I own a fd s6 rx7 and am looking and buying some rota grids for it that are for sale. they are 18x8.5 with a offset of e44? i am unsure about offsets, can anyone tell me if these will fit. cheers
tamarillo,
May 24, 3:14am
Are you asking about actual wheel bolts/studs? For that you need stud pattern info. For instance 5x112, or some such. Offset is about how far out the centre line of the wheel is from the hub. I don't know about your car but you should find info on Google.
attitudedesignz,
May 24, 3:35am
Series 6 have offset of 50, so 44 should be ok
MAZDA RX7 SERIES 1 & 2 79-83 4 X 110 E 13 MAZDA RX7 SERIES 3 84-85 4 X 114.3 E 40 MAZDA RX7 SERIES 4 86-88 5 X 114.3 E 36 MAZDA RX7 SERIES 5 89-91 5 X 114.3 E 42 MAZDA RX7 SERIES 6 92-95 5 X 114.3 E 50 MAZDA RX7 SERIES 7 RB 96-98 5 X 114.3 E 50 MAZDA RX7 SERIES 8 RS (FRONT) 98 > 5 X 114.3 E 50 MAZDA RX7 SERIES 8 RS (REAR) 98 > 5 X 114.3 E 50
done-deal17,
May 24, 8:52pm
^ thanks thats what i needed to know, cheers
lookoutas,
May 24, 9:04pm
This is a silly formula. Off-set is the distance from the center of the wheel to the hub. So comparing a standard skinny wheel with a wider wheel of the same Off-set, will end with a wheel that hangs inside further. For a start, wheels are normally measured in inches, and Off-set is measured in mm, so a conversion is needed. Whereas, all most people really want to know is if the inside of the new wheel will have clearance. This link will let you work it out, if you know the width of your current wheels. https://www.1010tires.com/Tools/Wheel-Offset-Calculator#
And then you need to know what clearance you had before.
lookoutas,
May 24, 9:20pm
If you've got a 7.5" rim now - that sez you're gunna have 7mm less clearance from the rim. It's hard to work out whether that means a 7mm gap, or 7mm less to play with. If you have an 8" rim - it will be the same. (whatever that is) Just remember the tyre overhang.
bill-robinson,
May 25, 12:35am
another person who does not understand bearings and loading of them
mrfxit,
May 25, 12:50am
We do understand but 99% of these questions involve only about a 20% max wider rim at the most on a DOMESTIC vehicle. Race cars, yep huge differences in bearing loading because of the speeds used. Most domestic vehicles won't have room for a super wide rim without modding suspension & guards to suit & then thats getting in to certs area.
The real FIRST measurement that needs to be taken in to consideration is rim Back Space, Ie: will the dang thing foul the suspension or not. NEXT, is the width ok for outside clearance (Ie: full suspension travel) & then, is the tyre choice where height is as important as width.
If backspace + width + tyre choice won't clear the full travel of the suspension & guards, then it's time to rethink the sizes.
Offset is fine when dealing with FACTORY supplied rims because the factory has already taken in to account the max width & also the best suitable tyre sizes FOR THAT VEHICLE.
mrfxit,
May 25, 12:58am
A good measurement indicator is directly from the OEM rims & tyres fitted to the original vehicle.
The OEM rims & tyres will tell you instantly how much backspace is available or not.
Case in point. 1996 Nissan Atessa AWD. Factory rims & tyre sizes fitted, (Front) you can't slide your hand between the bottom coil plate & the tyre. This means that I can go a little wider on the rim but not taller on the tyre. Back space MUST stay the same. If I chose a same size but wider rim with the same offset, then it would foul the suspension.
Overall height & back space must stay the same on that vehicle example
bill-robinson,
May 25, 12:59am
okay you do it your way. I will do it properly. end of debate
mrfxit,
May 25, 1:01am
Factory OEM specs Good to know if you have access to the OEM rims listed & already know their widths.
mrfxit,
May 25, 1:08am
So you compare offset, then add width, then check if the rim will fit. then check tyre height
I check backspace 1st, (instant yes/no), then width to see if it's going to clear the guard (instant yes/no), then chosen tyre width & height if the back space is a bit tight. If theres plenty of back space & the guard clearance is good, then most tyre specs to suit the vehicle will be ok.
mrfxit,
May 25, 1:22am
Nice calculator
rim 7" -- Offset 40 verses rim 9" -- offset 40 = 25mm More inside & outside To retain the same offset, I would have to find a 9" rim with 15mm offset.
Find me a few 9" rims, measure the back space with a flat edge & tape & I will already know if it's going to fit the suspension. No need to find the factory spec's or workout the rim center to hub face measurement on each rim + rim width to see if it might fit
Backspace clearances tend to be pretty tight on modern vehicles.
lookoutas,
May 25, 3:25am
Pull ya head in bill - OP asks a question, and the answers were supplied. Being La De Da Gunner Graham doesn't help the matter. Jeez - us Kiwi's have been fitting bigger wheels to cars since Jolly started widening them, and that hasn't depleted us of wheel bearings.
As mrfx has eluded - My angle of attack would be a straight-edge across the inside of the rim and measure into the hub. This will give you the best idea of clearance instead of relying on a formula.
toyboy3,
May 25, 3:51am
lookoutas wrote: Pull ya head in bill - OP asks a question, and the answers were supplied. Being La De Da Gunner Graham doesn't help the matter. Jeez - us Kiwi's have been fitting bigger wheels to cars since Jolly started widening them, and that hasn't depleted us of wheel bearings.
My guess is the car makers know nothing about wheel bearing loadings and wheel offset to minimise loadings on ball joints followed by tyres wearing on the edges Car makers spent a million bucks working it out , and good ole kiwis can work it all out on a beer mat
vivac,
May 25, 4:55am
The fact is that there are a few hundred vehicles I know of personally )and thousands around the country, millions around the world) with wider wheels with lower offsets (some of which are quite extreme and are starting to border ridiculous) and bugger all are spitting out wheel bearings left right and centre.
vivac,
May 25, 4:57am
Oh and FYI OP, +44 will look like shit on your FD.
Not like that at all. You need to understand how a vehicle is designed in the 1st place. They design & build to get the best they can for the final product template. This template is then dummied down to a minimum that they can afford to build on a mass scale for the base model. Upgrade options are then sold at a higher price & often it's just a case of (Eg:a different computer chip to get a sizable performance increase) We now call them "World cars" that are the base model with upgrades & extra options including different branding to suit different markets.
Everything is built within a safety margin so that nothing is pushed beyond it's safe limits easily. Public liability insurance issues play a big part of that thinking. Why do you think most speedo's read anything from 2 to 5kph fast. It's for the manufacture to avoid getting class action suits for ppl getting speeding tickets for speedo's that read low (eg: reading 100kph but ground speed is 97kph).
A lot of the issues with vehicle faults are the compromises in quality & design at manufacturing that fail over the years after a bit of abuse.
Time & usage has no equal when it comes to longevity & suitability for service.
esky-tastic,
Sep 17, 6:19pm
Yep, 10" wide rims where 5" ones used to be on my car. 30+ years later, 1000's of kms and the wheel-bearings still don't notice the difference.
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