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HSTuning RSR Clutch Kit Feedback
- Thread starter rupertpupkin
- Start date
rupertpupkin
Ready to race!
I was going to go with the Southbend Stage 2 or 3, which is 1100-1300 ish...I dont race or track I just drive aggressively. I did not want to deal with the downsides of the SB- NVH, chatter, on/off engagement, etc. I'm plenty happy with OEM but it cant hold the power. So the RSR makes me happy. I also like the fact that they are using OEM parts that have been proven in other vehicles. I have always wondered how a 400+ HP corvette has a normal clutch, but there was never an offering for our cars that held the power but remained civil. RSR seems to fit that bill.
lamb110
Go Kart Champion
I was an early adopter of the RSR, and have close to 16,000 miles on it (and Stage 3). It still grabs and holds the power without a hint of slip. I had a SouthBend Stage 2 in my GTI and after about a month I basically hated driving the car, it wasnt that it was too loud, but that with as many miles as I drive it gets old VERY fast.
The RSR is a bit pricey, but I'd glady buy another one if it ever comes to that.
On a side note, Jeff at HSTuning was awesome. He went to his wife's work and borrowed her GTI which had been running the clutch for some time, just so that I could drive it before I made the decision. They also had a SouthBend waiting incase I didnt like it, so obviously we know how that worked out.
If anyone in the Chicago area is on the fence about buying one let me know, I'll let you drive me car to try it out.
The RSR is a bit pricey, but I'd glady buy another one if it ever comes to that.
On a side note, Jeff at HSTuning was awesome. He went to his wife's work and borrowed her GTI which had been running the clutch for some time, just so that I could drive it before I made the decision. They also had a SouthBend waiting incase I didnt like it, so obviously we know how that worked out.
If anyone in the Chicago area is on the fence about buying one let me know, I'll let you drive me car to try it out.
HSTuning
Ready to race!
This isn't something that we'll easily be able to achieve. The FSI/TSI and 02Q cars don't have a pilot bearing in the crankshaft for the input shaft of the transmission. Any single mass unit will create more noise. We are focused on other projects right now and haven't seen much demand for a single mass unit. Most of our feedback from customers is that they are happy to not have noise :thumbsup:
If you can do it... you'd surely capture a huge chunk of the market as there are still plenty of folks who want the benefits of a lightened flywheel.
If you guys do toy with the idea, I would really press you guys to look at OEM solutions that utilize a lighter flywheel. I know the B8 S4 has a MUCH better rev motion than on this car. It's super quick. The flywheel weighs around 23lbs I think (vs our 29lb flywheel).
This might be the compromise needed to get the OEM performance/feel with added benefits over the stock part.
Most of our rev hang is due to the ECU and emissions control. This is supposed to be fixed with the upcoming APR tunes. I've went from the stock dual mass, to lightweight and back to the dual mass and noticed minimal differences. The noise on the other hand, was a huge change for the better.
I mean... no matter which way you slice it, its a 29lb flywheel... that is wildly heavy. I've seen videos of folks w/ aftermarket flywheels and the revs move quicker. That being said, I'm curious to see how it performs w/ this removed.
lamb110
Go Kart Champion
I had a SouthBend kit on my GTI, I honestly noticed very little difference in the way it rev'd. I think the whole lightened flywheel is overblown in it's effect on performance. Definitely not worth the trade off in noise and vibrations.
I'm not sure how you can discount it in terms of performance given its directly connected to your engine and translates power to the transmission. Generally speaking, less rotational weight = better performance. Same concept goes for our 29lb Detroits.
lamb110
Go Kart Champion
I'm not saying it has NO improvement on performance, just not one that you'd likely notice. The trade offs are not worth it.
HSTuning
Ready to race!
We've had flywheels out of the B8 S4 cars before, and I can assure you, there is not really a case to call those units lightweight. Comparing the flywheel in that car to the GTI or Golf R dual mass is not an apples to apples comparison. Completely different drivetrains, engines, powertrain management systems, and even small differences such as the throwout bearing/slave cylinder assemblies. To say that the S4 revs faster because it has a lighter flywheel is a bit of a misnomer.
There are so many different parameters that affect how the rev speed of the engine, the weight of the flywheel is just one of them. The push for a lighter flywheel is a throwback to the days of older engines. Modern technology in cars doesn't necessarily mean the same tricks that have been used in the past are as effective, or even desirable at all.
For example, we have done many back to back tests with lightweight flywheels and dual mass flywheels in stage 3 Golf R cars. When free revving the engine (with the clutch depressed), the lightweight flywheel does allow the engine to accelerate quicker than the dual mass flywheel allows. However, with the clutch engaged and the car accelerating, it's a different story. The dual mass flywheel may not rev as quickly, but the difference is hard to tell. What is noticeable, though, is how much quicker the turbocharger builds boost with a dual mass flywheel.
We had swapped out a lightweight flywheel on a stage 3 Golf R in favor of our RSR mated to the stock dual mass. The before and after driving characteristics of the two can only be described as night and day. The heavier flywheel and RSR put more load on the engine, helping the turbo to spool faster and at a lower RPM.
Additionally, our testing has found that some non organic clutch discs do not engage well unless they are in a very specific temperature range. The use of a non self adjusting pressure plate in this application can be very hit-or-miss, sometimes leading to improper clamping force.
Here's a fun thing about a slipping clutch on a turbocharged car: it can be a self limiting factor. When the clutch starts to slip, the engine loses the load, and the turbo starts to lose boost. As this happens, the engine loses power, and the clutch is able to hold again. So, a high clamping force pressure plate is nice. But, if it's coupled with a non organic disc that can slip, even with the higher clamping force, and using a lightweight flywheel that has a harder time keeping the engine under load, you can have a situation where the clutch is slipping just enough to actually cause you to lose power, but that doesn't necessarily feel like it's slipping.
This was the case with the Golf R that I described earlier. It had a kevlar clutch disc, which is known to be very temperature sensitive. Although the clutch did not feel like it was slipping, after installing the RSR, the difference in turbo lag and acceleration was significant. We have also found this to be the case on stage 2+ Golf Rs, although it is a far more noticeable improvement on the big turbo cars.
Each clutch is different, and some of the lightweight flywheels won't display the same level of turbo lag or clutch slip that we experienced in that case. But there is a severe inconsistency across the aftermarket clutch kits, and each one has shown different pedal efforts, clutch chatter, reliability, and effective clutch engagement, even within the same brands and stages. Our clutch was designed for smooth, quiet, repeatable operation. We reliably offer a clutch that doesn't require a high pedal effort, doesn't chatter, has a high clamping force and doesn't result in clutch slip, even under load. And although we are claiming this a street friendly clutch, it has also shown to hold up well to even stage 3 power levels, regular track use, and constant launching and hard acceleration. Although we don't recommend this level of abuse, it's not because we don't think it can handle it, it's because we don't yet know how much abuse it can handle. As many of the forum members who have our clutch will attest, so far they have been extremely reliable, even under the harshest of conditions.
Sorry for the long response. I tend to drone on when discussing technical data and our personal research results. There's a reason I try to keep off the forums
-Ken@HS Tuning
HSTuning
Ready to race!
lamb110, I'm not going to be the one to list the numbers, but if you feel like pointing out the numbers you did at the dyno day, compared to another stage 3 Golf R, that'd be fine with me. If I recall, you were both similarly equipped, both installed by HS Tuning, and the only differences were the clutches and the wheels?
-Ken@HS Tuning