718 GT4 Tyre upgrade 20"
04-08-2024, 11:51 PM
#16
Burning Brakes
Thanks. Don't know their spring rates but Manthey's are 120/140 up from the 100/120 stock. I wanted more front end, so I tried a pair of Longacre spring rubbers in the front axle when the first set of tires was going off. Definite push in the car that was immediately reduced with the simple addition of 12 Nm spring rubbers at each front corner. Drove home with them still on the car, and although the front was stiffer, it felt more balanced front to rear. There with less pogoing of the front end off expansion joints and the car felt more as one instead of two variable axles. The changes were very noticeable to me at the track and more subtle on the street.
I figured that when putting on camber plates front and rear it would be time to adjust the front spring rate. I thought splitting the difference with the Manthey rates made sense for were I wanted to go with my car. The spring rubbers were able to quickly and conveniently confirm my intentions would work. They are so easy to install and remove that you could theoretically just use them on a track day and then take them out for the rest of your street driving. Nascar does it all day long during their races to change the balance of the car.
We used the black ones at 70 lbs which is equivalent to about 12 Nm. You could also use the blue one at 50 lbs or approximately 9 Nm. Cool and inexpensive way to tune your suspension before you drop some coin to permanently replace them. Very easy to also add these to a GT4 front so the spring rates would go from 45/80 to 57/80. This would show you the improvements that the 60/80 spring rates would make, as I have advocated for in the past.
The car is starting to feel real good now with amazing front end grip. Still working on alignment, bar, and ride height adjustments to help the rear catch up with the front.
https://www.longacreracing.com/shop....-Spring-Rubber
I figured that when putting on camber plates front and rear it would be time to adjust the front spring rate. I thought splitting the difference with the Manthey rates made sense for were I wanted to go with my car. The spring rubbers were able to quickly and conveniently confirm my intentions would work. They are so easy to install and remove that you could theoretically just use them on a track day and then take them out for the rest of your street driving. Nascar does it all day long during their races to change the balance of the car.
We used the black ones at 70 lbs which is equivalent to about 12 Nm. You could also use the blue one at 50 lbs or approximately 9 Nm. Cool and inexpensive way to tune your suspension before you drop some coin to permanently replace them. Very easy to also add these to a GT4 front so the spring rates would go from 45/80 to 57/80. This would show you the improvements that the 60/80 spring rates would make, as I have advocated for in the past.
The car is starting to feel real good now with amazing front end grip. Still working on alignment, bar, and ride height adjustments to help the rear catch up with the front.
https://www.longacreracing.com/shop....-Spring-Rubber
Last edited by lovetoturn; 04-08-2024 at 11:53 PM.
04-09-2024, 04:22 PM
#17
Thanks. Don't know their spring rates but Manthey's are 120/140 up from the 100/120 stock. I wanted more front end, so I tried a pair of Longacre spring rubbers in the front axle when the first set of tires was going off. Definite push in the car that was immediately reduced with the simple addition of 12 Nm spring rubbers at each front corner. Drove home with them still on the car, and although the front was stiffer, it felt more balanced front to rear. There with less pogoing of the front end off expansion joints and the car felt more as one instead of two variable axles. The changes were very noticeable to me at the track and more subtle on the street.
I figured that when putting on camber plates front and rear it would be time to adjust the front spring rate. I thought splitting the difference with the Manthey rates made sense for were I wanted to go with my car. The spring rubbers were able to quickly and conveniently confirm my intentions would work. They are so easy to install and remove that you could theoretically just use them on a track day and then take them out for the rest of your street driving. Nascar does it all day long during their races to change the balance of the car.
We used the black ones at 70 lbs which is equivalent to about 12 Nm. You could also use the blue one at 50 lbs or approximately 9 Nm. Cool and inexpensive way to tune your suspension before you drop some coin to permanently replace them. Very easy to also add these to a GT4 front so the spring rates would go from 45/80 to 57/80. This would show you the improvements that the 60/80 spring rates would make, as I have advocated for in the past.
The car is starting to feel real good now with amazing front end grip. Still working on alignment, bar, and ride height adjustments to help the rear catch up with the front.
https://www.longacreracing.com/shop....-Spring-Rubber
I figured that when putting on camber plates front and rear it would be time to adjust the front spring rate. I thought splitting the difference with the Manthey rates made sense for were I wanted to go with my car. The spring rubbers were able to quickly and conveniently confirm my intentions would work. They are so easy to install and remove that you could theoretically just use them on a track day and then take them out for the rest of your street driving. Nascar does it all day long during their races to change the balance of the car.
We used the black ones at 70 lbs which is equivalent to about 12 Nm. You could also use the blue one at 50 lbs or approximately 9 Nm. Cool and inexpensive way to tune your suspension before you drop some coin to permanently replace them. Very easy to also add these to a GT4 front so the spring rates would go from 45/80 to 57/80. This would show you the improvements that the 60/80 spring rates would make, as I have advocated for in the past.
The car is starting to feel real good now with amazing front end grip. Still working on alignment, bar, and ride height adjustments to help the rear catch up with the front.
https://www.longacreracing.com/shop....-Spring-Rubber
It really amazed me when I first got my GT4 just have disconnected the front and rear axles felt from each other. Even though my car is awesome now with all the mods I have done, I am still pretty disappointed in Porsche's GT department for releasing the GT4 in the state it comes from the factory. A few simple changes in spring and damper tuning would have made the car so much better out of the box. They surely should have known this with all the testing they do.
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jpbacs12 (04-23-2024)
04-23-2024, 11:23 AM
#18
Rennlist Member
Thread Starter
Thanks. Don't know their spring rates but Manthey's are 120/140 up from the 100/120 stock. I wanted more front end, so I tried a pair of Longacre spring rubbers in the front axle when the first set of tires was going off. Definite push in the car that was immediately reduced with the simple addition of 12 Nm spring rubbers at each front corner. Drove home with them still on the car, and although the front was stiffer, it felt more balanced front to rear. There with less pogoing of the front end off expansion joints and the car felt more as one instead of two variable axles. The changes were very noticeable to me at the track and more subtle on the street.
I figured that when putting on camber plates front and rear it would be time to adjust the front spring rate. I thought splitting the difference with the Manthey rates made sense for were I wanted to go with my car. The spring rubbers were able to quickly and conveniently confirm my intentions would work. They are so easy to install and remove that you could theoretically just use them on a track day and then take them out for the rest of your street driving. Nascar does it all day long during their races to change the balance of the car.
We used the black ones at 70 lbs which is equivalent to about 12 Nm. You could also use the blue one at 50 lbs or approximately 9 Nm. Cool and inexpensive way to tune your suspension before you drop some coin to permanently replace them. Very easy to also add these to a GT4 front so the spring rates would go from 45/80 to 57/80. This would show you the improvements that the 60/80 spring rates would make, as I have advocated for in the past.
The car is starting to feel real good now with amazing front end grip. Still working on alignment, bar, and ride height adjustments to help the rear catch up with the front.
https://www.longacreracing.com/shop....-Spring-Rubber
I figured that when putting on camber plates front and rear it would be time to adjust the front spring rate. I thought splitting the difference with the Manthey rates made sense for were I wanted to go with my car. The spring rubbers were able to quickly and conveniently confirm my intentions would work. They are so easy to install and remove that you could theoretically just use them on a track day and then take them out for the rest of your street driving. Nascar does it all day long during their races to change the balance of the car.
We used the black ones at 70 lbs which is equivalent to about 12 Nm. You could also use the blue one at 50 lbs or approximately 9 Nm. Cool and inexpensive way to tune your suspension before you drop some coin to permanently replace them. Very easy to also add these to a GT4 front so the spring rates would go from 45/80 to 57/80. This would show you the improvements that the 60/80 spring rates would make, as I have advocated for in the past.
The car is starting to feel real good now with amazing front end grip. Still working on alignment, bar, and ride height adjustments to help the rear catch up with the front.
https://www.longacreracing.com/shop....-Spring-Rubber
04-23-2024, 11:24 AM
#19
Rennlist Member
Thread Starter
It really amazed me when I first got my GT4 just have disconnected the front and rear axles felt from each other. Even though my car is awesome now with all the mods I have done, I am still pretty disappointed in Porsche's GT department for releasing the GT4 in the state it comes from the factory. A few simple changes in spring and damper tuning would have made the car so much better out of the box. They surely should have known this with all the testing they do.
04-23-2024, 11:09 PM
#20
Burning Brakes
Manthey is for their whole KW kit which has the 120/140 springs.
With stiffer 110 springs, 9.5 inch rims, and 265 tires up front, I have so much front end grip that I am at M/H front and S/S rear for the bars and just also lowered the rear by 4mm (2 turns). Next time out will be H/H on the front and S/M for the rear to make it easier for future adjustments. I feel like I am developing a new car with these front end upgrades. This more than solves all the complaints from folks like Misha about the understeer in the OEM GT4 RS.
The front tires are 27.3" tall which seems to interfere with ECS. The next set will likely be 255, but when stretched a bit over the 9.5 inch rims will be nearly equal to 265 on just a 9.0 inch wheel. Believe it or not, within a certain spectrum, wider wheels yield lower lap times than just adding wider tires.
With stiffer 110 springs, 9.5 inch rims, and 265 tires up front, I have so much front end grip that I am at M/H front and S/S rear for the bars and just also lowered the rear by 4mm (2 turns). Next time out will be H/H on the front and S/M for the rear to make it easier for future adjustments. I feel like I am developing a new car with these front end upgrades. This more than solves all the complaints from folks like Misha about the understeer in the OEM GT4 RS.
The front tires are 27.3" tall which seems to interfere with ECS. The next set will likely be 255, but when stretched a bit over the 9.5 inch rims will be nearly equal to 265 on just a 9.0 inch wheel. Believe it or not, within a certain spectrum, wider wheels yield lower lap times than just adding wider tires.
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jpbacs12 (04-30-2024)
04-23-2024, 11:29 PM
#21
Manthey is for their whole KW kit which has the 120/140 springs.
With stiffer 110 springs, 9.5 inch rims, and 265 tires up front, I have so much front end grip that I am at M/H front and S/S rear for the bars and just also lowered the rear by 4mm (2 turns). Next time out will be H/H on the front and S/M for the rear to make it easier for future adjustments. I feel like I am developing a new car with these front end upgrades. This more than solves all the complaints from folks like Misha about the understeer in the OEM GT4 RS.
The front tires are 27.3" tall which seems to interfere with ECS. The next set will likely be 255, but when stretched a bit over the 9.5 inch rims will be nearly equal to 265 on just a 9.0 inch wheel. Believe it or not, within a certain spectrum, wider wheels yield lower lap times than just adding wider tires.
With stiffer 110 springs, 9.5 inch rims, and 265 tires up front, I have so much front end grip that I am at M/H front and S/S rear for the bars and just also lowered the rear by 4mm (2 turns). Next time out will be H/H on the front and S/M for the rear to make it easier for future adjustments. I feel like I am developing a new car with these front end upgrades. This more than solves all the complaints from folks like Misha about the understeer in the OEM GT4 RS.
The front tires are 27.3" tall which seems to interfere with ECS. The next set will likely be 255, but when stretched a bit over the 9.5 inch rims will be nearly equal to 265 on just a 9.0 inch wheel. Believe it or not, within a certain spectrum, wider wheels yield lower lap times than just adding wider tires.
A slightly stretched tire has a few benefits over oversizing the tire on a narrower wheel.
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jpbacs12 (07-08-2024)
07-08-2024, 12:01 PM
#22
Rennlist Member
Thread Starter
Sorry been slow with the updates, Did a nice geo and corner weight on the 718 GT4. Went with the 255 on the from and 305 Nankang CRS on the rear. Feedback was very positive and the CRS were a great tyre with sustained grip even into a half hour session at spa. Going to try this on a 981 also and see how it is.
07-08-2024, 01:46 PM
#23
Racer
Sorry been slow with the updates, Did a nice geo and corner weight on the 718 GT4. Went with the 255 on the from and 305 Nankang CRS on the rear. Feedback was very positive and the CRS were a great tyre with sustained grip even into a half hour session at spa. Going to try this on a 981 also and see how it is.
07-08-2024, 02:50 PM
#24
Manthey is for their whole KW kit which has the 120/140 springs.
With stiffer 110 springs, 9.5 inch rims, and 265 tires up front, I have so much front end grip that I am at M/H front and S/S rear for the bars and just also lowered the rear by 4mm (2 turns). Next time out will be H/H on the front and S/M for the rear to make it easier for future adjustments. I feel like I am developing a new car with these front end upgrades. This more than solves all the complaints from folks like Misha about the understeer in the OEM GT4 RS.
The front tires are 27.3" tall which seems to interfere with ECS. The next set will likely be 255, but when stretched a bit over the 9.5 inch rims will be nearly equal to 265 on just a 9.0 inch wheel. Believe it or not, within a certain spectrum, wider wheels yield lower lap times than just adding wider tires.
With stiffer 110 springs, 9.5 inch rims, and 265 tires up front, I have so much front end grip that I am at M/H front and S/S rear for the bars and just also lowered the rear by 4mm (2 turns). Next time out will be H/H on the front and S/M for the rear to make it easier for future adjustments. I feel like I am developing a new car with these front end upgrades. This more than solves all the complaints from folks like Misha about the understeer in the OEM GT4 RS.
The front tires are 27.3" tall which seems to interfere with ECS. The next set will likely be 255, but when stretched a bit over the 9.5 inch rims will be nearly equal to 265 on just a 9.0 inch wheel. Believe it or not, within a certain spectrum, wider wheels yield lower lap times than just adding wider tires.
I'm doing the geo setup now (-3 and -2.5 camber front/rear) and (-1mm and +2mm toe front/rear per wheel). I'm adding front and rear camber plates and PM toe links. Still on the OEM Dunlops
07-08-2024, 08:44 PM
#26
07-09-2024, 03:58 AM
#27
An Exige S3 with 430bhp also has 215 from factory and fitting 225 (the max it allows ) improves the front end behaviour, cornering and braking