WRXtranceformed

Hi all,
I wanted to get some feedback here from anyone who has driven their RDX on fairly rough roads. I realize this is definitely not an off road vehicle but we head up to the mountains to see family frequently and some of the areas we go don't have the greatest roads or are on gravel. Has anyone had any issues getting hard bumps / rocks banging on their underbody?

I watched a ToV video that did a review of an 07 RDX and from that video there didn't seem to be a lot of protection around the pan or the exposed oil filter. Here's the video:
https://youtu.be/sZvwdmlTOL0

FWIW we visited an old family farm and the road is rarely used and was pretty washed out (some 4-6" ruts). The car handled it like a champ. I was taking it pretty slow and some of the off camber drops I made sure to navigate both wheels into, but the car seemed just fine. I'm just wondering if it would make sense to examine the clearance and consider taller tires or some kind of extra protection. The only other thing that I have seen that drops down a bit is the stock exhaust.

RDX10

You will mess up the handling and safety characteristics by choosing a too tall tire. You will also make the speedo WAY off and possibly under or over read your current speed.

You could go to a custom offroad shop and have them fabricate a 1/8 inch aluminum skid plate and weld it to the underbody. The RDX obviously is not at all suited for any form of offroading as you know and I stress that you take it easy because it is actually a very fragile platform.

Jdrum1

The filter would worry me more than the oil pan. Not that you don't want to be careful, but I've seen some Honda oil pans get bent to heck without breaking.

I would think that a creative shop could come up with something to protect the filter. Obviously, it has to be removable or still give adequate access for changes. I never have cared for the way the filter hangs down.

While it's not made for it, the RDX isn't that delicate. I took my ex's CR-V into some places it was never intended for!

Off-road situations are the one time I miss my old 4Runner..........

RDX10

It is just my opinion that FWD platforms are not nearly as stiff or robust as RWD platforms. But this is all opinion and could be false.

Jdrum1

Didn't mean to make it sound like I was disagreeing with you. The undercarriage and drive-train are more akin to that of a sedan, so caution is a must!

RDX10

My response was more of a response to your comment on the platform not being that fragile. I was just stating that RWD platforms tend to be much more robust and therefore like we are both saying, the OP should still be extra careful with it.

WRXtranceformed

Yeah it would be interesting to see if some kind of plate could be fabbed up that would screw off and on to the subframe for oil changes and protect the filter / pan. I need to take another look at the underside of the car and maybe have a guy locally see what he thinks he could do.

As far as the tires that is a good point, although I definitely wouldn't put truck tires on it or anything so I'm not worried about the speedo (you could say the same thing about moving to a 20" or 21" rim). Also not super worried about the handling. I'll have to do some research here as well but I bet I could find the same tire I am looking for with a larger aspect ratio. Theoretically that would give me a bit more breathing room.

Either way caution is definitely important although I was really impressed with how the car handled a fairly rough road!

RDX10

Yeah you should find out if you can get some sort of custom plate prefabbed for it. What do you mean about going from a 20 inch rim to a 21 inch rim? When you do that, you still have the same rolling diameter, you only have more rim and less rubber and if you increased both the rim and the rubber, then your speedo will be way off. So what I am trying to say, is the only way to increase ground clearance is through some form of lift kit, and the only way to increase ground clearance via tires is to use larger tires and that would effect the speedo significantly.

I believe the SH-AWD system would be brilliant to have for the front and rear axles on an offroad vehicle, get 100% of the power to the wheel with more traction and capable of sending close to 100% of the power to either axle, it would do amazing in situations where there is an angled rut and the front and rear diagonal wheels are off the ground.

WRXtranceformed

Yeah I was just under the assumption that most people who put significantly larger wheels on their cars don't take into account the speedometer difference when also ordering new tires.

I just ran a calculation as an example for the tires I am looking at for the next replacement, the Nitto Motivo. Here are the three tire sizes that Nitto's site says will fit my 19"s:
245/45ZR19 - Diameter 27.7"
245/50ZR19 - Diameter 28.7"
255/45ZR19 - Diameter 28.1"

Using this calculator, by jumping up to a 50 aspect ratio from a 45, it would affect my speedo by varying levels depending on the speed.
Speedo reading: 25 mph, corrected speed 25.9 mph
Speedo reading: 35 mph, corrected speed 36.2 mph
Speedo reading: 60 mph, corrected speed 62.1 mph
Speedo reading: 70 mph, corrected speed 72.5mph

So I would have to figure out if the extra half inch of ground clearance I guess it would be is worth a .9-2.5mph variance for most of the speeds we would be driving. The other option I supposed would be to figure out some sort of mild suspension lift but I don't know if it is worth the cost to go that route.

RDX10

I have to admit that I am uber OCD about the speedo and that is the only reason I am making a big deal about it. A difference of 1-2mph is almost nothing at all. Though most factory speedos actually under read and by upsizing a little bit, you will get a more accurate reading actually.

I honestly don't think that extra half inch is worth it though, even a lift kit would be extreme for something like this. Adding bigger tires and raising it off the ground more will lead to much worse handling dynamics, floaty suspension, not to mention worse fuel economy. I hate to be "that" guy on a forum who shuts down fun ideas, but I just want to make sure you are aware of the outcome of doing something like this.

But if you still feel like you want to pursue this, let us know! This sounds like a really cool and fun plan.

WRXtranceformed

Oh yeah I have no plans to turn this into an off-road vehicle trust me haha. Based on the types of areas we go though it might be prudent to look into some kind of oil pan / filter guard. The clearance of the vehicle isn't actually that bad although it appears to be 2 inches less than the new generation (6.2" vs. 8.1")

Here's where it took us this weekend...

Makordx

My plan is to try to make or buy air cups for the shocks. Leave the RDX at stock height and use the air cups to raise the suspension 2". That way all of your normal suspension settings would not be affected on the street. When you went off road and raised the suspension, camber, toe in would be affected at a time when it would least impact the vehicle(slow speed). I still plan on making some lightweight steel skid plates because there is a lot of stuff hanging down. I do not plan on heavy off roading, but we do like to go off of asphalt on rough roads many other vehicles have gone down before us. It all comes down to compromise do you want a good road car or do you want a good off road car.
Mike

WRXtranceformed

That's a great point, I never thought about doing some kind of air ride suspension. That would give you the best of all worlds, great handling, softer ride for the highway and the ability to raise and lower the car as necessary without affecting the camber / toe 100% of the time...

RDX10

Yes I agree, very smart idea. I totally never thought about air suspension and I even had it on my Touareg. It is a BEAUTIFUL feature. I could raise the suspension and get as high as 11.4 inches of ground clearance, or lower it to 6.5 inches. It also had adaptive dampening and I could make it either soft comfort mode or harsh corner carving sport mode. Or in between at normal mode.

I suggest you look into something like this, but may be a little expensive. And btw that little cottage looks so fun and the RDX looks awesome.

WRXtranceformed

Thanks! It is a pretty neat place back in there, we took a bunch of guns up there, shot stuff and enjoyed the rare clear mountain weather That's where you would want to be at the end of the world...nobody in sight, plenty of fresh water and animals to eat.

The air suspension would be awesome but probably more money than I would want to dump into this car. I read a little into the cups and they are a good option but also not super cheap and it is not recommended that you really drive around much on them...a lot of them I guess were built for lowered cars to be able to raise the nose up a bit to get through low driveways and speed bumps. I think I am going to explore the skid plate route, and a friend of mine had a good idea for a hole to be cut to access the oil filter and drain plug. I need to look at the underside again to see how viable that is but that would be pretty cool...I could weld it on, set it and forget it.

I'll try to keep this thread updated with any progress...it's not a huge priority but I would like to get it done before we go back up there.

Makordx

I built skid plates for my tracker. I used countersunk flat head screws placed about every 3" to mount to the bottom of the vehicle. I usually like to weld things on as much as I can, but for skid plates they should be removable. Definitely make a hole for the filter and The oil drain.
Mike

RDX10

I hear you! On the other hand, I would prefer to be up there period, living in the city is so boring and monotonous. I eat meat, but don't have the heart to kill anything, I even feel guilty killing bugs haha.

Yeah I honestly think spending the money to put an air suspension system in is somewhat of a bad idea and investment (not that a car ever is). You won't ever get that money back at resale unless you took them off again and I just don't think the 2-3k is worth it for the few times you would use it.

A skid plate is probably your best bet. And yes please keep us updated, I love when people push things on car forums. You might want to look at the crv forum and see if anyone did the same thing as you.

mrgold35

There was a thread back in March about an RDX running over road debris and damaging the plastic fuel vapor canister under the vehicle. Not sure if skid plates would need to be extended for this area?

Link: https://acurazine.com/forums/problem...08-rdx-927926/

Makordx

I plan on laying underneath my RDX and imagining I am a rock trying to damage something important. Then look at what needs to be protected and then what can be protected. For instance it is hard to protect parts that need to move up and down like A arms. You also have to think about heat escaping parts that get hot. Weight is another important factor, I am not going to make a rock bouncer. My skid plates will be sacrificial, they will bend and hopefully save what they are supposed to protect. They will be removable. I will try to make them so I can back up when I get stuck(all the skid plates on my Tracker where made with back end open to help disapate heat. Great until I got stuck in sand and when I tried to back out, the skid plates acted like scoops.). It will also take me a great deal of time to make these because I am old and lazy, but I will post some photos when they are done. I always appreciate helpful tips
Mike

RDX10

I think it can be done, I just think you will have a hell of a situation on your hands because this vehicle was NEVER intended to leave the road so the engineers never even thought slightly about protecting parts.