Fordmods Logo

racing rim size 

 

Page 1 of 2 [ 27 posts ] Go to page 1, 2  Next

 
 Post subject: racing rim size
Posted: Tue Dec 08, 2009 8:34 pm 
Getting Side Ways
Offline

Posts: 1220

Joined: 11th Nov 2007

Ride: f6 rspec

Location: Sydney
NSW, Australia

Hey guys, just a bit of advice on rim sizes when drag racing, what is best?

i have 19"s and last time i raced in them i got poor times..

should i go 15's all round or will i get away with 19's on the front and 15's on the rear?
Top
 Profile  
 
 
 Post subject: Re: racing rim size
Posted: Tue Dec 08, 2009 8:35 pm 
Getting Side Ways
Offline

Age: 40

Posts: 6746

Joined: 13th Mar 2006

Gallery: 10 images

Ride: SF5 Forester

Location: Bathurst
NSW, Australia

FORDom wrote:
Hey guys, just a bit of advice on rim sizes when drag racing, what is best?

i have 19"s and last time i raced in them i got poor times..

should i go 15's all round or will i get away with 19's on the front and 15's on the rear?


if you could get some 17's that would be an ideal size.

 

_________________

R.I.P Tobias my son.

Top
 Profile  
 
 
 Post subject: Re: racing rim size
Posted: Tue Dec 08, 2009 8:38 pm 
Moderator
Offline

Posts: 14489

Joined: 7th Nov 2004

Ride: AU XR8

Location: a shit suburb in sydney
NSW, Australia

you could go with wide low profile 15" tyres to get your tyre diameter smaller/ slightly faster launches off the mark..
Top
 Profile  
 
 
 Post subject: Re: racing rim size
Posted: Tue Dec 08, 2009 9:08 pm 
Fordmods Addict
Offline
User avatar

Age: 38

Posts: 7958

Joined: 1st Jun 2005

Gallery: 13 images

Ride: Falcon

Power: 237 rwkw

Location: Melbourne
VIC, Australia

why were the times poor, no traction?
if traction wasn't an issue they only way you'll improve is with ligher wheel/tyres...

 

_________________

ED XR8 Sprint - S-Trim, V500, 249rwkw
BF MKII F6 Tornado - 237rwkw

Top
 Profile  
 
 
 Post subject: Re: racing rim size
Posted: Wed Dec 09, 2009 5:00 pm 
Getting Side Ways
Offline
User avatar

Age: 39

Posts: 1832

Joined: 3rd May 2007

Gallery: 8 images

Ride: AUII XR6 Uterus

Location: South Coast
NSW, Australia

it's a gearing issue, your gears don't stop at the diff... hehe

increasing the diameter of your wheels will increase your top speed for the cost of acceleration, and smaller wheels will achieve faster acceleration at the cost of top speed.

thats why v8 supercars still run 17's and not blingin' 20's.

thats why cars with 20's drive you more than you drive them lol

and lighter wheels will work like a lightened flywheel (less rotating mass/inertia) theres an equation that compares lightening wheels to reducing body weight and it's something like 3 times more effective by memory. if that makes sense..... heh

 

_________________

Not to get technical, but according to chemistry alcohol is a solution.

Top
 Profile  
 
 
 Post subject: Re: racing rim size
Posted: Wed Dec 09, 2009 5:20 pm 
Getting Side Ways
Offline

Age: 41

Posts: 1353

Joined: 15th Mar 2007

Gallery: 7 images

Ride: AU XR6

Power: 171 rwkw

Location: thornton
NSW, Australia

What sort of tyres do you intend on running? Full street, soft street, semi slick or drag radial? That should be the first thing to work out then go looking for rims to suit.

 

_________________

9/98 AU1 XR6hp-about to retire from the road and be reborn on the race track.
86 ZL mint grandpa spec with premo sound and 150000km
07 TTG 60000km stock as, mods to come.
97 el futura about to be MOCKed

Top
 Profile  
 
 
 Post subject: Re: racing rim size
Posted: Wed Dec 09, 2009 6:19 pm 
Fordmods Addict
Offline
User avatar

Age: 38

Posts: 7958

Joined: 1st Jun 2005

Gallery: 13 images

Ride: Falcon

Power: 237 rwkw

Location: Melbourne
VIC, Australia

low_ryda wrote:
it's a gearing issue, your gears don't stop at the diff... hehe

increasing the diameter of your wheels will increase your top speed for the cost of acceleration, and smaller wheels will achieve faster acceleration at the cost of top speed.

only if overall rolling diameter changes.

 

_________________

ED XR8 Sprint - S-Trim, V500, 249rwkw
BF MKII F6 Tornado - 237rwkw

Top
 Profile  
 
 
 Post subject: Re: racing rim size
Posted: Wed Dec 09, 2009 6:48 pm 
Getting Side Ways
Offline

Age: 41

Posts: 1353

Joined: 15th Mar 2007

Gallery: 7 images

Ride: AU XR6

Power: 171 rwkw

Location: thornton
NSW, Australia

Steady ED wrote:
low_ryda wrote:
it's a gearing issue, your gears don't stop at the diff... hehe

increasing the diameter of your wheels will increase your top speed for the cost of acceleration, and smaller wheels will achieve faster acceleration at the cost of top speed.

only if overall rolling diameter changes.



With 19s on an e series I'd be suprised if it didn't. The 20s I've got for my au are an inch taller than the standard wheels. Works out to be roughly 8-10%.

 

_________________

9/98 AU1 XR6hp-about to retire from the road and be reborn on the race track.
86 ZL mint grandpa spec with premo sound and 150000km
07 TTG 60000km stock as, mods to come.
97 el futura about to be MOCKed

Top
 Profile  
 
 
 Post subject: Re: racing rim size
Posted: Wed Dec 09, 2009 7:00 pm 
Fordmods Addict
Offline
User avatar

Age: 38

Posts: 7958

Joined: 1st Jun 2005

Gallery: 13 images

Ride: Falcon

Power: 237 rwkw

Location: Melbourne
VIC, Australia

about as much difference as running with brand new tyres vs worn tyres :lol:

my point was, saying that 'gearing' is changed by changing wheel size is wrong, it's changing the rolling diameter that does it.

 

_________________

ED XR8 Sprint - S-Trim, V500, 249rwkw
BF MKII F6 Tornado - 237rwkw

Top
 Profile  
 
 
 Post subject: Re: racing rim size
Posted: Wed Dec 09, 2009 8:10 pm 
Getting Side Ways
Offline

Age: 41

Posts: 1353

Joined: 15th Mar 2007

Gallery: 7 images

Ride: AU XR6

Power: 171 rwkw

Location: thornton
NSW, Australia

Steady ED wrote:
about as much difference as running with brand new tyres vs worn tyres :lol:

my point was, saying that 'gearing' is changed by changing wheel size is wrong, it's changing the rolling diameter that does it.


they're only car tyres not 35" muddies. The tread isn't that deep.

 

_________________

9/98 AU1 XR6hp-about to retire from the road and be reborn on the race track.
86 ZL mint grandpa spec with premo sound and 150000km
07 TTG 60000km stock as, mods to come.
97 el futura about to be MOCKed

Top
 Profile  
 
 
 Post subject: Re: racing rim size
Posted: Wed Dec 09, 2009 8:18 pm 
Fordmods Addict
Offline
User avatar

Age: 38

Posts: 7958

Joined: 1st Jun 2005

Gallery: 13 images

Ride: Falcon

Power: 237 rwkw

Location: Melbourne
VIC, Australia

no s**t sherlock, i'm saying the difference in rolling diameter is sfa between 205/65 15s and 245/35 19s.

 

_________________

ED XR8 Sprint - S-Trim, V500, 249rwkw
BF MKII F6 Tornado - 237rwkw

Top
 Profile  
 
 
 Post subject: Re: racing rim size
Posted: Wed Dec 09, 2009 8:32 pm 
Getting Side Ways
Offline

Age: 41

Posts: 1353

Joined: 15th Mar 2007

Gallery: 7 images

Ride: AU XR6

Power: 171 rwkw

Location: thornton
NSW, Australia

Steady ED wrote:
no s**t sherlock, i'm saying the difference in rolling diameter is sfa between 205/65 15s and 245/35 19s.



I don't care much for your attitude. :roll:

 

_________________

9/98 AU1 XR6hp-about to retire from the road and be reborn on the race track.
86 ZL mint grandpa spec with premo sound and 150000km
07 TTG 60000km stock as, mods to come.
97 el futura about to be MOCKed

Top
 Profile  
 
 
 Post subject: Re: racing rim size
Posted: Wed Dec 09, 2009 9:12 pm 
Moderator
Offline

Posts: 14489

Joined: 7th Nov 2004

Ride: AU XR8

Location: a shit suburb in sydney
NSW, Australia

Steady ED wrote:
no s**t sherlock, i'm saying the difference in rolling diameter is sfa between 205/65 15s and 245/35 19s.


but if you drop profile to 50 series 15" it could help! but not as much as changin the diff ratio..
Top
 Profile  
 
 
 Post subject: Re: racing rim size
Posted: Wed Dec 09, 2009 9:37 pm 
Getting Side Ways
Offline
User avatar

Age: 35

Posts: 4316

Joined: 30th Oct 2006

Gallery: 18 images

Ride: Envi EF

Location: Grafton
NSW, Australia

ebxr82nv wrote:
Steady ED wrote:
low_ryda wrote:
it's a gearing issue, your gears don't stop at the diff... hehe

increasing the diameter of your wheels will increase your top speed for the cost of acceleration, and smaller wheels will achieve faster acceleration at the cost of top speed.

only if overall rolling diameter changes.



With 19s on an e series I'd be suprised if it didn't. The 20s I've got for my au are an inch taller than the standard wheels. Works out to be roughly 8-10%.


Be surprised then.

205/65/15 = 2034.2mm circumference
235/35/19 = 2032.9mm circumference
Thats 0.1% difference.

235/30/20 = 2038.9mm circumference
Thats 0.2% difference.

It really really really helps when you get the right size tyre fitted. Even if you use 245s the difference is still 1% for 19s and 1.2% for 20s.

 

_________________

>>>EF Futura T build<<<

Top
 Profile  
 
 
 Post subject: Re: racing rim size
Posted: Wed Dec 09, 2009 9:51 pm 
Stock as a Rock
Offline

Age: 32

Posts: 120

Joined: 1st Jul 2009

Ride: XH falcon ute

Location: mudgee
NSW, Australia

but with 20'z you only get a very small contact patch and very little side wall flex.
so putting 20'z on fro racing is not the best bet.
for drag racing get some M/T street slicks or what every they are called in 15's.
Top
 Profile  
 
Display posts from previous:
Sort by  
 Page 1 of 2  [ 27 posts ]  Go to page 1, 2  Next

Who is online

Users browsing this forum: No registered users and 21 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

 

 

It is currently Sat Nov 23, 2024 8:36 pm All times are UTC + 11 hours

 

 

(c)2014 Total Web Solutions Australia - Australian Web Hosting and Domain Names