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So, I've got this crazy idea for a WRX modification that is inspired by the "Truggy" [Trophy Truck + AWD Buggy] R/C Car segment and the Jeep Lower Forty Wrangler Concept; though, not to the extreme degree shown on these vehicles.

It essentially boils down to this: lifting the vehicle with larger diameter tires, without modifying the suspension [no suspension or body lift]. This allows the center of gravity [relative to the suspension geometry and unsprung portions of vehicle] to remain the same, while gaining ground clearance.

Hopefully this will allow for blasting down rutted up fire roads with impunity, while still retaining handling for having fun on the pavement. Of course, I know skid plates will help with the WRX's all terrain lifespan, I'm looking for a little more.

I'm willing to drive it ugly, as I'm sure the fenders will go under the knife in some form or fashion to make the tires fit. I would like to keep mud off the windows, but other than that, I don't mind the loss of portions of the fender. Hell, I might enjoy the weight loss of losing all the body panels not integral to the unibody chassis. This might help offset the essentially taller gear ratio provided by the larger tires. I'm just wondering if anyone out there has seen or experimented with anything similar to this.

I know I'm gonna have to deal with steering lock issues as the tires will rub there as well. Maybe that will force my hand into some suspension mods, but I must stress I wanna preserve the center of gravity as best I can, so I would try to limit it to just widening the track with custom hubs or something.

I'm just talking anywhere from 4-7" taller tires [giving me 2-3.5" of increased ground clearance]. I've seen all sorts of stuff about wider tires, but nothing about taller tires.
 

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I'd be hesitant to do something like this because of added stress on the transmission; WRX's aren't known for having overly build transmissions. More so if you have an '06-'07 with the 3.X (X=7,8?) final drive ratio.

Love the bigger tire, minimal (no) lift approach however. A long travel WRX would be sick.
 

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thanks for all the help. i can't believe how fast y'all got back to me. the ducati forums have nothing on how active this place is...
 

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I'd be hesitant to do something like this because of added stress on the transmission; WRX's aren't known for having overly build transmissions. More so if you have an '06-'07 with the 3.X (X=7,8?) final drive ratio.

Love the bigger tire, minimal (no) lift approach however. A long travel WRX would be sick.
maybe if i try to drop unsprung weight with expensive lightweight rims, rotors, hubs, i could offset the tire weight and diameter effects some...
 

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I'd be hesitant to do something like this because of added stress on the transmission; WRX's aren't known for having overly build transmissions. More so if you have an '06-'07 with the 3.X (X=7,8?) final drive ratio.
This. Larger diameter tires will have the same effect as gearing down the drivetrain. It will make the car very sluggish and put more strain on the [already] weak transmission. If you plan on trekking down this path, you will have to choose revised gear ratios and/or a more aggressive differential ratios to negate the effects of the wider tires (assuming you want comparable performance)

BTW the 06-07 5spds have a 3.7 F/D but the center diff has a 1.1:1 ratio so that effectively makes the F/D to the front and rear diffs 3.9 (same as previous 5spd)
 

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BTW the 06-07 5spds have a 3.7 F/D but the center diff has a 1.1:1 ratio so that effectively makes the F/D to the front and rear diffs 3.9 (same as previous 5spd)
Hmmm...so does this mean that the strength of the drive train of the 06-07 isn't weakened compared to the '05 all things being equal?

I always did have this fantasy that 06 gears are stronger in some way...but it's probably just a fantasy.
 

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Hmmm...so does this mean that the strength of the drive train of the 06-07 isn't weakened compared to the '05 all things being equal?

I always did have this fantasy that 06 gears are stronger in some way...but it's probably just a fantasy.
no one seems to really no the answer... I don't think the driveline is any more susceptible to failure, because the stress on the transmission (as imparted by the wheels) is the same as the predecessors. I would think that Subaru would choose to strengthen the 5MT given the gearbox failures of the past (which they did for some MY2003 WRXs by increasing the width of 1-3 by 1 mm), but who really knows with Subaru... one thing is for sure, there have been less documented tranny failures with the 06-11 WRX 5MT than there were between 2002-2005, but correlation does not mean causation. Who knows, maybe the Subaru crowd "matured" a bit and stopped drop-clutching at 6000 RPM... :confused:
 

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So, I've got this crazy idea for a WRX modification that is inspired by the "Truggy" [Trophy Truck + AWD Buggy] R/C Car segment and the Jeep Lower Forty Wrangler Concept; though, not to the extreme degree shown on these vehicles.

It essentially boils down to this: lifting the vehicle with larger diameter tires, without modifying the suspension [no suspension or body lift]. This allows the center of gravity [relative to the suspension geometry and unsprung portions of vehicle] to remain the same, while gaining ground clearance.

Hopefully this will allow for blasting down rutted up fire roads with impunity, while still retaining handling for having fun on the pavement. Of course, I know skid plates will help with the WRX's all terrain lifespan, I'm looking for a little more.

I'm willing to drive it ugly, as I'm sure the fenders will go under the knife in some form or fashion to make the tires fit. I would like to keep mud off the windows, but other than that, I don't mind the loss of <a href="http://www.bcduplication.com" style="color: rgb(40, 40, 40) ! important; text-decoration: none ! important; cursor: default ! important;">next day cd duplication</a>. Hell, I might enjoy the weight loss of losing all the body panels not integral to the unibody chassis. This might help offset the essentially taller gear ratio provided by the larger tires. I'm just wondering if anyone out there has seen or experimented with anything similar to this.

I know I'm gonna have to deal with steering lock issues as the tires will rub there as well. Maybe that will force my hand into some suspension mods, but I must stress I wanna preserve the center of gravity as best I can, so I would try to limit it to just widening the track with custom hubs or something.

I'm just talking anywhere from 4-7" taller tires [giving me 2-3.5" of increased ground clearance]. I've seen all sorts of stuff about wider tires, but nothing about taller tires.

Hehe this sounds pretty sweet :whoa:
 
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