Bought some Lotus Elise S2 (16/17) wheels for track

Started by JB21, January 24, 2023, 18:23

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JB21

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.


Gaz2405

I'd be interested to hear your thoughts on these as I need a 16" front for my big brake kit.
1zz turbo. Home built and home mapped.

Now 2zz turbo. Home built and home mapped

Build thread https://www.mr2roc.org/forum/index.php?topic=67004.0

tets

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!!

JB21

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.

threepot

Sounds like a good idea to try!

I really buggered up the line into foulstons Chicane and proper walloped the first kerb with a very loud bang, big gooey high walled tyres are kinder to that sort of abuse.

This site is really helpful for looking at the geometry difference btw

https://www.willtheyfit.com/index.php?width=225&aspect=45&diameter=17&wheelwidth=7.5&offset=38&width2=215&aspect2=45&wheel_size=16&wheel_width=7&offset2=45

threepot

Now 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.

Dev

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.

JB21

Quote from: threepot 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.

Dev

Quote from: threepot 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.

threepot

Quote from: JB21 on January 24, 2023, 18:23Fronts:- 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.



Did they ever put those 6 spokes on the toyota engine elise?

This was something that I remember from a decade ago, if you try and swap K series wheel onto a toyota elise the offset of the rears are different, and people use a spacer that's nearly an inch thick.

I'm rambling out loud here about something I know bugger all about. But I thought I'd mention it because there are different offsets to be aware about.

Petrus

Quote from: threepot 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.



JB21

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

Joesson


Alex Knight

#13

JB21

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

Dev

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.

Petrus

Quote from: Dev on January 27, 2023, 16:16but I think it makes a silver car look exceptional with its stance.


No discussing taste. To mé it looks a style clash; war of the decennia  :))  But hey mine is hardly ´style police`  ;)