WHY do bigger alloys mean worse handling?

[Lauren]

OK i get it, thanks for the link. Seems like the 2 is doomed to sit on smaller wheels if you want performance (Which i do )

Yep afraid so. Thats what happens when you base the suspension for a sports car on a cheap mass produced hatch it seems.

Is such a shame really as with double wishbone suspension it would have been so much better.

[Frustrated Pilot]

understood philz..

just usually in my experience .. i take my alloys off and put them on the other persons car as an experiment... and a lot of the time people agree that their handling is improved.

but your right.... there are other factors...

[EarL]

OK i get it, thanks for the link. Seems like the 2 is doomed to sit on smaller wheels if you want performance (Which i do )

Yep afraid so. Thats what happens when you base the suspension for a sports car on a cheap mass produced hatch it seems.

Is such a shame really as with double wishbone suspension it would have been so much better.

...I'm sure Mr Woods can sort that out though.

[Lauren]

OK i get it, thanks for the link. Seems like the 2 is doomed to sit on smaller wheels if you want performance (Which i do )

Yep afraid so. Thats what happens when you base the suspension for a sports car on a cheap mass produced hatch it seems.

Is such a shame really as with double wishbone suspension it would have been so much better.

...I'm sure Mr Woods can sort that out though.

In summary: Space frame.

[jimGTS]

might be opening a can of worms but whats everyone think of
17s front 7j (to help with the handling) 215/40
18s rear (wider). 7.5j, 225/35



(my hopeful new setup)
bare in mind im not a track king and need new pants when i push to hard from bends.
(would be different on a skidpan tho)

[Lauren]

might be opening a can of worms but whats everyone think of
17s front 7j (to help with the handling) 215/40
18s rear (wider). 7.5j, 225/35



(my hopeful new setup)
bare in mind im not a track king and need new pants when i push to hard from bends.
(would be different on a skidpan tho)

Tbh i don't think its going to help the handling at all as you will still have 18s on the rear with the very low profile tyres.

If you want these sizes for looks, thats cool, but remember you are compromising the handling so just cruise in it.

[jimGTS]

might be opening a can of worms but whats everyone think of
17s front 7j (to help with the handling) 215/40
18s rear (wider). 7.5j, 225/35



(my hopeful new setup)
bare in mind im not a track king and need new pants when i push to hard from bends.
(would be different on a skidpan tho)

Tbh i don't think its going to help the handling at all as you will still have 18s on the rear with the very low profile tyres.

If you want these sizes for looks, thats cool, but remember you are compromising the handling so just cruise in it.

thats far do's, i appreciate that.

but have i chosen the right tyre sizes in your opinion for these size/width wheels???
im pretty close in keeping to the orginal RR i believe.
oh, theyd be toyo proxies T1-S all round.
still want to have safe handling at least with these wheels.

[Lauren]

205s would be a better bet wouldn't they? With 215s and 225s on the rear you may find it a bit oversteery and with such a low profile you won't get a lot of warning before the back goes. Mind you as long as you don't come over all Stirling Moss you ought to be okay.

[Speedy]

IIRC the toystar was having a complete replacement front subframe with double wishbones....

Double wishbones aren't the solution to all problems though - Lauren hit the nail on the head when she said that the rx8 had been setup for running on low profile tyres - Mazda would have compromised roll control for the camber control. Plus it runs on wiiide tyres.

Besides Struts aren't the worst setup you could have..

[Lauren]

IIRC the toystar was having a complete replacement front subframe with double wishbones....

Double wishbones aren't the solution to all problems though - Lauren hit the nail on the head when she said that the rx8 had been setup for running on low profile tyres - Mazda would have compromised roll control for the camber control. Plus it runs on wiiide tyres.

Besides Struts aren't the worst setup you could have..

good points Alex... there is the famed sliding pillar suspension, the MGB swing arm dampers, transverse leaf springs ala triumph herald etc.. it could be a lot worse for sure.

[jonb-]

I'm probably going to ruffle a few feathers but that's life.

I realise we're all talking about on the limit handling is worse on bigger alloys, which is fine on track, but should we /really/ be driving that close to the limit on the road with the nature of our cars.

I've had plenty of FF's, which lets be honest you can do anything to and the worst you'll get is understeer, FR's aren't even too bad on the limit but an MR car can swap ends so quickly and with such disastrous consequences, i'm of the opinion only a idiot would take it to the 10th 10th (which lets face it, it's what we're talking about here).

Again, just my opinion but if you want to thrash a car to an inch of it's life on the open roads, buy a FF. Someone said "why waste a MR sportscar", well every MR sports car SHOULD be wasted on public roads and only enjoyed to the full potential on the track where you're only risking your own life.

I'm very happy with my 18"s over my 16" for day to day driving, it's not noticable. If i want to track it, i'll put the 16"s back on (and i don't much think i'm going to track a 12 year old car).

[anna]

I realise we're all talking about on the limit handling is worse on bigger alloys, which is fine on track, but should we /really/ be driving that close to the limit on the road with the nature of our cars.

Yes, limit handling is extremely rare, but regardless of car layout, it is sooooooooooooo (how much can I stress this) important to get it right. 99.99% of driving is going to be well out of these bands, but i'm sure you'll agree, it's the 0.01% that matters because that's when really big accidents happen. If the car doesn't work well in a predictable and hopefully controllable manner, then, well, hopefully everybody will come out the other end ok.
Remember, it's not just your bad driving (to the limit) that can put you in these situations. What about when the road surface changes, and what was below limit suddenly becomes post limit? or someone pulling across you making you rely on good corner forces to get you out of a bad situation....
Compromise your limit handling, and i'm afraid even though you'll only need it that once, you'd rather wish you hadn't screwed it up.

FF cars can get oversteer by the way, you just need to know how. It is obviously prefereable to set up inherent understeer for safety purposes, and this is what manufacturers strive to achieve.

[raptor95GTS]

spot on anna, knowing you are pushing it means you are expecting it to bite back and so are looking for it

My own recent experiences, see driving experience, was I had backed off but the crap road still tried to spit me off. On the 15" tyres I knew it was going to xxxx before it actually did whereas I'm sure on 17" and 18" it would just have spat me off into the wall / hillside

[anna]

I suppose it's also worth pointing out that understeering vehicles can also have rather large accidents too, and I wouldn't condone 'thrashing a car within an inch of it's life' in any vehicle setup. Understeer is not a magical state where you can't end up in strife if you take your car to the limit on roads that are no place for it. You'll have more chance of saving it, granted.

It's just that with understeer, you might be able to see the ditch that you'll shortly be paying a visit......

[Simarshy]

Talking about MacPherson Strut's it's interesting to note that Porsche Boxsters use them so can't be all bad

Regarding Wheel size, I’ve seen a few Japanese tuned mr2's which use 16" alloys, with 205 front and 225 rear, and seemed a good compromise.

[jonno]

So, what mid engined car options do we have if we want double wishbone suspension all round?

PS. I also found this...
http://www.chris-longhurst.com/carbible ... bible.html

[Speedy]

Talking about MacPherson Strut's it's interesting to note that Porsche Boxsters use them so can't be all bad

Indeed - like I said, MacPhersons aren't all bad, it's just the designed in geometry and compliance. Fitting polybushes will help reduce the compliance in the system (so the moving parts of the suspension are better at doing what they are supposed to do), but there isn't a huge amount you can do about the geometry..

IIRC, Lauren said you can swap the eccentric washers on a mk1 struts to max out the camber - but thats getting OT as to why bigger wheels give you worse handling.

As for mid engined sports cars with double wishbones..
http://www.arielmotor.co.uk

[Lauren]

So, what mid engined car options do we have if we want double wishbone suspension all round?

PS. I also found this...
http://www.chris-longhurst.com/carbible ... bible.html

NoSeX, Elise/exige (or any mid-engined lotus), Noble etc.

[ryan]

So, what mid engined car options do we have if we want double wishbone suspension all round?

PS. I also found this...
http://www.chris-longhurst.com/carbible ... bible.html

NoSeX, Elise/exige (or any mid-engined lotus), Noble etc.

Very interesting thread this, but Lauren, NoSeX? I love the Honda, but why is it NoSeX? I'd be thinking "plenty of sex" if I had one?

[RichardPON]

Talking about MacPherson Strut's it's interesting to note that Porsche Boxsters use them so can't be all bad

Indeed - like I said, MacPhersons aren't all bad, it's just the designed in geometry and compliance. Fitting polybushes will help reduce the compliance in the system (so the moving parts of the suspension are better at doing what they are supposed to do), but there isn't a huge amount you can do about the geometry..

Agreed, and don't forget that it's also about compromise in all suspension situations on a road car.

For my racecar, although I still use a MacPherson setup on a trailing arm at the rear, I've had to go rose jointed on extended arms to counter the inherent problems caused by this design, and because moving pick up points is an issue.