Will 18x9 et20 fit stock arches?

[marco]

I know 'will these wheels fit' threads are 10 a penny, but the more I search, the more confused I get! In a nutshell, will 18x9 et20 fit under stock arches, or would they require fettling in terms of arch rolling, pulling, wider arches? And by fit is that with stretched tyres and a lot of camber, or would I be able to use a decent amount of rubber and performance orientated geometry?
Whilst we are at it, what is the consensus regarding tyre width and horsepower? How much tyre doesnt need to be able to do justice to say, 400, 500, 600 hp cars?
Marco

 

[Myocardial Infarction]

I've got 17x9 et30 all round on stock arches (no roll)

Running a 245/40 up front and that has caught the lip at some point (when it was very low) under compression and there are score marks on that set of tyres. I've raised the car 20mm since then and no further issues but it is a tight fit.

Rear was a 235/45 and no issue with those, think they could go to a wider tyre.

An 18x9 +20 I think would need a roll as a minimum and you would need to be careful to consider rolling diameter with tyre choices if you keep stock arches, but a roll and a flare and it should be ok and give you some options.

I want to keep stock arches and want to run wider rear rubber so looking at a better offset on a new set of rims.

 

[marco]

thanks for the info. looks like i will have to look for some other wheels then.

 

[jdmr_neil]

I have 17 x 9 and 17 x 9.5 et 20 and 15 and did get rub upon hard cornering. Rolled the rear and dropped a tyre width on the front and all good now.

Using various 235f and 255r

 

[marco]

just had a look at some of your photos, the wheels seem to fit quite nicely- maybe it is a goer after all!

 

[GAVBEY]

Hello

Here are mine.
Rota grid
Rear ET20 x 9.5 (225/40/18)
Front ET30 x 9.5 (225/40/18)

as for power 225 dosnt hold much power. im a track slag now and currently on 265/35/18 and im on the limit of them. front and back. I need wider. (500bhp)

then 265 tyres with 25mm wider feed arches. 20mm spacers on the rear zero on the front

 

[marco]

cheers for that- I tihnk this is getting more to what i need to work out- how much tyre do I need?!? only then i can work out what wheels i need, and then see if I can fit them into the stock arches. you are running 265 front and rear, and you think you need more? how much more?

 

[Cullen94]

I have 18x9.5 et22 all round, pretty perfect fitment on stock body FD.
225 40 18 fronts
255 35 18 rear

 

[GAVBEY]

I have 18x9.5 et22 all round, pretty perfect fitment on stock body FD.
225 40 18 fronts
255 35 18 rear

nice one bro. Im looking at 9.5" ET15 JR7 alloys. Gives me confidence tha tthey will fit with a slight roll of the arch

 

[MILLION]

Cullen94....have you got any more pics fella?

Sorry to hijack but i'm really interested in 18x9.5 fitment right now.

Something that can take some rubber like 223/235 front and 245/255 rear

 

[Cullen94]

Cullen94....have you got any more pics fella?

Sorry to hijack but i'm really interested in 18x9.5 fitment right now.

Something that can take some rubber like 223/235 front and 245/255 rear

Sure..

 

[marco]

what alignment are you running with those wheels? do they require a lot of camber to fit under the arches?

 

[MILLION]

I may be wrong but i think the top of the wheel doesn’t go in as much as everyone likes to think. Due to the nature of the double a arm, the bottom kicks out some.

 

[MILLION]

thank you callun!

 

[Ceylon]

You must have to go so slow when turning into places with any sort of steering angle. I'm paranoid about damaging my arches with how low I am and you're a fair bit lower!

 

[Cullen94]

what alignment are you running with those wheels? do they require a lot of camber to fit under the arches?

Can’t really remember but I think it was max 1.5 degrees.

You must have to go so slow when turning into places with any sort of steering angle. I'm paranoid about damaging my arches with how low I am and you're a fair bit lower!

Not too bad to be honest! The offset isn’t crazy aggressive so still get a fair bit of clearance

 

[Gunnytron]

I'm hijacking too

So this thread has now confused me. I was under the impression that with 18x9.5 you really needed an offset of +35 for decent fitment?

Or is that just for a square tyre setup? With suspension that isn't rock hard?

Car looks good Cullen.

 

[Cullen94]

I'm hijacking too

So this thread has now confused me. I was under the impression that with 18x9.5 you really needed an offset of +35 for decent fitment?

Or is that just for a square tyre setup? With suspension that isn't rock hard?

Car looks good Cullen.

Yes I would say +35 is the lowest offset you can run a square setup with a 255 tyre

 

[Gunnytron]

Ta for confirming. Pity really, there are a lot more options in lower offsets.

 

[MILLION]

So i have this Excel spread sheet (I copied it from rx7club.com) that calculates rim to arch & suspension clearances. You can vary the diameter, width, offset



It also calculates the overall rolling diameter of different width v profile combinations. Good to keep an eye on if you want the speedo reading true.



Just can’t figure how to attach it of even if admins would be happy for me to share it. But here a screen shot