Off-Road Hall of Fame inductee Robby Gordon shares the art of going fast in the dirt in a SPEED UTV design presentation series.
Take it from a guy that probably knows. Robby Gordon has been pushing the off-road racing industry to its limits for over 30 years and along the way, he’s picked up a thing or two. Now he is sharing his wealth of racing empirical engineering knowledge with the development of SPEED UTV.
Driven by a passion for a sport that launched a remarkable motorsports career, Robby is injecting what he learned from over thirty years of racing off-road, on-road, and everything in between, into born to perform utility terrain vehicles and trucks for the power sports industry.
28 Reasons to choose SPEED UTV
- Full tube frame with upper and lower “spines” and everything triangulated (Robby likes to point out the “A” s everywhere) but the bottom line is no dead-tubes and nothing in the frame is bolted together. The drawings Robby provides are colored to represent different tube sizes and/or wall-thicknesses. I’m not a structural engineer… but it tells me that actual structural engineers are really thinking it through and using the right tubes in the right places. This includes 2nd A-pillar bars (or “FIA bars”) and actual structure above and beyond the “intrusion” bars (he talks about why they’re so much more than intrusion bars, but even with the aftermarket cages like we have that add a V in an RZR or X3, it doesn’t tie down into anything below the dash). The only things keeping it from being race-legal in most sanctioning bodies are the door openings and lack of window nets. There will be an RG Edition later this year that has window nets stock, and SPEED will offer pre-cut and pre-notched tubes to weld-in across the door openings (at the top, as well as to either make a single diagonal door-bar or an “X”) to “finish” the fully legal frame. Obviously, 99% of the SxS market wants functioning doors, so the frame was built to be fully structurally sound without them, but he will offer them for racers
- True double-shear for all suspension steering using bolts exactly shouldered to the right length (threads never in the shear section), NO ball joints or single shear anywhere, no cheesy plastic “bulkhead” making up the 2nd side of the double shear (sorry X3 folks… but it’s true)
- The big aluminum front bulkhead that is the suspension and steering mounting points as well as the front diff with torque-limiter etc. This design is straight from his Unicorn trophy truck and was co-designed with Albin’s (they seem to know a few things). I see this as a big plus from an engineering perspective, BUT it’s a HUGE departure for the SxS industry and one of the few areas that I’m a little worried to see how it works out on the first run (which will include mine)
- Proper suspension geometry in the front end to virtually eliminate bump steer: Robby is claiming less than .5 degree through the whole 25″ of front suspension cycle… compare that to 4″ of bump steer in an X3 (I’m not sure what that translates to in degrees… I’ve heard it said it’s over 10 degrees). I’ve posted on this before, but just a quick recap… bump steer is NOT when you feel the steering wheel jerking around in your hand over bumps like it seems most people think. That phenomenon can be a product of bump steer. However, bump steer is when the front tire angle changes as a result of suspension movement. Say you took the front shocks off an X3 and just cycle the front suspension up and down… the front tires turn as much as 4″. THAT is bump steer. You can probably imagine why it’s bad… but in short, it means as each tire hits different bumps and does different things you have your tires constantly changing where they’re steering the car – and NOT in unison.
- Speaking of suspension and steering, forged aluminum front spindles
- Billet aluminum hubs that are the same on all 4 corners, and the bearing “carrier” bolts in (with the bearing being pressed into it). So, out on the trail or at camp you don’t need to press a bearing in/out of a spindle/upright to replace it. You just carry one already pressed into the carrier part and it’s the same for all 4 corners
- Speaking of things being the same, the upper and lower control arms are the same side to side in the front (obviously different top to bottom). All 4 shock bodies and shafts are the same (obviously different spring rates and valving front to back). As mentioned the hubs are the same on all 4 corners. Many other parts are made to be the same to make costs lower for keeping spares (think race teams here)
- And about those shocks, 3.25″ body internal bypass shocks with internal hydraulic bump stops and aluminum bodies and finned aluminum reservoirs. They have real dual-rate springs with adjustable cross-over ring etc. just like any real race shock vs. “helper springs” that have to go to coil-bind to get into the big spring in most of the competition
- 25″ of “usable” travel – it remains to be seen exactly how Robby is defining this, I would certainly HOPE he’s using wheel travel without bottoming not the Polaris measurement but he hasn’t gone too deep on that
- Oh, and through that travel, the width of the machine (77″ at the tire-bulges) does not change, other than a tiny bit at the very extremes
- As a benefit of ^this when you “pack” into a corner, the machine doesn’t become narrower and taller, like both X3 and RZR do, leading to some of the stability issues people point out in SxSs, whether just perceived or real
- It IS A CVT. Robby talked about this at length, but like I’ve spoken about before it’s the “right” trans for an SxS. You have a relatively heavy vehicle (I’ll cover weight in a bit…) with a relatively small (999cc) motor. Yes, the turbo makes it a wide powerband and torquey, but the CVT is still the optimal way to get power to the tires in an SxS… he compares it to the torque converter in a TT. If you’re not familiar, they run very loose torque converters (hence the Yuge trans coolers you see in them) to allow the engine to stay on the powerband even at lower speeds (listen to a TT… in many ways, they almost sound like CVTs with a flat-ish RPM even as the truck accelerates, at least until it gets up to stall speed then gains RPM)
- Like an RZR or X3 or XX or whatever yes it’s a CVT, but they also have a transmission to provide low and high, as well as things like park and reverse. However, in the SPEED you get low, high, and Cruise (which is basically a high-high) so if you’re doing a long day on fire roads, or even real roads in free States or in Mexico you don’t have to turn 7-8k RPM all day… Robby is also reporting it will be a shift on the fly. I know with the 5 RZRs I’ve owned, I’ve always been annoyed that I have to stop and drop it in low for technical stuff, then when you start going over 30 MPH (or don’t want to turn 8k+ RPM to just go 25 MPH) you have to stop and go back to high. It sounds silly, but where we ride it’s actually a pretty common issue
- Inside the trans, on the final drive AND in the front diff there will be torque limiters. These will keep torque-spikes from hurting parts (think coming down from a jump under throttle, or rock crawling and one tire all the sudden finds solid traction)
- The input shaft, gears, and bearings are roughly 2.5x the size of X3/RZR and they focused on quality bearings to avoid the problems with trans bearings you get with an RZR (and again, this was all designed with Albins)
- CVs and axles are way bigger than the competition, and the CVs are grease-able
- The engine is an all-new design (not Z1-derived as people, including me, had been wondering about or speculating) and Robby involved engineers from his NASCAR, Indy, and Baja programs. They’ve flipped the intake/exhaust sides of the motor so the turbo and exhaust are at the back of the vehicle, vs. being right behind the seats like it is in the RZR Turbos and X3. It’s a 2 cylinder, 4-valve per cylinder design (nothing too new about that) that they found provides more power at a lower peak RPM than the same displacement in 3 cylinders. The crank, rods, and pistons are FORGED stock to be ready for a big boost kit. They’ve put extensive engineering into the cooling system, and even water-jacket around the spark plugs. It will have 2 injectors per cylinder and a water to air intercooler
- Speaking of cooling, it has a large rear-mounted radiator with 3 large fans
- The fuel system is built to accommodate E85 from the get-go including a flex-fuel sensor and an ECU that will modify boost/timing/injector pulse width based on the actual % of ethanol in the tank (in other words, you don’t have to drain fuels when you switch and run either pure 91 or pure E85… you can have any blend of E in it and it’ll compensate)
- 15-gallon fuel tank and SPEED will offer a race-legal fuel cell that bolts directly in place of it
- 32″ tires stock, the body will clear 35″ (there will be a template for the minimal front fender trimming required, rear no trimming)
- 225 HP stock on 91 (20psi boost) and 300 HP stock with “SPEED key” on E85 stock (30psi boost)
- All versions will have a “bed” with room for a 35″ spare stock (the short 2-seater and 4-seater have a 35″ long, 48″ wide bed… the UTT has a 50″ long, 48″ wide bed)
- All versions (not just the pre-order Limited Edition) will have 5-point harnesses stock – this is a recent change, but RG felt there is just no way he can send these out without proper safety
- 10″ touch-screen mounted to move with the square-profile steering wheel for optimal visibility. The screen will be able to mirror your phone screen into a section of the screen while still having the necessary gauges and displays up to view your Nav apps (or whatever)
- Real alternator
- Real hydraulic power steering (he’s had too much trouble with EPS in places like Dakar and Baja)
- Random note: for our extra-tall friends out there, the UTT will have the option to move the seat back further than the “regular” 2 seat or the 4 seat