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"Throughout the corner, the RX-7's basic trait remains very mild understeer, however, the driver's perception is that of stable neutral steering characteristics"

No, trust me the trained driver's perception is of the reality of understeer...

Finding out the geometry is important if you want to make changes using more than expensive guesswork.

I could buy a bunch of different offset wheels to try and find the change I'd like, or I could get down the right road to begin with by doing the math.

It's very easy to go wrong if you don't know what's actually going on. It's very wrong to assume that stock equals good. Stock usually means safe and cheap, rather than optimal.

OK, good luck on that!

Hey all,

Just accquired some ccw's off a friend's supra. I have not rebored them yet as i wanted to see if they would work for me first before dropping at the machine shop. Here are the specs

F-18x10 +44 with a 7.25" backspacing
R-17X11.5 +51 with a 8.25" backspacing

with a well rolled fender can this be achieved?

if you run the 17's in the rear you will probably need a spacer to space it out from the trailing arm. the front should fit easy. perhaps a 10-15mm spacer is what you might want.

Thanks for the reply, i'm glad i will be able to use them!

Got some Work Emotions D9R in 18x9.5 offset +38 wrapped in Hankooks 255-35-18 all around.
Stock fenders, untouched, no roll no pull! car is in HKS Hipermax IV GT Coilovers, I haven't adjust them, just installed them with HKS presets settings.
No rubbing issues at all, I thought I would need to atleast roll my fenders in the front with this setup but they are fine!
Work Emotions D9R Weight 24Lb.

https://cimg4.ibsrv.net/gimg/www.rx7...d76cb93790.jpg

https://cimg5.ibsrv.net/gimg/www.rx7...74c8ff5c1d.jpg

https://cimg0.ibsrv.net/gimg/www.rx7...a747f2ab25.jpg

BBs RG-R Clearance
 

Hello

I was looking to get some help / confirmation with clearance regarding the Brembo BBK in the front (1b1.7010a) and RZ BBK in the rear.

With these rims:
BBS RG-R 18 x 8.5 +40 front and 18 x 9.5 +40 rear.

Any input would be greatly appreciated.

I would think you would be ok, as you are running 18s. I have no experience with brembo but am running RZ rear brakes. Only stipulation for them is at least 17" rims. Offset and rim profile (dish) will affect things and it doesn't sound like you are going too extreme.

Updating my previous post, I said it didn't rub in the front but after some miles the suspension looks to have settle and now it definitely rubs in the front, not so much but it rubs in the biiiig bumps on the road.

anyone running 18x10 +20 or similar up front with wide fenders, without rubbing the front frame? it seems like no matter what it rubs there when turning

What size tire?

Where is it rubbing?

When does it rub? Full lock? At some point, its going to rub unless you limit the steering angle.

285/35/18, rubs just a little before full lock, however its not aligned yet so im not even sure what the caster is at, hoping i can at least get 6 degrees with minimal rubbing. i guess full lock isnt used much other than in U turns :scratch:

should it be ok?

Nope- tire is too tall for the front of an FD if it really is 285/35-18.

25" diameter is the max.

285/30-18 is the correct tire for that width.

Still, as your offset gets further from stock +50 you could start to have problems with wide tires hitting the fender or even the body seam at the rear of the fender well.

Full lock is used on the track occasionally... and in drifting.

i'm an idiot, its a 265/35/18 R888R. running that size square all around.

sorry!

That R888R 265/35-18 is a little too tall at 25.3"

I ran 265/35-18 Federals that were that tall on 18x10.5 +38 and they rubbed the plastic fender liner up front on the inside a bit and the factory mudflap on the rear of the front fender arch as well.
The further from factory +50 offset the less clearance you will have.

To properly implement a wide body front fender on the FD and the resultant lower offset wheels you have to run without the fender liner, cut up the headlight buckets and smash the body seam flat at the rear of the front fender arch.

On the other hand you can fit 295/30-18 on 18x11 +45 on stock rolled front fenders without such issues.as I did.
https://www.rx7club.com/attachments/...tire-close-jpg

thanks for the info, i'm not running the fender liner right now and the only point of contact seems to be the back of the headlight bucket where that rectangular peice of metal is. tire being too tall would make sense, i will see if i can work it out on the alignment rack, but i guess a slight rub at full lock wont be too bad as im not drifting the car.

Aren't you running Hoosier A7 in that size up front as well?

The info from Hoosier says they are 25.3 inches.

Jim and Carter Thompson (and others) are running 315/30/18 in the front, though I have not asked them what was needed other than fenders to make this work. That size is 25.6 inches.

I would like to run those in front if all it required was fenders and wheels.

I would like to also run them in the rear, which can be done with (more) fender rolling and a slight pull

No, I haven't manned up and gotten Hoosiers yet.

I ran some used 285/30-18 BFG R1S and some 295/30-18 R888 and those Hankook TDs..

For those taller tires you have to cut the headlight bucket some on the inside front and then pound the body seam flat on the inside rear of the front fender arch.

That doesn't sound too bad.

Or raise the car ride height. I run 275/35-18 Nittos and similar size Pirelli DH slicks and raised the car about an inch to compensate. Rubs the finder liners to death but no hard metal parts. Not where I'd want it visually, but it works.

Sorry to kinda necro, but this seems like the most relevant thread. I'm trying to decide on wheels for my FD. I know I want to run 245s up front and I will probably never bring the car over 350 whp.

I already figured I want to get Rota Grid wheels since my only real other option for something under 20lbs which fits an FD are RPF1s which I don't like the look of. These are available in 3 possibly manageable sizes:
17x9 e42
17x9.5 e30 (seems like the worst fit)
17x10 e50

-The simplest option is 17x9 e42 front and rear with 245/40 up front and 255/40 in the rear.
This is similar to the Spirit R setup in having a slightly larger sized tire compared to the wheel in the rear than the front. Which is probably to give the rear tires a bit more give before they break traction. Except in this case, I'd have both tires stretched in a little bit instead of the front on the larger side and the rear on the maximum recommended side.

-I could do the same, but with a 17x9.5 e30 in the rear... but it's going to poke out a bit. 32mm further than Spirit R stock wheels do, though a bit less for the tire itself than that.

-17x9 e42 245/40 front, and 17x10 e50 265/40 rear
I would worry this could interfere with the rear arms being inset 0.75" over stock, though I have koni yellow coilovers and I'd guess not.
Blue II is running 18x11 e48 with 285 tires so I'd guess I'd be fine and need nothing more than an inner fender lip roll at the worst?
This does have the benefit that I could up to 275/35 tires, but I'm not going to be going up to 400+ horsepower, I don't think.

That said, I guess I'm still leaning toward the 17x9 e42 all around with 245/40 front and 255/40 rear. It's less flexible since I'm stuck with like 265 as the widest rear tire possible to fit, and the rear wheels won't be fitting as flush to the arches, but eh.

Careful comparing directly against OEM wheels, USDM or JDM. The factory leaves tons on the table wrt room to move outboard :)

The 9.5 plus 30 will fit the rear nicely actually if you have any kind of fender roll. With OEM stock fenders it's about 1/4 (6ish mm) out further than is normally recommended, but in the rear you can get away with more---especially with a slightly stretched tire and some negative camber.

You can go 17x9 plus 42 front with a 245/50 and the 9.5 with a 255 and IMO you'll be ok.

Anything I can do to talk you out of mounting Rotas on an FD :rofl: :D?

I don't want to do any fender modification except maybe tucking the inner lip.
And though like 1-1.5 degree negative camber is fine up front, I think I like to keep the rear neutral.

I don't really get the hate toward them. They're lighter than all the other wheels in the price range and come in many mounting options.
The only other alternative I could find are RPF1s which I think look hideous on an FD.

Volks cost as much for 1 wheel as Rotas cost for 4... From what I can see, Rotas are pretty similar spec to the Spirit-R wheels but cheap. And I think the look nice on an FD.
I'd love a set of Volks, but they simply cost too much.

Hey Folks,

I've been trolling the used market for a square set of 18x9.5 +45 for some time. I've come across a good buy on a set of 18x9.5 +40.

Can I get some feedback on fitment with that slight variance beyond what has been discussed as the far limit of front fitment?

I noticed "jonahau" above is running 18x9.5 +38 but with 255s. I was hoping to run Advan Neova AD08R in either 265/35/18 or possibly 285/30/18 as an alternative.

Thank you.

L T

Most 265/35-18 are too tall and will rub the inner fender near where you can see the fender liner under the hood.

Up front +40 offset will fit 265/35-18 with max front camber (~-2.4 depending on ride height) and a fender lip roll. +40 will fit 285/30-18 up front with max front camber and a fender lip roll with mild to moderate pull.

This rubbing would occur only on slammed cars or in a bottoming out scenario? I'm only on RB Sport springs and don't plan on ever going lower than my driveway will allow, which is about right where it is today.

Thank you. Any other tire sizes I should be considering that are friendlier? I guess 255/35/18. Would that help? Would that be too "stretchy"?

The rubbing from too tall a front tire happens anytime you turn the front wheels and yes, can also rub other places when you hit a bump and the tire bottoms before the suspension.

My experience was with 265/35-18 Federal 595 RS-R which are pretty short for 265/35-18 at 25.3" tall. These tires rubbed slightly where I mentioned on the plastic fender liner in the area you can see it in the engine bay when the wheels were turned and in addition my car has the factory mud flaps and the tire also rubbed these when turning. The problem subsided as the tires wore.

265/35-18 range in diameter from 25.2" tall (like Yokohama A048) to 25.5" tall (like Pirelli P-Zero Corsa).

My 295/30-18 are 25" tall and do not rub (in case you are not convinced it is a tire height issue not a tire width issue).

Thank you. But with the 295 (or 285), I would still need to work the front fenders, correct? I'd like to avoid anything drastic.

Any thoughts on 255/35/18? Seems like it checks most boxes, just not sure how the +40 still plays in.

Yes, but you will have to roll the front fender lip under for 265/35-18 on +40 offset as well.

Easier fit with +40 offset.

Ok got the wheels and about to buy tires. You think 245/35/18 would be too small of overall diameter? I'd hate to get 255/35/18 and have front fender rubbing when 245 was an option.

But maybe not an issue running moderate height RB springs?

Thanks for the feedback.

245/35-18 is pretty low profile/short at 24.5" when stock tire height is 24.8-24.9" tall.

I would risk the 255/35-18 up front and put at least 2 degrees negative camber on the front so the +40 wheels don't cause tire to catch your fender lip turning up slopes.

245/35-18 isn't too small, pretty much stock diameter at 24.8". I'd rather go slightly narrower and shorter and not have to worry as much about rubbing while also being able to run a lower front ride height if desired...

Ha! Already ordered some PSS on close out in 255 and should be here today. I know the diameters basically straddle stock so maybe the 5mm on each side will be negligible. Keeps the stretch a bit more moderate too. Hopefully I'll be ok considering my driveway keeps my ride height conservative. I'll let my alignment guy work his magic. We shall see.

Thanks for all the great input.

https://cimg6.ibsrv.net/gimg/www.rx7...f861ba9590.png
https://cimg7.ibsrv.net/gimg/www.rx7...0d49314673.png
https://cimg8.ibsrv.net/gimg/www.rx7...90a5d0a6c0.png

Can anyone provide input - browsing around wheel setups, and looking at the Enkei Lusso:

LUSSO Enkei Wheels

How would a 18x8 +40 on the front and 18x9 +40 fit on a FD? I've seen a few with 18x8 all around, but would prefer a staggered setup:

https://cimg3.ibsrv.net/gimg/www.rx7...9a93d69e2e.jpg


Thanks in advance

Yes, that setup will work.....you may want to think about an 8.5 up front an 9.5 rear they will fit nice with a +40 offset, and let you put on a bigger tire. I recommend having the front fender lips rolled, it just takes the stress off catching a fender, one rub an the fender is a mess! The rears should be fine, I have 18 x 9.5 +40's on my rear with the stock camber settings, the 275 x35 tire has never touched the fender. Nice looking wheel!

Thanks Greg for this answer - to follow this up, I should state that is is really the first time I'm actively thinking of offsets, instead of just buying whatever is off the shelf for the car, Tire Rack recommended, etc. The above pic is of a square 18x8" setup that I found, & one of the only FD's I've ever seen running these Enkeis. I haven't yet found anyone trying the 18x9's on the rear. Here's a pic of the 9's, with the associated lip that they have over the 8" version:

https://cimg1.ibsrv.net/gimg/www.rx7...0cccd7d90d.jpg
I plugged the specs of the 18x9 +40 into an offset calculator, in comparison to the stock 16x8 +50 FD wheels, and came up with:

https://cimg0.ibsrv.net/gimg/www.rx7...6652a571b2.png

So, that looks pretty good fitment wise as Greg described - given how sunken in the stock FD rears are, this sounds like this would be pretty close to flush, or maybe a little sunken in which is OK - what I absolutely want to avoid is any kind of "poke" past the fender as I'm not a fan of that look.

Then I came across this Reddit thread, where someone has other Enkei wheels mounted, including a 18x9 +40:

https://www.reddit.com/r/RX7/comments/4jz042/94_fd/?st=jfmmw3zq&sh=4f830386

https://cimg3.ibsrv.net/gimg/www.rx7...51c63e1caa.jpg

Now, just imagining that front 18x9 +40 moved to the rear, it looks like it'd stick out a good bit, and his rears are obviously way out there past the fender. Looking at the specs Enkei provides for the Lusso, they reference "Inset 40", which, if I'm correct, can be translated to "negative offset 40" or -40 (?). That seems pretty extreme - so maybe the internet lied to me and "inset" is the same as "positive offset"...

http://enkei.com/wp-content/uploads/2015/01/LUSSO.pdf

So, I guess my follow-up question is - will these 18x9 +/-/inset/whatever 40 Lusso wheels sit flush, inset (inside the fender) or poke out the fender? Why do the above 18x9 +40's in a different Enkei model stick out so much? Sorry if I'm beating a dead horse, but I want to be 110% sure and the terminology/math is somewhat confusing this first go-round.

You have created a false choice between 18x8 +40 and 18x9 +40 in your mind- there will be no difference in tire fitment. There is no reason to buy the 18x8 +40 over the 18x9 +40.

Offset fits the tire. The tire is what interferes with the body. That is all.

Here is the 18x8 +40 and the 18x9 +40 shown with the same 265/35-18. Note your choice of tire is problematic because it is too tall and causes rubbing on the fender liners when turning. 255/35-18 or 285/30-18 are the correct height tires.
https://www.willtheyfit.com/js/wtf/w...4.3&aspect2=35

EDIT: posted this at the same time as your reply above, BLUE TII

Thanks for the reply BLUE TII, I hadn't even really gotten to tire fitment in my mind yet - I just tossed the 265/35 into the calculator to put something in there that sounded appropriate for a 9" rim. I've so far been 100% focused on the question of fitting a 18x9 "inset 40" Enkei Lusso - whether it will be inset, flush, or poke with that sizing & offset relative to the rear fender lip. It's a given that a 18x8 "inset 40" Enkei Lusso will fit on the front of the FD as there is the aforementioned handful of FD's out there running them on the front, so I'm at this point totally concerned with the 18x9 on the rear and the above question.

That diagram you posted comparing the 8 & 9 does help, though I'm still confused as to why the above Enkei RS05 on the MB car, in a 18x9 "+40", sticks out so much past the front, or as it would, rear fenders. Imagine there would be no tires mounted on that wheel - the bare lip itself would be poking out there pretty healthily. Are not all wheels created equal when you talk offset in relation to overall width? Would you say the 18x9 "inset 40" Lusso would sit flush, inset, or poke out on the rear of a FD?

That is your mind imagining where the wheel is in relation to the fender.
It is impossible to tell by looking at a straight on picture of the side of the car, it would require a profile picture.

18x9 +40 without tire would fit inset on front and rear of an FD.
If you take a ruler and put it on a stock 16x8 +50 top wheel lip the 18x9 +40 would be 22.7mm more outward (0.89"). You can now check that for your self on your own car with its current alignment.

Excellent, I thought it might be an issue of optics using that pic, but it was just about the only one I could dig up with a 18x9 +40 on the FD. Thanks a ton for the help & confirmation. Just for the sake of providing information for any future searches, here's another pic I just found of the Lusso in 18x8 +40 on the front, and rear of a FD. Instagram user "hella_fd3s".

https://cimg8.ibsrv.net/gimg/www.rx7...50e21ff0b7.jpg

Thanks again, Greg & Blue TII

Before you buy any wheels, have a look at the TSW Valencia, and if you don't want the 3 piece rivet look, the Tremblant wheel (very close to the Enkei Lusso look), both wheels have a choice of a 9.5 wheel the Lusso only goes to 9 inches for the 18" wheel.....I did the Valencia 18x8 +40 front 255 x35 tire....18x9.5 +40 rear 275x35 tire.....rolled the front fenders, did not roll the rear. The car is lowered about an inch.....Tested for 2 years over bumps, rail road tracks etc.....never touched the fenders. I really like the 9.5 lip on the rear, it makes the back-end look more aggressive....and nothing sticks out....I don't like that look either!https://cimg4.ibsrv.net/gimg/www.rx7...3906b6aa82.jpg

Been searching for fd widebody fitment all I find are stock body FD fitment. I can get my hands on a set of work bersaglio 5
18x10 +7
18x12 +7

can anyone tell me how much these will stick out from stock body fd? I will post a picture i found online of what I'm planning on for my personal fd widebody.

Quick question. I have a pair of wheels that 17x8 +35 off set and im trying to buy tires for them on my stock body FD
Any recommendation of sizing so it dosent get too tall or potentially easy to rub on my fender lip ? 235 40 17 ? Or 225 45 17

225/40-18 is the right diameter and should fit, especially if you run some negative camber (which imo you should anyway...). You might consider 235/40-18 in back which would be slightly taller and wider. Up front 235/40-18 would likely tweak the fender lip if it isn't rolled...