Can anyone explain how much of the wheel must be covered by the wheel arches. My 8” wide wheels will just creep outside of the wheel arch so I'm going to fit some wheel arch extensions but want to make sure I'm doing the right thing.



The full build story is here
http://www.GaugingSystems.co.uk/Saabatage

i believe it's just the tread that needs to be inside the arch, so for example, if you had stretched tyres, the rim and sidewall of the tyre could be outside the arch, but as long as the tread is inside it's ok. That's for mot etc, but not sure for IVA...

For IVA it needs to cover the full width of the tyre when viewed vertically, but only for 30 degrees forward and 50 degrees rearwards from the centre of the wheel. Also the rear of the wheel guard must not terminate above a horizontal plane of 150mm above the wheel centre. Between the 50 degrees rear and the termination of the arch there is no need to cover the full width of the tyre.

Could you borrow a thinner set of wheels and tyres for the test? I think you need to be certain it's OK for the MOT, as it would be a real pain to borrow wheels every year.

kudos on using the saab motor ,im fitting one in my reliant kitten middie at the moment and have gone down the normal tuning route with my 9000 to get to 320hp but now run a holset hx35 on a 204 with volvo valve springs that made 520 hp on its last dyno run

Thiner wheels for IVA, bigger steering wheel, all the old tricks for an easier time.
Or take some spats that you can fit on the day if the testers says he's not happy.

Just take off any wheel spacers or put thinner ones on, as spacers are part of the chassis suspension kit (just for MOT IVA). Thats what I did with mine and it sailed through.
David

quote:

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Originally posted by froggy
normal tuning route with my 9000 to get to 320hp but now run a holset hx35 on a 204 with volvo valve springs that made 520 hp on its last dyno run

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Why not swap your wheels and tyres for units with greatrer inset? You might lose a bit of money in the process, but it will look a lot better than adding spats.

Having wheels sticking out is also I believe a pullable offence if a keen eyed anti-kit car policeman should spot it.

Think I might run out of steering with bigger wheel inset.

Totally agree about the Po Lice not liking exposed wheels. I know someone who got nicked for having fat tyres on a Jap Pickup. Must admit they were extremely fat!!!

The Wheel arch extensions are actually going to help tidy the back end of the car. There is a very big arch to wheel gap back there and these new arches will mask another 35mm so it's not all bad.

Is there actually a fault with the design then, that if you get wheels that won't poke out of the bodyywork, they interfere with the steering?

Yep. You are right. The car was designed for a narrower front wheel that is no longer available from anywhere affordable. So the wider wheel / offset is an issue. The down size compromise is a bad idea for handling so up size was the only way to go. Hence wheel arch extension.

Well the rear end looks good with the wheel arch extensions.

The primed arch looks clean and tidy.



The bonus at the rear end is the new arches lower (by 48mm) the original body arch. So the big gap between the arch and the wheel will look a hole lot neater than this



Esspecially when the suspension is lowerd to the correct level.

This finished article looks as if it should have been there all along



Now to attack the front end to keep Mr. IVA happy..........