When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Any idea on what the CF cage will set us back? That really has my attention... I told myself I was done modifying my car and then that shows up...
I'll not hijack this thread but SSR will sell the splitter separately and it isn't all that expensive in the Porsche performance parts world. I know lots of people rocking SR parts and would have no problem having them on my car, I just wanted to go in a different direction w.r.t. my splitter.
I like what you have done and I may end up in that direction too. I like to keep it as OEM looking as possible though.
Last edited by lovetoturn; 05-17-2024 at 12:08 AM.
This is what I would do for the spoiler like Manthey and I suspect SSR did for their cars. Flat bottom, larger diffuser for the wheel wells, bolts right up to stock holes, and fits in perfectly with the car. Nothing sticks out and it looks totally OEM, in fact you can't really tell that it is not the car unless it is on the lift. Even has a perfect lip on the front edge to fit flush with the stock bumper.
System won't let me upload pictures right now.
Last edited by lovetoturn; 05-17-2024 at 12:27 AM.
Yes, I like all of your options and agree that some more specifics on downforce would help. Real world values would be most helpful as numbers coming off of a CFD analysis and not being corellated to that can be over exaggerated. Also a simple gurney flap for the stock wing would be fantastic and I think would sell well. One with 3-4% of the cord length or 9-12 mm tall could add about 15% more downforce to the rear wing that starts at about 300 pounds at 300kph, which would make about 45 pounds of additional downforce. Nobody has made one yet for the 4RS.
Another question. Do you know what the OEM aero balance for an GT4 RS. The GT4 was stated to be 20/80 and the 992 GT3 RS is stated to be 30/70. So with what they did to the 4RS I would suspect it would be somewhere between the 20/80 and 25/75. I am going to go out on a limb and call it roughly 23/77.
Thanks for sharing the info and photos. We don't have any data on the aero balance of stock GT4RS. But we do test frequently all SR Aero parts on Shanghai F1 Track to verify their performance before releasing them to Customers.
SilverRocket GT4RS Clubsport&Street Car testing on Shanghai F1 Circuit. SilverRocket GT4RS testing on Shanghai F1 Circuit. SilverRocket GT4RS testing on Shanghai F1 Circuit.
__________________ - Alex Li
Racer, 2nd&3rd Place of GT4 Category@Porsche Sprint Challenge Asia 2018~2023/@Porsche Carrera Cup Asia 2021.
Product Manager& On-Track Tester@SilverRocket Racing, Asia's leading Porsche Race Team & Performance Kit Developer for Porsche GT4RS.
Follow us on Instagram: silverocket718 to stay updated on latest SR products in development.
Here are some number for everyone to use as a starting point for the aero on our cars. I have already done this homework, so this appears a good place to let out of the box. Please correct me if I am off base on anything SR.
As per Porsche the car has normal 138 and sport 220 pounds of downforce at 125 mph, so that translates into 305 and 488 pounds of downforce at 300 kph or 186 mph. That being the most universal speed at which to report maximum downforce. So for high downforce settings:
If at 20/80 balance there is 98 front and 390 rear.
If at 25/75 balance there is 122 front and 366
If at 23/73 balance then there is 112 front and 376 rear. (My estimate for these calculations)
The rear diffuser is 81 pounds of the rear downforce for the GT4 and the same parts for the 4RS so the rear wing on the 4RS (376-81) has 295 pounds of downforce in the highest setting.
The lower setting on the 4RS has 305 pounds of downforce, which at 23/73 balance is 70 front and 235 rear. Minus the 81 for the diffuser the rear wing in low setting has 154 pounds of downforce.
Therefore there is a (295-154) 141 pound difference between the low and high downforce settings of the wing. There are three holes for adjustment on the rear wing for three total settings of high-medium-low. Therefore there is 70.5 pounds between each setting of the rear wing. 70 more pounds more downforce just by moving it up or down about 3mm. Pretty amazing. Lets just call it (155 - 225 - 295) for L-M-H.
So lets look at the front too. There are 4 settings on the front air spats so a total of 3 changes to cover an increase in downforce from 70 to 112. This equates to a difference of 42 pounds of downforce divided by the 3 or 14 pounds for each change. So (70 - 84 - 98 - 112).
The Manthey CF rear spoiler is advertised to add 4% or about 25 pounds of downforce to the rear of the car so the SR one should be similar.
From the GT4 Clubsport manual, adding 5mm of rake adds 1.1% (5 lbs) total downforce and 1.6% (8 lbs) more of that in front. Adding 10mm more rake adds 1.9% (10 lbs) total downforce and 3.8% (19 lbs) more of that to the front. These are Clubsport numbers with a bigger wing and riding lower, but the 4RS should be similar numbers but a bit smaller. This is how Manthey balances their GT4 packages.
The Silver Rocket front canard and spoiler extension adds a stated 17% to the front downforce of the car. I am going to assume that is in high downforce mode of 112 pounds, so 17% of that would be about 19 pounds of additional downforce.
In all of my research it appeared that a well designed gurney flap added about 15% more downforce to a wing of our general stature when tested in the wind tunnel. So 295 times 15% is roughly 45 pounds of additional downforce.
Raising the wing into cleaner air 3 inches adds almost 30 pounds from extrapolating what others have stated in the past about the GT4 wings.
So for example, we need to add roughly 23 pounds in the front for every 77 we add in the back to maintain aero balance or about a 1.0 to 3.3 ratio. Having said that you will need to test any aero changes on the fastest corner of your track and see how the car feels. Which axle lets go first,or do they go together? Hopefully the latter if the mechanical and aero grip are in harmony.`
So maybe we add the SR front canards and spoiler extensions for 19 pounds. Then we add the SR wing height extensions and the rear spoiler for 75 (30 + 45) pounds more downforce in the rear. Total upgrade is 19+75 = 94 pounds and it is roughly balanced. If needed add touch more rake and it is spot on.
So to summarize the aero for the GT4 RS
FRONT: 70 - 84 - 98 - 112
REAR WING: 155 - 225 - 295
Rear Diffuser: 81 - 81 - 81
Oh wow, your calculation is very impressive. Thank you for sharing such detailed homework and data!
I want to share an insight about Aero balance from our continuous testing with the GT4RS Clubsport and GT4RS.
Ultimately, the final aero setup/balance must be decided by the driver. For instance, when setting the new lap record at the Shanghai F1 Track, SilverRocket Pro driver Daniel, the 2021 Carrera Cup Asia Champion, insisted on reducing the rear wing AOA to almost zero. He claimed this suited his driving style. Despite being an unbalanced setup, Daniel harnessed it to achieve the fastest lap time for the SRO GT4 Class at 2:10.34(Onboard Video Here: https://www.youtube.com/watch?v=rHKwTBQVLck
), beating the previous AMG GT4 EVO record of 2:16.99. I tried the GT4RS Clubsport with Daniel's setup on the Shanghai F1 Circuit, and it was terrifying. The car's rear end is extremely slippery on high-speed turns, and I couldn't handle it at all.
SR aero engineer also mentioned that in his previous factory race car aero design projects, CFD and wind tunnel tests only for the purpose of providing initial data, but ultimately, on-track testing makes the final decision.
In summary, beyond all the numbers, it's crucial to drive your car on the track and adjust the aero setup to find what suits your driving style.
Any idea on what the CF cage will set us back? That really has my attention... I told myself I was done modifying my car and then that shows up...
I'll not hijack this thread but SSR will sell the splitter separately and it isn't all that expensive in the Porsche performance parts world. I know lots of people rocking SR parts and would have no problem having them on my car, I just wanted to go in a different direction w.r.t. my splitter.
Regarding the CF Roll Cage: We are doing final testing on how to fit our SR CF Roll cage on U.S SPEC GT4RS perfectly, since U.S spec doesn't have clubsport options, so there is nothing prepared at Porsche Factory for installing an clubsport style full gate roll cage. During our testing fit with Clubsport optioned GT4RS in Asia, the installation time is < 40 minutes.
Regarding price, SR CF Roll Cage MSRP should be less than 50% of Porsche 992 GT3RS CF Roll Cage Price. We will launch a pre-order promotion on Rennlist once our U.S Spec Car fitting testing finished.
Some photos for SR CF Roll Cage testing installation on Clubsport optioned car:
I think the car can get away with just adding a bit more front front aero though it seems talking to these 3rd party people. stage one maybe just the small boot spoiler, the 3" risers and the front smaller cannards and lower splitter part. they have 2 sized cannards, the Pro I guess you then need the bigger rear wing.
But I think they should sell kits, stage 1, 2 and 3. So we know we are buying a balanced or working kit, over just buying one part.
We are finalizing SR Aero Packages for easier selection.
Here is the initial reason why we developed the SR PRO Diveplanes (working with SR CS Wing):
On the Shanghai F1 Track, some GT4RS owners, who installed CS Diveplanes and CS Wings, want to further improve high-speed cornering and lap times. Specifically, make their GT4RS easier to turn (slightly oversteer) on high speed turn. However, they don't want to achieve that goal by reducing rear downforce (as our pro driver does), which makes the rear end slippery. To address this, we developed the SR PRO Diveplanes to add slightly more front downforce while keeping the rear CS Wing AoA unchanged. This enhances high-speed turning (less understeer) while maintaining rear stability.
Some learnings about Aero balance adjustment on Track: Adjusting rear aero is straightforward by changing the Rear Wing AoA. However, front aero adjustments normally require additional components. When the front splitter can't be adjusted as our GT4RS, switching to a bigger diveplane is normally the easiest way to do the front aero fine tune.
You have to remove a metal panel from the front section for the full kit. No thanks
Part Number 9
991 501 431 01
I was specifically talking about the splitter and dive planes... as @lovetoturn says... looks very OEM.
But don't want to derail. Should create a seperate thread.
You have to remove a metal panel from the front section for the full kit. No thanks
Part Number 9
991 501 431 01
I believe, besides the front metal sheet, central radiator has to be removed as well. Otherwise the front central airinlet will be fully blocked by the radiator, which makes this Aero design nonsense.
I believe, besides the front metal sheet, central radiator has to be removed as well. Otherwise the front central airinlet will be fully blocked by the radiator, which makes this Aero design nonsense.
So whats going on with say…. 992 GT3 RS or GT3 R then?
So whats going on with say…. 992 GT3 RS or GT3 R then?
Since Silverrocket is a Manthey Racing local partner and learnt the MR Cup conversation before, the reason why Cup MR or GT3R moved all radiators into trunk for 2 reaaons:
1. reduce the risk of DNF during race. the front radiators have been major reason for cup car retired during race all the time. if the front end of cup hits anything, there is a big possibility the radiator will be damaged, then the race is finished.
2. make front end aero design much easier after all radiators removed and moved into trunk. the entire space occupied by radiators between bumper and trunk becomes huge empty space for airflow. Now can design and put any optimized Aero structure in there easily.
Regarding the CF Roll Cage: We are doing final testing on how to fit our SR CF Roll cage on U.S SPEC GT4RS perfectly, since U.S spec doesn't have clubsport options, so there is nothing prepared at Porsche Factory for installing an clubsport style full gate roll cage. During our testing fit with Clubsport optioned GT4RS in Asia, the installation time is < 40 minutes.
Regarding price, SR CF Roll Cage MSRP should be less than 50% of Porsche 992 GT3RS CF Roll Cage Price. We will launch a pre-order promotion on Rennlist once our U.S Spec Car fitting testing finished.
Some photos for SR CF Roll Cage testing installation on Clubsport optioned car:
Cage looks EPIC! Please send me a DM when it's finished and you have a clear picture on pricing.
Originally Posted by Kimbleli
I believe, besides the front metal sheet, central radiator has to be removed as well. Otherwise the front central airinlet will be fully blocked by the radiator, which makes this Aero design nonsense.
Central radiator is not impacted, Air continues to flow through the front radiator and then through the new hood opening. Let's keep this thread focused on the great products that SR is developing for this platform.
05-16-2024, 11:59 PM
I told myself I was done modifying my car and then that shows up...
