Jump to content
SAU Community

Does More Tyre Width = Less Power?

jake33

By jake33,
in Engines & Forced Induction

 Share

Recommended Posts

jake33 Experienced

jake33

Posted
Posted

had my 33 for roughly 2 weeks now. when i started off with it i was running stock rim and tyre specifiaction. now have upgraded 19's with perrrelli p zero's, which ive been told arent a bad tyre. anyway there 9.5's on the rear. now my delimea is obviously the title of the topic. am i feeling less power due to there being bigger tyre and rim diameter? or is it me just getting use to the car.? i mean this is not a big decrease or anything. it just seemed that my car went a bit harder with stock tyres and rims (still same performance mods). sorry i know the questions is kinda up in the air, just wondering if its my head or a fact /possibility. i mean i definetly know the tyres are quiet harder to spin than stock. but is there a power loss?

thanks

Jake

Link to comment
https://www.sau.com.au/forums/topic/157478-does-more-tyre-width-less-power/
Share on other sites
GTshortie Proficient

GTshortie

Posted
Posted

Go weigh your Stock 16" rims and compared to your new 19" rims, your new rims are heavy/wider rubber hence better traction and grip and more friction on the ground so your car will run slower then it use(thats taking into account you don't have 300rwkw that has no traction with the 16" and you have traction with the nice wide 19" rubber)

From Experience, my car same power nothing else changed other then Rims

Previous 17" Sparco 255 wide dunlop tyres ran Consistent 14.2 and best 14.0 qtr mile

Stockies 16" 205 wide Toyo t1r's tyres ran consistent 13.6 and best of 13.5 qtr mile.

So as you can see there is quite a difference in my qtr mile time just by going back to my lighter stock rims.

MANWHORE Grand Master

MANWHORE

Posted
Posted

yeah, seriously, it's the weight of the wheels.

the gtst wheels with tyres weight approximately 18-20kg give or take depending on what tyre.

I wouldn't be suprised if your 19 " wheels weighed 30-40kg.

Keep in mind that wheel weight is worse than static weight. It is rotational mass.

so that extra 40-80 kg overall could be the equivalent of having about 120-240 kg extra weight in your car

jake33 Experienced

jake33

Posted
  • Author
Posted (edited)
what rims u got? weight?

XIX exotic wheels (u.s company)

model: X-O5, 19x8.5 19x9.5

couldnt find the weight of the wheels.

what MANWHORE says makes a lot of sense.

post-35246-1172068242.jpg

Edited by jake33
GTR-Dad Explorer

GTR-Dad

Posted
Posted

An increase in rolling diameter gives you a taller overall gearing. This, in combination with heavier rims of larger diameter will result in you feeling less torque. (Seat of the pants dyno is working!)

Interesting thing on rotating mass...

Imagine two wheels that weigh exactly the same, but one is a 19" and the other is a 16" (very light 19" wheel, right?) fitted with tires that result in the same rolling diameter. The mass moment of inertia (I=mr²) of the 19" wheel will be 40% greater than the 16".

If the wheels are light enough, a 40% increase in 'effective mass' may be offset by benefits of stiffer sidewall or hawt looks :P, but directionaly you're making your car feel heavier.

I've read that the performance sweet spot for wheel diameter is around 17 or 18 inches. I suppose this would depend on your car, but this is one case of 'bigger is not always better.'

Cheers,

Dan

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Kapr
      Possible swap on R34 RB20DE NEO?

      By Kapr · Posted

      Hi. A little bit of an update. It maybe(hope not) looks like i would need a new tranny(it would be "maybe" a cheaper or better option anyway) So i need some info. I know i need a different propshaft(i can make custom one) LSD is not a problem cuz the engine will be still(for now) N/A RB20. So if i buy RB25DET NEO tranny...is there something else i need? I read something about push/pull type but i do not know if i need to "change" something or i can just plug n play onto my engine a go? Thanks for the advice  
    • OakvilleGTR
      Turn signal wiring question

      By OakvilleGTR · Posted

      Good morning all, Bit of a random question but figured I’d finally throw it out after wondering for a long while. Before I start, I'm hoping to do this purely out of personal preference. I think it would look better at night, and don't mind at all spending a few hours and dollars to get it done. I've copied this from a non-Skyline specific forum, so I apologize for the explanation of our headlight switch setup that we all know. Here we go: Zero lights (switch off) Parking lights (switch position 1) being a rectangular marker on the outside of the housing, my low beam being the projector in the centre (position 2), and a high beam triggered by my turn signal stalk. Most North American cars I’ve owned of this era have power to the amber corner (turning indicator) light as part of the first switch (parking lights). I’d love to have these amber corners receive power when the headlights and parking lights are on (headlight switch), yet still blink when using the turn signal which is of course a separate switch. Hopefully I’ve explained my question correctly. Is anyone aware of a way in which I might be able to achieve this? Thanks in advance
    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      My heads are cathedral port! It's likely possible, but I don't want to add any extra moving parts (I know they don't move) between the heads, manifolds, etc. It will also affect how injectors/fuel rails etc sit and I don't really know if it would change how the FAST manifold goes/sits/fits. I have the LS6 steam pipes already as I have a very late LS1 block so it should be fine. I couldn't find anyone who had ever actually used one for this purpose, it seems 100% of people grind the water pump. The thermal spacers are 12mm and are half way to the cost of the newer water pump anyhow... so if it comes to that I suppose I'd rather buy a new pump. The bearing in the pump I do have is a little.. clunky, but it hasn't done that much time and I never noticed it when the car was together in the past few years, so..
    • sonicii
      Lower A arm Skyline v35

      By sonicii · Posted

      The bushing has failed, not all that uncommon for a car of this age.  Any mechanic should be able to push in a new bushing for you, or you can probably buy the entire lower control arm, complete with bushes.
    • The Bogan
      Mistakes were made, my R34 Story

      By The Bogan · Posted

      Could you not use "thermal" spacers to give the clearance, like the ones I used between the blower and head? That raised the manifold height by around 10-15mm Albeit the ones I used were for cathedral ports, but I assume they have similar for rectangular ports????
×
×
  • Create New...