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Joe’s track adventures and hands-on experience will be fascinating.
By the time I pick mine up, I’ll know everything there is to know.
Ill try to do a full wrap and see if Manthey ever replies to setup my car as well.
I wonder how much labor it is to install a cage and take it out for shipping to US.
Interesting. All four off and the helper spring is essentially compressed still. Makes you wonder why they have it in the stack at all.
Originally Posted by orthojoe
Yeah, doesn't seem like it's doing much other than holding the main spring down
Weird. Judging from this, the helper spring would be fully compressed with the car sitting on the ground. I wonder what the explanation is. I’m assuming they’re using shorter main+helper spring combo on cars with a lift (to allow space for the lift) instead of just compressing the no-lift spring combo more.
Copying my post in another thread into here to spread the word:
In the GT4, there was a 'high downforce mode' where if you increased the attack angle of the wing, you were supposed to remove 2 small air dams in the front of the car to increase front downforce and balance out the aero. This was described in the GT4 manual
In the 991.2 GT3, the only setting involves the wing and the manual says increasing the rear downforce with the wing may increase understeer. No mention of removing any air dams in the front and, in fact, there are NO removable air dams in the front of the 991.2 GT3
In the 991.2 RS, the manual says the same as the GT3. They only describe adjusting the wing and that you may increase understeer. No mention of removing any air dams. HOWEVER, I have found that in the RS there are indeed front air dams that look identical to the removable air dams in the GT4.
I have removed them with the assumption that if I am adding more rear wing, this needs to be done to balance out the downforce
Weird. Judging from this, the helper spring would be fully compressed with the car sitting on the ground. I wonder what the explanation is. I’m assuming they’re using shorter main+helper spring combo on cars with a lift (to allow space for the lift) instead of just compressing the no-lift spring combo more.
Maybe it's to prevent rattling of the main spring for those that decide to lower the car?
The axle lift in the .2RS is a new system. I believe electric rather than hydraulic. Here is a pic of it.
Excellent photo.
So there is no more lines on the shock bottom to interfere with brake pad/rotor exchange work?
What is the speed of the new lift compared to old system?
Excellent photo.
So there is no more lines on the shock bottom to interfere with brake pad/rotor exchange work?
What is the speed of the new lift compared to old system?
Good question. I'll be switching over to the AP calipers this week and will look closer and let you know.
Speed of the lift seems similar. Maybe a touch faster? I can't say for sure
Weird. Judging from this, the helper spring would be fully compressed with the car sitting on the ground. I wonder what the explanation is. I’m assuming they’re using shorter main+helper spring combo on cars with a lift (to allow space for the lift) instead of just compressing the no-lift spring combo more.
The helper spring should be fully compressed when the car sits on the ground. It's meant to act as a solid piece during normal suspension travel and merely hold the main spring in place when flying over a jump (big droop). It looks like when the front axle lift is "down" (that is not using front axle lift), that the helper extends slightly (see Joes post: https://rennlist.com/forums/991-gt3-...l#post15471001). It makes sense that the car has helpers because the 991.2 RS is so much stiffer than previous RS's. It also makes sense that the helper only extends slightly because although it's stiffer, it's still not race car stiff, so the main springs don't have super short free lengths. (a very stiff race car has main springs with short free lengths because the compressed length is closer to the free length, i.e. they don't compress much because they are stiff. Also, short free main spring lengths are why without a helper the main spring would bounce around on its seat, it is shorter than the distance between the top and bottom spring mounts under droop).
Copying my post in another thread into here to spread the word:
In the GT4, there was a 'high downforce mode' where if you increased the attack angle of the wing, you were supposed to remove 2 small air dams in the front of the car to increase front downforce and balance out the aero. This was described in the GT4 manual
In the 991.2 GT3, the only setting involves the wing and the manual says increasing the rear downforce with the wing may increase understeer. No mention of removing any air dams in the front and, in fact, there are NO removable air dams in the front of the 991.2 GT3
In the 991.2 RS, the manual says the same as the GT3. They only describe adjusting the wing and that you may increase understeer. No mention of removing any air dams. HOWEVER, I have found that in the RS there are indeed front air dams that look identical to the removable air dams in the GT4.
I have removed them with the assumption that if I am adding more rear wing, this needs to be done to balance out the downforce
front air dam removed air dam
Very cool. More grip is just about always better and you found a way that is easier than adding dive planes to the front like Manthey did for the 6:40 Nurburgring GT2RS.
Interesting. All four off and the helper spring is essentially compressed still. Makes you wonder why they have it in the stack at all.
Looks like from the photo there's 8-10mm before the helper spring is fully compressed. As long as the helper spring is not fully compressed then it is functional in providing spring pressure to keep the main spring seated for the landing after a wheel is lifted. Should the ride height be lowered from the current setting then the helper springs will become less compressed to take up the slack.
Originally Posted by Wind911
I wonder how does that bellows mechanism raise the car. Does it extend the shock body? Or the shock slides up and down inside the upright?
Also, it looks like there is little room to lower the front further without shorter main springs
This new design is hydraulic and operates externally on the strut (whereas the previous design is pneumatic and operates internally in the strut like an race car air jack). The threaded tube and the spring perch(aka spring seat) is part of the new hydraulic lift mechanism. Hydraulic fluid is used to lift the threaded tube and the spring perch, substantially lifting the main spring to raise the body.
This hydraulic designed was first introduced in the '17 991.2 Carrera S/GTS. Here's an image of one that we extracted from a GTS. The hydraulic cylinder slips over the OD(Outside Diameter) for the strut. This one shown in this image doesn't have the threaded gold color tube because it came from a GTS which has non-adjustable fixed ride height. The hydraulic cylinder is the same, even has the bleeder screw for servicing. I think the benefit of this design is that if the hydraulic cylinder needs to be replaced it can be done without having to replace the entire strut. And probably the production cost per unit of the cylinder is reduced since the same hydraulic is used for more applications. Just for clarification, in the image below we added the orange color ring because we converted this lift mechanical to an aftermarket coilover. So, imagine the mechanism in the image without the orange color ring and with a threaded gold color tube.
It looks very similar to the KW HLS kit, which has been available through aftermarket for a few years. I wonder if this is the same tech since KW has been an OE supplier for dampers. https://www.kwsuspensions.net/produc...ic_lift_system
12-03-2018, 08:59 AM
Joe’s track adventures and hands-on experience will be fascinating.
