|
|
#31
July 7th 2005, 15:45
|
||||
|
||||
|
hmmm I think I see where the confusion is, offset is taken from centerline of the wheel so the back spacing will also change each time wheel width is increased. check this out
http://www.usacomp.com/terms.htm backspacing is the "T dimension" so the backspacing can't be larger than 6". That means anyhting more needs to be pushed out. Empi 8's are 5.5" wide with a +20mm offset. But this was not stock and because of the changes in suspension the allowable wheel/tire combo will change.
__________________
Rip H. Van Winkle "The Ultimate Sleeper" 
|
|
#32
July 7th 2005, 15:48
|
||||
|
||||
|
the best way to measure back space is to put a striaght edge accross the back of the rim, then measure down to the face of the bolting surface.
should be about 6.8"
__________________
Rip H. Van Winkle "The Ultimate Sleeper"
|
|
#33
July 7th 2005, 16:10
|
||||
|
||||
|
Alright...now I see....
Well, those wheels are in shipment...not here yet, but I'll measure and see what it is, but yeah, 6.8in backspacing sounds about right(I was figuring it out probably about the time when you made this post). Hmm.....this sucks, lol. Well, I have no problem being the 1st to do it...atleast this lets everybody else know what's definitly needed to do it as well..... Honestly, the reason I chose these wide wheels (other than looks and the contact patch) I kinda took to heart what that post said about "Hopefully "German look" doesn't turn out like Cal-look did....same set-ups, just different paintjobs..."...Seems like the tyical Porsche rims are already becoming common, twists, cups, Fuchs, Cookie Cutters.....gotta break that cycle. 
|
|
#34
July 7th 2005, 16:49
|
||||
|
||||
|
Hmm...good info for people who want to figure it out.
I think the term 'offset' has been incorrectly used sometimes, people are confusing it with 'backspacing'. The goal is to keep the stock 'backspacing' not the stock offset. To do so you need to choose the corresponding offset. Formulas: 25.4mm=1inch centerline = width/2 offset=backspacing-centerline backspacing=centerline+offset So with a my front wheel: 8.5 inch width, 52mm offset 6.3 inches of backspacing My rear wheel: 10 inch width, 52mm wheel 7.05 inches of backspacing So....that said. I'll need to push out ATLEAST .3 inches up front to meet the maximum required for use with Maxx struts. Not taking into account the additional pushing out of 2mm per side (2.5mm to 2.6mm for billet hubs)that 87 944T Brakes/hubs do.... Well, that's really nice to know.....all I'll need is widened fenders and a SMALL spacer if I go for Porsche Hubs, or just widened fenders if I can get the Billet hubs to accomodate. So, with wheels pushed out like this, what does that do in terms of wear and tear to your wheel bearings with the load being that far out? Or is that all negligible?
|
|
#35
July 7th 2005, 21:49
|
|||
|
|||
|
One small problem with your offset to backspacing calculation:
"offset=backspacing-centerline" The nominal width of a rim is from the mounting bead to mounting bead. So on a 8.5"J rim, if you actually measured it with a tape you'd see that it'll probably by about 9.25-9.5" in width. There is a lip on wheels that is not included in width dimensions of wheel, and it varies with wheel manufacturers. Typically, experience tells me that the lip is about 3/8" to 1/2" per side of wheel. Here's what I recommend for the front. Assuming you have a 1302 Super (3 bolt strut), the 1303 is another can of worms. I'll use my car as a baseline, 17x7et42 (still for sale), 215/40 tires, stock disk brakes (ehhw..stock. sold now), .12" spacer, crx coils. I have no issues with fender rubbing (stock fenders) or coil spring interference (a good .38-.5" clearance). I have some problems with the tire hitting the body cup in the top of the fender (where the strut goes). This only happens when I set the struts really low, am fully loaded (I'm a big bone-ded kinda fella) and hit sizable bumps on the road. If I'm loaded up for a long run or something, I switch to 1/4" spacers. I had 205 tires before and never had the problem. I have a very good turning circle and with readjusted steering stops I don't have any tire rubbing in 3-pointers. The daily ride is an ol' Honda civic, and the steering capabilities are similar. No comlaints. Let's put the inside of your wheel to the same place as mine. Since your wheel is 1.5" wider, the inside of the wheel will be .75" further in. Also, you have a 10mm deeper offset (.39"). So to put the inside edge of the wheel/tire to where I am, you need to increase your brake offset by .39 + .75 = 1.14. Now, a little bit of a spacer (.25) to prevent strut-cup interference, and the total offset required at the wheel is 1.39". The outside of your wheel will move out accordingly. So, you need a 2" wider fender will still allow you to tuck, and you'll need an offset increase of 1.39" (or so) at the brakes. As for the bearings, there is very little loading on the front of these cars. Some tough guys can pick up bugs from the bumper. You may have to check and service the bearings more often, but we all check/grease them like we're supposed to; semi-annually, RIGHT?  I feel like Jerry's mechanic on Seinfeld sometimes....Lanner
|
|
#36
July 7th 2005, 21:54
|
|||
|
|||
|
Quote:
Lanner
|
|
#37
July 7th 2005, 23:07
|
||||
|
||||
|
So, all I need is just need a 1/4 inch spacer and your billet hub right(brake spaceing will be supplied through you for the billet hub right?)??? Atleast, that's what my retard *** got from it, lol.
Quote:
 . I just personally HATE the way those plain brembo's look...it's a frickin sticker. That just screams cheap to me...regardless who makes it, it's just something stuck in my head... It's the ONLY thing that bothers me. Hmm...how about a Bracket/billet hub made so I can have the rotor the sized of "Project Pepper"? Cause I dunno, already needing an adaptor bracket, then getting Big Red adaptor brackets would just seem very unsafe to me, lol. Now that...I would definitly love, cause I get to keep my sexy machined calipers, and only have ONE caliper adapter bracket, hahaha....
|
|
#38
July 8th 2005, 03:01
|
||||
|
||||
|
Quote:
And oicdn you are braver than me, especially with a daily driver. Quote:
__________________
Rip H. Van Winkle "The Ultimate Sleeper"
|
|
#39
July 8th 2005, 03:09
|
||||
|
||||
|
Quote:
oh and if you want to spend more money well I think Lanner can fit 6 pot AP brake calipers with billet hubs.  But yea I drool when I get the new copy Racecar Engineering in.
__________________
Rip H. Van Winkle "The Ultimate Sleeper"
|
|
#40
July 8th 2005, 11:43
|
||||
|
||||
|
Yeah...I'm just trying to push the limits, that's all....be the same, but err, not really. Daily driver, yeah....it's scary, but I think the feeling is a little better, cause it doesn't feel like you're just building a driveable model car....you drove it through the phases.
We'll see what happens here...1/4inch spacer and a Billet hub...that's now getting written down.....
|
|
#41
July 13th 2005, 08:58
|
|||
|
|||
|
Rims
My 78 03 cabrio runs 7.5x17 et52 cup 2 replicas front and rear. Front tyres are 205/40x17 Avons with stock wings. It runs Kerscher struts with Kersher vented discs with 944 single pot calipers. Camber adjustment is set to max on the strut and track control arms and the tyres still occassionally rub but i can live with it, although i did think about going to 195 size front tyres.
Rears are same wheels with 215/45x17 Avons with stock trailing arms and early 944 rear brakes. Rear wings are stockers that i widened by 1.5 inches. No clearance problems here. Pix to follow soon.
|
 |
| Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | |
|
|
Linear Mode
