Wheel Spacers

[11Budlite]

I've never had to use wheel spacers before, but on the Birkin I have a serious gap (at least 1-1/4" ) between the outer edge of the rear tires and the fenders. See the following photo:

http://www.usa7s.com/aspnetforum/upload/1947103873_20080410_0022R.jpg

The wheels I'm using are 15" x 7" with a 35mm offset. I plan on getting some new lighter wheels/stickier tires at some point, but in the mean time I was thinking of getting some spacers to move the wheel out. Would something like the following be acceptable to use?
http://www.ezaccessory.com/Wheel_Adapter_4_Lug_100_To_4_Lug_100_p/4100-4100.htm

Any advice or previous experience would be appreciated.

Thanks, Bruce :7drive:

[Boxologist]

depends on teh strength of teh wheel hubs and bearings. subaru hubs (5x100) are notoriously weak and anything more than a 5mm spacer severely shortens the life of teh wheel bearings. Toyota hubs were fine with 15-25mm spacers.

u should contact someone who is more familair with teh birkin hubs.

[Mondo]

If you get some, I recommend Kics. I've used these as you don't have to mess with your studs. It's a straight bolt up deal (just locktite & torque). Don't know about hub strength but they use them on drift cars and they work fine on my Infiniti G35 coupe.
An inch is a pretty big spacer.. though I do have 1 inch spacers on the rear of my 67 Chev Pick Up.

http://www.evasivemotorsports.com/merchant2/merchant.mvc?Screen=CTGY&Category_Code=Kics_Wheel_Spacer

[scannon]

I had a set of spacer/adaptors machined at a local shop to allow me to use my Miata track wheels on the Caterham. They are 28mm thick and adapt the 4 x 100 mm Miata wheels to the Caterham 4 x 4 1/4" hubs. Cost was about $50 each and they are hub centric to the wheels and on the hub side the tolerances are so tight that I have to smack them with a rubber mallet several times to get them off.

It turned out that the front and rear hubs on the Cat are different and so I have a front set and a rear set.

They look alot like the ezaccessory ones.

Skip

[Davemk1]

One issue you might find on a Birkin (maybe other sevens too) is that the rear track is already almost 3" wider than the front. If you add to this substantially I'll bet you add understeer in a big way as the rear grip will go up a good bit while the front will stay the same.

I suppose you could consider doing the fronts too but this is project creep in a big way at the fenders would need to be modified...............not to mention the fact that your scrub radius would be huge and the stress on the front spindles might be scary.

In the end it might be easier to put on narrower fenders :)

dave

[11Budlite]

Thanks for the info guys!

I still have to do a little more research, but I could have sworn that some of the Birkins had wheels with less offset which would bring the wheel out closer to the fender. It wouldn't be enough to make up the gap but it would help. I'm also thinking of going to 205/50x15 tires because of the better selection, and that should help some as well.

"In the end it might be easier to put on narrower fenders " - I thought about that too, Dave! :)

I might just get a set of spacers for a temporary fix for the rear. Maybe the front sway could be adjusted to try to balance it out a little. Right now it seems to be a little loose as it is! :d

Bruce :7drive:

[Davemk1]

FWIW stock Birkin wheels are 15 x 7 with a 30mm offset.

dave

[11Budlite]

Could any of you guys with a Birkin measure the rear fender width from body to fender edge? I'm trying to eliminate any other variables. FYI my rear fenders measured out to between 12-3/8" to 12-1/2".

TIA, Bruce :7drive:

PS: Thanks for the offset info Dave.

[11Budlite]

Bump for Birkin rear fender width measurement...anybody?

I just weighed my wheel/tire combination and it came out to 38.44 lbs. The wheels are TSW and the tires are Firestone Firehawk 690's. Shouldn't be too hard to find a lighter/stickier combination! :)

Bruce :7drive:

[gjslutz]

Bruce,

11 7/16 in the front of the rear tires about axle height & 11 5/8 at the rear of the tire. I run 225's on the rear with either 30 or 38mm off set wheels. I also run 8mm spacers on all 4 wheels.

Gary

[gjslutz]

My measurement was to the inside lip of the fender to the body.

[11Budlite]

Thanks Gary!

[gjslutz]

Bruce,

I, like Dave would not be concerned with how much excess you have between the tires & inside of the fender lip. I run 225 / 45’s on the rear and to fit them in I need that extra room. I sure would not cut the fender just for aesthetics. I like the grip the 225’s have. With the either the Toyo R888 or Kumho V710 slicks it is outstanding. The Falken RT 615 205's won't hold even close to the other two. They are much better in the wet though. The compound is much harder and should wear better if that is what you want. The Rt 615 is stil a great tire for the $$.

[11Budlite]

Thanks again Gary. The Falken RT 615's have been at the top of my list for what I plan on using my car for right now. Still undecided on the wheels, but I do want to get back to the 30mm offset as well as a lighter wheel. I've been thinking of these:

http://www.usa7s.com/aspnetforum/upload/444393794_images.jpg

They're a little less than 10 lbs in a 15 x 7 size, but would require a 5mm spacer to get the 30mm offset. It's one of the few modern wheels that I like the looks of. I would really like some Minilite/Panasport type wheels but most of them are a bit heavier....

Bruce :7drive:

[Birkin42]

I have a set of RPF1's for my car. The quality is great and I hear they are pretty strong with the rolled rims. A pretty good value too for the weight compared to forged or 3 pc wheels. Just need to make or find a center cap since they don't make them for the 15" size.
I went with 15x7x35mm offset for the front and 16x8x38mm offset for the rear and plan to run 205/50/15 ft and 225/45/16 rears.

Jack

[11Budlite]

Thanks Jack. When you get them on your car would you mind taking a picture for me?

Thanks, Bruce :7drive:

PS: How's your car coming along?

[Birkin42]

Bruce,

No problem taking a picture of them once on the car, but you will likely be waiting a while. Progress was good through the winter but life has been busy with work, stuff around the house and a baby 6 weeks away keeping my occupied. The chassis mod's are done and am currently working on the rear suspension. Still a fairly long list of things to do after that. Having fun working on it when time permits though I can't wait to get the car on the road. I'm getting a small shop set up at work with a lathe, mill and CNC milling center so these will come in handy as the project progresses.
If in the mean time you want any pictures or measurements off the wheels, let me know.

Jack

[11Budlite]

Jack,

"Progress was good through the winter but life has been busy with work, stuff around the house and a baby 6 weeks away keeping my occupied." - I hear you on the busy part. Nancy and I have just recently become "parents" again with our 4-month old granddaughter that we're watching. I thought I forgot all that feeding, burping, changing diaper stuff, but it's just like riding a bicycle! :ack: :d Thank goodness she's been (for the most part) sleeping through the night! :blueangel: You are really in for an amazing experience and I wish you and your family the best!!

As far as your Birkin, weren't you putting in a Honda drivetrain with IRS? I really hope you're documenting your build because of the changes you're making....would love to see some pics if you get a chance. No problem with the wheel pictures, I think whatever wheels I get will be a Christmas present.

Bruce :7drive:

[Birkin42]

I figure it is going to be a life changing experience. I have a few friends that are in the same boat with having their first when they are in their 40's so that should help.

Yup I'm putting an S2000 engine and trany in a Birkin and building my own DeDion rear suspension. I'm not aware of anyone else who has tried to put this engine/trany is an original size 7, but I assume there are others out there. It's a tight fit.
The engine and transmission now fit in the chassis and the stock hood will just clear once I trim down the valve cover.
The diff and rear suspension mounts are now also in the chassis and I'm working on the axle and other rear suspension pieces.

Jack

[Davemk1]

I just recently put new wheels on my Birkin............ it sure is nice having wheels that are actually round. Crazy I know. I'm running 215/45's in the rear and 195/50's up front and they fill the fenders pretty well.

I got them from Good-Win Racing and they are Team Dynamics wheels meant for a Miata. They are 15 x 7 with a 30mm backspace. They are fairly light at 12 or so pounds and they are pretty cheap.

The center bore to fit the Spec Miata is too small for the Birkin (needs 60.1mm front on my car) so Good-Win had them bored out for me for $10 a wheel and he did a nice job.

So there are aren't too many 30mm BS wheels out there but there are a few.

Dave


http://www.usa7s.com/aspnetforum/upload/906589361_DSC_9996.jpg

[MHKflyer52]

http://www.usa7s.com/aspnetforum/upload/906589361_DSC_9996.jpg

Dave,

What is the setup under the nose of your 7. Looks like some sort of air scoop with a vent but it is flat.
Just woundering.

[Davemk1]

Dave,

What is the setup under the nose of your 7. Looks like some sort of air scoop with a vent but it is flat.
Just woundering.

It's my very simple and a bit crude front splitter. It's made from 1/8" ABS sheet. There is a vent in the front face of it that leads to a hose that runs back and pushes air into the bottom of the foot box to help keep my feet from getting cooked............ it works pretty well with a nice flow of air.

dave

[Birkin42]

Looks great on the car Dave.
I bought my RPF1's from Good-Win as well. Great to deal with and good prices. They were also the only NA source for the wider European size 16x8 that I found.
The RPF1's use a hubcentric ring so easy to adapt to the 60mm Birkin hubs.

Jack

[11Budlite]

Just thought I'd give an update on my wheel situation. I ended up ordering some Enkei RPF1 wheels in the 15x7, 35mm offset size, with 205/50/15 Falken Azenis RT-615 tires from Good-Win Racing. I still need to get some 5mm spacers but that should be pretty easy. I should lose about 8 lbs per corner with the new set-up. :)

Here's a VERY amateur photo-shop of what it should look like:
http://www.usa7s.com/aspnetforum/upload/1852422603_enkei dad.bmp

Bruce :7drive:

[Boxologist]

i would love if enkei made teh rpf1 in 13"...

[11Budlite]

Just rec'd my new Enkei wheels and Falken tires from Goodwin. It looks like they did a good job mounting and balancing them, and they didn't have to use much weight to get them balanced (some had only (2) 1/4 oz weights on them). The quality/weight of the Enkei wheels looks to be pretty impressive for the money. The wheel/tire combination ended up weighing 29.9 - 30.1 lbs on my shipping scale. The original TSW wheels/Firestone tires weighed between 38.2 - 38.9 lbs, the highest one being the unworn spare. I also removed the spare tire carrier that weighed a little over 5 lbs plus the spare tire, so adding everything up it looks like I lost about 76 lbs. :) Obviously the biggest weight savings is in the removal of the spare tire, but it does feel like it accelerates better and the grip is much better with the new rubber. Needless to say I'm pretty happy! Here's a photo that I took last night before the first test drive:

http://www.usa7s.com/aspnetforum/upload/1715483191_20080809_0003.JPG

Bruce :7drive: