Ohlins Coilovers and Wide Front Wheels

[turbofiveoh]

Can anybody using Ohlins R&T coilovers running 19X10.5 wheels tell me if spacers are needed with a 45mm offset. I inherited a set of 19x10.5 et45 wheels with 305 tires and they are hitting the strut body in front. Is this to be expected? If not, what adjustments should I make to get the wheels to fit without the need for spacers or with narrow spacers? Camber setting is -2.5 degrees.

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[NightmareMoon]

Well a 10”/285 wheel wont even fit a stock strut with that offset, so…

You want to be in the ET26 range to run a 305 on the front so, you meed something like a 20mm spacer to be safe. Its possible that you might get away with a 15 due to that 305 being pinched on a narrrow 10.5”. If the Ohlins are slotted to the outside then that helps a smidge at the strut but not at the fender. Typically with a 305 you want a little bit more camber than 2.5 too, but it may work.

 

[turbofiveoh]

Good info...thank you for the education.

 

[bnightstar]

Well a 10”/285 wheel wont even fit a stock strut with that offset, so…

You want to be in the ET26 range to run a 305 on the front so, you meed something like a 20mm spacer to be safe. Its possible that you might get away with a 15 due to that 305 being pinched on a narrrow 10.5”. If the Ohlins are slotted to the outside then that helps a smidge at the strut but not at the fender. Typically with a 305 you want a little bit more camber than 2.5 too, but it may work.

the top bolt is slotted so you can add a bit of clearance that way but I think he will still need the fender because it's not only the strut that is a problem with that wide wheels he will be hitting the inner fender wall as well ask me how I know .

Overall with the Ohlins I run 19x11 ET26 with 305 tires and it works like a charm minus the inner fender wall hitting.

 

[turbofiveoh]

Thanks for the additional detail.

Let me ask you guys this...is it worth the headache to go from a 295 on a 20x10 wheel to a 305 on a 19x10.5 or 19x11 wheel if my objective is not squeeze out every 10th on a lap?

 

[NightmareMoon]

Thanks for the additional detail.

Let me ask you guys this...is it worth the headache to go from a 295 on a 20x10 wheel to a 305 on a 19x10.5 or 19x11 wheel if my objective is not squeeze out every 10th on a lap?

I cant figure out why 2/3rds of those options have a tire slightly too wide for the wheel. I’ll come back and first answer your question.

No, if you arent chasing time, a 305 and the offsets to run them arent needed on a street car. The tires generally cost more and they tramline more on average. My daily setup are square 285s on 10s and they’re great.

So back to widths. Always strive to pick the tire first and then pick a wheel which will get the best out of the tire.

If you know you want to run a, say 285, then you want a wheel that size or ideally a little wider. The optimal setup for a 285 would be a 10,10.5 or even 11” wheel. For a 295 its a 10.5 or 11”, for a 305 its 11” minimum or 11.5”. If you want to run a 315, well ideally its going on an 11.5 or 12” wheel. I run a 315 on an 11” wheel but its a sacrifice (i wanted square 315s and with my coils, i simply cant fit the 18x12” without cutting my fender or changing to a different coilover My competition is on 12” wheels, and I’m on 11” front and 12” rear.

Tires work best when stretched out a little. Beyond 285 front tires you’re into territory with very particular offsets needed to fit those tires in the wheel wells, but most GT setups can fit 11” front wheels without all that much trouble. We’ve done it countless times. A 285 even works great on an 11” wheel. I have pictures of that somewhere…

 

[turbofiveoh]

I cant figure out why 2/3rds of those options have a tire slightly too wide for the wheel. I’ll come back and first answer your question.

Wheel manufacturers provide a range of acceptable widths for tire size. What I'm learning is what you stated farther down in your response as it relates to the ideal wheel width for a given tire size.

No, if you arent chasing time, a 305 and the offsets to run them arent needed on a street car. The tires generally cost more and they tramline more on average. My daily setup are square 285s on 10s and they’re great.

This car is not my daily driver, in fact it's a car I drive very seldom, so I don't necessarily mind the drivability sacrifices that come with wider wheels and tires. That being said, I have no desire to turn it into a track only, or track primarily, car.
When you say your 285 on 10s square setup is great, do you mean is great for daily driving or is great for performance related applications while still being acceptable for daily driving?

So back to widths. Always strive to pick the tire first and then pick a wheel which will get the best out of the tire.

If you know you want to run a, say 285, then you want a wheel that size or ideally a little wider. The optimal setup for a 285 would be a 10,10.5 or even 11” wheel. For a 295 its a 10.5 or 11”, for a 305 its 11” minimum or 11.5”. If you want to run a 315, well ideally its going on an 11.5 or 12” wheel. I run a 315 on an 11” wheel but its a sacrifice (i wanted square 315s and with my coils, i simply cant fit the 18x12” without cutting my fender or changing to a different coilover My competition is on 12” wheels, and I’m on 11” front and 12” rear.

Great information!

Tires work best when stretched out a little. Beyond 285 front tires you’re into territory with very particular offsets needed to fit those tires in the wheel wells, but most GT setups can fit 11” front wheels without all that much trouble. We’ve done it countless times. A 285 even works great on an 11” wheel. I have pictures of that somewhere…

Again, great information.

In addition to the Ohlins R&T coilovers the car also has the full Steeda catalog:
* LCA Spherical bearings
* FCA lateral and tension links with bearings
* F&R sway bars with billet brackets and adjustable end links
* Knuckle to toe link bearings
* Adjustable Toe Links
* Vertical links
* Differential bushing inserts (90 durometer)
* IRS lockout and braces
etc. etc.

The car also has Baer 6S calipers and 15" slotted rotors F&R so I am somewhat limited on my wheel choices.

Does this change any of your advice?

My takeaways so far are that:
1) It is very possible, presumably more so with the adjustability of the coilovers installed on the vehicle, to run a 19/20X11 wheel in front with minimal heartache or permanent modifcation to the vehicle.
2) Given what I am doing with the car, a 305 in front vs a 285 or 295 will offer marginal improvement in handling for a street car, with street car meaning a car that doesn't have all of the necessary and supporting modifications for track duty.
3) If I'm looking for optimized tire performance the ideal scenario is a wheel that is on the wider side of recommendation for the tire width.

 

[NightmareMoon]

You’re picking up the right takeways.

You've done so much to make the handling sharp with all of those bearings, it would b a shame to put a wide tire on a too narrow wheel (which makes the handling feel more squirmy, and wastes a little bit of the tire contact patch). You've sharpened up the feel so far already, so lets not waste those mods.

As for the optimum tire for your car, width is always a bit secondary to tire type, and we need to pay attention to the front/rear stagger and the effects of that on handling.

So I'd want to know what your current setup is as far as tire widths, tire model, and wheels. Can you tell me more about your current wheel/tire setup?

 

[turbofiveoh]

You’re picking up the right takeways.

You've done so much to make the handling sharp with all of those bearings, it would b a shame to put a wide tire on a too narrow wheel (which makes the handling feel more squirmy, and wastes a little bit of the tire contact patch). You've sharpened up the feel so far already, so lets not waste those mods.

As for the optimum tire for your car, width is always a bit secondary to tire type, and we need to pay attention to the front/rear stagger and the effects of that on handling.

So I'd want to know what your current setup is as far as tire widths, tire model, and wheels. Can you tell me more about your current wheel/tire setup?

The car is currently sitting on Project 6GR Seven 20X10F and 20X11R wheels wrapped in Nitto NT05s. It's been a little while since I've looked at the tire sizes and if memory serves 275/40/20F and 315/35/20R. The tires are 8 years old and I need to make some decisions.

I have not been happy with the NT05s and for how little I drive the car I was thinking about replacing the tires with Cup 2s. Then I had another thought, replace the NT05s with pilot super sports for street duty and buy a set of 19X11 Apex wheels and wrap them in R888Rs or Trofeos.

For how little I drive the car (300 miles in the last 2 years) I don't know that it makes sense to have street and track wheels. So I don't know if I should stick with the 20 inch wheels and put a better tire on them or sell the wheels and start over with 19s and potentially different widths.

Thanks for the continued education and guidance.

 

[NightmareMoon]

I have 19x10” P6GR Seven street wheels so you obviously have great tastes, but 8 year old NT05s are probably ice skates.

You’re not putting enough hard miles on the car per year to properly wear out low treatwear summer tires like those, so avoid any of the hot 200TW and drag radials. They’ll go from sticky gum to rocks before your get your money’s worth out of them.

Look at the Michellin MP4S, Goodyear Eagle Supercar 3 or the Conti ExtremeContact Sport 2 for your current 20” wheels. I’d prefer you had all-round all-star tire which you can use whenever you need them, the above are good options with few downsides

After about 4-6 years you need to schedule a tire replacement for a sports car, even if they’re basically just sitting (depending on how the car is stored)

 

[bnightstar]

When I was at the same situation I went with Apex 19x11 ET26/ET52 with 305/30/19 Nankang AR-1 tires square. The car is a dream to drive. Currently sitting on 295/35/19 Yokohama A052 here is a photo:

 

[shogun32]

The car also has Baer 6S calipers and 15" slotted rotors F&R so I am somewhat limited on my wheel choices.

You bought a track car.

Sc3 or ps4s and call it a day. After you fix the front offset screwup

 

[turbofiveoh]

I have 19x10” P6GR Seven street wheels so you obviously have great tastes, but 8 year old NT05s are probably ice skates.

You’re not putting enough hard miles on the car per year to properly wear out low treatwear summer tires like those, so avoid any of the hot 200TW and drag radials. They’ll go from sticky gum to rocks before your get your money’s worth out of them.

I think the P6GR wheels look great on the S550, sadly they don't have more options in terms of width and offsets. I never really cared for the NT05s, even when they were brand new.

Notionally speaking, how many hard miles does it take to justify a set of hot 200TW tires?

Look at the Michellin MP4S, Goodyear Eagle Supercar 3 or the Conti ExtremeContact Sport 2 for your current 20” wheels. I’d prefer you had all-round all-star tire which you can use whenever you need them, the above are good options with few downsides

After about 4-6 years you need to schedule a tire replacement for a sports car, even if they’re basically just sitting (depending on how the car is stored)

Thanks for the recommendations on tires, I'll take a deeper dive into those.

 

[turbofiveoh]

When I was at the same situation I went with Apex 19x11 ET26/ET52 with 305/30/19 Nankang AR-1 tires square. The car is a dream to drive. Currently sitting on 295/35/19 Yokohama A052 here is a photo:

Thanks for the recommendations. Based on the information shared in this thread I am not sure that a 19X11 combo makes the most sense given what I already have and how the car is used. If I do decide to invest in track wheels the 19X11 Apex wheels would be my first choice.

 

[turbofiveoh]

You bought a track car.

Respectfully, if Baer brakes signify track car your bar for a track car is pretty low.

Sc3 or ps4s and call it a day. After you fix the front offset screwup

I have a set of wheels that fit the car just fine. An inherited set of wheels hardly qualifies as a screw up.

Thanks for the recommendations of SC3 or PS4S.

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