Acceleration

1. dobsd001 Infrequent Poster Joined: Jul 2006 West Sussex Posts: 116 Citroen Saxo Vts

   #1 3rd July 2007, 10:28

   Just curious really...
   If I was to run 15" alloys instead of my standard 14" alloys, would I notice a decrease in accelartion.
   Or if I was to run some 17" alloys instead of the standard 14" vtr rims I have, would this slow me down a noticeable amount, of can you not really tell...
   
   many thanks
2. MaRiO89 Saxperience Post Whore Joined: Jan 2007 Posts: 7705 Saxo VTS

   #2 3rd July 2007, 10:31

   17's will kill the performane..
   
   15's not so much..
3. KamRacing Saxperience Addict Joined: Nov 2006 A farm shed in Aylesbury Posts: 14916 Corolla AE86 Peugeot 205 B18C (in bits)

   #3 3rd July 2007, 10:43

   Quote:

   Originally Posted by dobsd001 Just curious really... If I was to run 15" alloys instead of my standard 14" alloys, would I notice a decrease in accelartion. Or if I was to run some 17" alloys instead of the standard 14" vtr rims I have, would this slow me down a noticeable amount, of can you not really tell... many thanks

   In a simple world there are two things to consider. Rolling radius and rotating mass.
   
   If the wheels + Tyres are heavier then they will need more power to rotate therefore slowing you down.
   
   If the rolling radius is larger then the gearing will be longer slowing the car down. If you fit lower profile tyres then you can keep the RR the same and nulify this
   
   I like to complicate things though
   
   A wider tyre footprint will effect drag / grip
   lower profile tyres will have less movement of the tyre tranferring that energy to acceleration.
   
   So hmmm how to answer the question. I can only answer "It depends". Forced into a yes or no. Assume yes it would have a detrimental effect unless you took steps to nulify the negatives (ie lightweight alloys / Tyres & low profile rubber )
   
   Larger unsprung mass also effects the handling of the car so it should be thought out properly before increasing it. Tyre / Wheel / Disks and Calipers all affect this
4. dobsd001 Infrequent Poster Joined: Jul 2006 West Sussex Posts: 116 Citroen Saxo Vts

   #4 3rd July 2007, 10:55

   Am i right in saying then, that i fit a wider profile tyre i will slow accelartion but increase traction, therefore accelarte faster overall.
   Am taking your advice kam from the other week that i need to uprate other components as well as horse power to achieve a quicker 0-60 time.
5. KamRacing Saxperience Addict Joined: Nov 2006 A farm shed in Aylesbury Posts: 14916 Corolla AE86 Peugeot 205 B18C (in bits)

   #5 3rd July 2007, 11:05

   A wider tyre will probably not affect your 0-60 but it will be a bigger factor in top speed as it causes a lot more drag. I've spoken to a few racing drivers who fitted big tyres only to find they were slower round the lap when they should in theory have a lot more grip...
   I doubt the sizes most people use for road use make a difference too much. unsprung mass and rotational mass will be the biggest difference.
   
   A small wheel has the same affect as a lighter flywheel...
   
   Its a bit complicated in generalisation lol as different wheels weight different amounts etc
6. VTS_16v_Boy Saxperience Post Whore Joined: Aug 2006 Dartford Kent Posts: 5251 Pug 1007 HDi Sport (daily) / Abarth 500

   #6 3rd July 2007, 11:42

   Well I went from VTS 15's to 106 Rallye 14's
   
   I noticed the car pulled alot better due to the steel wheels being lighter, whether this effects top speed who knows.
   
   14 to 15 you might notice a slight drop in accelration but so small you may not notice, 14 or 15 to 17 you would notice a huge difference.
   
   Unless your hardcore track bound dont worry and just go for what you like the look of
7. Ryanp Super Moderator Joined: Feb 2004 Tonbridge United Kingdom (England) Posts: 38236 Vtr, 172, throttle bodied track slut

   #7 3rd July 2007, 11:44

   15s in most cases have the optimum rolling radius, for grip/speed.
8. Barry123 Saxperience Hardcore! Joined: Oct 2005 Aycliffe Posts: 32205 Saxo VTS

   #8 3rd July 2007, 12:27

   you'll find that
   
   195/45/R15 has a smaller rolling radius than a 185/55/R14 so provided the alloy chosen of light weight then you'll find a slight but probably unnoticeable increase in acceleration.
9. VTS_16v_Boy Saxperience Post Whore Joined: Aug 2006 Dartford Kent Posts: 5251 Pug 1007 HDi Sport (daily) / Abarth 500

   #9 3rd July 2007, 13:55

   Quote:

   Originally Posted by adsayer you'll find that 195/45/R15 has a smaller rolling radius than a 185/55/R14 so provided the alloy chosen of light weight then you'll find a slight but probably unnoticeable increase in acceleration.

   Interesting that I thought it would have been the otherway around Oh well, learn something new everyday
10. Barry123 Saxperience Hardcore! Joined: Oct 2005 Aycliffe Posts: 32205 Saxo VTS

    #10 3rd July 2007, 14:12

    Quote:

    Originally Posted by VTS_16v_Boy Interesting that I thought it would have been the otherway around Oh well, learn something new everyday

    think of torque applied. force x distance.
    
    the distance from the spindle point to the ground... if you have a large wheel you have large distance from the spindle to the ground. therefore the transmission has a larger torque to overcome in order to accelerate. small wheel less torque to overcome - better acceleration.
    
    like kam said you then have the rotational mass that you have to consider... VTS alloys are comparatively heavy (again acceleration will suffer) so anyone considering drag strip stuff should avoid using those.
11. VTS_16v_Boy Saxperience Post Whore Joined: Aug 2006 Dartford Kent Posts: 5251 Pug 1007 HDi Sport (daily) / Abarth 500

    #11 3rd July 2007, 14:49

    See thats what you get for having a good education, I was born in the geto's so all my education was done on the streets ieeeee
12. Ryanp Super Moderator Joined: Feb 2004 Tonbridge United Kingdom (England) Posts: 38236 Vtr, 172, throttle bodied track slut

    #12 3rd July 2007, 16:26

    Quote:

    Originally Posted by adsayer you'll find that 195/45/R15 has a smaller rolling radius than a 185/55/R14 so provided the alloy chosen of light weight then you'll find a slight but probably unnoticeable increase in acceleration.

    exactly why all my track wheels are 15s to run 195/45/r15
13. Toad Saxperience Post Whore Joined: Mar 2007 Reading Posts: 8980 French tin can

    #13 3rd July 2007, 21:38

    Don't forget that with the general size of wheels we're discussing here, the tyres tend to be almost the same weight as they alloys. Just to complicate things even more with regard to wheels and rotating mass - It also makes a difference on where the weight of the wheel is located with respect to the two extremes of centre and outer. It's beneficial to have the majority of the wheel's weight towards the centre as opposed to the outside.
14. Ryanp Super Moderator Joined: Feb 2004 Tonbridge United Kingdom (England) Posts: 38236 Vtr, 172, throttle bodied track slut

    #14 3rd July 2007, 21:39

    Quote:

    Originally Posted by Toad Don't forget that with the general size of wheels we're discussing here, the tyres tend to be almost the same weight as they alloys. Just to complicate things even more with regard to wheels and rotating mass - It also makes a difference on where the weight of the wheel is located with respect to the two extremes of centre and outer. It's beneficial to have the majority of the wheel's weight towards the centre as opposed to the outside.

    weight of wheels will also effect the suspension characteristics etc..
    
    theres so many tiny things, all of which 95% of saxo owners will never notice
15. bullit Saxperience Hardcore! Joined: Dec 2005 e-hollywood Posts: 17160 toyata hilux

    #15 3rd July 2007, 21:46

    me being in that 95
16. VTR-Chris-VTR Established Member Joined: Jun 2007 Bristol - St George Posts: 2364 Mk2 Saxo VTS

    #16 3rd July 2007, 23:17

    I put 17's on my car i didnt really feel much difference, thought it was quicker but thats me being silly......but wen i put my 16's back on i did notice it was then better on accelleration
17. MaRiO89 Saxperience Post Whore Joined: Jan 2007 Posts: 7705 Saxo VTS

    #17 4th July 2007, 00:15

    Quote:

    Originally Posted by VTR-Chris-VTR I put 17's on my car i didnt really feel much difference, thought it was quicker but thats me being silly......but wen i put my 16's back on i did notice it was then better on accelleration

    Lob some VTR's back on and feel the difference!
18. Ryanp Super Moderator Joined: Feb 2004 Tonbridge United Kingdom (England) Posts: 38236 Vtr, 172, throttle bodied track slut

    #18 4th July 2007, 00:30

    Quote:

    Originally Posted by James_Bristol Lob some VTR's back on and feel the difference!

    put some 15" TD pro race series wheels on with 195/45s and feel more difference
19. jimbo232 Frequent Poster Joined: Feb 2007 Leicester, UK Posts: 505 Saxo VTS (2000) Wicked Red

    #19 4th July 2007, 00:30

    I had 16s on mine and felt like 0 - 60 was out the window. Soon as i put the 14's on again it felt right for the car and pulled nicely. I duno if it changed anything but i definatly felt like it was making the car slugish and car felt like it had to pull alot more weight to move.
20. MaRiO89 Saxperience Post Whore Joined: Jan 2007 Posts: 7705 Saxo VTS

    #20 4th July 2007, 00:31

    Quote:

    Originally Posted by jimbo232 I had 16s on mine and felt like 0 - 60 was out the window. Soon as i put the 14's on again it felt right for the car and pulled nicely. I duno if it changed anything but i definatly felt like it was making the car slugish and car felt like it had to pull alot more weight to move.

    Same as what i felt!!
21. Ryanp Super Moderator Joined: Feb 2004 Tonbridge United Kingdom (England) Posts: 38236 Vtr, 172, throttle bodied track slut

    #21 4th July 2007, 00:33

    because 16s are gay!
22. MaRiO89 Saxperience Post Whore Joined: Jan 2007 Posts: 7705 Saxo VTS

    #22 4th July 2007, 00:35

    Quote:

    Originally Posted by Itsafastworld85 because 16s are gay!

    I prefer 17's tbh!!
    
    White oz super t's on a Saxo Kit Car..mmmm
23. Ryanp Super Moderator Joined: Feb 2004 Tonbridge United Kingdom (England) Posts: 38236 Vtr, 172, throttle bodied track slut

    #23 4th July 2007, 00:39

    Quote:

    Originally Posted by James_Bristol I prefer 17's tbh!! White oz super t's on a Saxo Kit Car..mmmm

    and widetrack and decent bhp.......etc.......... and are not built for 0-60
24. Barry123 Saxperience Hardcore! Joined: Oct 2005 Aycliffe Posts: 32205 Saxo VTS

    #24 4th July 2007, 00:40

    17s have never looked good on a standard saxo.
25. MaRiO89 Saxperience Post Whore Joined: Jan 2007 Posts: 7705 Saxo VTS

    #25 4th July 2007, 00:43

    Quote:

    Originally Posted by Itsafastworld85 and widetrack and decent bhp.......etc.......... and are not built for 0-60

    I know..Still look mental though!!
    
    16's are as big as std arches can look good with imo!
26. Ryanp Super Moderator Joined: Feb 2004 Tonbridge United Kingdom (England) Posts: 38236 Vtr, 172, throttle bodied track slut

    #26 4th July 2007, 00:46

    Quote:

    Originally Posted by James_Bristol I know..Still look mental though!! 16's are as big as std arches can look good with imo!

    style whore bollocks if you ask me!
27. MaRiO89 Saxperience Post Whore Joined: Jan 2007 Posts: 7705 Saxo VTS

    #27 4th July 2007, 00:53

    Quote:

    Originally Posted by Itsafastworld85 style whore bollocks if you ask me!

    Sue me..
    
    Or spank me..whichever you prefer..
28. Ryanp Super Moderator Joined: Feb 2004 Tonbridge United Kingdom (England) Posts: 38236 Vtr, 172, throttle bodied track slut

    #28 4th July 2007, 00:55

    Quote:

    Originally Posted by James_Bristol Sue me.. Or spank me..whichever you prefer..

    you missed off kick you in the cunt!
29. MaRiO89 Saxperience Post Whore Joined: Jan 2007 Posts: 7705 Saxo VTS

    #29 4th July 2007, 00:56

    Quote:

    Originally Posted by Itsafastworld85 you missed off kick you in the cunt!

    
    My bad..
30. FILVTR Regular Poster Joined: Oct 2006 Manchester Posts: 440 VTR '52.

    #30 4th July 2007, 12:52

    Check out Redline magazine this month - there's a special on choosing lightweight alloy wheels and why they are important. They cover all sizes too.
    
    Overall, iirc, the larger the wheels the higher top speed, the smaller the wheels, the faster acceleration. AS above, it all depends on the type of wheel, the weight, tyre size and all the other scientific variables that come into play...