Would 205/45-16R on 7.5" rims fit on a stock 1st Gen GSL-SE? Are there any drawbacks to this size, given stock springs? I got a chance on a used set at a good deal... Thanks!!

 

it'll be fine.

I have the same size tire but on a 16x7 rim and theres tons of room left.

I wish I had gone wider!

 

I have that exact wheel and tire size, and it fits fine. At first I was concerned about the 7.5 inch width, but the fit is perfect. Search my other posts or website for pics...

 

just be careful to not get too high of an offset or you'll rub up front...


miles of space in the rear though... but a 205/45-16 is a pretty narrow tire for a 7.5" rim. I run that size on 16x7 with no issues.

 

the width of the rubber is smaller then a 7.5" rim so the rubber will be stretched to fit the rim, it's very minor but it's noticable

eg. \_/ instead of |_|

 

I'm going to ask some stupid questions, since I know very little about offset. When I've purchased wheels in the past, it never came up in conversation. All I know that it's a measure (38mm, 40mm, 42mm), and I think stock is 38mm or so.

Is offset something inherent in the wheel, or can it be adjusted up or down?

What offset should I use with this wheel/tire/ RX-7 combo?

Will the too much/ too little offset cause rubbing? Or result the wheel/tire to stick out too far?

What can I say? Wheel newbie!

 

Yea, the wrong offset could look wierd, and in the worst case, rub.

 

Offset is critical

Too much positive and you will be rubbing on the inner side - zero or negitive offset will give you the skate board look and tire / fendor lip rub.

 

ok, offset is the measure of how far the "pad" of the wheel (inside part that seats against the brake rotor) is fron the centerline of the wheel...

So if you have a 7" wide wheel, the centerline is 3.5" in, right?

Well a 40mm offset would 3.5" + 40mm. =128.9mm.
(128.9mm is the "backspace" = 5.07")

that's what I run and that's damn near as close to the shock body as you can get (but I run coil overs) so anything with a numerically HIGHER offset woudl rub on the inside.

With a 7.5" wheel you'd be starting with 3.75" + XXmm offset. = _____ backspace


Offset is inherent to teh wheel itself. you may be able to shave the pad or use a spacer to coreect it, butthese are bandaid fixed and not the proper way to run.


tirerack has an excellent writeup on this as well.

 

Thanks for the help folks..really appreciated. The Tire Rack (pictures and text) were great as well.

Anyhow, let's say I want to order a set of Kosei K1 wheels. The 4x110 pattern is common among many models of cars; each could require different amounts of offset, right?

So, would then Kosei make several versions of the K1, each with different amounts of offset so that dealers can order it to fit the specific offset needs of a car? Or do I have to ask the dealer the amount of offset in each model of wheel, and determine if that's the right amount for the RX-7?

And if I'm using a 7.5" wheel, how much offset do I need to have for this 1st gen installation?

Thanks again!!!

 

No, the 4 x 110 is extreamly uncommon, found only on early RX-7's and few other cars.

But, Yes differant car/tire size combinations would have differant offset requirements to make the wheel fit just right.

 

Oh crap... I have a GSL-SE. Went totally brain dead on this one. I need the 4x114.3 pattern, right?

 

yep.


FYI, most wheels run a pretty narrow offset range... Generaly 32-45mm so the differences between the cars isn't as much as you think.

Although I do think that the 12a 1st gens run a lower offset than that (~25m?) but I've really only paid attention to the GSL-SE (which happens to have the same fitment as 4 lug accords, preludes, etc etc etc)

 

thats the way you want it ... the stock tyres are the other way round /_\

P.S I run a -40mm ET on my car and the tyre only just clears the strut (< 3-4mm!) thats with 7" wide rims so with wider wheels you might want to change the offset slightly.
Don't forget the rim width is actually this distance across the sealing faces and not the maximum width.
The compomotives on my car are 8 1/2" wide at the widest point and the sidewall is a little wider again.

Mike

 

Well, turns out the wheels were 4x100 anyhow... from a Miata. The info still helps...thx!