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Fri Apr 25, 2014 7:32 am

I picked up some 15" mercedes wheels and would like to put the biggest tire on. Would a 235/75 fit? Is there any way to lift a 85? I heard that stock 85's are the highest and the 2" lift from gowesty wont do anything. Any help would be great.

Fri Apr 25, 2014 7:52 am

Measure your center of hub to your fender lip on all four corners. I have the 2wd GW all terrain package with the 1.5" springs and it will give you a lift of 18" from wheel center to fender lip. I have an 84'.

If you are close to this and someone else can tell you the tire size, you also have the option of adding 1/2" spacers to your current springs to give you what you need or want. 18" of lift seems to be the agreed max you can lift a 2wd. Syncros seem to run around 20-21" at the same measure points.

Fri Apr 25, 2014 8:07 am

What would I have to do to make 235/75 fit my 85. Where do I buy lift spacers? I will measure my wheel hub to fender height.

Fri Apr 25, 2014 8:12 am

maybe a good place to ask is in the WHAT TIRES FIT THREAD?
http://www.thesamba.com/vw/forum/viewtopic.php?t=584507

Fri Apr 25, 2014 8:14 am

You can buy them from GW but they are like $20 a piece. I have read where some will make them from a cutting board or other hard plastic resource.

Here is a tire size chart that is very useful

http://tire-size-conversion.com/tire-size-chart/

With my 18" center to fender I can accommodate 215/70-16's. Tire chart puts those tires at 28"x8.5 outside diameter. GW considers this combination to be the maximum for a Westy. For the lighter tin top 2wds they don't recommend their springs as they ar to much. Disclaimer on their website.

Fri Apr 25, 2014 8:57 am

235/75 will not fit. To make them fit you would need to do serious mods to the suspension (think Burley control arms front and rear) as well as cut fenders in the front possibly. You would need a different axle/CV set up in rear to handle the increased angle. I have stock 85 front springs with coil over load assist shocks and syncro springs in the rear and ride about as high I think you can go without serious mods (18.5"). I have 16" BFGs (215/70) and rub the front fender under full compression in a turn. A 235/75-15 BFG is 717 revs/mile. Mine are 743 revs/mile and I would certainly not want to go that big even with a Subaru engine. What power plant do you have?

Fri Apr 25, 2014 9:11 am

idahoskier wrote: 235/75 will not fit. To make them fit you would need to do serious mods to the suspension (think Burley control arms front and rear) as well as cut fenders in the front possibly. You would need a different axle/CV set up in rear to handle the increased angle. I have stock 85 front springs with coil over load assist shocks and syncro springs in the rear and ride about as high I think you can go without serious mods (18.5"). I have 16" BFGs (215/70) and rub the front fender under full compression in a turn. A 235/75-15 BFG is 717 revs/mile. Mine are 743 revs/mile and I would certainly not want to go that big even with a Subaru engine. What power plant do you have?
This^^^
Except that I run 29.5 tires and have been (with a 2.1 WBXer) for several years. Its a different type of driving and one you have to come to grips with.
Trade-offs, no doubt.

I am in the minority, here.. and that said, I would not recommend that size to anyone unless they want to, and enjoy, modifying stuff and spending a good deal of coin to do so.
I would recommend no bigger than 215 wide and 28.5 inches tall...

LOTS has been written on what tires work.. and that thread listed above is a good place to start.
After that.. do a search on "pre-runner vans" and THAT thread discusses suspension mods in good detail...
Here:
http://www.thesamba.com/vw/forum/viewtopic.php?t=389820&highlight=prerunner+van

ALL your answers are already type out here on this forum.
Have a look thru the FAQs.. which our moderator Kamz has put a great deal of work into.

Fri Apr 25, 2014 9:40 am

Running 27x8.5r14's I notice a significant loss of tractive effort at higher elevations, so unless you are adding a lot of extra HP or are willing to downshift more often then go with something smaller.

Fri Apr 25, 2014 11:55 am

Yep, you ask a specific question and get a totally different answer. But you may be asking the wrong question, which is what is the biggest tire I would want to put on an 85. Since you didn't mention an engine conversion you probably have an 80hp stock engine and stock gearing. That combo isn't capable of running that tire. 215/75-15 is also way pushing it, but it would fit and look nice.

Searching "prerunner" or "lifting 2wd" should answer your question in detail.

Fri Apr 25, 2014 4:30 pm

Here's my 85' with 215/75 15". I added 1" of lift in the rear using the cutting board lift. Kept the stock engine, didn't really notice much of a loss power. I am doing a suby swap because the engine is tired, but if i didn't need to replace the motor i wouldn't. I think the distance from the fender to the centreline is around 19".

Fri Apr 25, 2014 10:11 pm

Why do people so often assume that "bigger must be better"? Maybe it's just the American way :roll: . It's more than likely a compensation for something else that's lacking ;)... In the case of Westy tires, what is the problem and what is the ideal outcome? Swaying in the wind? Autocross times not competitive against the Miatas? Nurburgring times not low enough? What about the current condition of sway bars, bushings, ball joints, wheel bearings, etc, etc, etc?

I get wanting to upgrade to 15" wheels. I'd go 215/65/15 or 215/75/15 max. 205s probably just as good if not better. Again, what engine do you have powering your van? That's a very valid consideration when considering upsizing wheels/tires.

Check the "What tires fit" sticky for other options. Or, I see you are in Sacramento.... Go talk to Stephan at Stephan's Auto Haus.

Sat Apr 26, 2014 9:16 am

dillon schuh wrote: I picked up some 15" mercedes wheels

contact Christopher Schimke for info on proper hardware and spacers. Depends on the wheel specs. He knows how to make things fit. Be ready to add lift, possible fender mods and trailing arm mods, and a motor swap.

Big tires rob the van of power.

Hammy1 wrote: 215/75 15"... I added 1" of lift ... I am doing a suby swap because the engine is tired

nice pic :-)
instead of a motor swap, try 205x65x15 tires to put some pep back into your van's gearing

Sat Apr 26, 2014 10:05 am

Jon_slider wrote: dillon schuh wrote: I picked up some 15" mercedes wheels

contact Christopher Schimke for info on proper hardware and spacers. Depends on the wheel specs. He knows how to make things fit. Be ready to add lift, possible fender mods and trailing arm mods, and a motor swap.

Big tires rob the van of power.

Hammy1 wrote: 215/75 15"... I added 1" of lift ... I am doing a suby swap because the engine is tired

nice pic :-)
instead of a motor swap, try 205x65x15 tires to put some pep back into your van's gearing

I can attest to what Jon_Slider says about the bigger tires.

I have 215/75/15 on my 85 Westy, automatic with a 92 Jetta 1.8L engine. It really bogs down going up hills. I have a set of 205/70/15 I'm going to try to see if it gives better drivability. I can't imagine what 235s would be like.

Sat Apr 26, 2014 4:52 pm

I hear ya on the gearing. Once I get the swap done and flush out the bugs I'll sort out the gears. One thing that I can say about the van is, it was gutless before the bigger tires and gutless after the bigger tires. Either way people are are gonna be pissed off at you on the long hills stock wheels or not. :lol:

Regards'

Jon

Sun Apr 27, 2014 8:52 am

U could do as i did on rear window=PASS NOW AVOID THE RUSH

Sun Apr 27, 2014 9:29 am

morymob wrote: U could do as i did on rear window=PASS NOW AVOID THE RUSH

LoL and so true!

Sun Apr 27, 2014 9:52 am

Wildthings wrote: Running 27x8.5r14's I notice a significant loss of tractive effort at higher elevations, so unless you are adding a lot of extra HP or are willing to downshift more often then go with something smaller.
Yep..
And downshifting is just a fact of life with a WBXer...
I just don't see all the hullah baloo over having to downshift on a hill... I've always had to do it.. 25" tires or 29" tires.. I just have to downshift earlier with my 29s.

When I see my rpms dropping below 3k, and I see I have more hill left to go? downshift..
And this is true all the way down to 1st gear.
The trade off, is a I can accelerate to HWY speeds in 3rd gear (manual).. and settle into 4th once speed is attained..

The main drawback, for me, is that I run out of gearing in 1st.. and I wish I had a granny.. particularly off road and at higher altitudes.
This was true with my tall 14" tires, it is even more pronounced with my much taller 16" tires..

There I also the problem of the big gearing gap between 2nd and 3rd in the manual.. where dropping to 2nd on a HWY grade limits your speed as you wind out to 5k.. but shift to 3rd and it lugs.. Not good, but rare circumstance.
This may not be an issue with the auto, however.

I find there are grades, offroad and at altitudes of 6000'+, 1st gear territory,.. where the smaller 14" tires made it up OK, but I had to SERIOUSLY slip the clutch to get the van up with the much bigger 29.5s.
I know of one road in particular where the van could not do it with the big tires where I had gone before with smaller ones.. but that could have due in part to a big camping load, as well.

The 25" tire and the gearing that VW chose was done, in part, to optimize the van for 55mph HWY speeds...
My personal opinion that a lower cruising rpm with 27-28s is a good tradeoff. But mostly just for reducing engine noise levels.

MPGs suffers slightly due to more windeage as tires get bigger.. AND due to ease of traveling at higher speeds. I.E. Cruising at 70 in a van 1" taller is going to consume noticeably more gas than cruising at 60 and is 1" lower.

I have lost about 10% fuel economy with a 3" over stock ride height and the 29s make for 2" of that. That is not a trade off too many people would take..
And in my opinion it is this fuel economy issue that would be the biggest compromise.. not the perceived loss of power.

My next set of tires will likely be 28-28.5s.. regardless whether I change powerplants. The choice to limit to 28.5 has mostly to do with re-gaining full suspension arcticulation in the front wheel well...

Sun Apr 27, 2014 12:50 pm

j_dirge wrote: The choice to limit to 28.5 has mostly to do with re-gaining full suspension arcticulation in the front wheel well...

This is an important factor. Are you warning the OP that if he goes to 235's his tire will rub the front wheel arch?

Does that mean he would need to modify his fender, or use higher lift?

How much lift do you have, and how much more would be needed to solve the problem?

Sun Apr 27, 2014 2:01 pm

Jon_slider wrote: j_dirge wrote: The choice to limit to 28.5 has mostly to do with re-gaining full suspension arcticulation in the front wheel well...

This is an important factor. Are you warning the OP that if he goes to 235's his tire will rub the front wheel arch?

Does that mean he would need to modify his fender, or use higher lift?

How much lift do you have, and how much more would be needed to solve the problem?
Yes.
This contact occurs when the wheel is turned outward and compression is moderate to extreme.
235s are almost sure to hit the top of the fender lip, It is not just "rubbing" The contact results in "fender bang" and cut up tires.

Before you even get that far:
The 235 will require effective ET of ~25 to even fit without the tire hitting the upright inside.. and that pushes out the outer edge of tire even beyond where mine (a 225) is located

No amount of lift will fix that, as the suspension will compress regardless what height spring you put in.
The ONLY way to stop it is to modify the fender lip (push out and reshape) and/or introduce added bump-stop to slow/stop the upward travel of the wheel. Adding bump-stops reduces overall suspension travel.. and that begins the law of diminishing returns. You'd be limiting upward travel to about 2-3" depending on spring used.

I believe there is potential in lifting the van (2WD) by lowering entire front suspension.. not just a spring lift.. but that would require cutting and welding of the lower control arm mounting points, relocating steering rack, etc. RCA bulkhead..
I was jawing with Burley about this once.. building new longer LCAs that pivot from further inboard.. lengthening RCAs.. building a "long travel" 2WD.. prerunner style..
Sadly, my pocket book can not support that idea coming to fruition...
:D

Sun Apr 27, 2014 2:34 pm

By design I have never seen any reason to put larger tires on my '85. The ground clearance is already very significant and with skill you can drive over some pretty ugly terrain if want to. A little wider would not be an issue but taller seems like a waste of time. I have 205/65/15's , but may go to a 215/75/15 to be able to get into an AT tire.