Originally posted by kaivball
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Spacers versus more rotating mass?
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Can you get a 2D clearance diagram from the brake manufacturer? When I was shopping for wheels, I sent one out to a couple companies to check for wheel to caliper clearance. Are you dead set on the set of 15's you've already picked or somewhat flexible? Personally, I'd pick the wheel based on the required diameter and width for the tire you want to run, not the other way around.
Also, I'm with Nando on the physics of the wider wheel spacers. I don't see why it would be an issue. Longer stud length is better for maintaining clamp load anyway. The anti-rotation load shouldn't be carried in shear of the stud, it should be the friction between the hub & spacer / spacer & wheel. The main issue with running a spacer is that you're increasing the moment at the hub/bearing and increasing force on the LCA. It's more a function of the distance from contact patch to hub, rather than running a spacer or not. A wide wheel with a negative offset creates the exact same forces.Last edited by citizen_insane; 02-11-2019, 03:16 PM.
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We're talking about an inch of increased moment (leverage). In engineering terms, that's rounding error. And it doesn't take into account the base hub center of the wheels. People do dumb crap like run ET0 wheels with adapters. That's way more leverage than a spacer.
Feelings, thoughts, it's all bs. The difference between a 15mm and a 25mm spacer is meaningless and the comfort threshold is completely arbitrary.
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Originally posted by nando View PostWe're talking about an inch of increased moment (leverage). In engineering terms, that's rounding error. And it doesn't take into account the base hub center of the wheels. People do dumb crap like run ET0 wheels with adapters. That's way more leverage than a spacer.
Feelings, thoughts, it's all bs. The difference between a 15mm and a 25mm spacer is meaningless and the comfort threshold is completely arbitrary.
People can "do" all sorts of spacers and / or adapters.
Im not, nor would I ever recommend someone to run 1" spacers on a race car.
I'd fix my car first so that I dont need 1" thick spacers.Jimmy P.
87 E30 M3 Prodrive British Touring Car
88 E30 M3 Zinnoberot - Garage Queen
88 E30 M3 Lachsilber - SCCA SPU #98
92 M Technic Cabrio - S14 Powered!
98 318Ti Morea Green
04 Ford F350 Dually Tow Machine
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If you're doing W2W racing in an E30, you're probably running a spec tire and not 16" wheels anyway, and probably a spec wheel that just fits like you said.
for an HDPE, daily driver, whatever - it's nothing to worry about.
I didn't know they still made the RT615. Was a great tire back in the day.
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Yeah, I think the Hankook RS-4s are better but the Azenis are still perfectly serviceable for track days and relatively cheap.
A 200 tread wear rating is the minimum for ChampCar Jimmy, that's what I had in mind when I posted that one.Last edited by agent; 02-12-2019, 10:02 AM.
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Originally posted by agent View PostYeah, I think the Hankook RS-4s are better but the Azenis are still perfectly serviceable for track days and relatively cheap.
A 200 tread wear rating is the minimum for ChampCar Jimmy, that's what I had in mind when I posted that one.
They are not something I think about when I think about track tires, my mind goes to the old standard of Hoosiers, Goodyears, BFGR1, Toyo, etc. but I know that lots of guys are using the 200TW street tires as track day tires as well as the race series that spec that 200TW rating.
They do seem pretty impressive for what is considered a street tire.Jimmy P.
87 E30 M3 Prodrive British Touring Car
88 E30 M3 Zinnoberot - Garage Queen
88 E30 M3 Lachsilber - SCCA SPU #98
92 M Technic Cabrio - S14 Powered!
98 318Ti Morea Green
04 Ford F350 Dually Tow Machine
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Originally posted by nando View PostIf you're doing W2W racing in an E30, you're probably running a spec tire and not 16" wheels anyway, and probably a spec wheel that just fits like you said.
for an HDPE, daily driver, whatever - it's nothing to worry about.
I didn't know they still made the RT615. Was a great tire back in the day.Originally posted by agent View PostYeah, I think the Hankook RS-4s are better but the Azenis are still perfectly serviceable for track days and relatively cheap.
A 200 tread wear rating is the minimum for ChampCar Jimmy, that's what I had in mind when I posted that one.
We have been running the 615k"+" since they came out a few years ago - they are softer than the 615, for sure as I had new a set of each at the same time.
This time around, we tried the Maxxis VR1 and they are even stickier. One of our friends did a back to back at Sebring with the 615+ vs the VR1 - same car, same day, three hot laps each and the VR's were worth almost 2 sec with an extremely talented driver. I liked tham, and they are actually a little cheaper than the 615's when buying direct from the MFGR.
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Mechanically, there is no difference between a given wheel with the wrong offset and 1" hubcentric spacer to make up for it and the wheel with the correct offset unless you don't torque your nuts adequately. The clamping loads are immense, thus the friction is immense and the forces involved are far too small to cause the spacer or wheel to slide on the hub let alone deflect the metal spacer itself. Having a spacer isn't going to overload the hub, if the center of the contact patch is in the same place as a stock setup it makes no difference at all a even in scrub radius. If the tire is further out
Then you're changing scrub radius, wheel rate, and putting more load on the hub.Last edited by varg; 02-13-2019, 08:47 AM.
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Lol!Mtech1 v8 build thread - https://www.r3vlimited.com/board/sho...d.php?t=413205
OEM v8 manual chip or dme - https://www.r3vlimited.com/board/sho....php?p=4938827
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