09-27-2011, 08:09 PM | #45 |
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There are always going to be haters....Your car looks awesome!
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09-27-2011, 08:27 PM | #46 | ||
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1. He added about 3 lbs of unsprung, rotating weight with those spacers. It's not much, but unsprung, rotating weight is the worst kind- by definition it hurts ride, grip and acceleration. 2. He moved the front wheels outboard by 12mm, increasing scrub radius by that much. For those that don't know what scrub radius does, it defines steering feedback and feel. When a magazine article complains that an audi has dead steering feel while the BMW's is full of feedback, that's largely the effect of scrub radius. I don't have the 1M's numbers, but it is generally under 10mm, to which you're adding 12mm with those spacers. A small amount of scrub is needed for steering feedback and feel; a large amount is recognized to hurt performance. 3. Springs and shocks are a carefully matched pair from the factory. The wheel plus spring combo will bounce/ resonate as a certain frequency depending on the spring rate, wheel rate and suspension geometry. The shock's job is to damp this bouncing, as bouncing reduces grip, so the shock is designed with a certain amount of damping (% of critical damping) to rapidly control the bouncing. By changing the springs for stiffer ones but not changing the shock valving he reduced the % of critical damping- this means it takes longer for the shock to control the wheel balancing, and this in turn reduces grip. 4. Shock length/ bump stops- you want to avoid hitting the shock bump stops, as doing so upsets the car. By reducing the ride height significantly but not increasing the spring rate in proportion or changing the bump stop location he's going to be smacking them regularly, perhaps damaging the shocks in the process. This is worse on the street than the track generally as the street tends to be bumpier. 5. Rubbing. Not the end of the world, never desirable... If one wanted to do similar modifications but improve handling (or at least speed around a course, as "handling" is subjective) one would: a) Use wider, lighter wheels with the correct offset so that spacers are not required and the scrub radius isn't changed significantly. This would fill out the fenders and not changed the scrub radius. b) Use significantly stiffer springs when lowering the car that amount to avoid hitting the bump stops. c) Use a different shock or a re-valved shock that is matched to the springs. d) Re-align the car. With the above you'd have a package that improves handling and where form would follow function. In that case I wouldn't have mentioned posing... BTW, I don't hate. I laugh. And cry a little...
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09-27-2011, 09:35 PM | #47 |
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Fair enough He does mention going a full matched coilover setup in the future as funds allow. I'm guessing this setup simply was tried as the opportunity to do so came up from a friend. I know I would do the same if I were in his shoes, the more variety the better IMO.
Honest question, I wasn't aware of the outer limits as to what spacers can be run before steering is significantly affected. I understand the downsides of being too low/hitting the bump stops, from looking at how low he is right now it appears that there is still a decent amount of travel left before that occurs. My previous 135i was lower a bit beyond where JJ's 1M is sitting now and didn't have much issue with hitting the stops unless driven very hard over uneven road. Since he doesn't plan on pushing the car too badly I don't think this will be too big of an issue. I guess the question here is how much stiffer % wise the KW springs are compared to the stock 1M springs. I would hope the car was realigned after lowering. Depending on where it's rubbing it should be an easy fix.
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09-27-2011, 09:56 PM | #48 | |
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1M is not an M3 and you should not install parts that doesn't belong to it. Good Luck |
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09-27-2011, 10:41 PM | #50 |
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True haha! We're ready when you are!!
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09-27-2011, 11:11 PM | #51 | |
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As a generalization, a smaller scrub radius is desirable for tight, low speed corners, such as autocross, while a larger scub radius is good for higher speed and steering feedback. By adding a spacer to the 1M you're moving it towards more scrub radius, but realize that's not true for most cars. Porsche, for example, runs a negative scrub radius on its newer cars, so it you add a 6mm spacer to a 996 you go from negative 7mm scrub down to just negative 1mm scrub. As you might imagine things start to get wonky around 0 scrub, as the forces to the steering wheel get reversed as you cross zero scrub radius. This changes all kinds of things- the direction the steering wheel will jerk when ABS kicks in, etc, and really ideally needs a different setup and alignment. For this reason you'd notice the effect of moving the 1M's wheel inboard quite quickly- off the top of my head I think I'd try to stay within ~3mm of stock moving in that direction unless I was doing a competition/ autocross setup. Outboard is less sensitive, but you're still dealing with small numbers, so adding 6mm to the spacer would certainly be noticeable if you were looking for it, as it might be doubling the scrub radius. The wheel will jerk side to side harder under ABS, the wheel will kick harder over bumpy pavement in cornering, and steering effort (and feedback) will generally increase. For street use for the best feel I'd really try to stick close to stock- it's one of the more sensitive number in the suspension. I guarantee you BMW engineers agonized over a 2mm difference in scrub and this is what they came up with. Seems a shame to chuck that hard work without a good reason when you can "do it right" with lighter, wider wheels.
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09-28-2011, 08:52 AM | #52 |
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Just so we clear the record for you, "Ohh Wise One", a 5 or 6mm spacer would not be hubcentric, therefore your wheel would be relying soley on your lugs/studs to remain completely centered to the hub face, thereby increasing the chance of vibration. But one with such intellect would know this.
And btw, if you feel that the KW spring included in their kit has a lower spring rate than stock, I suggest you sell your Porsche as an obvious dip shit owns it. You come on here and run your mouth (i.e. "poser"). Granted, everyone has different tastes, but if you were to read my entire thread, nowhere did I say this is the "best" setup for performance. Your attack on my intellect, and your need to suggest I don't deserve your holy grail of a 1M leads me to my next suggestion..... If one should be looking for the best in performance and most likely tracking their car and measuring "scrub radius", why would they pay for iDrive, NAV, Power Seats, and further more why would they fit it with heavy ass 19" CAST wheels. The wiser man would purchase an EVO 9 MR, gut it, bolt a GT35R on it, wrap it in 18 x 10"s and spank the ever loving shit out of you all day, and all night my man. If you are ever feeling froggy, take me up on an offer to go toe to toe on the track. I have a feeling you will reconsider your "poser" comment.
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09-28-2011, 08:54 AM | #53 |
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09-28-2011, 10:28 AM | #55 |
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09-28-2011, 04:31 PM | #58 | |
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This is pretty simple. You wanted your car to look faster. So you made some changes that did that, but you actually made the car slower. And you seem fine with that. OK, have fun, but that's the definition of poser. Sorry, just calling a spade a spade. If you didn't want feedback perhaps you shouldn't have asked, and you can take comfort that I have the minority opinion here so you're in good company.
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09-28-2011, 08:12 PM | #60 | |
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I believe there is a good reason why KW themselves designed new kit of V3 coilovers for 1M and didn't use the existing M3 kit ... Since you sell KW parts you probably know that KW had to changed the springs rate for 1M on V3 kit. That's pretty much the only difference right ? |
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09-28-2011, 08:24 PM | #61 | |
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Looks like neither the shop that did the work or OP fully understand what they did to the car ! |
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09-29-2011, 09:18 AM | #63 |
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That's right. I figured I needed to lower my car to make it look faster. Maybe you should check out some more of my posts my man.
And the more you speak, the more it is obvious you are just a hater. Bottom line, my car looks good. Yours looks like it is ready for the baja 500. Scrub radius, quit talking about the distance it takes for you to reach around your gut to scrub your ass. And if you were as smart as you try to make yourself out to be, you would realize that the maximum drop in rear is .5" that's less than most coilovers or lowering springs. And at the end of the day, I really don't give a shit what a bald old man thinks of my car.
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09-29-2011, 10:16 AM | #64 | |
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HaaaaHaaa! good one!!
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09-29-2011, 11:57 AM | #65 |
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Whip look incredible man! Thats the PERFECT ride height! And the 12millies on the rear really complete the look! Great work!
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09-29-2011, 11:59 AM | #66 | |
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