New rear wing
01-29-2023, 03:07 PM
#61
01-29-2023, 07:02 PM
#63
Three Wheelin'
Cool idea, but are the piston sizes within the calipers the same inorder to maintain the OEM front to rear brake bias?
01-29-2023, 09:09 PM
#64
01-29-2023, 10:23 PM
#65
Three Wheelin'
Good to know.
01-29-2023, 10:38 PM
#66
Three Wheelin'
Actually, I just looked up the piston sizes and they are virtually the same. The 718 GT4's pistons are 30-30-30 while the 997.2 GT3 RS's pistons are 28-30-32. They appear to be about the same at first glance, and it turns out when calculating the surface area, they are within .3% of each other. So I would say on paper they are a perfect match. With the 997's varying sizes you will have less pad taper on the leading edge of the brake pads with the smaller less powerful 28 mm piston hitting the surface of the pad first. Identical sized pistons are better for the street, while variable piston sizes are generally better for the track.
Now there is a relatively affordable way to get an 18 inch while set up for a GT4 or 991 GT3.
Sorry to be off topic here, but sometime the discussion deviates from the original thread title. If so, I always try to be factual or informative rather than opinionated.
Now there is a relatively affordable way to get an 18 inch while set up for a GT4 or 991 GT3.
Sorry to be off topic here, but sometime the discussion deviates from the original thread title. If so, I always try to be factual or informative rather than opinionated.
Last edited by lovetoturn; 01-29-2023 at 10:40 PM.
01-29-2023, 10:49 PM
#67
Actually, I just looked up the piston sizes and they are virtually the same. The 718 GT4's pistons are 30-30-30 while the 997.2 GT3 RS's pistons are 28-30-32. They appear to be about the same at first glance, and it turns out when calculating the surface area, they are within .3% of each other. So I would say on paper they are a perfect match. With the 997's varying sizes you will have less pad taper on the leading edge of the brake pads with the smaller less powerful 28 mm piston hitting the surface of the pad first. Identical sized pistons are better for the street, while variable piston sizes are generally better for the track.
Now there is a relatively affordable way to get an 18 inch while set up for a GT4 or 991 GT3.
Sorry to be off topic here, but sometime the discussion deviates from the original thread title. If so, I always try to be factual or informative rather than opinionated.
Now there is a relatively affordable way to get an 18 inch while set up for a GT4 or 991 GT3.
Sorry to be off topic here, but sometime the discussion deviates from the original thread title. If so, I always try to be factual or informative rather than opinionated.
01-30-2023, 04:20 AM
#68
Quite a lot of us with 981s (I have also had a 718 and now an RS) have been fitting 997.2 RS or Cup calipers for ages so we can run 18s. The OEM rears just fit. The older calipers also come with the advantage that pad changes only take a few minutes. Just watch tyre fitments. Try and keep as close as possible to the OEM rears in particular. Use the Clunsport Michelin slicks (27/68-18 and 25/64-18) as a guide. Can go a little less in height but if you run a 295/30-18 R spec on the rear I have found the car prone to problematic mid corner oversteer and you can't tune it out; the GT4 chassis just does not like small rears.
03-08-2023, 06:44 PM
#69
Rennlist Member
Thread Starter
