Bigger tires possible?

[chetubi]

Hi there,

Yes. I used the search function and even went through 90 % of the tire and wheel thread.

Nevertheless questions remained.

I have a 2008 e350 EB QuadVan 5.4 V8. 4" lift. I run 285/70/17.

John @QuadVan said this to be the maximum without modifications.

Hm. I see. But they still look tiny in there.

1. What are your experiences with a similar setup?
2. How much bigger/how big could I go without mods?
3. If anything would have to be done/trimmed: What would it be? Is there a "how to" thread?
4. I have 4:30 gears so this should be fine with bigger tires?!
5. When tires get bigger the speedo will get wrong. This is quite a problem according to German law. Is there an easy fix (how?) to adjust the speedo afterwards?
6. Is there any known correlation between bigger tires and higher risk of a "death wobble"?
7. Any other pros and cons? (Gas mileage is familiar. More so a problem over here: 1 gallon = 6.16 US$ )

Btw at the moment I run Hankook ATs but want to go to Cooper Discoverer STT PROs.

Hope you got my point? It's just school english.

Thx

Philipp

[Stillvanin]

As far as fitting bigger tires I can't help you because I have a 6" lift but the speedo can be fixed easily with a tuner, try 5star Custom Dynomometer Chassis Tuning Products and Services - 5 Star Tuning They can also help with a tune for more power. Not sure if you have big hills over there but my 5.4 with 4:88 gears and 35" tires definitely stays in the high rpm's on long climbs.

[rallypanam]

1. My observation is these are all a little different, so what fits on one van might not fit on another.
2. Probably not much, if anything, before you start rubbing front tires when turning.
3. Here's one way to handle that: http://www.sportsmobileforum.com/for...ers-18043.html
4. yes, that would be fine. I have 3.73s (and diesel) and thinking of upsizing tires next time, will probably need to regear.
5. yes, see above
6. rumored correlation, but I don't know if anyone has any proof or anything
7. sure, worse gas mileage, taller to get in and out, but better ride offroad, looks better.

[chetubi]

Thanks.

Helpful.

[opt overland]

Anything bigger is going to rub unless your able to drive in a straight line and never turn. This is true with a zero offset wheel and a -12 offset. With a gas motor I wouldn't go much bigger than what you have currently. How heavily loaded is your van? Because the bigger you go the worse performance your going to have both fuel and starting from a stand still. Unless regeared 33" is the absolute largest I recommend with a gas motor. Now again most folks never use their vans in situations where heavy flexing is involved, so trimming the fenders a bit should work. If 35's or 37's are desired? A lot of trimming will be needed and it's going to drive like crap. Thankfully you have the v8 and not the unnecessary v10 which even 33's are horrible when it comes to performance. But I suppose we all drive differently, I'm more like the hare not the tortoise

[chetubi]

thanks again ...

hearing all that I tend to stick with the 285s ...

Just might bring trouble going bigger. And to be honest: It would more or less just be for the looks.

Thankfully you have the v8 and not the unnecessary v10 which even 33's are horrible when it comes to performance.

I did not get that. Sorry. I'm not a native speaker. Is it some kind of irony I did not get?

[REF]

Not sure what engine you're running has to do with this....
There are some threads on here, somewhere. Anyway, I posted up a while back the mods that were needed to fit larger tires on my quigley, this was not only for looks as my goal was improve clearance and get better articulation and ride quality out of the suspension, esp with the R.I.P kit.
You'll need adjustable or longer fixed length torque arms to move the axle forward, several places to source these, CCV(adj), Boulder Off Road(fixed), Ujoint and maybe now mg? Usually can get away with using same front drive shaft, Derek at CCV used the existing quigley torque arm mounts at the time, but I may swap those out since he's got his own brackets now that will help line things up a bit better.
By moving the axle forward you'll need to weld on a new track bar mount to gain front diff clearance and get things back in line.
I ditched the stock front sway bar and had BOR install a larger one with new brackets, and they added end links, helping to eliminate bump steer. You can keep the stock one, just make sure you replace the I beam bushings if you've got them, they usually wallow out and create front end slop.
Other things to consider replacing while you're at it-ball joints, tie rod ends, steering stabilizer and any other bushings that look worn. Good luck, it's not cheap, but the gains are huge, my rig handles and rides better than ever.....with 315's



'03 Ford E350 7.3L Diesel
RB "50" SMB
Quigley 4X4, Deaver's and RIP kit
CCV high profile pop top

[schluchtenflitzer]

Hello Chetubi
I think for 35" it should be OK to trimm the front fender and bumber. For 37 you also have to trim the rear fender (both sides) and as i know your van you need to bring the front axle 1" to the front
I (37") do not feel any difference in the driving on the road except of course the brakes getting weaker. The van still go perfect straight even at 150 km.
I am shure for 37 you need to regear your van to 4.56 or even more
I can give you more information if you still need it. Now i have more internet possibility as we are back in the more civilisized part of africa