Which are the five lightest wheels for the 997 turbo?
#77
Wow, it is very nice to have seasoned pro's (you & Champion) give their inputs -- this thread has become quite interesting all of a sudden. Let me re-ask the question to make sure I, and maybe other amateurs like me ;-), understand you correctly. (I am a complete amateur and had to read about gyroscopic effect and precession on wikipedia http://en.wikipedia.org/wiki/Precession when you started mentioning the word! )
So... are you saying:
1. Yes gyroscopic effect is a problem, but the heavier wheel is not at an advantage because:
2. With road irregularities, the force on the heavier wheel is larger, and therefore it suffers just as much from precession?
So... are you saying:
1. Yes gyroscopic effect is a problem, but the heavier wheel is not at an advantage because:
2. With road irregularities, the force on the heavier wheel is larger, and therefore it suffers just as much from precession?
The vertical forces of road irregularities cause the "gyroscopes" to precess at right angles, even with tiny inputs. The faster the wheel is turning and the greater the moment of inertia, the worse the precession. Thus, the heavier wheels add nothing on perfectly smooth roads and cause a left to right oscillation on rougher roads.
The gyroscopic theory regarding vehicle stability is very interesting to think about and quite logical, but has no foundation in science. Gyroscopes are actually used primarily to provide "error" signals to control surfaces that in turn create stability in aircraft, spacecraft and marine vehicles. They are positioned in a known attitude, spin at a known rate, and have a fixed moment of inertia. Therefore tiny inputs of force cause the Gyro to precess, acting on an electronic circuit that creates a corrective input to a control surface. The Gyro then senses the correction and neutralizes the control surface. This happens very quickly and reliably, stabilizing the vehicle.
However, the gyro itself doesn't directly stabilize anything, only indirectly.
Fun subject.
BTW, #2 is actually correct.
#78
^^^Mike, thanks so much for taking the time to explain; clearly it's a subject you know much and care much about. Let me brush up on precession & think about your response for a few days & and see if I have any more questions.
Last edited by cannga; 04-08-2010 at 12:16 AM.
#79
...snip...
Multi-piece wheels like the Dymag are very difficult to manufacture with such high levels of concentricity. The more the pieces, the more difficult it is.
Not impossible, mind you, just difficult.
Forged monoblock wheels can be built with practically zero runout if one builds the proper tooling and fixtures. Not cheap, but very smooth at high speed. ...snip...
Multi-piece wheels like the Dymag are very difficult to manufacture with such high levels of concentricity. The more the pieces, the more difficult it is.
Not impossible, mind you, just difficult.
Forged monoblock wheels can be built with practically zero runout if one builds the proper tooling and fixtures. Not cheap, but very smooth at high speed. ...snip...
1. Does what you wrote imply forged monoblock wheels are inherently better than multi-piece wheels?
2. I seem to notice the lightest wheels tend to be multi-piece (Champion RG5, HRE Competition Series). Is there something about monoblock that makes it heavier?
Thank you.
Last edited by cannga; 04-08-2010 at 12:17 AM.
#80
Hi Jesse,
1. Does what you wrote imply forged monoblock wheels are inherently better than multi-piece wheels?
2. I seem to notice the lightest wheels tend to be multi-piece (Champion RG5, HRE Competition Series). Is there something about monoblock that makes it heavier?
Thank you.
1. Does what you wrote imply forged monoblock wheels are inherently better than multi-piece wheels?
2. I seem to notice the lightest wheels tend to be multi-piece (Champion RG5, HRE Competition Series). Is there something about monoblock that makes it heavier?
Thank you.
Monoblocks also easily accept factory air valves and TPMS sensors, and there is no problem with vibration caused by water retention, a common problem with 3-piece wheels. Lastly, they are usually easier to clean, not having to deal with all the bolts (PLEASE don't call them rivets) used in 3-piece wheels. And since there is no rim sealing to worry about, no air leaks.
So, lighter, stronger, truer, less expensive and more trouble-free: thats my case.
In fairness, 3-piece wheels are easier to repair, and they can also incorporate complex finishes easier than a monoblock.
And for the record, the two lightest wheel designs available are monoblocks, made by BBS and Tech1.
#82
Our Tech1-200 series for the Turbo are also very light.
The Tech1-210 front in 19x8.5 is 7.48 kg. Rear in 19x11.5 is 8.95 kg.
The 19x12 for the GT3 is 9.08 Kg.
We have been trying to find stocking distributors for this line.
However, in the meantime we will announce a group buy next Monday on all the Tech1-100 and Tech1-200 series wheels. Under $4k per set.
PM me if you want a quotation.
The Tech1-210 front in 19x8.5 is 7.48 kg. Rear in 19x11.5 is 8.95 kg.
The 19x12 for the GT3 is 9.08 Kg.
We have been trying to find stocking distributors for this line.
However, in the meantime we will announce a group buy next Monday on all the Tech1-100 and Tech1-200 series wheels. Under $4k per set.
PM me if you want a quotation.
#83
So far we came across:
Dymags (not available any more)
HRE C/F series
BBS Forged individuals
OZ ulraleggera
Tech1
PES GP7 (Not available any more)
RG5
FORZA FORGED F97
Dymags (not available any more)
HRE C/F series
BBS Forged individuals
OZ ulraleggera
Tech1
PES GP7 (Not available any more)
RG5
FORZA FORGED F97
#84
There are some good pictures of the Tech1-109 and 110 on our website:
www.forgedalloysUSA.com
The Tech1-200 series pics I will add here.
This group buy is for any 19 or 20 inch 997 Porsche fitment.
PM me for 996 fitments.
Finish is limited to Matte Black, Satin Black, Gloss Charcoal, Brushed/Clear and Brilliant Silver.
$3995 per set, 4-5 week delivery
PM me with questions.
Mike
www.forgedalloysUSA.com
The Tech1-200 series pics I will add here.
This group buy is for any 19 or 20 inch 997 Porsche fitment.
PM me for 996 fitments.
Finish is limited to Matte Black, Satin Black, Gloss Charcoal, Brushed/Clear and Brilliant Silver.
$3995 per set, 4-5 week delivery
PM me with questions.
Mike
Last edited by Tech1_Mike; 04-08-2010 at 08:14 AM.
#90
so of the available wheels
Tech 1
BBS FI
Champion Mag ?
or any others.
Can we get a listing of actual weights for the same size wheels and pics for comparison?
Since this is posted in the 997TT lets have each vendor (or interested individual) post a picture of two of the wheel that they feel best represents light and strong, and the actual weight for the 99TT fitment, and whether they are TPMS compatible.
Tech 1
BBS FI
Champion Mag ?
or any others.
Can we get a listing of actual weights for the same size wheels and pics for comparison?
Since this is posted in the 997TT lets have each vendor (or interested individual) post a picture of two of the wheel that they feel best represents light and strong, and the actual weight for the 99TT fitment, and whether they are TPMS compatible.