Hey, I'm a fan of quick, easy fixes that work. Nicely done. 
Photography by Tom Suddard
Our GTI has seen some track time. Lots of it, in fact, as evidenced by its podium finish in our class at the Tire Rack One Lap of America.
Each day on One Lap, we’d launch the car repeatedly from a standing start. And each time, we’d cringe as the car’s front wheels hopped like crazy, gaining then breaking traction in rapid succession for a few seconds until the car was in motion.
Wheel hop doesn’t just cost time–it costs money, as each time the tires regain traction is like a miniature neutral drop that reverberates through the chassis looking for the weakest link.
So as soon as we got home, we went to work fixing the problem. And it didn’t take years of effort or billions of dollars: It took less than $100 and about 20 minutes. Yeah, maybe we should have addressed the problem before a week of hard launches.
How did we solve it so simply? With two parts from 034Motorsport, both aimed at stiffening the car’s lower drivetrain mount, called a dogbone mount in VW circles.
This mount restricts the engine from twisting away from the wheels when power is applied, and its bushing is pretty flimsy in stock form. Volkswagen literally filled the rubber bushing with holes, introducing lots of voids in order to isolate the passengers from NVH caused by the drivetrain.
Replacing the bushing is a pretty difficult process, so to stiffen it up, we just jammed some aluminum in there to turn a metal-rubber-air-rubber-metal sandwich into a metal-rubber-metal-rubber-metal sandwich.
034Motorsport’s billet aluminum upper and lower dogbone mount inserts are CNC-machined to perfectly fill the OEM voids, and installation only took a few minutes. Basically, just unbolt the mount, pit the inserts, then bolt everything back together.
There’s no bushing press, torch, or agony required. And at $89 for the pair of inserts, this is one of the least expensive modifications we’ve made to the GTI.
But did they work? To find out, we took the car to a local autocross where we could launch to our heart’s content without fear of police or pedestrians.
[What can our GTI daily also do? Win at autocross.]
And instead of wheel-hop, we were treated to a clean, progressive breakaway no matter how much we played with the throttle or the launch control. In short, the modification was a success, and should make the rest of the car last far longer.
Of course, there is a downside: NVH has increased. On the highway, it’s a barely perceptible change, but at red lights you’ll be wondering when you installed solid engine mounts.
For the performance increase it’s a small price to pay, and it’s also easily reversible if we ever change our mind. We doubt we will, though, as there’s something magical about being able to cleanly shred the front tires on a whim. Have we mentioned lately that we love this car
Hey, I'm a fan of quick, easy fixes that work. Nicely done.
NVH?
In reply to jkstill :
Noise, Vibration, Harshness
In reply to TJL (Forum Supporter) :
thanks!
Any photos of the inserts in rubber bushings?
I did the same mod to my GTI a year ago and I experienced the same NVH, but it seems to go away after a while. Either it "breaks-in" or you just get used to it. I really like how it hooks up from a launch. I mainly noticed the harshness at startup and coming to a stop. It was almost like the DSG was confused, and was tentatively working the clutches.
I know that 034 is a sponsor of the segment, and they make the aluminum inserts featured. There are alternatives that fill the void in the factory mount with a stiffer elastomer, and don't come with the NVH of the solid insert. It's all a matter of how much street car is your track car?
Either way, a great mod that really helps get the power down for little cash.
In reply to Schnitzel760 :
I recall using those inserts from Brand ES, in a ZX2.
Wheelhop was entirely eliminated, but the car buzzed at idle and you could feel the drivetrain vibrations more the rest of the time.
It's almost like engineers are good at their jobs, eliminating NVH while only sacrificing edge cases.
The cheaper, less harsh, ghetto fix to bushing voids has been to fill them with urethane caulking, basically turning them into solid rubber bushings.
For engine mounts, you might want to leave a small void left to reduce engine vibrations felt, but quickly take up the void under acceleration?
engineered said:The cheaper, less harsh, ghetto fix to bushing voids has been to fill them with urethane caulking, basically turning them into solid rubber bushings.
For engine mounts, you might want to leave a small void left to reduce engine vibrations felt, but quickly take up the void under acceleration?
It has been recommended using plastic straws in the areas you plan to fill with urethane can help reduce some of the NVH by allowing some deflection of the mount still. Cut the straw to the width of the area being filled, stick them in place and then urethane around them in the voids of the stock rubber mounts. Once cured you will have "compliance" voids where the straws were placed.
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