MR2 Roadster Owners Club

The Workshop => Performance Related => Topic started by: JB21 on January 24, 2023, 18:23

Title: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: JB21 on January 24, 2023, 18:23
Always wanted to try the 16/17" set up for track since watching the Techno pro spirt video were he recommends this wheel size set up for smooth tracks.

Specs as below:

Fronts:- 5.5 x 16 ET 31.5
Rears :- 7.5 x 17 ET 38

I'll be running 195/50/16 fronts and 225/45/17 rear tyres, probably Dunlop Direzza DZ03G's.

They should look ok on the car too.

(https://i.postimg.cc/L6WdTtbc/s-l400.jpg)
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: Gaz2405 on January 24, 2023, 18:26
I'd be interested to hear your thoughts on these as I need a 16" front for my big brake kit.
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: tets on January 24, 2023, 19:32
I bought a set for mine before Christmas for the same reason - They feel a bit heavy but got to try!
You're welcome to give them a try @Gaz2405 They are on legal road tyres atm but might serve a purpose!

I'll probably put R888's on for the hillclimbs when I eventually get to work from home for any length of time and finish the thing! Paris in the morning!!
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: JB21 on January 24, 2023, 19:41
Just found this thread from 2019 :-\

https://www.mr2roc.org/index.php?topic=68097.0

Rear offset is fine on these S2 Toyota spec wheels though. Others are Rover K-series spec cars.

The only debate now is 16/17. Even with the extra weight over a 15/15 and 15/16 set ups the reduced sidewalls and optimum final drive for my home tracks I think they'll be surprising.
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: Dev on January 25, 2023, 16:27
From the other thread I thought 17s ruin the handling.

 Actually I do run a 16/17 set up and mostly happy with it. You just need to get the right wheels and tires to make it more communicative at the limit but with the lower profile tires the reaction is more precise with less sidewall flex which feels good.
 
As far as looks go the 16/17 set up is more noticeable and less subtile as a double stagger over the 15/16 combo which you could not really make out especially at a distance. It makes our budget roadsters look a little more special.
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: JB21 on January 25, 2023, 17:15
Quote from: Anon on January 25, 2023, 15:05Now if you google it or speak to petrol heads, they will always tell you that low profile tyres have more grip. Fashion puts bigger wheels at pole position every time so to speak.

When you look at Formula type cars F2000 F3000 F1 etc, all the really fast single seater stuff, radicals etc - they do not run low profile tyres.

That seems like a contradiction to me?

Typical low noise, high fuel economy tyres are all pretty wibbily wobberly when you fit them and so obviously wallow about under load. So the lower profile will give a more direct feel.

When you are playing with big boy tyres like Direzza's etc, I've personally fitted some of these semi slick tyres and they are very hard work fitting them. The core/walls are very strong and offer very little flex. Sometimes two lads are needed to get them over bead on the tyre machine! Two lads who end up sweaty and swearing. They don't even squidge out at the bottom when flat  :)) 

(oh you've got a flat tyre... don't worry its only flat at the bottom)

I've drove lots of little cars on oversized wheels, and they can sometimes steer awful. Some call it track lining. I think it has to do with the wheels moment of inertia, I'm no engineering mathematician... but you could have 2 wheels with identical total mass of e.g. 10kg, but if the mass is concentrated further outwards its MOI would be higher. I think if this gets beyond some ratio of the mass of the car and the steering/suspension components, then the wheel will become more of the boss. The wheel and tyre combination has a gyroscopic effect and doesn't like to shift vector.

Lotus will have spent quite a bit of time balancing aesthetics verses performance hopefully.

I personally don't really know either way though. Thus interested in your experience.

I've always been one to experiment with my cars, so I'll take one for the team on this one. If its terrible I can just get my money back for what I paid, no biggie. I see wheels and such as assets.

Thinking now to go with a 195/45/16 front and 225/40/17 resr to lower the sidewalls further and lower the weight. These will only be track wheels for the fast open tracks like Oulton and Donington so don't have to worry about road compliance.
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: Dev on January 25, 2023, 17:31
Quote from: Anon on January 25, 2023, 15:05Now if you google it or speak to petrol heads, they will always tell you that low profile tyres have more grip. Fashion puts bigger wheels at pole position every time so to speak.

When you look at Formula type cars F2000 F3000 F1 etc, all the really fast single seater stuff, radicals etc - they do not run low profile tyres.

That seems like a contradiction to me?

Typical low noise, high fuel economy tyres are all pretty wibbily wobberly when you fit them and so obviously wallow about under load. So the lower profile will give a more direct feel.

When you are playing with big boy tyres like Direzza's etc, I've personally fitted some of these semi slick tyres and they are very hard work fitting them. The core/walls are very strong and offer very little flex. Sometimes two lads are needed to get them over bead on the tyre machine! Two lads who end up sweaty and swearing. They don't even squidge out at the bottom when flat  :)) 

(oh you've got a flat tyre... don't worry its only flat at the bottom)

I've drove lots of little cars on oversized wheels, and they can sometimes steer awful. Some call it track lining. I think it has to do with the wheels moment of inertia, I'm no engineering mathematician... but you could have 2 wheels with identical total mass of e.g. 10kg, but if the mass is concentrated further outwards its MOI would be higher. I think if this gets beyond some ratio of the mass of the car and the steering/suspension components, then the wheel will become more of the boss. The wheel and tyre combination has a gyroscopic effect and doesn't like to shift vector.

Lotus will have spent quite a bit of time balancing aesthetics verses performance hopefully.

I personally don't really know either way though. Thus interested in your experience.

This is very true and that is why it is harder to get it right but it can be done as long as the wheels are the right offset and equal to or less weight than the factory wheels which is possible but that costs money.
Also using budgeted light weight larger wheels will come out of balance easily. 
The only way around this is to buy wheels from a highly reputable manufacture that makes them for OEM or obtaining them from an OEM car like in this case. Unfortunately many in our hobby do not know what they are doing and buy cheap weighty wheels and then have these issues that they lump in with every 17" option.

  I am not in favor of larger wheels but I have them and enjoy them.  I have 19" factory wheels on my other car and it does just fine once I got the right tires that have a softer sidewalls that match the dampers better.
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: Petrus on January 25, 2023, 21:14
Quote from: Anon on January 25, 2023, 15:05Now if you google it or speak to petrol heads, they will always tell you that low profile tyres have more grip. Fashion puts bigger wheels at pole position every time so to speak.

When you look at Formula type cars F2000 F3000 F1 etc, all the really fast single seater stuff, radicals etc - they do not run low profile tyres.

That seems like a contradiction to me?

Tyres are part of the suspension. It is air springs with also some shock damping. This greatly aids the actual suspension in maintaining the rubber patch in the road surface. Reducing the chamber volume by fitting larger diameter rims means more work for the suspension. Some more travel too making the geometry more tricky.

A larger diameter rim is, ceteris paribus, heavier.

See here the two reasosn why F1 engineers resisted the marketing of larger rims for yéars.

The only reasons too go larger rims on an existing car like our Spyder is to get more precise/response directional control through stiffer, lower sidewalls. Ideally it needs suspension adjustment but on smooth tracks you might get away with the loss of conformation.

The ham question is whý on éarth the marketing of larger rims???
Looking better is relative and mostly manipulated taste by marketing. That being what it is, if one happens to prefer the look there is no discussing that. By all menas go for it. Just be aware of the down sides.
The téchnical reason is ever heavier cars. Those need larger brake disc and thus larger diameter rims to house them. Thát is in a nutshell the only reason.
So, because ever lardier road cars, especialle EVs/hybrids need húge wheels, F1 must be seen with bigger ones too  ::)

If for a track ZZW30 there is no hard reason to stick to the overal diameter, a smaller one will give a lower gearing and at the front better braking because the disc rotates faster.
Thus if you can get away with the ground clearance, same width lower stiffer sidewalls do not have to come at the price of larger/heavier wheels. Actually the tyres would be líghter. That would be one drawback less, make it several wins.


Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: JB21 on January 27, 2023, 09:04
Thinking I may use the rear 17's for slicks now, and couple them to my OZ 15x7 fronts  :))

200/580/15 - fronts

215/630/17 - rears
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: Joesson on January 27, 2023, 09:27
Towards the dragster look?
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: Alex Knight on January 27, 2023, 09:44
@justinread72 fitted these wheels IIRC:

https://www.mr2roc.org/index.php?topic=64839.100

Post 105
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: JB21 on January 27, 2023, 10:11
Quote from: Joesson on January 27, 2023, 09:27Towards the dragster look?

215/630/17 - are actually a smaller diameter than my current 225/50/16
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: Dev on January 27, 2023, 16:16
Although it is often true that larger wheels makes everything worse there are some exceptions to this rule.
You can have more wheel fill than tire fill and still maintain close to the OEM diameter.  The front 16s inch wheels I had was fitted with 205/40/16 tires which actually reduced the over all diameter from the OEM wheels. The rear 17s were just a tad larger but pretty much on par with the OEM.  Also compared to the FL OEM wheels my combo is lighter especially for the rears by a significant margin.
Most people don't realize how heavy the OEM 16 inch wheels are. Also keep in mind that the tire industry has changed these low profile tires to be softer than the previous generation so they dont damage wheels and offer more road comfort, that is why all new cars have much larger wheel diameters and no longer offer 15" wheels.

I had this photo of a members car for a long time that lives in the south of France I believe. He has the same wheels I have except they are 17/18 inch combo. Not something I would do but I think it makes a silver car look exceptional with its stance.
(https://i.ibb.co/pJ1KmNh/dscn1132s9lx1-1.jpg) (https://ibb.co/3BTFJVR)
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: Petrus on January 27, 2023, 17:03
Quote from: Dev on January 27, 2023, 16:16but I think it makes a silver car look exceptional with its stance.
(https://i.ibb.co/pJ1KmNh/dscn1132s9lx1-1.jpg) (https://ibb.co/3BTFJVR)

No discussing taste. To mé it looks a style clash; war of the decennia  :))  But hey mine is hardly ´style police`  ;)
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: JB21 on February 9, 2023, 09:13
Lotus OE (Rimstock 6 spoke) wheels have arrived and obviously the first thing to do was weigh them.

Front 16x5.5J = 8.1kg

Rear 17x7.5J = 10.1kg

Not exactly Lotus lightness but not terrible.

(https://i.postimg.cc/63BGkGMB/Lotus-rear.jpg)

(https://i.postimg.cc/4nRG0p15/Lotus-front.jpg)
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: JB21 on February 9, 2023, 16:20
Quote from: Anon on February  9, 2023, 13:32Condition looks really good!
Do you know the offsets of them?

These sold on ebay a couple of weeks back at a banging price...
https://www.ebay.co.uk/itm/lotus-elise-s2-Alloy-Wheels-/225281688264

Rears 38, fronts 31.5
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: Dev on February 9, 2023, 16:33
Nice looking wheels but it is heavier than I was expecting probably because of OEM durability. 
Because of the offsets especially the front the car is going to be less responsive because it will change the scrub radius greatly. It probably works better with the way the Lotus suspension is set up since it is not a McPherson design. It may prove to be a good thing or bad depending on what you are looking for as you will trade the dart like response for stability. I would like to hear your experience once they are on the car as it should drive different. 

 
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: JB21 on February 9, 2023, 17:21
Quote from: Dev on February  9, 2023, 16:33Nice looking wheels but it is heavier than I was expecting probably because of OEM durability. 
Because of the offsets especially the front the car is going to be less responsive because it will change the scrub radius greatly. It probably works better with the way the Lotus suspension is set up since it is not a McPherson design. It may prove to be a good thing or bad depending on what you are looking for as you will trade the dart like response for stability. I would like to hear your experience once they are on the car as it should drive different. 

 

My OZ Ultraleggera's are 38 and I didn't notice much difference compared to the OE 45. 31 is a big difference compared to OE though so this should show up in some form.
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: Dev on February 9, 2023, 17:35
Quote from: JB21 on February  9, 2023, 17:21My OZ Ultraleggera's are 38 and I didn't notice much difference compared to the OE 45. 31 is a big difference compared to OE though so this should show up in some form.

 As you know I have Ultraleggeras and the same offsets however I did notice the change. I suppose it depends on the driver and the over all suspension set up. What I felt was less responsiveness which was good in one way as the car drives smoother, stable and less of a handful when things let go but bad in another as I have less playfulness in the road feel.

The jump to 31 is large enough to notice but who really knows until you find out first hand. It should be interesting.
 I wish there was a service that can shave down the wheels by a few millimeters as I would like to have 42. 
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: tets on May 18, 2023, 08:53
did you ever give these a try?
I'm still debating whether to shod my Lotus alloys or get some ultra light 7x15's all round
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: JB21 on May 18, 2023, 09:54
Quote from: tets on May 18, 2023, 08:53did you ever give these a try?
I'm still debating whether to shod my Lotus alloys or get some ultra light 7x15's all round

No not yet. I now plan on running only the rears with 235/40/17 slicks. I'll probably sell the fronts.

I also run super lightweight 15X7 OZ Ultaleggeras (4.9kg each) with Yokohama A048 tyres. I may sell these but they wont be cheap.
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: tets on May 18, 2023, 10:57
Look forward to seeing how you get on - I just couldn't believe how heavy they were when I picked them up. Really surprised me




Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: Zens on June 14, 2023, 14:02
Interesting thread as I also looked into Elise S1 wheels. But the offsets were too different at ET10, ET14 and ET16. Plus they weigh considerably more than the OEM wheels. So for now I decided to just keep the OEM wheels, for weight and also style, as I didn't really find anything I liked the style more which was lighter. But I would love some Lotus Victory wheels. :) Pity the offset would probably not work and they are a whooping 2kg heavier each than OEM.
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: Alex Knight on June 14, 2023, 16:19
Enkei RPF1 would be my next choice.
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: Petrus on June 14, 2023, 17:31
Quote from: Alex Knight on June 14, 2023, 16:19Enkei RPF1 would be my next choice.

I went those and they are what they are famed to be. A véry nice extra is that they are a doddle to keep clean. Imo very good value for money.
I like the JDM look too for the MR2 but that is subjective.
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: Zens on June 14, 2023, 19:25
Quote from: Alex Knight on June 14, 2023, 16:19Enkei RPF1 would be my next choice.

Very light weight. But the design just doesn't speak to me. I find the OEM much nicer styled and more fitting to the car's styling. But one of the few wheels which manages to be lighter enough than OEM to be considered. Downside is a staggered set is not available. 
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: Petrus on June 14, 2023, 20:01
Quote from: Zens on June 14, 2023, 19:25Very light weight. But the design just doesn't speak to me. I find the OEM much nicer styled and more fitting to the car's styling. But one of the few wheels which manages to be lighter enough than OEM to be considered. Downside is a staggered set is not available. 

I like the OEM design very much too.
Apart from weight and quality, the RPF1 has two extra selling points imo. It is both a classic in its own right ánd befitting Japanese cars as much as Minilights UK ones and the ´five star´ Cromodora / ATS classic European mainland ones.
It´s TOTALLY subjective though; imagined, conservative historic perception even.  Much like no british racing green but réd for  a classic sports Alfa or no Doxa orange dial for a Rolex desk diver.
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: Zens on June 14, 2023, 23:14
Quote from: Petrus on June 14, 2023, 20:01I like the OEM design very much too.
Apart from weight and quality, the RPF1 has two extra selling points imo. It is both a classic in its own right ánd befitting Japanese cars as much as Minilights UK ones and the ´five star´ Cromodora / ATS classic European mainland ones.
It´s TOTALLY subjective though; imagined, conservative historic perception even.  Much like no british racing green but réd for  a classic sports Alfa or no Doxa orange dial for a Rolex desk diver.

I see where you are coming from. :)

But the lack of staggering option bothers me the most. I really want to keep the stagerring. So much so I have decided to stick to my PFL wheels for now. I can't find a tyre + lighter rim combo that allows me to keep 185 at the front or even a proper staggering. So I will get some new tyres and get some time in with the PFL wheels, both on the road and on the track. Then I will decide if I really want or need new wheels or even 16" at the rear. Maybe I will just refinish them in a different colour than silver.
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: JB21 on June 15, 2023, 08:09
MR2 tyre staggering is over rated, its really not essential. It was designed like this from factory to make the car more understeer bias for safety. I've ran 195 square and 205 square on track even in the wet and it wasn't an issue at all. My slicks are 205/50/15 square and my wets are 195/50/15 square. It just makes thing much cheaper and the only downside for me is the gearing on longer tracks, hence why I will be using the Lotus 17s at the rear and currently use 16s but the side walls are to tall for circuit racing.
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: Petrus on June 15, 2023, 08:26
Quote from: JB21 on June 15, 2023, 08:09MR2 tyre staggering is over rated, its really not essential. It was designed like this from factory to make the car more understeer bias for safety.

and the 215 on 16" is principally a step further towards that.

As I wrote earlier, on the tech specs of míne, there is an extra observation specifically stating that 205/50R15 is permitted up front too.

Stiffness of sidewall is a tricky one becauce lower is only stiffer it the týre is designed to be. Usually the lower section tyre sizes are designed with a softer sidewall to compensate for the smaller air chamber (which is a progressive spring/damper).
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: JB21 on October 12, 2023, 13:00
Finally got some tyres fitted to the Lotus wheels. Avon ZZRs 195/50/16-225/45/17 Elise/Exige spec.

Oulton 18/11 for testing

(https://i.postimg.cc/GmgFRw1s/20231012-123232.jpg)

(https://i.postimg.cc/CM6SbcYs/20231012-123204.jpg)

No issue with 195 tyres on 5.5J rims

(https://i.postimg.cc/gjGXRNWW/20231012-123028.jpg)

(https://i.postimg.cc/W3Tbfzfm/20231012-123033.jpg)
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: Alex Knight on October 12, 2023, 19:08
Tyres look mega. Be interested in feedback.
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: AdamR28 on October 13, 2023, 14:03
ZZRs are excellent. As long as its dry  ;D
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: SuperArt on October 14, 2023, 20:07
Do you notice the difference when running larger diameter wheels at the back?

Why not keep 16's all round just with wider width rears? I'd have thought the get-up-and-go would be blunted with a bigger diameter rear wheel.

I'm on 205 R16 front 225 R16 rear. I don't like this setup, can't explain it but it doesn't feel nimble like stock sizes.
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: JB21 on October 18, 2023, 14:14
I've just weighed the Lotus wheels and Avon ZZR tyres and also my lightweight 15X7 OZ Ultraleggera's with Yoko A048 tyres and the difference is staggering.

Lotus/ZZR - 195/50/16 = 18kg
Lotus/ZZR - 225/45/17 = 21kg
Total mass 78kg

OZ/A048 - 195/50/15 = 13.5kg
OZ/A048 - 225/50/15 = 15.2kg
Total mass 57.4kg

So that's a difference of 20.6kg in unsprung weight total, and 11.6kg difference in rotational mass on the rear wheels  :o

I'm now putting these up for sale if anyone is interested as this is just to much extra weight to cart around track. They come with aluminum spigot rings and slimline wheel nuts to fit straight onto the ZZW30 - £500.

Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: Alex Knight on October 18, 2023, 18:18
20KGs! Wow. Fully not worth it.

Well done to you for putting function in front of form.

Shame that, as they look lovely!
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: AJRFulton on October 18, 2023, 20:14
Quote from: JB21 on October 18, 2023, 14:14I've just weighed the Lotus wheels and Avon ZZR tyres and also my lightweight 15X7 OZ Ultraleggera's with Yoko A048 tyres and the difference is staggering.

Lotus/ZZR - 195/50/16 = 18kg
Lotus/ZZR - 225/45/17 = 21kg
Total mass 78kg

OZ/A048 - 195/50/15 = 13.5kg
OZ/A048 - 225/50/15 = 15.2kg
Total mass 57.4kg

So that's a difference of 20.6kg in unsprung weight total, and 11.6kg difference in rotational mass on the rear wheels  :o

I'm now putting these up for sale if anyone is interested as this is just to much extra weight to cart around track. They come with aluminum spigot rings and slimline wheel nuts to fit straight onto the ZZW30 - £500.



Yeah on road that's fine, but on track that is going to absolutely kill time and handling.
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: Petrus on October 19, 2023, 12:31
Quote from: AJRFulton on October 18, 2023, 20:14Yeah on road that's fine, but on track that is going to absolutely kill time and handling.

How come that´s ´fine´ on the road?
Ok, not adding travel time but adding stopping distance is even more of an issue thére than on a track where it is only time.
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: JB21 on October 19, 2023, 14:54
Quote from: JB21 on October 18, 2023, 14:14I've just weighed the Lotus wheels and Avon ZZR tyres and also my lightweight 15X7 OZ Ultraleggera's with Yoko A048 tyres and the difference is staggering.

Lotus/ZZR - 195/50/16 = 18kg
Lotus/ZZR - 225/45/17 = 21kg
Total mass 78kg

OZ/A048 - 195/50/15 = 13.5kg
OZ/A048 - 225/50/15 = 15.2kg
Total mass 57.4kg

So that's a difference of 20.6kg in unsprung weight total, and 11.6kg difference in rotational mass on the rear wheels  :o

I'm now putting these up for sale if anyone is interested as this is just to much extra weight to cart around track. They come with aluminum spigot rings and slimline wheel nuts to fit straight onto the ZZW30 - £500.



OK so a bit more wheel and tyre weighing, this time my OE FL wheels and Yokohama A052's.

FL 15" front/A052 - 205/50/15 = 15.1kg
FL 16" rear/A052 - 225/50/16 = 17.6kg

So this is a much more respectable 8kg difference vs one of the lightest wheels on the market.
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: Petrus on October 19, 2023, 19:03
Quote from: JB21 on October 19, 2023, 14:54OK so a bit more wheel and tyre weighing, this time my OE FL wheels and Yokohama A052's.

FL 15" front/A052 - 205/50/15 = 15.1kg
FL 16" rear/A052 - 225/50/16 = 17.6kg

So this is a much more respectable 8kg difference vs one of the lightest wheels on the market.

The difference is even negatively influenced by a wider front tyre and larger real wheel diameter: All in all OEM is quíte lightweight!!
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: JB21 on October 20, 2023, 07:36
Quote from: Petrus on October 19, 2023, 19:03The difference is even negatively influenced by a wider front tyre and larger real wheel diameter: All in all OEM is quíte lightweight!!

I'll be going down to 195/50/15 front and 225/45/16 rear so this will shave a kilo maybe.
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: Petrus on October 20, 2023, 08:53
Quote from: JB21 on October 20, 2023, 07:36I'll be going down to 195/50/15 front and 225/45/16 rear so this will shave a kilo maybe.

I réally appreciate you weighing and writing about it. It is totally underestimated and largely denied/ignored whereas F1 having been obliged to go bigger and heavier makes it fashionable and the nórm without questioning the safety of it.
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: JB21 on October 24, 2023, 11:44
Ok latest and last weight update. I have now decided to go with 205/50/15 square on my OZ Ultraleggera wheels. This works out at 13.4kg per wheel/tyre and a total mass of 53.6kg.

Over the current FL set-up with A052's 205/50/15 - 225/50/16 there will be a saving of 11.8kg total.
Over the current OZ ultra/A048 set-up 195/50/15 - 225/50/15 there will be a saving of 3.8kg total.

The test will now be can I beat the best lap time at Oulton of 200:05 with the narrower 205 rear but 11.8kg lighter wheels/tyre combo. Funnily enough my best time on the OZ Ultraleggera's with 195/225 A048's was a 2:00.5.

What do you think weight saving over additional grip, which wins?
Title: Re: Bought some Lotus Elise S2 (16/17) wheels for track
Post by: AJRFulton on October 25, 2023, 01:00
I think there will be little in it.

My hunch will be weight wins.