Bolt on Spacers for Track - Yes or No

[fcruz3r]

read all the threads on this forum...and a couple of others regarding using spacers. seems to be a recurring quote that porsches have been using them so its fine and others that say its outright dangerous... but mostly speculate from what they've heard or seen from internet pics

want to hear from mx5 owners who has used them on the track and whether there's any danger in doing so. Have a set of wheels that i've bought and kinda like the weight & design but the offsets are too sunken. also plan on using the stock wheels at the track with the spacers.

for those who have used spacers at the track...where did you purchase these from and any mods you had to do to fit them. whats the recommended size..15, 20, 25, 30mm??

thanks all

[spikes]

Read into ideal offsets for the track before you go putting spacers on because "they're too sunken"

[manga_blue]

You need to think about total offset first rather than size of the spacers. The range for track work depends on the driver, but for most drivers the sweet spot is somewhere between 25mm and 35mm. I've tried everything from 15mm to 42mm and I prefer about 32-35mm. Rascal has much better hands and technique than me and goes for 25mm. At the end of the day the variations make buggar all difference to lap times unless you're at an exceptionally high skill level.

CAMS has banned slip-on spacers from time to time in different classes. I've seen slip-on ones fail at the track a few times, but not on MX5s. That's purely because I've never seen anyone use them for our cars.

Bolt on spacers are a bit problematical too. Wheel nuts for track cars need regular checking. I've had a few come loose and now I check torque after every 2 or 3 runs. I've seen bolt-on spacers work loose on other MX5s too. If you've got bolt-on spacers you have to remove the wheels to check the spacer nut torques and that becomes a real pain. Really you're better off selling your wheels and buying a set with the right offsets.

[emily_mx5]

What width and offset are they currently?
And what width tyre will you run?

[Apu]

From my limited experience (and with RC cars, haha!) it's got more to do with increasing the track (ie measurement from centre of wheel-to-wheel).

As a not necessarily right example, I didn't like the understeer I used to get in my Alfa and I used 10mm (or was it 15mm?) spacers in the front. This widened the front track width relative to the rear. The result was next to no understeer, with the tail more likely to step out.

That seemed to work well for the way I drove around the Pasir Gudang / Johor Circuit (which is tight and twisty) but if I wasn't careful, it could be a bastard around a couple of the turns at Sepang.

[fcruz3r]

wheel is 8inch wide with +44 offsets so it's contacting inner wheel well on the rears. Thought of 20mm to bring this closer to +24

+15mm spacers will have put this closer to where I'd like the offsets to be at, but there's just not enough meat on a 15mm spacer to give it much rigidity.

i'd be running these with a 205/40 16 or 45

Manga's comments describes my exact concerns. It's easy to torque wheels when the car's on the ground, but because i need to remove the wheel to torque down the spacer..this could get tricky without an impact wrench handy

[fcruz3r]

From my limited experience (and with RC cars, haha!) it's got more to do with increasing the track (ie measurement from centre of wheel-to-wheel).

As a not necessarily right example, I didn't like the understeer I used to get in my Alfa and I used 10mm (or was it 15mm?) spacers in the front. This widened the front track width relative to the rear. The result was next to no understeer, with the tail more likely to step out.

That seemed to work well for the way I drove around the Pasir Gudang / Johor Circuit (which is tight and twisty) but if I wasn't careful, it could be a bastard around a couple of the turns at Sepang.

hey Apu, I used to drive down to johor to see the moto gp races at Pasir Gudang and been to some drag races at Sepang.

[Apu]

Where were you based? How long ago was this?

[fcruz3r]

subang jaya, going back about 18 years now.

[Apu]

Mmm...about the same time.

You would have been there when Batu Tiga was open then? That was a great track. Bigger than Pasir Gudang and not as ridiculously large as Sepang.

[stb]

Like most things if done properly there should be no issues, but done poorly could be prone to failure.

For example, with slip-on spacers provided there is enough stud engagement into the wheel nut, and enough thickness of nut land on the wheel, there should be no problems. I know people who have run the same spacers for >10 years including track use with no problems. Bolt-on are the same - I'd be worried with thin spacers because of the lack of thickness of the spacer and the engagement with the stud. For this reason I'd feel safer on slip-on spacers with extended wheel studs than bolt on spacers. But they'd have to be pretty special wheels for me to actually bother.

[fcruz3r]

Like most things if done properly there should be no issues, but done poorly could be prone to failure.

For example, with slip-on spacers provided there is enough stud engagement into the wheel nut, and enough thickness of nut land on the wheel, there should be no problems. I know people who have run the same spacers for >10 years including track use with no problems. Bolt-on are the same - I'd be worried with thin spacers because of the lack of thickness of the spacer and the engagement with the stud. For this reason I'd feel safer on slip-on spacers with extended wheel studs than bolt on spacers. But they'd have to be pretty special wheels for me to actually bother.

how is there lack of engagement of the wheel nuts with bolt on spacers? the spacers usually come with it's own studs normally of equal or longer length than the hub studs?

on another note, can someone please tell me whether I need spacers with M12 1.5 or 1.25 thread pitch?

[emily_mx5]

hes talking about slip on spacers, as they reduce the amount of thread you can use / shorted the stud.

I would never use bolt on spacers, only longer studs with slip ons if necessary.

mx5 thread pitch is 1.5

[fcruz3r]

thanks Emily.

Guess I'd need to accept the different opinions with this. I've had different responses with people saying bolt on spacers are much safer than the slip on/floating spacers.

[stb]

When you think about how the stud is supported, there is a difference between bolt on and slip on. The OE studs are supported by the whole hub flange, but bolt on spacers have the studs holding the wheels on only supported by the spacer ring itself. The stress conditions between the 2 are quite different (in theory at least).