-roll bars, but usually full soft
- Brembo GT-R brake kit (323x28mm disc, 4 piston, nothing crazy)
- diff is 3.91 for mosport, 4.33 for short tracks. Diffsonline
- 5 speed ZF (junkyard)
- clutch is a 4.5" AP Rasing triple disc (the flywheel busted, so last weekend I ran our spare e36 sachs 8.5" cltch)
- Engine is m54b30, full race spec (12.5:1 cr, custom cams, custom intake, etc). 8000 rpm redline (but I shift at 7600). Depends on whos dyno you look at, but around 270-290 rwhp
- electric power steering, electric water pump
- race weight is 2750 with driver (2840 now with all my "reward" weight )
- wheels are BBS RG-R 17x9 with conti 245/40/17 rubber (basically Hoosiers)

[craz azn]

What kind of damper do you use on the front of that engine?

BTW, got any incar vids you can share with us?

[ScotcH]

Originally Posted by craz azn

What kind of damper do you use on the front of that engine?

BTW, got any incar vids you can share with us?

No damper at all ... just an aluminum pulley for the alternator belt (alternator is where A/C compressor used to be, and it's from an integra )

I'm working on getting vids ... will have last weekend's soon!

[SiR]

what kind of electric water pump and power steering?

thanks for sharing

[BigD]

Originally Posted by ScotcH

No damper at all ... just an aluminum pulley for the alternator belt (alternator is where A/C compressor used to be, and it's from an integra )

Hmm, interesting! So much for the internet racers saying that these motors don't survive long being wound out to 7.5k+ due to crank harmonics... How long have you been racing this motor (how many races/hours)?

[ScotcH]

Originally Posted by SiR

what kind of electric water pump and power steering?

thanks for sharing

PS pump is from A class merc or Porsche GT3 Cup car (same pump, made by LuK). Nice and easy to install ... 2 hoses for the fluid, and a +12 and GND for power. All the smarts are in the pump. Feels just like OE

The water pump is this one: http://www.stewartcomponents.net/Mer...Code=ElectPump

[ScotcH]

Originally Posted by BigD

Hmm, interesting! So much for the internet racers saying that these motors don't survive long being wound out to 7.5k+ due to crank harmonics... How long have you been racing this motor (how many races/hours)?

It was refreshed 3 races before I got it, and I've been running it all this year, so say 13 races on it, plus practice, qualifying, etc. Say 30hrs maybe? I could check the Motec logs for an exact number. I'm probably on borrowed time, but can't afford a rebuild mid season

A lot of work went into this engine ... nothing at all is standard and it's all super light weight. the pistons and super light, pins are smaller, the cams are smaller base circle, valves stems are smaller, etc. All to reduce mass. Also the rod length is longer, I assume to have a smaller rod angle. The entire thing is also very well balanced of course. Its a very well built engine, but it really sucks getting parts for it. We have a second similar engine for the #11 car that has given us nothing but headachs all year

[BigD]

Cool man, thanks. I'm not sure the component weight affects this much. As far as I understand the problem as it's stated, it's the length of the 6 cylinder crankshaft, that it's nearly impossible to get rid of the crank harmonics at high rpm. Did you guys change the crank at all, or do a stud girdle for the mains?

I hear you on the parts. I waited 6 months for my rods and pistons. I'm sure if my name was Penske I'd have my shit in 2 days.

[ScotcH]

Crank is just a balanced OE 3.0L crank. The mains are ARP studs, but otherwise the bottom end is stock using BMW OE bearings. Nothing fancy there. YTR did break a crank last year, but they attribute that to an unbalanced flywheel after the ring gear sheared off.

[BigD]

For what it's worth, I asked a consultant to professional racing teams (incl F1) about the BMW i6s, which he also has in racing trim, and specifically about the front dampener and ATI, this is what he said:

The flywheel is just part of the system, and it can dampen some orders of harmonics, but it's not the most critical part of the equation.

Visualize the crank as being a big floppy piece of foam connected to a flywheel on a bearing shaft. Now grab that piece of foam at the front, farthest away from the flywheel, and start to twist it. The foam starts to twist before the flywheel starts to move. Then release the foam, and you'll see it springs back as it releases that stored energy that has not been used to move the flywheel. This is what's happening in all I6 engines, and cylinder #1 creates the strongest harmonics; cylinder #6 creates the least. Adding a harmonic damper is like adding a spring and shock absorber to the front of the crankshaft to dampen it's movements back and forth. Just as you have a spring/shock suspension under your car to keep it from being hammered by the road, the crankshaft has a "suspension" system to help it from hammering everything it is attached to. In reality, we're really talking about something like Renault F1's mass damper system from 2005 and 2006, but you get the point. A harmonic damper absorbs that torsional force and turns it into heat either by using rubber or fluid. The OEM system uses rubber, but it's a very low capacity system. ATI uses rubber, but it's both a very high capacity system with regard to heat handling, and they use multiple pieces of rubber so they can tune to more than 1 frequency.

As a real world example, PTG used the passenger side brake duct scoop to route air through a 3" duct directly at the harmonic damper on the I6 engines installed in the M3GTRs.

I think I'm going to post the above...it probably can help a few to see the problem.

Regarding that RPM point. I ran my engine above that and never had a failure with the OEM oil pump and an ATI damper. I think I was lucky though, as when I tore down the engine the OPN was loose. Even with the ATI damper, I still think you need to have hardware that can handle harmonics. (This is what F1 engines have as a major issue)

So I do think that a flywheel can help dampen harmonics, but I don't think it has the most leverage to do so. The best place to be is at the front of the engine....