19" rims/smaller tires bad idea? Any pic of Emira on 19s?

[wallstbear]

Been playing with the idea of going with 19 inch wheels and a slightly smaller tire size than stock (eg 255/35/19 or 235/40/19) which lowers ride height (and increases fender gap) by 5mm~9mm. Assuming no suspension change at this point.

Am ok with the ride height drop but not too sure about the overall looks of a smaller wheel/tire. Handling will be a tad quicker but should be acceptable. That said, the car is 5%~7% shorter than most mainstream sports cars so 5% decrease in wheel size hopefully won't be too bad?

Has anyone seen a setup like this and can share a pic or link? BTW I am ingoring speedo adjustment for now.

 

[Speedy Emira]

I’m sure it can be done but I’m not sure if I’d want an even bigger arch gap as it’s one point a lot of owners have commented is too big.
You may want to factor in the cost of adjustable height coil overs just in case you don’t like it.

 

[pec]

I’m sure it can be done but I’m not sure if I’d want an even bigger arch gap as it’s one point a lot of owners have commented is too big.
You may want to factor in the cost of adjustable height coil overs just in case you don’t like it.

The Emira GT4 is on 19s; could be worth looking at pictures of it. Probably lowered though.

 

[Time2Fly]

The Emira GT4 is on 19s; could be worth looking at pictures of it. Probably lowered though.

It does look lowered. But it also looks better than the stock 20s regardless. And that livery is

 

[kitkat]

I'll be on 18s for my track wheelset.

 

[Time2Fly]

I'll be on 18s for my track wheelset.

Because the sidewall allows more deformation before you break traction? Or because the tires absorb more of the unevenness of the surface before upsetting the suspension?

 

[kitkat]

Because the sidewall allows more deformation before you break traction? Or because the tires absorb more of the unevenness of the surface before upsetting the suspension?

Because I don't need 19s or 20s at the track and the cost of consumables is lower with 18" tires -- and variety with 18" of brands and compounds to use in both the 200tw categories and almost-r comp categories is huge.

 

[Eagle7]

Because the sidewall allows more deformation before you break traction? Or because the tires absorb more of the unevenness of the surface before upsetting the suspension?

Not to mention dropping a good amount of unsprung rotating weight which helps performance everywhere.

 

[Porter]

Been playing with the idea of going with 19 inch wheels and a slightly smaller tire size than stock (eg 255/35/19 or 235/40/19) which lowers ride height (and increases fender gap) by 5mm~9mm. Assuming no suspension change at this point.

Am ok with the ride height drop but not too sure about the overall looks of a smaller wheel/tire. Handling will be a tad quicker but should be acceptable. That said, the car is 5%~7% shorter than most mainstream sports cars so 5% decrease in wheel size hopefully won't be too bad?

Has anyone seen a setup like this and can share a pic or link? BTW I am ingoring speedo adjustment for now.

Why not choose a tire that matches the total rolling radius of the the original? As the wheel shrinks, the sidewall grows. Speedo error can be minimal if the tire size is chosen appropriately. And no change to fender gap.

 

[pec]

View attachment 37464
It does look lowered. But it also looks better than the stock 20s regardless. And that livery is

Indeed but does have a lot of wheel gap so perhaps still low profile. Don’t know the tire dimensions. Lower wheel mass advantages I suppose.

 

[wallstbear]

Why not choose a tire that matches the total rolling radius of the the original? As the wheel shrinks, the sidewall grows. Speedo error can be minimal if the tire size is chosen appropriately. And no change to fender gap.

I can definitely do that, but I am trying to see if I could achieve a few things by going slightly smaller:

1. drop the ride height by a few mms;
2. lighten the wheels;
3. make the car look a bit bigger (Honestly 20" wheel seems to make the car look small);
4. a lot more options for 19" wheels/tires like Speedy was saying.

 

[wallstbear]

The Emira GT4 is on 19s; could be worth looking at pictures of it. Probably lowered though.

Here are some closeup pics of the GT4 for everyone's benefit.

 

[pec]

I stand corrected. GT4 tyres are on 18s.
Tyres: Pirelli GT4 26/645x18 (front) and 305/660x18 (rear)

 

[pec]

Here are some closeup pics of the GT4 for everyone's benefit.

Nice pics, but if I zoom in on the tyre photo, it reads 20s. Strange.

 

[lynchy73]

I can definitely do that, but I am trying to see if I could achieve a few things by going slightly smaller:

1. drop the ride height by a few mms;
2. lighten the wheels;
3. make the car look a bit bigger (Honestly 20" wheel seems to make the car look small);
4. a lot more options for 19" wheels/tires like Speedy was saying.

Smaller rims without matching the rolling radius of the original tyre may lower the car very slighty, but it will also give you more wheel gap and will look worse.

I think it’s fair to say, that a slightly smaller wheel rim, with more tyre sidewall gives the impression of less wheel gap.

 

[Speedy Emira]

I'll be on 18s for my track wheelset.

Hi Kitkat,
I personally like the look of the 18s on the GT4 but what I’ve been told have have read is the complete suspension was built bespoke to have those profiles. To simply swap to 18s won’t be the same for cornering as the GT4 set up so I’m interested in what you intend to do.
The GT4 is slightly lowered as was the original car designed for the press days and demo track days before production.
If it was possible to improve handling with 18s I’d be interested but I also don’t want to mess it all up.

 

[kitkat]

Hi Kitkat,
I personally like the look of the 18s on the GT4 but what I’ve been told have have read is the complete suspension was built bespoke to have those profiles. To simply swap to 18s won’t be the same for cornering as the GT4 set up so I’m interested in what you intend to do.
The GT4 is slightly lowered as was the original car designed for the press days and demo track days before production.
If it was possible to improve handling with 18s I’d be interested but I also don’t want to mess it all up.

We may or may not have irreconcilable differences here just in the way we think about Lotus.

I don't see the Lotus setup as perfect, I believe the Lotus setup a decent road going sports car with a balance of looks, comfort, driving engagement, and price -- a set of compromises. There's nothing to say you can't make modifications to those compromises to skew that balance towards objectives that better meets your goals.

I'm not looking to replicate the GT4 car, my modifications will be centered around some track time for enjoyment which might be different to your goals, and so I'll use my knowledge and experience as well as community knowledge to help me achieve those goals.

Wheel and Tire Changes:

- 18" diameter wheels for tire selection
- larger section width up front
- stickier and more heat tolerant tire compound
- baffled oiling to match increased grip

This will probably lead to:

- stiffer and shorter springs than oem sport
- different damping to match stiffer springs

 

[Porter]

Nice pics, but if I zoom in on the tyre photo, it reads 20s. Strange.

It's a rendering, not a photo. The tire is just a digital model that's been scaled to size.

 

[dgrace]

Any concerns about clearing the brake calipers with 18" wheels?

 

[Porter]

Hi Kitkat,
I personally like the look of the 18s on the GT4 but what I’ve been told have have read is the complete suspension was built bespoke to have those profiles. To simply swap to 18s won’t be the same for cornering as the GT4 set up so I’m interested in what you intend to do.
The GT4 is slightly lowered as was the original car designed for the press days and demo track days before production.
If it was possible to improve handling with 18s I’d be interested but I also don’t want to mess it all up.

The "bespoke suspension" and chassis tuning is for competition, both to take advantage of the racing slick tires and provide a good starting point for a team to begin their development of the car for their own purposes.

I'm pretty sure the suspension is Öhlins TTX. There are no sacred cows and no special sauce, where racing vehicles are concerned. Nothing is magic, it's all calculations and iterative adjustments.