Hats off to the Scion Racing Rally xD team once again. A great result for a less-than-perfect event.
For those that have not been following the Rally America series, the TEIN-sponsored Rally xD has been leading the 2wd pack, taking back-to-back wins in its last two outings.
This time, however, proved to be a true challenge for the crew. Mechanical woes hampered their performance for most of the event. As we understand, boost related problems were later resolved during the last day of the event. Through the final day of the event, a blown head gasket threatened to take the team out of the race entirely. Enough time for driver Andrew Comrie-Picard to make his push for yet another podium finish (3rd place). Well done, ACP.
As has been mentioned several times before, rally racing ain’t easy. Parts will break and driver and co-driver will be tested. But, persistence is key in getting everything in running order.
As the famous Rick Mears saying goes, “To finish first, you must first finish”.
Let’s look forward to their next event (Susquehannock Trail Rally starting May 31).
As we previously mentioned, the Sparco Rally xD team had a rear twist beam axle failure during the last event, Susquehannock Trail Rally in PA. Once they got the car back down to California, they dropped off the rear dampers to us for inspection/repair.
Like we stated before, we knew that the dampers had some damage and broke the piston shafts. Here’s a look at the carnage
Remote hose was ripped right off. The shell case took a few hard impacts causing some dents. Now onto the piston shafts
The above picture shows the top of the shell case where the ring nut seals off the damper. The piston shaft broke midway and the remaining pieces recessed into the damper with oil coming out this ring nut portion. The top portion of the piston shaft was still attached to the shock tower.
This pic below shows the piston shaft broken towards the top, snapping right off after the twist beam axle gave way.
But after a full teardown, we saw that the inner tube (where the piston is inside of) was still intact. The outer shell case took a hit, but the inner tube was unscathed during this violent axle breakage. Here’s a pic showing the dent
The second pic from the top shows the other indentation on the shell case.
On a mono tube damper, this wouldn’t fare so well with that type of dent. Since the piston would reside right against the inner lining of the shell case of a mono tube damper any imperfection to the case will make it either impossible to function properly, or to be field stripped, or both. This is what I meant as testament to the durability of the twin tube damper structure and this case shows it well!
If you’re wondering why we would make a twin tube damper for a rally car, there’s a bit more to it than just the damage that could be inflicted to it physically. Our HG twin tube structure isn’t like a normal damper.
In a standard twin tube damper, there is still an inner tube that contains the piston shaft and piston. This area is fully submersed in damper oil. From the bottom of the damper and through the base valve controlling oil flow into the outside of the inner tube (inside of the shell case) is where there is some oil and the nitrogen gas charge. This charge is important in sufficiently providing rebound force to the damper.
What we do with the HG is fill the inner and outer tube with damper oil.
But wait. If you fill a damper full of incompressible oil and no compressible gas like nitrogen, then technically the piston shaft will never recess into the damper and it wouldn’t function at all.
That is true. But this is also why we utilize an external reservoir to keep the nitrogen charge separate. With this, we can eliminate any chance of aeration (nitrogen gas mixing with damper oil, causing it to froth, decreasing damping effectiveness) while still being able to secure sufficient rebound. The twin tube structure also allows ample stroke length for a given shell case size compared to a similarly built mono tube damper.
So why not utilize this design into all rally suspension? Mono tube dampers still have many great benefits- they dissipate heat better; when inverted, they decrease unsprung weight (you can technically invert our HG damper, btw); they allow a larger piston size; overall damper oil volume can be much higher. They also allow for us to use our Group N.technologies, which aren’t readily applicable to twin tube dampers
But mono tube rally dampers are a much higher investment as development costs are quite high. Also, they are physically much larger in length and body diameter. the pistons used in them are much larger too, which is key for precise damping control.
So in the end, the HG is still very capable and also very durable at a much more reasonable price!
Anyway, enough ranting. We went right to work getting it rebuilt with new shafts and internal seals. this time, we stuck with our shorter length reservoir hose, still giving the team the freedom to reposition the external tank for their needs.
Awwww. Looking as spiffy as it will ever be! Ready for more abuse!!!
Speaking of which, here’s a video the Rally xD team posted from their blog showing the twist beam axle breakage
If you’ve been following the Sparco Rally xD team as much as we have, then you know that they have consistently placed podium finishes. As of the Oregon Trail Rally (May 4-6), they temporarily held 1st in championship points under the 2wd class. Good stuff! That’s not an easy task, mind you!
Consistency is key. If you follow these dudes on Facebook and/or Twitter, you’ll see that they completely rework the car after every event, going down their laundry list of items to check, making sure that all components are good to go or replaced if needed well before the next race. I must add that they run a very tight ship- only a handful of guys working on this car. They not only serve as pit crew and transportation, but I’m guessing also as entertainment for their driver and co-driver Andrew Comrie-Picard and Andrew Wimpey. Geez. That’s a lot of work!
After every three or four events, they normally send their custom HG dampers to us for inspection. In some cases, they go longer without inspection, especially when they quickly have to prep for the next event. As with anything rally, these parts take a beating! In our case, it’s normally exterior coatings that get blasted off by dirt and gravel. Minor concern, i suppose.
Before the Oregon Trail Rally on May 4th-6th, Crew Chief Philip Chase brought in the dampers for a quick check. Surprisingly, nothing to really change on the front dampers.
Jon a.k.a. Sir Smiles-A-Lot Inspects The Front Dampers.
But for the rear, he requested remote reservoir mounting (tank detached from damper body), rather than the external mounting (tank attached to damper body) to give them freedom to reposition the external tank and add some needed clearance in the wheel well. Since that kind of work requires complete damper tear down, we overhauled the rear dampers for them. Now they have the reservoir attached by way of a braided steel hose, allowing them to reconfigure reservoir arrangement (they still keep the reservoir close to the damper body, just upside down and a few degrees in towards the chassis).
Still, even with all this preparation and constant rebuilding, something is bound to go wrong in the world of rally. Case in point- the Susquehannock Trail Rally (June 1-3) proved to be the breaking point for the Rally xD. This time, a fatigued rear twist beam axle gave way, pulling apart the axle and the damper assemblies. Ouch! Seven consecutive events can easily do this to a car and its parts. But seven events is also a long time of service! Seems the xD ain’t no cheapo box, afterall!
Susquehannock is no joke. check out this video showing the driving conditions they face
Fortunately, the break was at the beam. So it looks like they’ll be able to repair the car in time for the next event. Also, it seems that our customized HG rear dampers may be able to be repaired, too! That’s testament to the strong twin tube structure of the dampers that can take a good amount of punishment!
Next up is preparation for Pikes Peak, then off to New England Forest Rally (NEFR). They’ve got some time to knock out repairs.
I wish them the best this season, as these hard-working guys continue to do a great job time and again. On our end, we’ll continue to do the best we can to make sure their TEIN HG dampers are in top working order!
Keep it up, guys!
For an econobox, this Rally xD is one tough shoe!.
There’s some good recap of the events at Rally America’s website
www.rally-america.com
And of course, the dudes at Sparco Rally xD keep their blog up-to-date!
www.rallyxd.com
You can also follow them on Facebook (Rally xD) and Twitter (@RallyxD)! Oh, and you can follow us on Facebook, too (TEIN USA, Inc.)!
P.S.- if you were to look up the Finnish term “Sisu”, I’m almost positive that you’d find a picture of the Rally xD team. Look it up!
