My (new to me) stock 991.2 manual on track @ Spa Francorchamps
#16
I am in reflexion about a 718 GT4 -> 991.2 GT3 upgrade and I have just seen your posts and videos
Is the change really important? Do you feel more power?
Are there less parasitic movements of the rear suspension on bump?
Gearbox feel the same ?
Thanks !
Is the change really important? Do you feel more power?
Are there less parasitic movements of the rear suspension on bump?
Gearbox feel the same ?
Thanks !
Last edited by borisjnt; 12-16-2022 at 06:50 PM.
#17
Rennlist Member
yes, yes and yes esp. on a bumpy track... same with 4RS and 992GT3
Last edited by Larry Cable; 12-16-2022 at 07:28 PM.
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borisjnt (12-19-2022)
#18
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Thread Starter
The engine is from a different world, and it's mated to a gearbox with really good ratios. The rear end of the car doesn't care about bumps much but in slower corners it has a bit of trouble staying in line whereas a Cayman just changes direction without any fuss. That's the one part where the 911 can't match the mid-engine cars. See the final chicane in the Spa video. It's not problematic that it steps out a bit but the Cayman never did that and the 911 is consistent with it. It needs a bit more time for the mass at the back to change direction.
The gearbox is similar but different. The GT3 box feels a bit tighter than the one in the Cayman and I feel there is a bit less travel in the gear stick, also the gears are spaced closer together on the pattern so it takes a tad more concentration/accuracy from me with the shifting on track whereas I didn't really think about it in the GT4. Not a big change but certainly noticeable when you've been used to one or the other.
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borisjnt (12-19-2022)
#19
Rennlist Member
Yeah like Larry said
The engine is from a different world, and it's mated to a gearbox with really good ratios. The rear end of the car doesn't care about bumps much but in slower corners it has a bit of trouble staying in line whereas a Cayman just changes direction without any fuss. That's the one part where the 911 can't match the mid-engine cars. See the final chicane in the Spa video. It's not problematic that it steps out a bit but the Cayman never did that and the 911 is consistent with it. It needs a bit more time for the mass at the back to change direction.
The gearbox is similar but different. The GT3 box feels a bit tighter than the one in the Cayman and I feel there is a bit less travel in the gear stick, also the gears are spaced closer together on the pattern so it takes a tad more concentration/accuracy from me with the shifting on track whereas I didn't really think about it in the GT4. Not a big change but certainly noticeable when you've been used to one or the other.
The engine is from a different world, and it's mated to a gearbox with really good ratios. The rear end of the car doesn't care about bumps much but in slower corners it has a bit of trouble staying in line whereas a Cayman just changes direction without any fuss. That's the one part where the 911 can't match the mid-engine cars. See the final chicane in the Spa video. It's not problematic that it steps out a bit but the Cayman never did that and the 911 is consistent with it. It needs a bit more time for the mass at the back to change direction.
The gearbox is similar but different. The GT3 box feels a bit tighter than the one in the Cayman and I feel there is a bit less travel in the gear stick, also the gears are spaced closer together on the pattern so it takes a tad more concentration/accuracy from me with the shifting on track whereas I didn't really think about it in the GT4. Not a big change but certainly noticeable when you've been used to one or the other.
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borisjnt (12-19-2022)
#20
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Thanks for the write up! I just sold my 981 GT4, loved a lot about it but really want to experience the GT3 drivetrain. Will go same, 991.2 manual.
#21
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#22
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Thread Starter
After a long and painful 6 month winter break, I went back for another go with a 2-day trackday.
Changes to the car: MR "standard suspension upgrade pkg" with their alignment and corner balance, 5lb lightweight battery, side muffler delete, GT4RS underbody main strakes, Apex wheels w/ Trofeo R.
Lap time change: -1.2 seconds*
*OK so there were some issues with traffic. It was a cheap(ish) trackday which meant loads of cars were booked and most of the time it was just impossible to go flat out for more than a couple of corners at a time. The speed of a GT3 isn't helpful because most of the cars are 20 to 40 seconds a lap slower so you're not going to be able to avoid them. On day 2 however near to the end lots of them packed up and went home early to catch their train or ferry to the UK and that left the track pretty nice for a quick lap, but at this stage the rear tires had gone off a lot. There just wasn't the rear grip and stability anymore that had been there earlier. It was very cold out, 5 degrees C ambient (40F) which meant the track wasn't particularly grippy either.
So I was still 1.6s off my optimal time based on sectors done earlier on fresher tires, mind you my optimal time would have beaten the fastest time of a .2 3RS at Spa with a pro driver and not been far off the "YouTube record" of a mid 2:33 on Cup 2R.
Car was excellent through the challenging Eau Rouge / Raidillon corner however, struggling mainly with rear grip in slower sections.
Car looked good tho. Apex in motorsport gold work really well.
Changes to the car: MR "standard suspension upgrade pkg" with their alignment and corner balance, 5lb lightweight battery, side muffler delete, GT4RS underbody main strakes, Apex wheels w/ Trofeo R.
Lap time change: -1.2 seconds*
*OK so there were some issues with traffic. It was a cheap(ish) trackday which meant loads of cars were booked and most of the time it was just impossible to go flat out for more than a couple of corners at a time. The speed of a GT3 isn't helpful because most of the cars are 20 to 40 seconds a lap slower so you're not going to be able to avoid them. On day 2 however near to the end lots of them packed up and went home early to catch their train or ferry to the UK and that left the track pretty nice for a quick lap, but at this stage the rear tires had gone off a lot. There just wasn't the rear grip and stability anymore that had been there earlier. It was very cold out, 5 degrees C ambient (40F) which meant the track wasn't particularly grippy either.
So I was still 1.6s off my optimal time based on sectors done earlier on fresher tires, mind you my optimal time would have beaten the fastest time of a .2 3RS at Spa with a pro driver and not been far off the "YouTube record" of a mid 2:33 on Cup 2R.
Car was excellent through the challenging Eau Rouge / Raidillon corner however, struggling mainly with rear grip in slower sections.
Car looked good tho. Apex in motorsport gold work really well.
Last edited by JCviggen; 04-07-2023 at 08:13 AM.
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#23
Rennlist Member
After a long and painful 6 month winter break, I went back for another go with a 2-day trackday.
Changes to the car: MR "standard suspension upgrade pkg" with their alignment and corner balance, 5lb lightweight battery, side muffler delete, GT4RS underbody main strakes, Apex wheels w/ Trofeo R.
Lap time change: -1.2 seconds*
*OK so there were some issues with traffic. It was a cheap(ish) trackday which meant loads of cars were booked and most of the time it was just impossible to go flat out for more than a couple of corners at a time. The speed of a GT3 isn't helpful because most of the cars are 20 to 40 seconds a lap slower so you're not going to be able to avoid them. On day 2 however near to the end lots of them packed up and went home early to catch their train or ferry to the UK and that left the track pretty nice for a quick lap, but at this stage the rear tires had gone off a lot. There just wasn't the rear grip and stability anymore that had been there earlier. It was very cold out, 5 degrees C ambient (40F) which meant the track wasn't particularly grippy either.
So I was still 1.6s off my optimal time based on sectors done earlier on fresher tires, mind you my optimal time would have beaten the fastest time of a .2 3RS at Spa with a pro driver and not been far off the "YouTube record" of a mid 2:33 on Cup 2R.
Car was excellent through the challenging Eau Rouge / Raidillon corner however, struggling mainly with rear grip in slower sections.
Car looked good tho. Apex in motorsport gold work really well.
Changes to the car: MR "standard suspension upgrade pkg" with their alignment and corner balance, 5lb lightweight battery, side muffler delete, GT4RS underbody main strakes, Apex wheels w/ Trofeo R.
Lap time change: -1.2 seconds*
*OK so there were some issues with traffic. It was a cheap(ish) trackday which meant loads of cars were booked and most of the time it was just impossible to go flat out for more than a couple of corners at a time. The speed of a GT3 isn't helpful because most of the cars are 20 to 40 seconds a lap slower so you're not going to be able to avoid them. On day 2 however near to the end lots of them packed up and went home early to catch their train or ferry to the UK and that left the track pretty nice for a quick lap, but at this stage the rear tires had gone off a lot. There just wasn't the rear grip and stability anymore that had been there earlier. It was very cold out, 5 degrees C ambient (40F) which meant the track wasn't particularly grippy either.
So I was still 1.6s off my optimal time based on sectors done earlier on fresher tires, mind you my optimal time would have beaten the fastest time of a .2 3RS at Spa with a pro driver and not been far off the "YouTube record" of a mid 2:33 on Cup 2R.
Car was excellent through the challenging Eau Rouge / Raidillon corner however, struggling mainly with rear grip in slower sections.
Car looked good tho. Apex in motorsport gold work really well.
A great update on the new car.....
I have a 718GT4 and followed your upgrades and suggestions pretty carefully, you were the first to let us know of some unique tendencies on that car...
Thank you for educating us and saving us some paintwork!!
Some questions on your .2 GT3 as I also have access to one, and am considering a switch from the GT4.....
- could you specify the MR track alignment details and advise if it is "streetable" ??
- was the "stock" suspension inadequate such that you saw the MR upgrade as necessary, and could you let us know what the MR upgrade consists of??
- are the "4RS main strakes" the front ones only, or both front and rear??
Please continue with these helpful threads!
Thanks again JC!!
Cheers,
Colin
-
#24
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Thread Starter
Hey Colin,
- They just "set it up" to their specs which they didn't disclose (and I didn't ask) but clearly there is more camber and also more rake in the car since they dropped the front quite a bit. The comfort is the same, I'd just be a bit more careful around potholes with the lower ride height.
- They really don't add much to the suspension, a couple of small bits to allow them to get the alignment they want without the wheels sticking out or the caster getting out of whack.
- Front only, it was cheap and bolted on and it should do "something" probably imperceptible.
- They just "set it up" to their specs which they didn't disclose (and I didn't ask) but clearly there is more camber and also more rake in the car since they dropped the front quite a bit. The comfort is the same, I'd just be a bit more careful around potholes with the lower ride height.
- They really don't add much to the suspension, a couple of small bits to allow them to get the alignment they want without the wheels sticking out or the caster getting out of whack.
- Front only, it was cheap and bolted on and it should do "something" probably imperceptible.
#25
Rennlist Member
Hey Colin,
- They just "set it up" to their specs which they didn't disclose (and I didn't ask) but clearly there is more camber and also more rake in the car since they dropped the front quite a bit. The comfort is the same, I'd just be a bit more careful around potholes with the lower ride height.
- They really don't add much to the suspension, a couple of small bits to allow them to get the alignment they want without the wheels sticking out or the caster getting out of whack.
- Front only, it was cheap and bolted on and it should do "something" probably imperceptible.
- They just "set it up" to their specs which they didn't disclose (and I didn't ask) but clearly there is more camber and also more rake in the car since they dropped the front quite a bit. The comfort is the same, I'd just be a bit more careful around potholes with the lower ride height.
- They really don't add much to the suspension, a couple of small bits to allow them to get the alignment they want without the wheels sticking out or the caster getting out of whack.
- Front only, it was cheap and bolted on and it should do "something" probably imperceptible.
#26
Rennlist Member
Thread Starter
Yeah they add a few small bits, it's not a big thing. I'm not going the coilover way for now.
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Larry Cable (04-07-2023)
#27
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#28
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#29
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Thread Starter
I actually plugged in a DSC halfway through the first day and to my considerable surprise did not feel much of a difference. It was a clear difference on my GT4 before so I was expecting quite a noticeable change but whatever it did was subtle. May need to play with the maps. I don't expect much of a lap time difference either way, but I was hoping to get a bit less body roll.
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Larry Cable (04-10-2023)
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