kweezy31

"Moton Club Sport Damper System". That'll take a huge chunk of your budget, but a good handling car is just as, if not more important than a powerful car. But I don't think you'll really have to worry about the power thing

Myke951

I know that, but the cost of wheels to lbs shaved off of unsprung weight is not very efficient money wise IMHO if he is merely going for quickest 0-100... I know shaving weight is not equivalent, i was using it as an analogy as hp/weight ratio is changed in the same manner, so obviously there is some similarity. He asked for an opinion on what he wants so i gave him my opinion to what he asked or else i would recommend the suspension mods myself... He may never see the track and just wants an advantage on the street...

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2004 Mini Cooper S: Alta supercharger 15% pulley upgrade, Dinan cold-air intake, Skunk2 header back exhaust, RMW CUSTOM TUNE, Alta oil catch can, OMP Strut brace, Eibach pro-kit springs, H-Sport camber links, 19mm Rear sway bar w/ adj. end links, 18 in. Breyton mini magics, 6lbs lighter crank pulley, polyeurathane tranny and engine bushings, wheel Studs, Wilwood BBK... More to come soon!

RIP=White 944 turbo: KKK K-27/6 turbo, upgraded intercooler, Lindsey Racing hardpipes, Autothority MAF, B&B exhaust with 4.5" oval tip, Siemens #55 fuel injectors, Lindsey Racing MaxHP custom Chip set, 3 bar fuel pressure regulator, Re-worked head and slightly overbored pistons, Spec Lightened 6 puck stage 3 clutch, Quaif torque biase differential, Apexi AVC Type-R Electronic boost controller, HKS type-1 turbo timer, Shimmed wastegate, Champion Motorsports adj. bypass valve, Weltmeister front and rear sway bars, Weltmeister strut tower brace, Koni adj. "yellows", unknown springs, Turbo Twist rims, Kumho Ecsta Supra tires... And a couple of more unknown mods...

Revo

While I don't agree at all with that "this power mod is equal to 130lbs less" mumbo jumbo, I would like to point out something about wheel weights.

Stock M5 tire diameter is 26.9 inches in rear. So the circumference is roughly 85.5 inches. At 200mph, your wheels are rotating at mere 2470RPM. 100mph is (obviously) half that at 1235RPM. 50mph is obviously again half at 617.5RPM.

Stock M5 wheels are light as they are (not 8000 set of Neez QD7 light, but light enough for an OEM wheel). Say (optimistically) you save 10lbs of rotating mass by switching, but like most, you get 20 inch rims, negating some of the benefits of having a lighter wheel (since larger rim means the weight of the wheel is further from the axis of rotating, effectively increasing rotating mass).

So what do you think provides an improvement? A light (underdriving pulley) that is revved to over 8000RPM 7 times on the path to 200mph? (in the OP's case, 3 times to 100mph) or wheels spinning at 2470RPM at 200mph (1235RPM for the OP's 100mph) and are slowly increased to that speed as the car accelerates from a stop.

I'm not saying wheels don't make a difference, cause they make a huge difference - and also help with braking and cornering.

I'm simply pointing out that the OP asked to provide a list of mods to help his car do 0-100.

Considering a full exhaust provides a significant increase in torque, and a pulley reducing rotating mass making a solid difference in the critical gears 1, 2, and 3 where the engine typically winds out quite quickly.

Why don't you buy a set of $6000 wheels and tires and race against the $6000 in power mods and see who hits 100mph first (to keep things even, you must run similar tires, such as PS2's - it would be stupid to compare some drag radials to stock Continentals)?

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The M5 is my dad's - but I drive it more than he does!

BMWPower06

Actually saving unsprung weight is probably even better than getting a full RPi stage 2. A lightweight 18" set up could save ~20lbs/corner, multiply that by 4 corners = 80 lbs of unsprung mass saved. Convert that to sprung mass using the standard 10:1 ratio and you have the equivalent of roughly 800lbs of sprung mass shaved off the car by just picking up lighter wheels. I'd love to see a full RPi stage 2 take that on

This article explains the above in much more detail:
Unsprung Weight, Part 2

So as I said several posts ago, don't waste your money on these so called performance mods and just get some nice wheels. Hell even a nice set of forged 19s will still save you about ~10lbs/corner

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BMWPower06

My 20" forged 3 Piece DPE REAR wheels and tires were a pound lighter than my OEM 19" FRONT wheels and tires. Also, the overall diameter (tire and rim) barely changed from my 19s to 20s. With 20" wheels comes thinner tires.

What does the RPM that the rim or pulley spin at have do with acceleration?? by your logic, I see the following:
.1lb saving for pulley at 8000rpm (8000rpm*.1lb)= 800
10lb saving PER wheel at 2470rpm (2470rpm*10lbs)= 24,700

According to your numbers the rims make a MUCH bigger difference than a pulley. Also, you have 4 wheels and only 1 pulley, so should we multiply 24,700 by 4?

Also, my experience with full exhaust's (on NA cars) has always been a gain of hp at the expense of loss of tq in the low rpms. You always want to have some back pressure to help with low end tq.

Revo

You also need to consider the rate at which the pulley is accelerated.

In first gear the pulley goes from 1500RPM (clutch engagement point a casual start) to 8250RPM. The wheels go from 0RPM (still) to 580 RPM at 47mph. Now lets see, shift to second gear and the engine speed goes from 5000RPM back up to 8250RPM while the wheel speed goes from 580 RPM to 863 RPM. A small increase of 283RPM vs the again, 3250RPM span of the engine.

Also, the weight savings by a pulley is far more than .1lbs, not to mention the reduced load of aftermarket pulleys under-driving.

Secondly, prove to me you can save 80lbs by getting new wheels and tires. First off, when you go from 19 to 20" using the correct size tires (same outer diameter/width) - yes, the barrel of the rim only goes .5 inch further way from the axis of rotation, but it still goes out further. What you lose in this increased torque from this rotating mass totally outweighs the small gain you have by having slightly less sidewall rubber (your contact patch rubber barrel is still the same on both a 19" and 20" tire - the only difference is sidewall.

Going wider than stock further impedes by adding more rotating mass since you are adding weight at the worst point (outer diameter of a wheel - where it has the most effect on rotating inertia).

This is not to mention that a pulley costs about $500 and high end, light weight wheels you seem to referring to cost about 8-10 grand per set.





But again, all that aside, I want PROOF you can save 20lbs per corner. Cause otherwise, I call BS on that one.

Revo

FYI, super lightweight BBS wheels saved a mere 4.5lbs per corner vs OEM wheels.

18lbs total.

Please show me a setup that saved over 4 times that.

Thanks.

Myke951

Exactly... 18lbs a corner? what are you smoking? unless it is a wheel made of carbon fiber (yes i am aware of them)... Again revo I acknowledge that its not the same as shaving weight, BUT it does share similarities in acceleration through hp/weight ratio... (like a lotus versus an e46 m3 lotus= 2000lbs with 200hp, m3=3300lbs with 333hp)... I think you guys are taking what I said the wrong way... BMWPOWER06 I would LOVE to see your car with your wheels go against an rpi stage 2 car with stock wheels on... lol, itll almost be as good as you saying AFE actually made power...

triplesiks

From everything I have read, it is my opinion that the M5 is pretty close to maxed out unless you go for supercharger. I could see the exhaust. But I doubt I would ever change anything. I like the stock car and if you think 20 horsepower is gonna make the difference in beating someone in a street race, if its that close, you would have to race several times to see who was really faster. A split second on reaction time is worth 20 horsepower. Don't get me wrong I love reading about all the mods and love watching the you tube videos too. I would be tempted to go the Dinan route because your dealer will install and I do not think it voids anything. Good Luck and post a video when you are done.

Ahmed

You know... for 6k, if you shop from the classified section of members here, you can probably go the whole nine yards! FULL BOLT ON's and wheels too!

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2006 E60 M5 Sepang Bronze/Natural Brown/Olive Ash (RIP)
2013 C63 AMG P31 Magnetite Black/Classic Red & Black/Carbon Fibre