Mazda Rotary Club

General => General Technical => Wheels & Tyres, Suspension & Brakes => Topic started by: elford_tim on December 15, 2007, 03:32:28 PM

Title: Help - 17x8.5JJ, ET40 should fit the front of an FD, right?
Post by: elford_tim on December 15, 2007, 03:32:28 PM
Oh buggeration, I\'ve just tried to fit my new-to-me TE37s. The front ones are as above, and unfortunately on full lock rub the front wheelarch liner. And that\'s with the very well worn Japanese tyres on them (235/45 - I\'m sure they\'d fit without tyres but that\'s not that useful) Actually I haven\'t checked the back liner but they look like they\'ve got enough clearance there. I\'ll check that in a minute.

My impression from reading the stick offset thread was that ET40 in these dimensions should be a straight fit.

Any ideas? Are there any alternative wheelarch liners around or somesuch?

This is getting on my nerves as this is the second set of wheels that almost fit to this car.
Title: Help - 17x8.5JJ, ET40 should fit the front of an FD, right?
Post by: rx7veilside on December 15, 2007, 04:01:56 PM
i thing u will need a 225 tyre
Title: Help - 17x8.5JJ, ET40 should fit the front of an FD, right?
Post by: elford_tim on December 15, 2007, 04:28:23 PM
I just played with the recommended Tyresave calculator and supposedly the difference between the two wheels with their respective tyres (225/50/16 and 235/45/17) is about 12mm diameter-wise. Which is certainly noticeable, but I\'m surprised that the wheelarch liner would have that little clearance - after all, that\'s 6mm difference in radius, which is roughly the depth of the thread.

That said, 225/45/17 is within 3mm of the diameter, but it\'s a tad expensive to find out if they do fit better or not.
Title: Help - 17x8.5JJ, ET40 should fit the front of an FD, right?
Post by: rx7veilside on December 15, 2007, 05:18:13 PM
is it 225/40/17 at front and 255/35/17 for rears
Title: Help - 17x8.5JJ, ET40 should fit the front of an FD, right?
Post by: batman on December 15, 2007, 06:58:50 PM
wheel arch liners what are they ????? he he
Title: Help - 17x8.5JJ, ET40 should fit the front of an FD, right?
Post by: elford_tim on December 15, 2007, 07:03:20 PM
Strange contraptions used by odd people like me who insist on driving their cars even if it\'s wet outside.
Title: Help - 17x8.5JJ, ET40 should fit the front of an FD, right?
Post by: batman on December 15, 2007, 07:05:22 PM
i drive in all conditions just avoid the big puddles and never suffered from water problems mate not like a piston problem seem fine without them
Title: Help - 17x8.5JJ, ET40 should fit the front of an FD, right?
Post by: elford_tim on December 15, 2007, 07:07:11 PM
Quote from: rx7veilsideis it 225/40/17 at front and 255/35/17 for rears

Weeellllll. I assume you\'re suggesting that I should have 225/40/17 on the front then?

Those FDs that came with 17" from the factory have 235/45s on them according to the tyre thread. Which incidentally is what I\'ve got on those wheels at the moment. But then again mine\'s a 92 so originally came with 16" wheels, which is indeed what it\'s wearing now.

The odd thing is that these wheels have been on a \'93 FD (which still had its wheelarch liners) without any rubbing.

Is there anything about the \'92 front suspension that is different?
Title: Help - 17x8.5JJ, ET40 should fit the front of an FD, right?
Post by: batman on December 15, 2007, 08:20:29 PM
no no dear friend i have 245 40 17s extra width no rub >:)
and my coil overs are set low
Title: Help - 17x8.5JJ, ET40 should fit the front of an FD, right?
Post by: rx7veilside on December 15, 2007, 08:22:29 PM
but the offset on the factory cars was probably higher the offset can make a lot of difference..the suspension wld be the same assuming standard suspension
i have the ultralite alloys 8.5x18 at front with 225 tyres and get no rubbing at all but it is tight
if they were on a fd prev and didnt rub then its illogical that they rub on yours
either they rubbed on the other car or ur liners our out of position
Title: Help - 17x8.5JJ, ET40 should fit the front of an FD, right?
Post by: elford_tim on December 15, 2007, 08:57:55 PM
The \'original\' offset is ET50, on both the 16" and 17" rims. Just out of interest, what\'s the offset on your 18s?

I\'m beginning to suspect that I need to check the way that the front wheelarch liners are mounted - they seem to be a lot closer to the wheel than the rear ones are, for starters. Maybe they\'re mounted slightly out of position or something.

At the end of the day if they came of an FD of similar age, they should fit so I better find out what is different. If I can, that is... I guess I could always fit 225/45s or 225/40s at the front to get a bit more clearance, but it shouldn\'t be that critical in the first place.
Title: Help - 17x8.5JJ, ET40 should fit the front of an FD, right?
Post by: Ricco_04 on December 16, 2007, 12:59:32 AM
Well the standard size on a 92 FD is 225 on a 8" width rim and +50 offset (offset taken from your post above).  Compared to your 8.5 & +40 offset this gives you 4mm more clearance on the inside but the wheel extends 16 mm more to the outside.  So although it\'s not much maybe that\'s whats causing it?

If it is and a 225 sits on safely (I have no idea) then this should help your clearance (as above by mr veilside)
Title: Help - 17x8.5JJ, ET40 should fit the front of an FD, right?
Post by: elford_tim on January 20, 2008, 11:11:43 AM
Finally got my act together today and removed the wheelarch liner. While pulling that out I noticed that something already wore a hole into the liner! I don\'t know if that something were my standard 16" wheels or not but I don\'t think that\'s good news.

With the liner off, the wheel fits and at full lock I can get my hand between the windscreen washer tank and the tyre so I\'d think I\'ve got just about enough clearance.

My wheelarch liner did look a bit bodged on and is also missing some fasteners; I knew the car had a front bumper replaced at one point and that doesn\'t seem to have been fitted with the usual Japanese, erm, precision. Guess it\'s time to see if wiggling some brackets will give me a bit more clearance.

Hrmpf.

Anybody got some spare wheelarch liner fasteners?
Title: Help - 17x8.5JJ, ET40 should fit the front of an FD, right?
Post by: 20B_boy on January 20, 2008, 12:34:56 PM
Quote from: elford_timMy impression from reading the stick offset thread was that ET40 in these dimensions should be a straight fit.
I wouldnt have expected them to fit properly due to the reasons give above i.e. running a 235 on a half inch wider rim with -10 difference compared to the stock offset.

If you buy less than a 50 offset you have to expect problems. If you drive like a pansy (assuming no rubbing on lock issues) then a lower offset might work. If you drive on track or generally more aggressively then low offset = ballache.
Title: Help - 17x8.5JJ, ET40 should fit the front of an FD, right?
Post by: elford_tim on January 20, 2008, 12:59:21 PM
Did you see the post above that said those wheels have been on another FD with wheelarch liners and there were no problems with them rubbing said liners? Oh, and the bit where I posted today that the wheelarch liners on my car have been damaged despite me running the original wheels?
Title: Help - 17x8.5JJ, ET40 should fit the front of an FD, right?
Post by: 20B_boy on January 20, 2008, 03:12:00 PM
Quote from: elford_timDid you see the post above that said those wheels have been on another FD with wheelarch liners and there were no problems with them rubbing said liners? Oh, and the bit where I posted today that the wheelarch liners on my car have been damaged despite me running the original wheels?
Yup, doesnt change my view tho. Did u personally inspect the previous owners arch liners? is your car running the same tyres as him? how different are your/his ride heights? the only way stock rims/rubber are going to fk up stock liners is with the wrong tyres and/or changes to ride height, unless some thing was jammed in the arch at some point...
Title: Help - 17x8.5JJ, ET40 should fit the front of an FD, right?
Post by: elford_tim on January 20, 2008, 03:48:40 PM
Yes, they\'ve got the same tyres on as they had when they were on the other FD. If anything, the other FD is slightly lower as mine is stock ride height.

And as I haven\'t run my car with those wheels on it as I tend to check the clearance first before buying new tyres, the hole in my wheelarch liner was either there when I got the car or has been caused by my stock wheels with stock size tyres on. And that hole looks \'worn in\' and not \'jammed in\' if you know what I mean.
Title: Help - 17x8.5JJ, ET40 should fit the front of an FD, right?
Post by: Papercup on January 27, 2008, 06:53:47 PM
http://www.driftworks.com/resources/wheel-offset-calculator,17.html (http://www.driftworks.com/resources/wheel-offset-calculator,17.html)
 
i have found this very useful. Its the first one i\'ve seen that puts it in plain english for my feeble brain; \'The outside edge of the wheel will be 3mm further out.\'
 
For what its worth, i run:
 
235/45/17 on 8J ET40 at the front and
255/40/17 on 9J ET40 the rear.
 
Mine are VERY close to the wheelarch at the rear but do not rub, and the car is lowered a fair bit. It is set up for fast track work so if it was going to rub it would do so. At the front again i have no rubbing even on full lock but my arch liner is a little \'holey\'; not sure if its happening very lightly when in a hurry as i haven\'t noticed it, or it predates this wheel setup (i didnt set this car up originally). Its probably worn in the same place yours is.
 
My fronts are the same as your fronts,...apart from being 8J not 8.5J. Your problem is the extra half inch, not the offset; proven by me having no problems with my above set-up.
 
Andy