View Full Version : Saving Unsprung Weight
Hi All
I have just changed my wheels - old were 16x7 (F) and 16x7.5 (R) Compomotive MO's with Goodyear Eagle F1's 205/45/16.
Ace wheels and tyres and will be used as wet track tyres and regular road tyres in future.
New wheels are 16x7 OZ Superleggaras (F+R) with 205/45/16 Kumho tyres.
The weight saving on switching one to the other was 14.8 kg in total - I think this is staggering !
Unsprung weight savings (i.e that that is wheel/tyre/disk/caliper/strut/wishbone - all wheel side of chassis pivots) are much more dramatic on handling than sprung weight savings (body) as the suspension has less work to do to keep the tyre in contact with the road. Also, rotational masses are less and thus the car should accelerate and brake quicker / more effeciently.
Probably worth thinking about this when considering swapping to 17's...........
Cheers
Rob
ibizacupra
30-07-2002, 13:02
Originally posted by RobT
Hi All
I have just changed my wheels - old were 16x7 (F) and 16x7.5 (R) Compomotive MO's with Goodyear Eagle F1's 205/45/16.
Ace wheels and tyres and will be used as wet track tyres and regular road tyres in future.
New wheels are 16x7 OZ Superleggaras (F+R) with 205/45/16 Kumho tyres.
The weight saving on switching one to the other was 14.8 kg in total - I think this is staggering !
Unsprung weight savings (i.e that that is wheel/tyre/disk/caliper/strut/wishbone - all wheel side of chassis pivots) are much more dramatic on handling than sprung weight savings (body) as the suspension has less work to do to keep the tyre in contact with the road. Also, rotational masses are less and thus the car should accelerate and brake quicker / more effeciently.
Probably worth thinking about this when considering swapping to 17's...........
Cheers
Rob
Kumho tyres then Rob...
Do they look any good?
Work well etc? Did you run them at Oulton Park?
Very interested to hear if they work well and if they need warming up much etc.
cheers
Bill
Originally posted by RobT
Hi All
I have just changed my wheels - old were 16x7 (F) and 16x7.5 (R) Compomotive MO's with Goodyear Eagle F1's 205/45/16.
Ace wheels and tyres and will be used as wet track tyres and regular road tyres in future.
New wheels are 16x7 OZ Superleggaras (F+R) with 205/45/16 Kumho tyres.
The weight saving on switching one to the other was 14.8 kg in total - I think this is staggering !
Unsprung weight savings (i.e that that is wheel/tyre/disk/caliper/strut/wishbone - all wheel side of chassis pivots) are much more dramatic on handling than sprung weight savings (body) as the suspension has less work to do to keep the tyre in contact with the road. Also, rotational masses are less and thus the car should accelerate and brake quicker / more effeciently.
Probably worth thinking about this when considering swapping to 17's...........
Cheers
Rob
I got 17" Superleggeras ... 6,9 kilo... not that much.
Originally posted by ibizacupra
Kumho tyres then Rob...
Do they look any good?
Work well etc? Did you run them at Oulton Park?
Very interested to hear if they work well and if they need warming up much etc.
cheers
Bill
Kumho V700 Ecsta's 205/45/16 - they were spectacular at Oulton Pk in dry/damp, so much grip and feel - Evo7 pulling up behind on straights but he was nowhere in the corners, we pulled maybe 50 yds in each bend, more through island and druids. Never been as fast in a hatchback - 100mph into island bend. Not recommended for standing water as not much tread depth - F1's for wet. Not sure how will be at sprint venue - we will see how quick they warm up, should be ok as not a full slick. Curby will be test. Very stiff sidewalls so ace turn-in and dont have to run them too high pressures - 32-34psi max when hot - Oulton was 27F, 24R cold - nice balance.
There is no way back now for circuit use - road tyres CRAP big time by comparison.
Kumho supplying quite a few race series this year - another guy at Oulton with same tyres on old M3 (4 cyl one) race car - says he liked them.
Cheers
Rob
Originally posted by Johnnie
I got 17" Superleggeras ... 6,9 kilo... not that much.
16" is 6 kilo and 15" only 4.9 kilo - then add weight of tyre on top (a little bit more than rim weight)
And 17" places weight further from center of rotation so inertia is more than smaller rim.
Cheers
Rob
supperlegerra's are a very soft wheel. watch out for pot holes
Are the Khumos competition rubber? road legal? What sizes do they do and what sort of price?
Originally posted by RobT
16" is 6 kilo and 15" only 4.9 kilo - then add weight of tyre on top (a little bit more than rim weight)
And 17" places weight further from center of rotation so inertia is more than smaller rim.
Cheers
Rob
As for the look I wouldn't go for the 15" =)
But 16" as the stock alloys would have been nice too.
... as I got the Cordoba Cupra -01 16" looks quite small on the car....
Originally posted by vibrio
supperlegerra's are a very soft wheel. watch out for pot holes
Thanks for the tip... the roads here in Sweden sucks.
Originally posted by whelme
Are the Khumos competition rubber? road legal? What sizes do they do and what sort of price?
They are road legal (just - like A032 Yoko's and Dunlop Formula R's) but due to design wouldnot make a very good road tyre - you wouldnot want to be on the motorway in a heavy shower with them on for eg. Very firm ride also. And fairly soft rubber so I guess not many miles would be possible.
Available in many popular sizes - mine were £90+vat apiece - dear relatively for a road tyre but very reasonable for a semi-race tyre - Hoosiers are £150+ (if you can get them) and Yoko's £120
Cheers
Rob
cordobabrendy
30-07-2002, 15:55
kumho and marshall are the sam company aint they?
Originally posted by cordobabrendy
kumho and marshall are the sam company aint they?
???????????????:confused:
Cheers
Rob
Lucky_32
30-07-2002, 18:27
Pot holes.... pah
Ran over the discarded bottom bit of a metal contraflow barrier tingy (not a pole, not a cone but somethere in between - you know....) at 70 - coming out of the speed restriction (officer) completely knacked the front wheel 17 inch rimstock motorsport and the rear at the same time!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Is it just me?
It is? ........ Your sure? Oh.
Must have been all the downforce from the f2 bumper splitter and WRC spoiler and zero ride height. Ahh...
Incidentaly with an F2 bumper a splitter ready is a splitter Eh cordobabrendy?
:rolleyes:
kumho and marshall are the same company, kumho are now standard equipment on new polo too!had the cheapy version in 17s on my last car, very hard wearing(20k on the front) and no real complaints whatsoever. wet/dry did what theyre supposed to!
cordobabrendy
30-07-2002, 18:53
Originally posted by RobT
???????????????:confused:
Cheers
Rob
http://www.kumho-euro.com/home.htm i knew id seen this page before.
oops rob, i meant "same" !!!:cheers:
ibizacupra
30-07-2002, 19:07
Originally posted by RobT
Kumho V700 Ecsta's 205/45/16 - they were spectacular at Oulton Pk in dry/damp, so much grip and feel - Evo7 pulling up behind on straights but he was nowhere in the corners, we pulled maybe 50 yds in each bend, more through island and druids. Never been as fast in a hatchback - 100mph into island bend. Not recommended for standing water as not much tread depth - F1's for wet. Not sure how will be at sprint venue - we will see how quick they warm up, should be ok as not a full slick. Curby will be test. Very stiff sidewalls so ace turn-in and dont have to run them too high pressures - 32-34psi max when hot - Oulton was 27F, 24R cold - nice balance.
There is no way back now for circuit use - road tyres CRAP big time by comparison.
Kumho supplying quite a few race series this year - another guy at Oulton with same tyres on old M3 (4 cyl one) race car - says he liked them.
Cheers
Rob
Cheers Rob.
I will be keen to see how they get on. Hope the day is a dry one.
I would like to run 16" on my Jetta to allow me to run Brembo's, but the appeal of 15" affordable rubber in soft compound also appeals! If these match the A038R's I will definately look to try a set of them on the 16" rims I have.
Good find tho Rob. Nice one. :)
regards
Bill
PS. Did you get any more info from Dave Walker?
Originally posted by ibizacupra
PS. Did you get any more info from Dave Walker?
No but I will call him for a date today.
Cheers
Rob
Hi Bill
Latest from Dave Walker is Sat morning 14th or 21st Sept - I prefer the latter. How about you ?
Cheers
Rob
ibizacupra
31-07-2002, 20:58
Originally posted by RobT
Hi Bill
Latest from Dave Walker is Sat morning 14th or 21st Sept - I prefer the latter. How about you ?
Cheers
Rob
21st Sounds good to me. :D
Rock on...
Best get it running 110% for that day then :p
cheers Rob.
regards
Bill
Originally posted by Lucky_32
Pot holes.... pah
Ran over the discarded bottom bit of a metal contraflow barrier tingy (not a pole, not a cone but somethere in between - you know....) at 70 - coming out of the speed restriction (officer) completely knacked the front wheel 17 inch rimstock motorsport and the rear at the same time!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Is it just me?
It is? ........ Your sure? Oh.
Must have been all the downforce from the f2 bumper splitter and WRC spoiler and zero ride height. Ahh...
Incidentaly with an F2 bumper a splitter ready is a splitter Eh cordobabrendy?
:rolleyes:
rimstock are duff wheels too
Originally posted by ibizacupra
21st Sounds good to me. :D
Rock on...
Best get it running 110% for that day then :p
cheers Rob.
regards
Bill
21st Sept confirmed - to London for 10am. Details to be sorted later.
Cheers
Rob
ibizacupra
02-08-2002, 08:09
Originally posted by RobT
21st Sept confirmed - to London for 10am. Details to be sorted later.
Cheers
Rob
Cheers Rob.
Venturing down to the "smoke"... have'nt done that that for quite some time.
It would be good to meet and find "our" way there together. You think?
cheers
Bill
Originally posted by RobT
Hi All
I have just changed my wheels - old were 16x7 (F) and 16x7.5 (R) Compomotive MO's with Goodyear Eagle F1's 205/45/16.
Ace wheels and tyres and will be used as wet track tyres and regular road tyres in future.
New wheels are 16x7 OZ Superleggaras (F+R) with 205/45/16 Kumho tyres.
No shit!
Took off my 7x16 Compomotive MO's today as they are going to be refurbed next monday, replacing with my track day wheels 7x16 Ace 112's. while I was at it I wieghed them to find out that the Compomotive's were 2kg heavier than the Ace wheels Per wheel!