Bridgestone/Praxis Suspension System
Dexter ... PM-ed you ... some debugging to do, but car is in paint shop Monday. That forces us to think out a plan. 
For the record ... I like having new stuff to figure out; and it is a controls system problem making it even better.
For the record ... I like having new stuff to figure out; and it is a controls system problem making it even better.
Thread Starter
Registered User
Joined: Mar 2003
Posts: 681
From: Warsaw, Indiana
Car Info: 02 WRX Wagon White
It indeed fits perfectly. I'd like to be the first to try it. Maybe I should keep one of those credit card apps I get in the mail - for my own personal ultra-stealth "toys" account...
BTW - does anybody know of an air tank designed to fit in a spare tire location? I recall seeing one years ago - don't remember where.
BTW - does anybody know of an air tank designed to fit in a spare tire location? I recall seeing one years ago - don't remember where.
praxis definition, practice, as distinguished from theory; application or use
The Praxis system installed in my WRX works perfectly!
And, "praxis" is a word. In this case, it seems their marketing found a name that separates theory & hand waving of what ought to work or what you could do ... to real world design application that works, works well, *and* with solid theory & design engineering behind it. All done & manufactured in the US of A, who is doing that these days?
Be sure to get the current issue, November, 2003, of "Sport Compact Car". It has an extensive technical description of the Praxis system. Also, don't miss the Technobabble discussion on p 16. I won't even try to match this article as it is very well written & describes the system perfectly.
There is another article in the Nov., 2003, “turbo” magazine though not quite as technically descriptive as the Sport Compact Car article.
Orignally, I had very strange effects that made no sense after the installation was finished last Friday night. On Monday, Dexter@tirerack & I talked extensively and he consulted with Praxis engineering. The result; a Praxis engineer drove 5 hours today to the shop where I had the work finished. The original offer was to come to my home. Since Isabel was starting to blow through (with plenty of rain), the service shop location was a good thing. The shop, Dove's in Mechanicsburg PA, let us use a lift so the Praxis engineer could easily examine the install. He discovered that 2 air lines were swapped at the air valve control block!
These particular connections were in the *only* confusing section of the excellently written installation instructions. But, still!!!! Aaargh!?!?! The fix was so-o-o simple. On the other hand, it is a really good thing that there were no component failures or defects.
This system works. Height changes are in seconds. Very smooth of course, but quick. After Isabel blows out of the way, I will get a few short videos of the car changing levels & make them available ... some how.
Just some observations until I can some video posted. Allowing ~40 seconds between height changes, each height can be easily selected while parked or cruising. I am running Sumitomo HTR+ 225/40-18 (purchased from tirerack) on Enkei Senecas (offset 48, I think) with no interference at the Track Height (lowest) setting. The fronts are really close and I have not had the chance to put the car into any sort of quasi-performance turn. However, a few moderately hard quick turns at the stops produced no rubbing.
Last .. I need to be quick, I think Isabel is going to blow the power out here .... install for me was 2 full days. According to the engineer, he can do an install in ~12 or 14 hours (I forget which he said). Work is required under the car & in the front wheel wells, so some means of getting the car completely off the ground is necessary. This is why I had it finished at a local service center with a lift & by a 1st class mechanic. Additionally, to calibrate the height level sensors, some means of accurately positioning the car at the 3 desired heights is necessary.
And, "praxis" is a word. In this case, it seems their marketing found a name that separates theory & hand waving of what ought to work or what you could do ... to real world design application that works, works well, *and* with solid theory & design engineering behind it. All done & manufactured in the US of A, who is doing that these days?
Be sure to get the current issue, November, 2003, of "Sport Compact Car". It has an extensive technical description of the Praxis system. Also, don't miss the Technobabble discussion on p 16. I won't even try to match this article as it is very well written & describes the system perfectly.
There is another article in the Nov., 2003, “turbo” magazine though not quite as technically descriptive as the Sport Compact Car article.
Orignally, I had very strange effects that made no sense after the installation was finished last Friday night. On Monday, Dexter@tirerack & I talked extensively and he consulted with Praxis engineering. The result; a Praxis engineer drove 5 hours today to the shop where I had the work finished. The original offer was to come to my home. Since Isabel was starting to blow through (with plenty of rain), the service shop location was a good thing. The shop, Dove's in Mechanicsburg PA, let us use a lift so the Praxis engineer could easily examine the install. He discovered that 2 air lines were swapped at the air valve control block!
These particular connections were in the *only* confusing section of the excellently written installation instructions. But, still!!!! Aaargh!?!?! The fix was so-o-o simple. On the other hand, it is a really good thing that there were no component failures or defects.This system works. Height changes are in seconds. Very smooth of course, but quick. After Isabel blows out of the way, I will get a few short videos of the car changing levels & make them available ... some how.
Just some observations until I can some video posted. Allowing ~40 seconds between height changes, each height can be easily selected while parked or cruising. I am running Sumitomo HTR+ 225/40-18 (purchased from tirerack) on Enkei Senecas (offset 48, I think) with no interference at the Track Height (lowest) setting. The fronts are really close and I have not had the chance to put the car into any sort of quasi-performance turn. However, a few moderately hard quick turns at the stops produced no rubbing.
Last .. I need to be quick, I think Isabel is going to blow the power out here .... install for me was 2 full days. According to the engineer, he can do an install in ~12 or 14 hours (I forget which he said). Work is required under the car & in the front wheel wells, so some means of getting the car completely off the ground is necessary. This is why I had it finished at a local service center with a lift & by a 1st class mechanic. Additionally, to calibrate the height level sensors, some means of accurately positioning the car at the 3 desired heights is necessary.
Last edited by PsiStar; Sep 18, 2003 at 09:47 PM.
... continuation ...
Unfortunately, I neglected to get a photo of how the system was packaged. All the hardware was individually packaged & well labeled for the components that they are intended for. This may not be a biggy, but there is definitely no confusion as what goes where or with what. And, having experience with some after market products & kits, seeing bar codes on all the packages, though clearly of no value to me, speaks clearly of a “real” company behind the product.
So I think the sales pitch could be ….
Imagine driving to the track in touring mode … in comfort vs. a nauseating hay wagon feeling. E e e v v v er er ex p p p eri nce th th th at? At the track, change the stiffness of the dampers appropriately for the event or track, lower the car with a push button … and race with a suspension system that is about as tunable as there is. Is there anything else available as flexible? Rhetorical question.
OR
It’s January & there is a foot of fresh fallen snow on the ground. If you had springs lowering your car .. its low. (period) Good luck with your snow plow. On the other hand, with a Praxis, you go out, push the button to raise the car to Touring Ht (possibly even a little higher depending on the wheel travel you’re willing to calibrate to & live with for a couple of months) and a couple of hisses later your approaching SUV height. I don’t mean get carried away with that idea … the point is that you are not stuck or committed to a particular height.
So why would anyone spend this much on a suspension upgrade? I my case, my experience with Tire Rack has been better than perfect. I have bought 2 sets of tires from them in the past 6 months. Without getting off topic to far here, one of my Sumitomos was out of round ... no problem getting it swapped. They took care of everything with UPS. It took 2 days, but would have been the next day had I called in the issue an hour earlier. Additionally, Vance whom I dealt with at the time, suggested that I find a service center with the Hunter GSP9700 tire balancing machine ... nothing else will touch my tires again! Tire Rack offers superior customer service, and considering the response that I received from Praxis ... clearly one company that excels in customer recognizes that capability in others that it wishes to represent. And, all of this over the internet amidst all of this organ enalrgement stuff ... well, there is absolutely no scamming here, just quality.
And, why spend $1K or $2K on something that is rarely what you want or certain of what it will be like? That is just a couple of K pi$$ed away never useful to anyone else. With this system, if there is something that you (or your wife) doesn't like ... tweak it & a minute later it is what you need.
I'm so happy I think I'm crying ... or maybe my eyes are watering 'cause I'm up so late ... hmmm, a short quick drive would be fun
I'll be back with more
Unfortunately, I neglected to get a photo of how the system was packaged. All the hardware was individually packaged & well labeled for the components that they are intended for. This may not be a biggy, but there is definitely no confusion as what goes where or with what. And, having experience with some after market products & kits, seeing bar codes on all the packages, though clearly of no value to me, speaks clearly of a “real” company behind the product.
So I think the sales pitch could be ….
Imagine driving to the track in touring mode … in comfort vs. a nauseating hay wagon feeling. E e e v v v er er ex p p p eri nce th th th at? At the track, change the stiffness of the dampers appropriately for the event or track, lower the car with a push button … and race with a suspension system that is about as tunable as there is. Is there anything else available as flexible? Rhetorical question.
OR
It’s January & there is a foot of fresh fallen snow on the ground. If you had springs lowering your car .. its low. (period) Good luck with your snow plow. On the other hand, with a Praxis, you go out, push the button to raise the car to Touring Ht (possibly even a little higher depending on the wheel travel you’re willing to calibrate to & live with for a couple of months) and a couple of hisses later your approaching SUV height. I don’t mean get carried away with that idea … the point is that you are not stuck or committed to a particular height.
So why would anyone spend this much on a suspension upgrade? I my case, my experience with Tire Rack has been better than perfect. I have bought 2 sets of tires from them in the past 6 months. Without getting off topic to far here, one of my Sumitomos was out of round ... no problem getting it swapped. They took care of everything with UPS. It took 2 days, but would have been the next day had I called in the issue an hour earlier. Additionally, Vance whom I dealt with at the time, suggested that I find a service center with the Hunter GSP9700 tire balancing machine ... nothing else will touch my tires again! Tire Rack offers superior customer service, and considering the response that I received from Praxis ... clearly one company that excels in customer recognizes that capability in others that it wishes to represent. And, all of this over the internet amidst all of this organ enalrgement stuff ... well, there is absolutely no scamming here, just quality.
And, why spend $1K or $2K on something that is rarely what you want or certain of what it will be like? That is just a couple of K pi$$ed away never useful to anyone else. With this system, if there is something that you (or your wife) doesn't like ... tweak it & a minute later it is what you need.
I'm so happy I think I'm crying ... or maybe my eyes are watering 'cause I'm up so late ... hmmm, a short quick drive would be fun
I'll be back with more
Last edited by PsiStar; Sep 18, 2003 at 10:08 PM.
Registered User
Joined: Mar 2003
Posts: 48
This system looks interesting. ALOT like what I run on my Jeep in fact. Does it do a calibration 'dance' or do you have to adjust the sensors manually?
Looks cool. I also run bridestone/firestone airsprings and the Jeep and can attest to the durability. I've scaled 3ft tall rock ledges with them, done water crossings, and other really nasty things in the woods. They hold up well.
I'm not sure If I'd want the setup for the WRX or not.. But it would be really cool to have for the forester.
Jason
Looks cool. I also run bridestone/firestone airsprings and the Jeep and can attest to the durability. I've scaled 3ft tall rock ledges with them, done water crossings, and other really nasty things in the woods. They hold up well.
I'm not sure If I'd want the setup for the WRX or not.. But it would be really cool to have for the forester.
Jason
Registered User
Joined: Nov 2002
Posts: 39
From: Lindsay Lohan's Cleavage
Car Info: MY02 WRX
Dexter,
Has the developers done any lateral grip, 700 ft. slalom & track time comparisons versus various well known coilover brands (JIC, DMS, Tein, HKS, APEXi, etc.)? If not, can you find out if it can be done?
I've been searching for something like these since I first got my car. The flexability of the Praxis system sounds amazing. Everyday driveability on rough roads like the stock suspension and tight "rail-like" feel on the twisties like a set of coilovers.
If we can see comparison numbers and even if they're slightly less than the best coliover numbers, I'd get them in an instant. I know others feel the same.
- Logan
Has the developers done any lateral grip, 700 ft. slalom & track time comparisons versus various well known coilover brands (JIC, DMS, Tein, HKS, APEXi, etc.)? If not, can you find out if it can be done?
I've been searching for something like these since I first got my car. The flexability of the Praxis system sounds amazing. Everyday driveability on rough roads like the stock suspension and tight "rail-like" feel on the twisties like a set of coilovers.
If we can see comparison numbers and even if they're slightly less than the best coliover numbers, I'd get them in an instant. I know others feel the same.
- Logan
Thread Starter
Registered User
Joined: Mar 2003
Posts: 681
From: Warsaw, Indiana
Car Info: 02 WRX Wagon White
I'll post any results as soon as I get them. They are working on comparisons, but it's difficult to get in a controlled situation.
I have a PDF copy of the instruction/install manual. If you're interested, please email me at dexter@tirerack.com and I'll send it to you. It is 3.1 mb - no free email servers will work. You must be able to accept large attachments.
I have a PDF copy of the instruction/install manual. If you're interested, please email me at dexter@tirerack.com and I'll send it to you. It is 3.1 mb - no free email servers will work. You must be able to accept large attachments.
Registered User
iTrader: (3)
Joined: Nov 2002
Posts: 512
From: www.nasioc.com
Car Info: 2003 STX Pro-Solo/Solo-II National Champion
I've been following this system closely... and I kinda like it.
However, it has one large shortcoming that would prevent me from using it.....
For those that race in sanctioning bodies that have the similar verbage:
will have problems in your class. IN SCCA, you cannot use this setup in Stock, Street Prepared, STS or STX. I'm not sure if it would even be allowed in prepared. SM, yes. (They allow anything)
Just something to keep in mind when looking at a suspension for racing with sanctioning bodies that have rules.
Street Prepared 14.8.A & STS/STX 17.8.A: Springs must be of the same type as the original (coil, leaf, torsion bar, etc.)
Because the spring type has changed, not legal.
SM: 18.1.E (Allows it) Suspension components are unrestricted as long as they use the original attachment points.
--kC
However, it has one large shortcoming that would prevent me from using it.....
For those that race in sanctioning bodies that have the similar verbage:
Springs must be of the same type as the original (coil, leaf, torsion bar, etc.)
Just something to keep in mind when looking at a suspension for racing with sanctioning bodies that have rules.
Street Prepared 14.8.A & STS/STX 17.8.A: Springs must be of the same type as the original (coil, leaf, torsion bar, etc.)
Because the spring type has changed, not legal.
SM: 18.1.E (Allows it) Suspension components are unrestricted as long as they use the original attachment points.
--kC
Last edited by KC; Oct 20, 2003 at 12:09 PM.