Bump stop cutting

[pshirley]

Bump stop cutting. I recently replaced the factory shocks for Bilstein Touring shocks because the ride was rough. The car already had BavAuto springs. Even after the new shocks the ride was harsh. I read that you need to cut down the bump stops, so I removed about 1.5" from the front and back. It helped a bunch but the larger bumps still seem a little hard. Do I need to remove more of the bump stop, not much left, maybe an 1"? Are the springs bottoming out? They springs are 4 years old. What about the shocks, could they be bottoming out? I have BF Goodyear RS-A tires, are they known for hard side walls? What should I try next? Thanks for the help. Paul

[Jon K]

Bump stop cutting. I recently replaced the factory shocks for Bilstein Touring shocks because the ride was rough. The car already had BavAuto springs. Even after the new shocks the ride was harsh. I read that you need to cut down the bump stops, so I removed about 1.5" from the front and back. It helped a bunch but the larger bumps still seem a little hard. Do I need to remove more of the bump stop, not much left, maybe an 1"? Are the springs bottoming out? They springs are 4 years old. What about the shocks, could they be bottoming out? I have BF Goodyear RS-A tires, are they known for hard side walls? What should I try next? Thanks for the help. Paul

P Shirley wallabee way sydney...

sorry your name reminds me of Finding Nemo.

As for the suspension. It is VERY common that BavAuto springs bottom out. You should have used Bilstein Sport or HD shocks though, because they allow for the lowered ride hide with less chance of bottoming the shock. Essentially, if you've cut the bump stop down already, you're more than likely bottoming something. The BavAuto springs are so sloppy sometimes that they bottom over dips and such. I think you have the wrong shocks for that spring application.

[Kalevera]

The BavAuto springs are garbage. I just pulled a set from my car after 1000 miles and I'm glad to be rid of them.

According to Don Gale, they sag over time, so after 4 years of service, an already shitty spring is probably even shittier...explaining why it's bottoming out all the time.

Hopefully you've still got some tread on those tires after all of the negative camber. I would change them out for a different spring altogether. Chances are that the bilsteins are okay, but it'd be wise to check them out, regardless.

Do a forum search...you'll find oodles.

Best, whit

[Brandon J]

BavAuto springs are known to bottom out. Bilstein HD shocks are NOT right for sport or lowered springs. The Bilstein Sport and the Konis are the right ones for the sport springs as they are made for the shorter springs. BTW, IMHO Konis are much better than the sports. They have a longer travel, have rebound adjustability, and allows the user to cut the external bumpstops to best length. Bilstein Sports have internal bumpstops (so no adjustability by cutting), have a shorter travel (so less compliant), and do not have any adjustability.

[632 Regal]

the travel with a lowering spring is only about 3 inches max, the Bavautos with a V8 will bottom out on anything larger than a cigarette butt. With the 6 you will get some more travel but still is limited by the shocks bottoming. I have the Eibachs now and they still bottom out on everything too. You should get the Bilstein sports with the internal bumpstop so you dont have to worry about cutting them things and them popping out and having a direct bottom and break stuff.

[pshirley]

the travel with a lowering spring is only about 3 inches max, the Bavautos with a V8 will bottom out on anything larger than a cigarette butt. With the 6 you will get some more travel but still is limited by the shocks bottoming. I have the Eibachs now and they still bottom out on everything too. You should get the Bilstein sports with the internal bumpstop so you dont have to worry about cutting them things and them popping out and having a direct bottom and break stuff.

Thanks for all the feedback, I really appreciate it. If I don't want to give up the stock comfortable ride should I go back to the stock springs or is there a set that are too much stiffer than stock, but not as low as the Bavautos? This is my daily driver and I want a smooth quiet ride. Thanks again and look forward to your replies. Paul

[632 Regal]

M-tech only lower it about a half inch...why bother.

[Brandon J]

the travel with a lowering spring is only about 3 inches max, the Bavautos with a V8 will bottom out on anything larger than a cigarette butt. With the 6 you will get some more travel but still is limited by the shocks bottoming. I have the Eibachs now and they still bottom out on everything too. You should get the Bilstein sports with the internal bumpstop so you dont have to worry about cutting them things and them popping out and having a direct bottom and break stuff.

I would still disagree with you. With bottoming out, you are mainly comparing the loaded ride height to it compressing. You are still forgetting when the springs extend, you want to keep the wheels on the ground. A very good way to get a compliant ride out of a sport suspension is to increase travel. That's how the e34 M5s are. Have you ever seen the travel on a Nurburgring suspension? They travel a lot.

Again, the benefit of the external bumpstop is that you have adjustability by cutting the bumpstops to the length that best works. I did this by keeping them on and cutting a little by little until I thought they worked well. Remember that if you shorten the bumpstop that you increase the distance the shock has to work. So, it has more room to dampen before it bottoms out and hits the bumpstop. That is why travel is important. Finally, if the shock can extend further, then the wheels are more likely to stay on the ground. Just imaging going over rough roads and a wheel does not reach the ground.... a la pothole. Now imagine the wheel just drops to the ground as the car drops. There is a moment where tire and road do not meet because the shocks can't travel that far. Now if there was more travel, then the wheel would stay on the ground and dampen as soon as the car goes down. Make sense? Again, more distance to cushion.

Now with the konis, add the adjustability of compression. Konis are the way to go.

[liquidtiger720]

I think I would have went with koni's/h&r's if I didnt life in san francisco. Even with the sachs sporting kit (which is great by the way)...its pretty rough driving around.

[JonE]

Paul,
Ask Whit Lowell if he still has his stock springs, if that's what you're going to do...