Since space is at a premium in most late model cars nowadays, we agonized where we were going to mount the pump. Jeff had the great idea of using an Antigravity ATX-30 super light and compact lithium Iron Phosphate battery in order to mount the battery and hydraulic pump in the location the stock battery took up.
The ATX-30 is an advanced battery with many amazing features. First off it has advanced on-board electronics that protect the battery from overcharging, thermal overload, reverse polarity, improper charging and over discharging. Most importantly the on-board electronics automatically balance the charge between the cells. Imbalanced cells is a leading cause of failure with lithium batteries.
The ATX-30 has another extremely useful feature. If the battery’s charge gets too low due to discharging the battery cuts itself off from the car to eliminate drain and goes into a “sleep mode”. When you need to restart the car, you just push a button on the battery which will still have enough reserve power to start the car up. Thus internally jump starting the car! With the ATX-30 a car can sit for up to a year without discharging it to the point where it won’t restart. With the ATX-30 you won’t get stranded with a dead battery.
This amazing little battery puts out 880 cranking amps and has a 30 amp hour capacity. Most impressive is the fact it only weighs an unbelievable 5.75 lbs! This saves 33.25 lbs! The battery more than makes up for the weight of the HLS system. The ATX-30 can last over 2x longer than the stock battery and is mechanically isolated internally from heat and vibration. It can also be mounted in any direction due to having 4 terminals with right or left and positive and negative terminals located on both sides of the battery. Due to not having a gell or liquid electrolyte to shift or spill the ATX-30 can be mounted in any position as well.
With the super light Antigravity battery we were able to add the hydraulic lift system and still come out lighter afterward!
As a first step, Howard removed and unbolted the front shocks from the chassis by starting at the top.
Next, the lower shock mount was removed. The front shock end-links were removed on one side as well, so we could completely drop the arm to remove the leaf spring.
Now the front shocks could be taken off the car.
38 comments
It would be nice to know the weights of the parts removed (not just battery) vs the replacement parts. I’m thinking some of the leaf spring is considered unsprung?
That’s an interesting “captured” nut!
This. The leaf springs may be big, but they’re a composite material and actually pretty light. It wouldn’t surprise me if a vette leaf spring is actually lighter than 2 coilovers steel springs (1 leaf spring is used for both sides of the car).
the oem shock/spring setup is 40.3lb for all 4 corners, LG coilovers, which use aluminum Bilstein dampers and billet aluminum mounts, are 30.8lb. Aluminum Penske’s with remote reservoirs are 34.4lb. The steel KW’s, with their built in reservoirs, are gonna be heavier… then taking the lift cups into account, the KW with the lift system is definitely gonna be heavier than stock before even taking the pump into account. And its definitely more unsprung weight, cause with the way the leaf spring is mounted, most of its weight isn’t really sprung weight…
That being said, if I had a Vette, it’d definitely have coilovers on it. But prolly LG’s…
The LG’s are either non-adjustable or single adjustable. Double adjustable like KW is big advantage as you can really dial in the suspension for specific conditions or combinations of parts.
oh yeah, nothing against KW… KW’s are great, just a random note on the route I’d go. Mostly cause of price and I’ve seen and experienced how well they perform first hand. If I’m spending KW Clubsport money, I’m going with MCS.
but either way, I was more trying to make a point about the weight… the Vette’s leaf spring setup isn’t exactly heavy. Its actually pretty light considering its an OEM and the cars price point. And I wouldn’t be at all surprised if the stainless bodied KW’s are actually a little heavier.
Great article,! I’d echo what the others have requested with the weight difference being published.
I am going to weight the leaf springs and ask KW if they have the Clubsport weight.
front is 11.4 and rear is 12.1 including mounting hardware, for the FE3 leaf springs anyway
Let’s see if I can get a weight tomorrow for the coilovers. Do you happen to know the weight of the stock shocks?
4.2 each for the T1 / later year Z51 shocks (I think it was 2016 that Z51 got the T1 shocks)
That seems really light.
here are pics
https://lh3.googleusercontent.com/-flh8lFno-qc/V1Pyfo99wqI/AAAAAAAC9q0/TegJWDlWxK8MIs6K5kWRoFQrUfleZl2qgCL0B/w926-h693-no/IMG_20160604_232302.jpg
https://lh5.googleusercontent.com/-gZ4lfyFMdLE/V1Pyfun5doI/AAAAAAAC9q0/gtpkf1xeczg2PTvJMpttlromZxfefesHQCL0B/w926-h693-no/IMG_20160604_232234.jpg
I tried to post links to the pics of the shocks on the scale, but the comment just disappeared when I clicked post… I can show you pics of all this stuff on scales if there’s someway to share pics/links
Mike, were you able to get the weights on the KW’s?
Are the T1s helium charged instead of nitrogen?
Remove that straight piece under de splitter. The ones in front of the wheel. It’s only there for mileage, and some minor road noise, but they create lift….
Oh man… I had that exact thought a while back and was wondering why nobody made it. Leave it to KW I guess. I assume there’s some cutoff valves or something to prevent cross-talk between the corners, or is it just either all the way up or all the way down?
From what i understand the HLS is usually installed on the fronts only and due to a lack of height measuring electronics it looks like an all the way up or down scenario. The valving and one line from the pump (no return lines) would lead me to believe that there is no way to prevent cross talk, meaning if one lift cup goes the other one wouldn’t work. The HLS system looks to be designed to only help raise the car for entry and exit into parking areas/driveways and not to be driven on long distances so cross-talk shouldn’t be an issue..
Yes, its either up or down. It can be driven in the up position for distances. It was originally designed as an active aero/suspension element for DTM like the articles says. It’s not like a soft air spring like an air cup.
OK; probably more than adequate for most purposes and having it only all the way up or down certainly simplifies things. Pretty cool still; it solves a lot of problems. I just dream about stuff with significant downforce and low-frequency active suspension all the time.
Having driven this car for several weeks now on the HLS system I can say without a doubt that it completely transformed the car in terms of its comfort and practicality as a daily driver. the roads in my neighborhood aren’t the greatest and i often find myself lifting the front end as soon as leave the house and then lowering it back down once i get on the freeway. Pretty much every driveway/parking lot entry around Los Angeles was impassable without scraping the carbon fiber front lip before the HLS (one of the worst sounds ever btw). Now unless i know the roads in the area are smooth i’m in i basically use the system like a “city”/”highway” mode. It’s awesome! 🙂
Just reading the other comments as I was fixated (overly?) on the weight of the dampers. And I’m going to sound like a fanboi here, but parallel with the gt3rs, if you make something much more durable without being significantly heavier, as was the exhaust system, then I consider that a win. Similarly, the ‘Vette gets an upgrade in practicality, and overall comfort, along with better handling (can’t wait to see lap times!) then if there’s a pound added, it’s worth it.
Cool stuff.
Is there any concern regarding the strength of the mounting points when going to a coilover suspension on these cars? I assume the mounting points were designed for just the damping force but now are dealing with all of the motion control. I know on E36/E46 rear suspension that if you go to true coilover then you need to do strengthening of the upper (body) mount.
it’s a common Corvette thing to go coilover.
Considering the factory C7.R race cars go to a coilover setup, I don’t think its an issue…
Do you need to add stiffer sway bars when switching to coilovers because the transverse leaf springs are removed?
Can the HLS cups be placed above the coils for less unsprung weight?
Did you have to make custom wiring and battery cables to mount the battery? I just want to do an RS30 or ATX30 in my c7 but Ive heard there are issues with the aux box mounting. Can you do a feature on just a lightweight battery install in a c7 with little to no changes?
no we used the existing cables.. you will probably have to drill through the composite floor to mount a box in that location. we were able to secure it and the HLS pump together using the existing mounting points.
Mike, any chance you guys could bring this full circle with your Suspension 101 course and show how to find the vehicle CG and Roll center for this car? I may be slightly biased/more interested since I have a C7 GrandSport of my own…
No, because I don’t see any need to change it.
Hello Mike, Jeff, I know this might be a loaded question……but how difficult was it to install the KW Coilovers? I have the V3s ready to install on my ’15 C7 here in SoCal. I may also be interested in the pump setup that you have at a later date.
I out on headers myself, but never Coilovers. Thanks in advance!!!
It’s not too bad, header are probably harder!
Just what I was looking for! I need this on C7. Do you install or recommend anyone specifically? If so, please email me info, to include product pricing- thanks.
I assume it interacts well with magride after living with the install?
PS… please work on a C8 version ASAP. I didn’t order front lift as it eliminates the option of lowering the car. To add the system afterwards will be a hot seller.
You can go to our home page and click on the MotoIQ Garage Link and we can get you an estimate.
I have a 2017 stingray 3lt with magnetic ride control. Will these shocks work on my C7 and how high will go. Military discount. KW V3 coil overs and hydraulic lift system (HLS). What’s the price.
They will work, but we are a web magazine, follow the links to the manufacture to purchase.
Thanks so much for advice! I enjoy reading and learning from your posts!