Need to Increase Ground Clearance on a Coupe
 

Hello!

First time poster here - been a member of the forum for a day now, had my 2006 G35 Coupe for 2! :icon17:

I've used the search function on the site to read old threads and discussions, and while I've found some useful information in past topics, I have some follow-on questions I thought I would ask here.

I seem to be in a very small minority of owners that need to raise their car up... (I know, I know) The ground clearance on the car seems to be stock from what I can tell - 5.5" or so - but unfortunately this is simply not enough room to get up and over the crest of my building's driveway.

From what I have read here already there seems to be two schools of thought: larger tires, or modify the springs/suspension(?)


Both of these bring up some questions I have, so in no particular order:

Tires

I believe the car has come with the OEM tires, 225/50R17 in the front and 235/50R17 in the rear. Reading online and in the owner's manual, I've found reference on 225/45R18s and 225/40R19s also used on the coupe. Obviously, I'm playing a numbers game here - I'm no tire expert, and when I use online calculators for tire size, most if not all systems say I should not exceed 3% of the original size. From what I understand, this would mean my hope of getting a larger wheel, along with a larger tire is not possible, correct?

I've had my only "car friends" also tell me this is a bad idea - that getting larger wheels could damage the suspension and brakes, however I've read comments here on G35Driver about 19 and even 20 inch sizes on a coupe.

Can anyone say out there with experience that a larger tire/wheel combination is safe and practical on the car?

Suspension

If not the tires, I'm not sure what to do next. I have read a single posting on the web that references placing G35 Sedan springs in the Coupe to gain a half an inch of ground clearance, however I can't find similar comments expressed elsewhere, and in talking to the Infiniti Tech from the dealership on the phone this morning, he thought I was crazy.

Is this a legitimate approach? Again, does anyone have real world experience with this modification?

The other recommendation I have received from a few people are "spring spacers." I'm a bit hesitant to trust my entire car to four $10 buck chunks of metal though. Anyone used them on a G35?


Ok - so that is all I've got! I have an appointment with the dealer today, they're going to do an inspection to verify that the correct springs are in place (I'm pretty sure they are), and after that, I'm afraid all they will do is offer to sell me new wheels. Anyone here have a better idea? (And yes, before it gets tossed out, moving and parking on the street are simply not an option and I've tries the whole "attack the hill at an angle" concept to get over it - no luck in a reduction of scraping/damage there either... sigh :icon43:)


Thanks to anyone with thoughts, I can't begin to explain the heartache this is causing... to go from "new coupe elation" to the sound of grinding metal trying to park it at home has got to be one of the worst feelings in the world.


Cheers,
Josh

well the problem is with bigger wheels, is that the tires get smaller, so i don't think you're really going to gain anything significant with that.

and i don't know of anyone that makes taller springs for the g, but maybe there is :dunno:


you could always get hydraulics :p

get airbags so you can rase it when you need to and lower it the rest of the time lol

how about a 4" lift kit from

http://img7.imageshack.us/img7/2984/...truckchall.jpg

You would need a larger wheel/tire (diameter) combo to increase ground clearance, but you would also impact the speedometer reading error by doing so, and possibly impact the VDC system. Most folks who go with larger aftermarket wheels and tires try to stay within 3% of the total diameter of the stock wheel/tire combos. Try taller aspect ratio tires as a starting point and see what the speedo error will be:
http://www.miata.net/garage/tirecalc.html

As for springs, check out the sticky in the Brakes and Suspension forum.

Can you approach the driveway at an angle? Even if you find a way to raise the car is it really going to screw with your handling, not to mention the looks of the car. It might be pointless but maybe you could talk to the building management to see if they would install some of the short ramps designed to help with this issue but still have a pathway underneath for water to flow down the gutter. Something like this:

http://www.griotsgarage.com/product/...curb+bridge.do

If your car has problems then at least a few other people in the building probably do too.

https://g35driver.com/forums/suspens...uspension.html

https://g35driver.com/forums/classif...g-out-car.html

^^links^^

both selling air suspension

"getting larger wheels could damage the suspension and brakes, however I've read comments here on G35Driver about 19 and even 20 inch sizes on a coupe."

Not sure why they told you that but getting larger wheels and tires wont hurt your suspension at all or your brakes. Hell ive seen up to 22's and 24's on the G before.

When you get a larger rim usually the stock brakes on cars arnt designed for the extra bulk and require minor upgrades to the brakes. My buddy put 20's on his IS300 and he upgraded the brakes because he felt a real loss of stopping power with the larger wheels.

Your biggest problem would be VDC, tire pressure system and speedo. Depending on what kind and size of wheel and tire you get could make this a big pain.

I noticed your sitting on 17's from your post. Have you looked into OEM 19's from the G and maybe going with a slighty larger tire size for more clearence?

Thats a good idea, I want one of those for my driveway! But that price is an absolute rip off for a piece of plastic.

Wow - this is a great forum! Thanks for all the info to date...


Would like to keep airbags/pneumatics as a place of last resort - although it looks like that may be an option. How long does a decent "conversion" take do you think? Is this something I ask an Infiniti dealer to install? (Would they?!)


yourdoingitwrong

Any change to the building is a no go (man I'd love it if they would!).

Approaching at an angle was tried this morning - it does lesson the contact, but it is still quite severe.


07PEARL6MT

Understood on the larger wheels - and that was my initial hope - however, unless I'm not understanding tires 101 (which is very possible), any gain I make with the tire, say - going from the 17" to the 19" (which I think would help a lot) will be undone as the tire itself becomes smaller, correct? (like the 225/50 going to a 225/35 or something of the sort?)

Overall, I'm not going to see the difference of the 2" gain as the sidewall lessons, no?


Cheers,
Josh

its not that hard, there are a few members in th LA area that can install them for you.

airbags would be the best thing to do, you dont want to mess up the look of the sexy G. :)

You could just trade the G in for a Lamborghini Gallardo, it comes with a feature to lift the front for curbs! Seriously though, I would have a custom shop do airbags for you, most dealers wouldn't do anything like that. My dealer is so anal they noted the fact that I have an Amsoil air filter in my car instead of a Nissan/Infiniti filter. It's not even any type of cold air setup, just a regular 'ol air filter in the stock box. They also wouldn't install a FACTORY exhaust to replace the piece of crap that was on my car when I bought it. Guess Nissan has some dealers scared to do much of anything.

you're correct, you won't see a 2" gain, there will be some gain, but not 2". not only because of the smaller tires, but also, the RADIUS difference from 17" to 19" is only 1", so you only get 1 additional inch of ground clearance from upgrading to a 19" wheel (assuming the tire wall size was the same)

however, all these little things can add up, and you might be able to make it


you could also try backing into the parking lot :p... it would seem like the rear is much higher than the front.... but you'd have to watch the exhaust

Thats true youll loose some with a smaller side wall but thats why I was thinking if you went with over sized tires it may help :dunno: Go to large and then you start running into those other problems. I know a shop that can do air ride install if it comes down to it but hes not in LA so you might have an easier time finding someone local

Go back and read my post again. Check out the tire size calculator and see what will fit on your stock rims and not put the speedo off by too much. You can keep your stock rims and add taller ratio tires and gain a bit of ground clearance.

See what cars in your housing complex can clear the driveway. Measure their clearance and see how much you need to raise. Try oem 19s