Watanabe Offset Decision

[S30TRBO]

Here are my choices:

 

For the fronts will 16x8.0†zero offset work? I have fitted 16x7 Epsilons with 225-50-16 with no issue.

 

 

and for the rear here are my choices:

 

16x8.5†-6 offset

 

16x9.0†-13 offset

 

16x9.5†-19 offset

 

 

I don't plan on running flares, the fenders and quarters are stock 240Z.

 

Does anyone have any insight on this??

[Sparks280zt]

where are you getting these wheels from?

[S15 200sx owner]

I will be interested to see how this thread goes, as i pulled a wheel off the rear of my car last night, to measure back space of the current 16x7's(which was 5") also to measure how much clearance i have to my coil overs and the outer edge of the fender.

 

On my calculations from last nights efforts it appears that i could possibly go in about half an inch max (so backspace of 5.5") this would leave me with about .25" clearance to lower spring platform on the coil over, and possibly 1.5" out max, so a rim width of 8.5" in the rear without flaring the guards. I havnt looked at the front yet.

 

It looks like 9" would be REAL tight in the rear.

 

Look forward to comments from others.

[260DET]

Its very difficult to advise someone else specifically on wheel fit unless you are familiar with their car and the wheels. You can't go wrong by measuring what backspace will clear everything and then projecting the various widths you have in mind to see if they clear.

 

Forget measuring offset for that purpose, backspace is the important one.

 

I've seen two cars apparently the same involving identical wheels where one fits and the other doesn't. Inexplicable but true

[S30TRBO]

where are you getting these wheels from?

 

 

Talk to Joji and http://www.wheelchoice.com they had the best prices and support.

[S30TRBO]

Its very difficult to advise someone else specifically on wheel fit unless you are familiar with their car and the wheels. You can't go wrong by measuring what backspace will clear everything and then projecting the various widths you have in mind to see if they clear.

 

Forget measuring offset for that purpose' date=' [b']backspace[/b] is the important one.

 

I've seen two cars apparently the same involving identical wheels where one fits and the other doesn't. Inexplicable but true

 

 

Well I had these 16x7 0 offset 16x8 0 offset with 225/50 245-45 on my 240Z on a loan type trial from my friend. Now without my coil-overs it would be close if not impossible to make those work.

 

 

Joji said he was going to call RS Watanabe and see what offset will work on my stock fender, none flair 240Z. He should be calling me back with an answer today.

[S30TRBO]

Placed order today:

 

*16x8.5 -6

*16x9.5 -19

*Gunmetal w/ machined lip

*Watanabe black center caps

*Watanabe lugs and locks

 

 

6-8 Weeks...

 

I'm so happy, I finally bit the bullet... You know I will post pics when I get them...

[zguitar71]

Well I wish I had read this earlier, The wheels you bought will require flares. The rear wheels will be about 3/4" past the fender and the front will be about even or just past the fender. Those are the sizes ZG cars used when they came equipt with ZG flares. If you put on flares they will look awesome though. With out flares you have to stay with a 0, or close to that, offset on a 7"-8" (7.5 max on the front) wheel with 225/50's and no coil overs (all stock).

[S15 200sx owner]

Well I wish I had read this earlier, The wheels you bought will require flares. The rear wheels will be about 3/4" past the fender and the front will be about even or just past the fender. Those are the sizes ZG cars used when they came equipt with ZG flares. If you put on flares they will look awesome though. With out flares you have to stay with a 0, or close to that, offset on a 7"-8" (7.5 max on the front) wheel with 225/50's and no coil overs (all stock).

 

What about with coil overs and stock fenders? any ideas, you sound like you know what you are on about.

[KUBO-Z]

Are they the two piece wheel (RS-8 or what? Watanabes are spectacular wheels. Be careful not to hit any curbs, because they damage easily. The two piece wheel rim is made of spun aluminum and is light weight. I have a set for my Z, brought those about ten years ago while living in Japan. The Proper size for a Z without flares are 0 offset in front and -12 in the rear, (8F and 9R) this is a prefect fit and you will be happy with the intense look of your z, especially from the rear. You made an excellent choice in buying Watanabes wheels, as for the offset maybe not.

[NZeder]

Are they the two piece wheel (RS-8 or what? Watanabes are spectacular wheels. Be careful not to hit any curbs, because they damage easily. The two piece wheel rim is made of spun aluminum and is light weight. I have a set for my Z, brought those about ten years ago while living in Japan. The Proper size for a Z without flares are 0 offset in front and -12 in the rear, (8F and 9R) this is a prefect fit and you will be happy with the intense look of your z, especially from the rear. You made an excellent choice in buying Watanabes wheels, as for the offset maybe not. [/size']

 

Ok time for me to join-in (will try not to hyjack this thread but please tell me if this is off target).

 

I am about to order a new set of RS Watanabe's from Japan. I will be using the same rim front and rear (I have custom steel flares). currently I plan to purchase 16x9.5J -19. I have stock spring diameter (but the shocks are sectioned to correct the travel with lower springs). My flares look to be a little larger than the ZG in the rears and the fronts are bigger than ZG overfenders. Going by my calculation and messurements the 9.5j -19 will work (I might need to get the fronts made a little larger or roll the lip, to give me an extra 1/4") see my gallary for pics.

 

So KUBO-Z reading your post are you saying that 8j 0 offset (approx 4.5 BS and 4.5 FS) and 9j -12 offset (approx 4.5 BS and 5.5 FS) will fit stock fenders? I assume you will have to roll the lip or trim the lip to ensure that the 9j will fit?

 

Even if the flares are not big enough on my car my panelbeater will modify the flares to suit the rims I purchase (handy that he is my brother). I will keep you posted once I have my rims - we have the dimensions of the custom flares and I will try and post as much information re clearances etc once the job is complete. Currently the flares are the following specs. All measurements are from the inner stock lip to the new inner lip.

 

Front - 1.75" wider than stock with 0.5" lip (can me rolled or trimmed for more clearance)

Rear - 2" wider than stock with 0.5" lip (same as fronts re roll/trim)

 

Most Z sites state that 7" 0 offset rims will fit stock fenders with stock spring diameter. A 7" rims is approx 8" from outer bead (inside) to outer bead (outside). So with a 0 offset this give 4" BS (back space) and 4" FS. All the research I have done shows that stock diameter springs the max BS is 4.5". So using this info you can say that a 7.5" rim with +6 offset will fit stock springs and fenders.

 

So using this info this is what I get.

8" 0 offset = 4.5" BS and 4.5" FS (might be a very tight fit - negative camber and slight trim on the lip and they should fit)

8.5" -6 offset = 4.5" BS and 5" FS (0.5" too wide flares/overfender required)

9" -12 offset = 4.5" BS and 5.5" FS (will be 1" too wide for stock fenders)

9.5" -19 offset = 4.5"BS and 6" FS (flares/overfender will be required)

 

Clint - with coilovers and the research I have done you can get away with 5.25" BS (5.5" is just a bit to close - but does depend on the location of the coilover ie 10" or 8" springs ie lower or higher platforms)

So using the info above I would say the following.

4.5" FS max and 5.5max BS = 10" total rim = 9" rim with +12/13 and that would be about it. Any more and mods would be required (some might be required to get these to fit on some cars)

 

I know a Z that has 9.5" front and rear that look like stock fender with coilovers and 5" BS but the fenders were modified a rolling of the lip in the front and small strech of about 1" in the rear, and -2.5 camber to ensure the fronts clear. So in this case a 5.5" FS works on the front with the coilovers, rolled lip and - camber. So this guys Zed has 9.5" -6 offset coilovers and stock fender in the front and a modified in the rear to if the same size/offset wheel.

 

Hope some of this info helps and as stated I will post more info/pics when I get my wheels.

 

Here is pic of some rims I purchased a while back (will be replacing with the RS Watanabe R Type) as they are not wide enough and will fit a stock fender 240z (pic show this). They are the following spec.

15x7 -6 offset (3.75" BS and 4.25" FS) fronts

15x8 -12 offset (4" BS and 5" FS - some lip rolling and - camber required to work on stock 240z fenders)

[zguitar71]

What about with coil overs and stock fenders? any ideas, you sound like you know what you are on about.

 

I have not ever measured for coilovers because I do not have them. I learned the hard way to measure offset and tire wheel combinations. I ordered race tires and wheels once with out measuring properly and ended up with 4 wheels with too much negative offset and they are not refundable, fortunatly they were cheep steel race wheels (Diamond).

[S15 200sx owner]

Cheers Mike, thanks for the info, are you back from Aussie yet?

[SR240Z]

240ztt, i ordered my wheels from joji about a year ago, but i got 16x9 -13 in the front and 16x9.5 -19 in the rear and there is no way those would fit without flares or coilovers.

 

[NZeder]

240ztt, i ordered my wheels from joji about a year ago, but i got 16x9 -13 in the front and 16x9.5 -19 in the rear and there is no way those would fit without flares or coilovers.

 

Sr240z - car looks great by the way.

 

So the 16x9.5 -19 will not fit without coilovers? Did you try these with stock spring sizing before hand or did you already have the coilovers? Reason I ask is the all the research I have done a rim with 4.5" BS will fit a stock setup (my suspension is out of the car so I can't confirm this to be 100% true) and a 9.5 - 19 will have approx 4.5" BS.

[S30TRBO]

Are they the two piece wheel (RS-8 or what? Watanabes are spectacular wheels. Be careful not to hit any curbs, because they damage easily. The two piece wheel rim is made of spun aluminum and is light weight. I have a set for my Z, brought those about ten years ago while living in Japan. The Proper size for a Z without flares are 0 offset in front and -12 in the rear, (8F and 9R) this is a prefect fit and you will be happy with the intense look of your z, especially from the rear. You made an excellent choice in buying Watanabes wheels, as for the offset maybe not. [/size']

 

Kubo,

 

They are Type R Watanabe. Funny you say that I found a picture on RS Watanabe site of a ZG with the exact same wheels and offset.

 

 

 

If flares are my only option does anyone have any tips on mounting them and what hardware to use. I heard horror stories of guys in Japan that after putting flares on and not treating the insides the wheel wells rusted out. How should I treat the inside POR 15/ Rust Bullet?

 

My fender lips are perfect and wheel arches are straight with no rust. I wish there was a way to mold them on instead of drilling holes in the damn body.

[S30TRBO]

240ztt, i ordered my wheels from joji about a year ago, but i got 16x9 -13 in the front and 16x9.5 -19 in the rear and there is no way those would fit without flares or coilovers.

 

Thanks SR240Z,

 

I PM'ed you a while back and you told me about Joji and wheelchoice. How did you mount your flares? Did you have to cut the fenders too? Did you get your flares from classicdatsun or Japan.

[jessejames]

I'm in the middle of an SR20 swap but will be need to upgrade my wheels in the spring. I would like to keep the stock fenders. I have not yet decided on what brake or suspension setup to go with. I have fallen in love with the Watanabe RS 2 piece here http://www.aerodyne.net/rs_watanabe/8SpokeA2_spec.htm

 

Could I run the 17x7s without rolling the fenders and what offset should i be going with? Thanks for you help.

[e_racer1999]

17x7s? yeah. not sure of the offset though, but i have 15x7s on my car. i did have to roll the fender, but with 17s you can BS them more. i think my 15s are 0 offset. it also depends on what size tire you put on the wheels.

[S30TRBO]

I'm in the middle of an SR20 swap but will be need to upgrade my wheels in the spring. I would like to keep the stock fenders. I have not yet decided on what brake or suspension setup to go with. I have fallen in love with the Watanabe RS 2 piece here http://www.aerodyne.net/rs_watanabe/8SpokeA2_spec.htm

 

Could I run the 17x7s without rolling the fenders and what offset should i be going with? Thanks for you help.

 

I am not sure if the 17's will work. I have R Type 16x8.5 -6 all around, no flares but I did roll my rear lip w/ 225/50/16. You might want to contact Eiji at datsunspirit.com for pricing and fitment.