Newest spacer sizing tests I did in the "field" and attempt to summarize accumulated D3 posts
08-24-2008, 10:51 PM
#1
AudiWorld Super User
Thread Starter
Newest spacer sizing tests I did in the "field" and attempt to summarize accumulated D3 posts
Poking through posts on spacers for D3's again, I found a range of reported experiences and fitments, commonly in the 10-20mm range in front, and in the 15-20mm range in the rear, occasionally 25mm. While it's fresh, I'll write up here what I distilled and then what I checked out in more depth on my own car.
What I didn't realize before in reading the posts but now think I do is that many posts appear to be with 255 tires (OEM 18's or 19's) while some (including mine) are with 275's (OEM 20's except S8's usually at 265 to start). Netting that down, because the offset of all the Audi wheels is about the same (mid 40's) as the tire width goes up (and the rim too; to 9"), it is decreasing the tire to fender gap. While you might guess as a rule of thumb the optimum spacer difference is about 10mm less if you have the 275's with OEM wheels, my sense from the posts is it is more like 5mm. There are some offset nuances in the 255 sizing with 8 vs. 8 1/2 inch wheels too perhaps, but I'll leave that aside.
Here's my current best guess trying to assimilate the "field" data from the accumulated D3 posts I searched (over 80 came up with perhaps 6-10 distinct data points):
Really maxed with the 275's: 20mm front spacers, 25 mm rear spacers. Really maxed means few venture here and worries about issues go up a good amount.
Aggressive with the 275's: 12-15mm front, 20 rear
Mild with the 275's: 10 front, 15 rear
Really maxed with the 255's: (little data here) 20 front, 30 rear?
Aggressive with 255's: 20 front, 25 rear
Mild with the 255's: 15 front, 15-20 rear
Here's what I found today playing with 20 and 25mm spacers on the W12 with the optional 20" OEM "old style" RS4 9 spoke polished wheels with 275/35 20 OEM Dunlop Sport Maxx's. For reference the "new style" RS4 twin 7 spoke polished wheel used on 4.2's with the sport package in the past few years has the same offset and wheel width. Remember, with my rule of thumb, likely add 5mm's to anything below if you are in the 255 tire world with OEM wheels.
a. I have been running 20mm rear spacers for many months now. No signs of rubbing. I jacked up the car to then get a floor jack under the wheel, and then loaded the wheel starting from the "sports" setting. Net, the tire does not hit the fender metal at all. At extreme compression with the top of the tire up into the wheel well probably 1-1/2 inches plus, it eventually hits the felt sound absorbing material. It hits along the upper side edge of the tire very slightly. Rather than hitting at 12 o'clock high as you might think, it hit at about the 11 o'clock position as you look at the right rear wheel, probably due to the tapering of the body work in that area toward the back bumper. In the real world, my guess it you would never see this kind of compression--other than having a sumo wrestling team in the car and a trunk loaded with barbells, or running over a railroad tie sized obstacle or a major hole in the road and also destroying the tire and wheel outright. And again it only hit the felt a bit. My guess to avoid hitting even the felt might be to back it off (in 275's) to 15mm.
b. Still with the 20 mm spacers in the rear and the suspension really loaded up, I checked the gap to the fender sheet metal. I did this since one poster reported previously rubbing on the metal and needing repainting. Using Allen wrenches akin to thick feeler gauges I checked the critical fit areas. Again, it was at the 11 o'clock position (right rear wheel) that it was at minimum clearance. Net, a 7mm wrench just cleared it, suggesting indeed the 25mm spacers could just pass, though they would hit the felt pretty early above the inner fender metal.
c. I did the same loading tests in front, so far with no spacer. I found there was about 7/8 inch (about 22mm) clearance to the fender metal from near the top edge of the tire at the side of the tread, and around 5/8 inch (15+mm) apparent clearance even if I measured pretty far down along the sidewall of the tire where it bulges out more. Again, I probably had the tire up into the fender a good 1-1/2 inches or more, so this was an extreme scenario for a normal ride height suspension that would be destroying wheels if not the front end if encountered at speed.
d. I didn't realize, but by then I had really confused the air suspension. When I let it off the jack the suspension went all the way down to the full "low rider" position with the wheels tucked under the fenders. Gave me another chance to check my front calcs.
e. Then I moved the 20mm spacer to the front, and installed a 25mm spacer in the rear. I had already done some straight edge measurements and concluded the front tire would not hit the fender with the spacer installed, but it would be tight. Because I could see pretty early on this was probably not where I was going to end up, I did not repeat all the suspension loading stuff with the jack. What I saw visually on the rear was that the top of the tire did just tuck inside the fender metal as the measurements had already told me it would. But, the tire was protruding beyond the fender not to far away from the 12 o'clock position, particularly toward the rear bumper. I didn't want quite that look, and it looked like the car would really get dirty in winter with the road splash from the tires (saw it before on the C5 4.2 with the fender flares). In the front it looked awfully tight. Again, it was protruding too much on the sides, particularly toward the bumper for my taste. I didn't test it, but I was also somewhat concerned with the possibility of interference with the fender if the suspension was loaded up in a turning movement with the tire turned out through the fender opening.
f. Now that I knew I could really drop it, I let the jack down again. The car sank low, particularly in front--my jack head is about 4" off the ground and I was using the front jack point behind the wheel well. The wheels probably tucked an inch inside the fender up front. Had to admit it had the cool show car look, but wouldn't be practical. What it did show me was real world how it might look loaded up in a really aggressive turn or if it did hit some significant bumps that are out there. Again it cleared in straight ahead tracking and it didn't hit the fender liner. But, it still left me thinking in a corner with the front of the wheel turned outward, it might make contact.
Net, I concluded to stick with the 20mm spacers in the rear as the most aggressive that would leave me with few worries about rubbing. In the front my sense was likely 15mm spacers, and backing down to 12's if it seems a bit too close. Others' practical experience says 15's are likely fine even with the 275's. On the other hand, the 20 mm data with 255's (all of which sounded positive to me) arguably mathematically lines up closer to 12mm in the 275's.
Having been surprised by the variable spacer diameter in DRA's, I'm hopeful someone will be confirming the 15mm spacers in DR's do line up with the hub and wheel nicely--needs to be about 150mm outer diameter for reference to optimize appearance. DRA's only go down to 20mm and I prefer them, but I need to go to DR's (or some other brand) below 20mm. Oh yeah, and in the 12mm spacers there are variables having to do with the center hub shape and depth too.
What I didn't realize before in reading the posts but now think I do is that many posts appear to be with 255 tires (OEM 18's or 19's) while some (including mine) are with 275's (OEM 20's except S8's usually at 265 to start). Netting that down, because the offset of all the Audi wheels is about the same (mid 40's) as the tire width goes up (and the rim too; to 9"), it is decreasing the tire to fender gap. While you might guess as a rule of thumb the optimum spacer difference is about 10mm less if you have the 275's with OEM wheels, my sense from the posts is it is more like 5mm. There are some offset nuances in the 255 sizing with 8 vs. 8 1/2 inch wheels too perhaps, but I'll leave that aside.
Here's my current best guess trying to assimilate the "field" data from the accumulated D3 posts I searched (over 80 came up with perhaps 6-10 distinct data points):
Really maxed with the 275's: 20mm front spacers, 25 mm rear spacers. Really maxed means few venture here and worries about issues go up a good amount.
Aggressive with the 275's: 12-15mm front, 20 rear
Mild with the 275's: 10 front, 15 rear
Really maxed with the 255's: (little data here) 20 front, 30 rear?
Aggressive with 255's: 20 front, 25 rear
Mild with the 255's: 15 front, 15-20 rear
Here's what I found today playing with 20 and 25mm spacers on the W12 with the optional 20" OEM "old style" RS4 9 spoke polished wheels with 275/35 20 OEM Dunlop Sport Maxx's. For reference the "new style" RS4 twin 7 spoke polished wheel used on 4.2's with the sport package in the past few years has the same offset and wheel width. Remember, with my rule of thumb, likely add 5mm's to anything below if you are in the 255 tire world with OEM wheels.
a. I have been running 20mm rear spacers for many months now. No signs of rubbing. I jacked up the car to then get a floor jack under the wheel, and then loaded the wheel starting from the "sports" setting. Net, the tire does not hit the fender metal at all. At extreme compression with the top of the tire up into the wheel well probably 1-1/2 inches plus, it eventually hits the felt sound absorbing material. It hits along the upper side edge of the tire very slightly. Rather than hitting at 12 o'clock high as you might think, it hit at about the 11 o'clock position as you look at the right rear wheel, probably due to the tapering of the body work in that area toward the back bumper. In the real world, my guess it you would never see this kind of compression--other than having a sumo wrestling team in the car and a trunk loaded with barbells, or running over a railroad tie sized obstacle or a major hole in the road and also destroying the tire and wheel outright. And again it only hit the felt a bit. My guess to avoid hitting even the felt might be to back it off (in 275's) to 15mm.
b. Still with the 20 mm spacers in the rear and the suspension really loaded up, I checked the gap to the fender sheet metal. I did this since one poster reported previously rubbing on the metal and needing repainting. Using Allen wrenches akin to thick feeler gauges I checked the critical fit areas. Again, it was at the 11 o'clock position (right rear wheel) that it was at minimum clearance. Net, a 7mm wrench just cleared it, suggesting indeed the 25mm spacers could just pass, though they would hit the felt pretty early above the inner fender metal.
c. I did the same loading tests in front, so far with no spacer. I found there was about 7/8 inch (about 22mm) clearance to the fender metal from near the top edge of the tire at the side of the tread, and around 5/8 inch (15+mm) apparent clearance even if I measured pretty far down along the sidewall of the tire where it bulges out more. Again, I probably had the tire up into the fender a good 1-1/2 inches or more, so this was an extreme scenario for a normal ride height suspension that would be destroying wheels if not the front end if encountered at speed.
d. I didn't realize, but by then I had really confused the air suspension. When I let it off the jack the suspension went all the way down to the full "low rider" position with the wheels tucked under the fenders. Gave me another chance to check my front calcs.
e. Then I moved the 20mm spacer to the front, and installed a 25mm spacer in the rear. I had already done some straight edge measurements and concluded the front tire would not hit the fender with the spacer installed, but it would be tight. Because I could see pretty early on this was probably not where I was going to end up, I did not repeat all the suspension loading stuff with the jack. What I saw visually on the rear was that the top of the tire did just tuck inside the fender metal as the measurements had already told me it would. But, the tire was protruding beyond the fender not to far away from the 12 o'clock position, particularly toward the rear bumper. I didn't want quite that look, and it looked like the car would really get dirty in winter with the road splash from the tires (saw it before on the C5 4.2 with the fender flares). In the front it looked awfully tight. Again, it was protruding too much on the sides, particularly toward the bumper for my taste. I didn't test it, but I was also somewhat concerned with the possibility of interference with the fender if the suspension was loaded up in a turning movement with the tire turned out through the fender opening.
f. Now that I knew I could really drop it, I let the jack down again. The car sank low, particularly in front--my jack head is about 4" off the ground and I was using the front jack point behind the wheel well. The wheels probably tucked an inch inside the fender up front. Had to admit it had the cool show car look, but wouldn't be practical. What it did show me was real world how it might look loaded up in a really aggressive turn or if it did hit some significant bumps that are out there. Again it cleared in straight ahead tracking and it didn't hit the fender liner. But, it still left me thinking in a corner with the front of the wheel turned outward, it might make contact.
Net, I concluded to stick with the 20mm spacers in the rear as the most aggressive that would leave me with few worries about rubbing. In the front my sense was likely 15mm spacers, and backing down to 12's if it seems a bit too close. Others' practical experience says 15's are likely fine even with the 275's. On the other hand, the 20 mm data with 255's (all of which sounded positive to me) arguably mathematically lines up closer to 12mm in the 275's.
Having been surprised by the variable spacer diameter in DRA's, I'm hopeful someone will be confirming the 15mm spacers in DR's do line up with the hub and wheel nicely--needs to be about 150mm outer diameter for reference to optimize appearance. DRA's only go down to 20mm and I prefer them, but I need to go to DR's (or some other brand) below 20mm. Oh yeah, and in the 12mm spacers there are variables having to do with the center hub shape and depth too.
08-28-2008, 01:13 PM
#2
couple of quick questions if you don't mind...?
First off, great info thankyou !!
I'm about to go 20 front and 25 rear with my 255/40/19 oems, seems fairly safe based on your research.
first q: will any of the trak DR or DRA spacers in 112X5 with a 57.1 center bore work ? some fitment guides such asthis one : www.livermoreperformance.com/h&r_wheel_spacers.html#Audi only include the A8 up to 15mm...
Second Q: you say you prefer the DRA to the DR, can I ask why ?
I was going to do this myself (have jack, have torque wrench) and the simplicity of the DR and straight through longer bolts appealed. Is the DRA as easy ?
much appreciated !<ul><li><a href="http://www.livermoreperformance.com/h&r_wheel_spacers.html#Audi">http://www.livermoreperformance.com/h&r_wheel_spacers.html#Audi</a</li></ul>
I'm about to go 20 front and 25 rear with my 255/40/19 oems, seems fairly safe based on your research.
first q: will any of the trak DR or DRA spacers in 112X5 with a 57.1 center bore work ? some fitment guides such asthis one : www.livermoreperformance.com/h&r_wheel_spacers.html#Audi only include the A8 up to 15mm...
Second Q: you say you prefer the DRA to the DR, can I ask why ?
I was going to do this myself (have jack, have torque wrench) and the simplicity of the DR and straight through longer bolts appealed. Is the DRA as easy ?
much appreciated !<ul><li><a href="http://www.livermoreperformance.com/h&r_wheel_spacers.html#Audi">http://www.livermoreperformance.com/h&r_wheel_spacers.html#Audi</a</li></ul>
08-30-2008, 10:09 AM
#3
Member
Join Date: Jun 2008
Posts: 358
Likes: 0
Received 0 Likes
on
0 Posts
I stayed with 10mm (per wheel) as to not strain the wheelbearings to much...
If you go to the outside too much, the wheelbearing starts working outside the parameters it was designed for.
The D2 is a ET48 car and as Audi made wheels with 8Jx18" ET39, the 10mm spacer modifies the ET to 38. Only one mm outside Audi's specs.
That one mm will not kill the wheelbearings as the bearings of the A8 are quite strong.
In my heart i would have loved to go with 12 or 15mm spacers as it makes the car look even better but i kept it to 10mm per wheel for the beforementioned technical reason.
The D2 is a ET48 car and as Audi made wheels with 8Jx18" ET39, the 10mm spacer modifies the ET to 38. Only one mm outside Audi's specs.
That one mm will not kill the wheelbearings as the bearings of the A8 are quite strong.
In my heart i would have loved to go with 12 or 15mm spacers as it makes the car look even better but i kept it to 10mm per wheel for the beforementioned technical reason.
09-02-2008, 08:39 PM
#4
AudiWorld Super User
Thread Starter
Answers
Yes, the DRA's in 20mm work great. Installed in my car in the rear currently. In 25mm, the outer diameter of the spacers will be about 160mm, rather than approximately 150mm at both the disk mounting face and the inside of the wheel at the bolt up point. Thus the spacer will seem a little too big in diameter. If you have a closed appearance wheel like the D3 A8 19" 12 spokes (aka fans, turbines and sometimes pie plates), you probably could hardly see it. On an open wheel like new or old style RS4 9 spokes you would see it more.
See top of p. 11 of link to H&R's Audi catalog section. A D3 A8 is the "Typ 4E" in Audi speak. The DRA 40 mm's (20 per side) and DRA 50 mm's (25 per side) are the ones I discuss by part number, and I just bought and have in hand the DR 30's (15mm per side). Having received them, the DR 30's are indeed the 150mm diameter I was hoping for.
In 25mm you can only get DRA's, at 20 mm you can get either. At less than 20mm, only DR's are sold. I like DRA's because they bolt up nice and securely to the brake hub face. Then your lug bolts are completely stock (and on D3's anyway that means the really nice fully washered bolts that are more accurate for torquing), you can use factory wheel locks, you don't have different bolt lengths front to rear if you have different width spacers, etc. Easier to mount the wheel I suspect too since the spacer is bolted in before the wheel is ever put on, instead of loose and moving around some like with DR's.<ul><li><a href="http://www.h-r.com/katalog_download_en/Audi_04-2008.pdf">H-R catalog link for Audi's.</a></li></ul>
See top of p. 11 of link to H&R's Audi catalog section. A D3 A8 is the "Typ 4E" in Audi speak. The DRA 40 mm's (20 per side) and DRA 50 mm's (25 per side) are the ones I discuss by part number, and I just bought and have in hand the DR 30's (15mm per side). Having received them, the DR 30's are indeed the 150mm diameter I was hoping for.
In 25mm you can only get DRA's, at 20 mm you can get either. At less than 20mm, only DR's are sold. I like DRA's because they bolt up nice and securely to the brake hub face. Then your lug bolts are completely stock (and on D3's anyway that means the really nice fully washered bolts that are more accurate for torquing), you can use factory wheel locks, you don't have different bolt lengths front to rear if you have different width spacers, etc. Easier to mount the wheel I suspect too since the spacer is bolted in before the wheel is ever put on, instead of loose and moving around some like with DR's.<ul><li><a href="http://www.h-r.com/katalog_download_en/Audi_04-2008.pdf">H-R catalog link for Audi's.</a></li></ul>
Thread
Thread Starter
Forum
Replies
Last Post
veteq
RS4 (B7 Platform) Discussion
9
03-26-2020 10:52 AM
