Are Lightweight Rims worth the investment?

gunnerzz

2,000 RPM
Jul 3, 2014
2,109
695
713
38
Melaka
The difference in diameter is just the wheels but not the overall diameter, at least not significantly. But the weight difference are significant there. This is talking about transferring power to the ground. If there's no additional power going to the ground to move the car quicker then what does?? Power at the engine is the same but there's not as much loss used to rotate the mass of the wheels hence enabling the power more to move the car.
I suck at math and only loves to look at the outcome.

However, since we all agree that gb eats up some hp from the engine thus making hp at the wheel lower to hp at the flywheel...i am guessing whatever parts (including the rims) which are there to transfer the power from the engine to the road will have impact in hp figure. Its a matter of how much.

Would be interesting to see a dyno chart though. Then do the dyno again...this time removes the drive wheel disc brakes...i would love to see the outcome.
 

leinnz

Known Member
Senior Member
Sep 28, 2005
333
57
3,028
Then i should start making friend with their staff. Most probably can get something at discounted price...hihihi
dont forget me. i want to TT in MLK for discounted advanti.
 

Izso

NA NA NA NA NA
Helmet Clan
Moderator
Mar 28, 2004
15,389
6,411
5,213
KL
The difference in diameter is just the wheels but not the overall diameter, at least not significantly. But the weight difference are significant there. This is talking about transferring power to the ground. If there's no additional power going to the ground to move the car quicker then what does?? Power at the engine is the same but there's not as much loss used to rotate the mass of the wheels hence enabling the power more to move the car.
Ok I'm beginning to see the disconnect now. What you're saying here is you'll potentially regain some lost power. You won't gain power like what was said originally. This much I can agree! But I also did say the gains is minimal in the beginning.

Diameter of the whole wheel package (tyres and all) between a 20" and 18" is pretty significant. Based on the dimension given by the bloke in the 2nd video, it's roughly 5% difference. That alone would contribute to the slower acceleration on top of the wheel weight. Anyway, the 2nd and 3rd video has too many discrepancies. What we should do is make a video comparison between same diameter, same tyre and just a difference in wheel weight.

Anyway thinking too much about this is giving me a bloody headache. I'm done thinking. Hahaha! We all generally agree that lightweight means more better.

I suck at math and only loves to look at the outcome.

However, since we all agree that gb eats up some hp from the engine thus making hp at the wheel lower to hp at the flywheel...i am guessing whatever parts (including the rims) which are there to transfer the power from the engine to the road will have impact in hp figure. Its a matter of how much.

Would be interesting to see a dyno chart though. Then do the dyno again...this time removes the drive wheel disc brakes...i would love to see the outcome.
You know what we should do? We should start a ZTH video channel where members get together to properly mythbust or discuss topics like this and share on Youtube.

Cuz I sure would like to see for myself how this'll turn out on a wheel dyno and hub dyno.
 

leinnz

Known Member
Senior Member
Sep 28, 2005
333
57
3,028
You know what we should do? We should start a ZTH video channel where members get together to properly mythbust or discuss topics like this and share on Youtube.

Cuz I sure would like to see for myself how this'll turn out on a wheel dyno and hub dyno.
racenotrice revival too
 

DNGFashion

Known Member
Thread starter
Apr 20, 2017
95
14
508
love the discussions here.

Maybe we need to define what is HP?
HP rated at engine or HP rated effectively on the ground (BHP)?

Engineering Explained has a very good point on rotational mass. Having a lightweight piston, crankshaft, driveshaft, flywheel and all parts that delivered power to the ground essentially increases BHP and probably slight increment in HP rated at engine for the same engine capacity.
 

lsm1991

1,000 RPM
Senior Member
Sep 30, 2011
1,469
185
1,663
PJ
love the discussions here.

Maybe we need to define what is HP?
HP rated at engine or HP rated effectively on the ground (BHP)?

Engineering Explained has a very good point on rotational mass. Having a lightweight piston, crankshaft, driveshaft, flywheel and all parts that delivered power to the ground essentially increases BHP and probably slight increment in HP rated at engine for the same engine capacity.
erm..... hp vs bhp??

i think you want to discuss crank hp (i believe this what you are referencing to as is the bhp) vs wheel hp (at the wheels)

hp vs bhp, no real point thinking bout it
 

6UE5t

6,000 RPM
Senior Member
Oct 8, 2010
6,756
1,300
1,713
Kuala Lumpur
Ok I'm beginning to see the disconnect now. What you're saying here is you'll potentially regain some lost power. You won't gain power like what was said originally. This much I can agree! But I also did say the gains is minimal in the beginning.

Diameter of the whole wheel package (tyres and all) between a 20" and 18" is pretty significant. Based on the dimension given by the bloke in the 2nd video, it's roughly 5% difference. That alone would contribute to the slower acceleration on top of the wheel weight. Anyway, the 2nd and 3rd video has too many discrepancies. What we should do is make a video comparison between same diameter, same tyre and just a difference in wheel weight.

Anyway thinking too much about this is giving me a bloody headache. I'm done thinking. Hahaha! We all generally agree that lightweight means more better.


You know what we should do? We should start a ZTH video channel where members get together to properly mythbust or discuss topics like this and share on Youtube.

Cuz I sure would like to see for myself how this'll turn out on a wheel dyno and hub dyno.
Nope the 5% difference he mentioned is not the rolling diameter difference but he expected around 5% difference in dyno results! The 20' tyre he used was 255/35/20 while stock 18' should be 235/50/18 which is actually bigger rolling diameter than the 20' tires! So despite running bigger rolling diameter, it actually got 20whp more than the heavier 20' setup with slightly smaller rolling diameter. To me it's pretty conclusive. I had seen many other tests long time ago but just cannot find them anymore.
 

DNGFashion

Known Member
Thread starter
Apr 20, 2017
95
14
508
erm..... hp vs bhp??

i think you want to discuss crank hp (i believe this what you are referencing to as is the bhp) vs wheel hp (at the wheels)

hp vs bhp, no real point thinking bout it

yes, you are correct.
 

vr2turbo

Beyond 20,000 RPM!
Helmet Clan
Moderator
May 11, 2010
29,998
8,385
1,713
Petaling Jaya
Then i should start making friend with their staff. Most probably can get something at discounted price...hihihi
If the factory can sell direct, then okay. Like my ex company, the factory only manufacture for export and sales to local sales company for local sales. Even factory staff who wants to buy the goods, need to get then through the sales company as the factory cannot sell direct...
 

Izso

NA NA NA NA NA
Helmet Clan
Moderator
Mar 28, 2004
15,389
6,411
5,213
KL
Nope the 5% difference he mentioned is not the rolling diameter difference but he expected around 5% difference in dyno results! The 20' tyre he used was 255/35/20 while stock 18' should be 235/50/18 which is actually bigger rolling diameter than the 20' tires! So despite running bigger rolling diameter, it actually got 20whp more than the heavier 20' setup with slightly smaller rolling diameter. To me it's pretty conclusive. I had seen many other tests long time ago but just cannot find them anymore.
the 5% I'm talking about the size difference based on tyre profile and wheel size. Not what the dyno was referring to.

It's not conclusive to me. But to each his own.
 

6UE5t

6,000 RPM
Senior Member
Oct 8, 2010
6,756
1,300
1,713
Kuala Lumpur
the 5% I'm talking about the size difference based on tyre profile and wheel size. Not what the dyno was referring to.

It's not conclusive to me. But to each his own.
Hmm I think that should not matter much if at all as long as the rolling diameter is about the same. Weight on the other hand plays a significant role.
 

Random Post Every 5 Minutes

We had always believe that by maintain our finishing standards, our Zero Compromising Policy, we had nothing to fear. But this time round, we were scared shitless. We received a request from this client that had his car worked on by a well known detailing, so well know that the company is in many famous automotive forums. zerotohundred, lowyat, bmw owner forums and many more. We were scared shitless when we were appointed to work on a car that had undergone his so called "god hands" We were...
Ask a question, start a discussion or post something for sale!
Post thread

Online now

Enjoying Zerotohundred?

Log-in for an ad-less experience