Slix has the nail on the head....it's about how quickly the tyre can regain grip after hitting a bump. Heavy wheels affect the damper rebound. But you can tune that if you have adjustable suspension.
If you can find a bigger wheel that's no heavier (or preferably lighter) than stock, you'll be fine.
Continental seem to make the lightest tyres out of the big players in my experience. I went through all this in my Corrado days. The combo of a 7x17 ProRace 1 + 205/40/17 ContiSport 3 was 2Kg lighter than the OEM 15" Speedlines with a cheapy 15" ditch finder
It is very possible to go large without the calories mate, but it's just the faff of researching weights and fitments, it can take a while! Worth it though
Have you driven an R32? If you haven't, it would give an idea of how a Golf with extra porkiness will feel.
I don't mind doing the research, that's half the fun of modding for me - having confidence in an upgrade/mod by actually understanding the science of it, rather than looking for a brand name or copying others and blindly throwing money at things!
Completely agree with you and Slix regarding wheel and tyre weight. Adding unsprung weight would be going in the wrong direction. I suppose if I was really serious about this (at competition level or something) I'd also consider 17x9 rather than 18x9, to keep the weight closer to the hub, as well as making sure the wheels were of a mega light construction.
This gets closer and closer to proper race technology the more you define an ideal - and goes up in cost massively - but I like to think some ideas from those kind of cars can be passed down to our hatchbacks.
So, FWD race cars. What do they have to aid rotation and straight line grip? A diff, naturally, but I'm sure I've read about 'reverse stagger' - wider at the front than the back. It all makes interesting reading, anyway..!
I haven't driven an R32, Kev. But everything I've heard makes them sound a bit 'lardy' :)
Yeah all of that! Aggressive geometry, fat (light) wheels, light weight slicks, wide track (longer control arms, not spacers), camber plates, rock hard suspension, plated diffs (not torsens), ditching the interior, sequential boxes...all the good stuff
The one thing race cars don't care about is refinement and lifespan, so that is always something to consider with a road car.
Do you remember Fiesta XR2s? They had staggered axles, much wider front track
It worked really well as those things handled very nicely indeed.
Perhaps go wide track with TTRS control arms?
If you spent a week with an R32 and then got back into your car again, you'd be amazed at the difference. The GTI is way more nimble.
Azev A, epic wheel. StilAuto Sigma as well