I would really like some advice on using spacers (or fitting lower ET wheels in the future). Currently running the stock Tibor 8.25x18 ET68 wheels with 235/40/18 tyres. I fitted coilovers recently, with ride height drop of 30mm front and 25mm rear. Camber set at -2 and toe out at 10’. Shocks set from soft front 8/30 , rear 9/30. All feels good on the road and good grip and balance in corners. Then I tried spacers this weekend. I installed 15mm front spacers and 10mm rear. It felt nice and planted on the straights, smooth ride, but perhaps a bit less feel from the steering? But in fast, sharper corners, where I thought it would be amazing, the front wheels lost a bit of grip and pushed wide on corner entry – understeer on the way in. Everything I’ve read suggests that a wider front track should increase cornering grip. So I then changed the 15mm front spacers for 5mm, keeping the rear 10mm, and it feels good again in normal driving, but the surprise was that the car went around the same sharper corners like it was on rails – perfect. Anyone know why this should be? The rear track is effectively a bit wider than the front – everything I read suggests that this should make it understeer, but my experience is reversed? I checked the tracking and it only shifted 4’ more total toe out with 15mm front spacers. It’s put me off saving up for those nice looking ET48 alloys tbh… any experience anyone can share on spacers/wheel ET affecting cornering and feel like this?
Hi Billy! As you said, the front ride must be wider than rear. That´s the theory and, at least in my experience, in the practice too. In your test, maybe has taking part another factor that you don´t have in mind, I don´t know. A good friend of mine and pretty experimented use to say when we are testing a set up, we must to asume a 5% of the test can be pure casuality or lucky. I agree with that!
I might test it again! Perhaps tyres warmed up? Are you running a different wheel offset, and if so how does it feel? I also tested a 10mm slip-on spacer, which felt good on the road and cornering, but i didn’t do it for long because the wheel is basically only mounted with the wheel bolts - the hub extension that fits inside the wheel centre is 17mm length, so the spacer takes 10mm and there is a 7mm deep chamfer in the alloy wheel mounting face, so there is basically zero interference between hub and wheel centre!! That’s dangerous, but I ran it long enough to sense that ET55 feels alright too (my error - stock Tibor alloy is ET65...). It shows that on the front you can safely mount any slip-on spacer up to ~7mm, then there’s a jump to 15mm+ hub-centric spacer, with longer bolts to match.
No man, I run with stock set up. I would like to change my wheels(I like the Speedline 2120 or Braid ones), but I´m afraid to loose our wonderfull handling. About interference between hub and wheel centre, absolutely agree.
What you forgot to take into account is by fitting the wheel centre further away from the steering rotation axis you are changing the whole setup and how it behave, because the point where the steering axis and the wheel centre meet are too low maybe below the road
What is Scrub Radius? A Guide to Positive, Negative & Zero Scrub Radius | Low Offset (low-offset.com)
I read somewhere that the scrub for a Mk2 is set at -14mm. Not sure what a Mk3 is, but it must be similar. That would explain why 5mm and 10mm spacers feel ok, but 15mm not good. How do people run ET48 wheels with no problems because this would push the scrub positive? Or perhaps they just put up with it...
once start messing with ET of vehicle either with spacers or wheel offset you're going to compromise the factory handling and essentially its no longer a typical Reno Megane lot folks go upto 20mm away from factory setting ie ET65 to ET45 as looks good but mess up straight line braking and cornering and just live with it, more than 20mm and its way out the ball park, you can try regain the handling with toe and camber, adding neg camber is big cornering plus for these cars but also adds to ET offset effect changing the ET cant affect the toe but adding or reducing camber certainly will
