| Author |
Message |
Xvisor
Level 7 User
Joined: 06 Sep 2004
Posts: 230
|
| Posted:
Sun May 29, 2005 3:31 pm |
|
ATM I got cms rims with goodyear hydragrip 195/50/15 tyres my speedo reads about 10kmph to much (like it says 130 i am actually going 120) now when I buy new rims thinking about 17" MAK R-Action rims with toyo T1-R 205/40/17 how much will my speedo be out then aprox.? And how much speed/pulling will i loose with the bigger rims/tyres?? |
|
|
|
|
Dan
Site Subscriber
Joined: 28 Jan 2005
Posts: 3547
|
| Posted:
Sun May 29, 2005 3:58 pm |
|
right, you wont loose any speed as you are keeping the rolling radius the same, i.e 15" rim with 50 profile (195 50 r 15) will be the same as ypou have gone down to 40 profile but gone up in rim size. |
|
|
|
|
Xvisor
Level 7 User
Joined: 06 Sep 2004
Posts: 230
|
| Posted:
Sun May 29, 2005 4:01 pm |
|
at the moment i have a tyre wich is 576 in dia and i will be going up to 600mm dia |
|
|
|
|
Neal
Forum Moderator
Joined: 18 Feb 2004
Posts: 7432
|
| Posted:
Sun May 29, 2005 4:07 pm |
|
the speedo will be roughly accurate at lower speeds, and less accurate the faster you go, thats normal.
If we take things literally then going from 576mm dia to 600mm dia is approx a 4% increase in diameter/circumference/speed error. ie, bugger all.
If you get 17" that are nice and light, such as OZ superleggeras, which are much, much lighter than the standard 15"s, then the performance difference will also be bugger all. |
|
|
|
|
Bridges
Level 3 User
Joined: 13 May 2004
Posts: 79
|
| Posted:
Mon May 30, 2005 3:15 am |
|
Are you sure that a 195/50/15 is the same as a 17" with a 40 profile.  Only saying because my 205/40/17 are bigger side by side than my 195/50/15. Or do you mean 40 profile for a 16" wheel? Or am I wrong, again. |
|
|
|
|
Xvisor
Level 7 User
Joined: 06 Sep 2004
Posts: 230
|
| Posted:
Mon May 30, 2005 4:34 am |
|
The dia is about the same and only differs in milimeters when you take 15" with 195/50 and compare it to 16" with 205/40 but as i said above the dia is larger when using 17" with 205/40! It would have been nice if Toyo had 205/35/17 of 215/35/17 but they don't  So i decided to go with the bigger wheel MAK R-Action 17" 4x100Pcd ET38 with Toyo Proxes T1-R 205/40/17 |
|
|
|
|
Chris H
Forum Moderator
Joined: 02 Mar 2004
Posts: 19978
|
| Posted:
Mon May 30, 2005 8:40 am |
|
does it really matter?
All the tyre siszes are different but the same speedo heads etc are used through out the range so all the speedos are wonky. |
|
|
|
|
Xvisor
Level 7 User
Joined: 06 Sep 2004
Posts: 230
|
| Posted:
Mon May 30, 2005 9:59 am |
|
Chris when your dutch it does because holland is one big box of flashlights with speedtraps en kilometer/speed registration (measured over a few km) so when you look at your speedo and see your going 120kmph which is good but then a week later get the bill from mister justice here and see you drove 126 that S*CKS bigtime!! |
|
|
|
|
Chris H
Forum Moderator
Joined: 02 Mar 2004
Posts: 19978
|
| Posted:
Tue May 31, 2005 12:24 am |
|
go slower then, simple.
The manufacturer is allowed a 5% tolerence on it |
|
|
|
|
R1916S
Site Subscriber
Joined: 23 Jan 2005
Posts: 502
|
| Posted:
Tue May 31, 2005 8:52 am |
|
Get a hand held GPS reciver, if you know someone into boating for sure you can borrow one. Stick it under the windscreen, the metal roof will block the signal. Get out on a long quiet road or the motor way, run at steady speeds. Read off the speeds and compare with the speedo. It will record max speed if you realy want to see how fast she goes. |
|
|
|
|
JB
Mr Quoter-vator
Joined: 16 Feb 2004
Posts: 7405
|
| Posted:
Tue May 31, 2005 2:40 pm |
|
or u can time urself between the posts on the side of the motorway....every 1/8 of a mile those little black and white posts are. time yourself at a constant speed over a mile. |
|
|
|
|
|
|
