Hi there group, Im looking to upgrade my front and rear anti roll bars from factory (28.8 mm Front and 17.5 mm rear ) as we were getting guard rub on the track last year.
I am running 16Kgf/mm (900 Lb/in) front and 14Hgf/mm (780 Lb/in rears) car was running 27-650/18 rears and 25-640/18 front Michelin pilot slicks on 10.5 and 9.5" rims respectively.
Going to 280-650/18 Kuhmo slicks on 10.5" rims all around for next season.
Ideally looking for adjustable front and rear bars similar to the old Tri-point design.
Feedback and comments most welcome.

 

I think you're up for a bit of fabrication rather than off the shelf unless $$$$ involved.

Revolution in Japan do a bladed front ARB, never seen one in the wild though. Some of the speedway mobs do bars, but you'd still need to make/buy the blade, weld/ream the mounting for the bearings, get push/pulls, adjuster, yada, yada. This car was running adjustables front and rear 15 + years ago, didn't get anything worthwhile from the rear. Can't remember if I asked who did it, or it was an in-house job, the needle bearing mounts look suspiciously like Harrop and the in-car adjusters definitely looked to be theirs so wouldn't have been cheap in that case.

The change from Michelin to Kumho seems a bit odd unless a tyre rule, we run that size Kuhmo in the rear just on price.....did get a bit of occasional rubbing though because the spacer insists on running too low. One of the local cars did run them that size front and rear in club endurance events with fibreglass guards, ride height always looked a bit weird to me and wouldn't surprised if they were hitting something on lock, we ran 245s with all steel....pumped, rolled, etc.


The change

 

Im not saying you dont need a higher spring rate and/or more swaybar with the real slicks, but

If your tire is rubbing in the top of the wheel well you need to adjust your shock/bump stop stroke.

If your tire is rubbing on the inner fender area you need to change your wheel offset and/or clearance your unibody/fender.

Trying to limit suspension travel with spring rate to mask either issue means you will still rub tire when you hit a bump under load and this could have catastrophic results (wheel lock or tire damage).

The 650mm tall slicks you want to run next are "too tall" for the FD up front and will rub a couple places even with the perfect offset wheels.

Common issue with FD and real slicks. Tires taller than ~640mm (25.2") will rub the headlight bucket area and rear of fender arch depending on how much caster you run.

Some people raise the car to limit suspension stroke and or limit steering angle and some move/remove unibody and fender or run feed style fender with rear relief.

I ran some shorter 305/640-18 Continentals rain tires on 18x11 +45 wheel without issue. This example highlighting the issue is tire height not width on the FD.

 

Thanks Gents,
I should have mentioned that last season we were running non ideal offsets being: 18x10.5 ET rear and 18x9.5 ET35 front. Class change means we need to run Kuhmo for their series and the closest 18" slick is the Ecsta S700 280/650R18 where we are looking at running these front and rear on a square set on 18x10.5 ET45 custom rims.
This car has had the headlight buckets modified at the bottom when raced in japan, so compared to other FD's ive seen has considerable more clearance than stock. It came with the FEED fromt and rear guards wih the rears moderately tubbed.

 

Mazda Motorsports has an adjustable speedway-style front torsion bar, pretty sure that Pro Parts is the supplier, but being a motorsport part you can purchase it without race results



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It all shows as being in stock.


I’ll leave it up to the FD3 pros to recommend which thickness torsion bar and accompanying rear bar to match

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Thanks for that, is there a web address I can look these parts up on?

 

^^Based on enquiries in the distant past, you'd have to have someone US based to purchase them.

This is the car that ran the square Kumho set-up you're seeking, probably about the last time it ran too. No idea on offsets and no tricky bars.

 

my apology, missed that you were in NZ
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