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[lolachampcar] Performance Upgrade Efforts

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I had some spare time this afternoon so I ran by my buddy's shop with the shock dyno. This time I brought the coil spring dampers for reference and the new Performance Plus dampers I just pulled off my car. The results were interesting. There is very little if any difference in damping in the rear dampers (coil to P+) but there is a big difference on the front dampers. It looks like I'll need to update my "ideal configuration" to include front P+ dampers :)

This time I represented the shock data using "football" plots to reduce the number of plots needed. I also compared todays coil damper data with the last time I was on the dyno and the data repeated nicely.
 

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So for us coil guys, can we just swap out the front dampeners for the P+ version and get P+ like performance assuming we don't want to change the ride height? Or are the standard air dampeners better to use? Thanks for all your work on this. Great to see someone working to improve the handling of our already great cars.
 
WRT the fronts, let me get the P+ fronts on and report back.
WRT the rears, let me plot the air rear against the coil rear in a football plot and we can check out the absolute difference (and determine if it is worth the change).
Lastly, using coils installed on air dampers always requires you machine a lower perch landing C clip groove as the air springs land way down the damper in comparison to the coil perch. Given this, you might as well pick the exact ride height you want (even stock coil) and set it where you like.
 
The lower spring perch on this MS damper looks just like the one in the Bilstein document. Both just slide up and off the C clip.
So, to answer your question, it is a simple matter to disassemble the damper units (with proper spring compressors) and have more grooves cut in them for different ride heights. The ID is the same all the way down (else the pistons would not function) and the OD is obviously the same all the way down which means the damper wall thickness is the same all the way down. Adding more grooves did not seem like a problem to me and it has not been problematic in my testing. Oh, and the air and coil cars use the same damper body but with radically different C clip locations.

For reference, the higher spring perch on the left is stock coil springs while the adjustable sleeve on the right is sitting on the stock air suspension C clip location. As you can see, they are vastly different.
 

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I used 1:1 when I based the grooves on my air dampers against those on the coil dampers. The front worked out perfectly while the back was off by 1/2". I suspect the back was off because of gas pressure changing the spring rate but have yet to go back to the shock dyno data to verify this. The fronts were spot on.

If I were doing coil dampers, I'd do grooves at .25" intervals around my desired ride height.

I have a spare set of coil dampers. Perhaps I should have them grooved for a local owner (?).
 
I just put the front P+ dampers back on the car with coils. It was definitely worth swapping out the standard air fronts for the P+ fronts as the car points much better at speed. I'd say the front dampers are a vast majority of the P+ kit.

The following was for those asking about different ride height grooves and their affect. Of the two dampers pictured, the one on the left is a coil spring unit while the one on the right is a modified air spring unit. You can see that the air spring damper's normal groove position is much lower on the damper body. I added grooves to the air damper referenced from the coil damper to provide the desired ride height adjustability. Note that, even though the top of the dampers are not lined up, the bottom mounting points (the only point that counts) are lined up (out of frame). Also, the c-clips are in their original positions for both coil and air.
 

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Note that, even though the top of the dampers are not lined up, the bottom mounting points (the only point that counts) are lined up (out of frame). Also, the c-clips are in their original positions for both coil and air.
Interesting, so the air struts are shorter than the coil-spring struts? So you probably get a bit more bump travel with the air struts as well which is really nice when lowering a vehicle.
 
Thanks again for your continued quest for handling upgrades. If I understand it correctly, the best handling combination so far is coils with P+ dampeners? If I were to simply swap out for the P+ dampeners in my coil car, how would the ride height be?
 
It stinks that the answer to your question is difficult in many respects.

The complex answer is that the P+ dampers only come in a complete air spring/damper assembly form and are bloody expensive (see full P+ conversion costs which others have posted). Once you get these, you need to disassemble them to extract the dampers then have coil spring landing perch C clip groove(s) cut in them. The air spring landing C clip position is way down the damper from anything remotely close to a reasonable coil spring ride height location. Now you can reassemble the package and put them on your car. If your car is a late enough serial number (10/6 delivery should be), you will have the stiffer lower a-arm bushings which is a big plus.

I did learn one interesting thing at the SC today. Coil spring cars feel very firm both front and rear so it made sense when they told me that the coil cars do not have a rear sway bar. This is a reasonable thing to do to maintain over steer margin. My wife's car feels fine without the rear bar.

I think the most entertaining first step would be a lowered coil car on all coil parts :)
 
My machinist charged me $40 for the last set of P+ fronts I dropped by. I suspect it would have been $60 if he had set up and cut all four at the same time.

The real PITA will be pulling all the dampers while they get machined. Anyone interested in doing this in S. Florida should PM me as I just happen to have a spare set of new coil dampers.

One concern I would have is that the air dampers are actually shorter than the coils by a small amount and are designed to function at lower ride heights. Care should be taken to properly test if you lower coil damper spring perches. It may work just fine but it's worth taking the time to test and make sure.

On a completely different note, I need to find a Bilstien dealer to see if I can have a set of fronts and rears made to my valving. Now that we have dyno plots for all dampers as a starting point, it would be nice to build up an experimental set with 2.5" coils so we can test higher spring rates as well as different damping (adjustable dampers).
 
I recently test drove a P85+ and coming from a Porsche 997s i didn't like the suspension. I still think the Tesla is a great car but stumbled on this thread while looking for a stiffer suspension for the MS.

As it stands currently, is the solution just bolting on parts or is machining required ?

What would you recommend for someone who's on the fence for a MS:
- Get the P85 and mod it.
- Get the P85+ and mod it.
- Wait until you guys figured out what's the best aftermarket solution.
- Wait for Tesla to develop a stiffer suspension.(I heard they were working on an "Autobahn package" with stiffer suspension for better high-speed handling)

Keep up the great work! :)