How much difference will -5lbs make?

[Jond63]

I want to get RP-F1s and they are approximately 5lbs less than the stockers -- how much difference will it make in handling and road feel?

I'm also considering PF-01s which are a little heavier, would I even notice a 3lb. weight reduction?

Both scenarios would use stock tires for now...

[TM]

I don't know too much about it, but they say every 1lb of unsprung weight is equivalent to ~10lbs sprung weight.

[CSG Mike]

In a drag race against an otherwise equivalent car? More than power bolt-ons will do.

[MmmHamSandwich]

-5 is per wheel is pretty substantial. As Mike said you'll mostly notice the difference (granted it would be fairly small) in acceleration and to quite a lesser extent, braking.

[smellslikecurry]

You have to factor in the weight of the tires as well.

[dradernh]

Originally Posted by Jond63

how much difference will it make in handling and road feel?

Enough to notice. And you'd probably notice a 3# difference if you did an A/B test.

[Vracer111]

Originally Posted by smellslikecurry

You have to factor in the weight of the tires as well.

Stock tires = no change in weight...

You will not really notice a big acceleration/deceleration increase with a 5lbm unsprung weight drop, but what you will notice is a better ride quality with a more planted and secure feeling (because you have less mass trying to upset the suspension, allowing the suspension to do it's job with increased efficiency.) If you want to feel a more noticeable change in acceleration and engine response, drop down to a 205/45-17 (.3" shorter) tire... or both drop the unsprung mass 5lbs and decrease the tire diameter for the best results.

[troek]

i have 205/55r16 R-S3 on 16x7 rpf1s right now and it feels amazing. i would have loved 205/50, but it wasnt available in the r-s3 sadly. its only about 2lbs less per wheel, and 2 lbs less per tire than previously, but i can realy feel the difference in the suspension responding to bumps at speed. it was a bit sloppy before(mostly im assuming in part to the bulgy soft tires i had on).

[Jond63]

Originally Posted by Vracer111

Stock tires = no change in weight...

You will not really notice a big acceleration/deceleration increase with a 5lbm unsprung weight drop, but what you will notice is a better ride quality with a more planted and secure feeling (because you have less mass trying to upset the suspension, allowing the suspension to do it's job with increased efficiency.) If you want to feel a more noticeable change in acceleration and engine response, drop down to a 205/45-17 (.3" shorter) tire... or both drop the unsprung mass 5lbs and decrease the tire diameter for the best results.

Yeah, this is what I was thinking too. Less weight to throw the rest of the car around, and should be more responsive to turning due to lower gyroscopic effect?

[Fizz]

I recently installed 2-piece front rotors that shaved almost 8lbs in total, and I'm certain the improved ride was no placebo effect. I'm now waiting for my new wheels to arrive which will knock off another 20lbs so that's going to be interesting to see.

[Cheeseballs]

From Enkei themselves:

"Every pound of unsprung weight savings has the effect of reducing overall vehicle weight by 20lbs."

http://www.enkei.com/rpf1.shtml

[OmarGC]

What's the stock wheel and tire combo weight again?

Edit: disregard found 42lbs, my wheel and tire combo is 45.8 lbs inflated with nitrogen. I guess it's a small price to pay for 18x10's and 265/35's

[Yui-Chan]

Originally Posted by troek

i have 205/55r16 R-S3 on 16x7 rpf1s right now and it feels amazing. i would have loved 205/50, but it wasnt available in the r-s3 sadly. its only about 2lbs less per wheel, and 2 lbs less per tire than previously, but i can realy feel the difference in the suspension responding to bumps at speed. it was a bit sloppy before(mostly im assuming in part to the bulgy soft tires i had on).

VERY interested in this setup. Have any pics please????


From what I have gathered:

16x7 +35 5x100 = 13.7-14.3 lbs (weight for this exact wheel spec isn’t listed on enkei, but these are the weights of the other wheels in diff spec but in the same size)

RS3 205/55 = 22 lbs

Total = 35.7-36.3 lbs

Total weight reduce per wheel (41.4 lbs stock) = 5.7-5.1 lbs !!!

[dradernh]

Originally Posted by Cheeseballs

From Enkei themselves:

"Every pound of unsprung weight savings has the effect of reducing overall vehicle weight by 20lbs."

So if I drop 15# per corner, that's an effective 1200# total reduction for the car, and I now have, effectively, a 1550# car...instead of a 2750# car. Gadzooks!