Driving your GT3!
Discussion
Yellow491 said:
The weight of some one sat in the passenger seat or in the rear is completely different ,to weight elsewhere in the car.30 kg or 50 willnot make much if any difference on the clock in a road car.
You will notice fuel load dropping,if the car is well set up in a 911.
My batteries weigh 0.9 of a kg and only £200 but thats in a car that weights 895kg,did i notice taking a 14kg battery out,no not really,did it make any differance on the clock,no not really.
A question how do you flat shift in a H pattern gt3 box with helical gears,no one has answered this for me yet.
Stay flat and wait for the engine to hit the limiter, when the limiter kicks in keep flat, button the clutch and shift as quickly as you can. It’s worth a decent chunk of time but it’s hard on the box and will half your rebuild hours. I used it only on a quali lap. You will notice fuel load dropping,if the car is well set up in a 911.
My batteries weigh 0.9 of a kg and only £200 but thats in a car that weights 895kg,did i notice taking a 14kg battery out,no not really,did it make any differance on the clock,no not really.
A question how do you flat shift in a H pattern gt3 box with helical gears,no one has answered this for me yet.
Edited by Yellow491 on Saturday 27th October 12:34
Porsche911R said:
Taffy66 said:
A Manual has about 15% parasitic losses and a good dual clutch has about 16-17%..US guys have dynoed PDK vs Manual and at full revs only between 5 and 10HP between the two.
10 is 10 :-) if I have gained 15/20 with my current mods it should be a bit faster than the non RS PDK cars now.once my brain can get into flat shift mode mind you as I still do a lift ! that's a >million miles of driving for you over 33 years !.
hunter 66 said:
Yes .... made some money for Parr ....Steve .
As far as Passengers hardly notice on track in the Road RS , but in the Race RS which is 300 kg lighter it has a big effect....especially if a bigger passenger ..
In my Spyder a 80kg person feels like a anchor! As far as Passengers hardly notice on track in the Road RS , but in the Race RS which is 300 kg lighter it has a big effect....especially if a bigger passenger ..
As for braking and corners it,s pretty horrible.
That’s in a 1250 kg car with 350bhp.
It’s odd how a 80kg weight added feels 4x the amount as a 40kg weight added.
Must be some maths in it some where.
So while saving 15kg seems pointless save that in 5 items and it’s 75kg and that’s well worth it.
I noticed a big difference - even a small passenger. The GT cup used to give weight penalties in the next race for the podium winners. From memory it was 35kg for the winner with slightly less for second and third. I found that the 35kg cost a lot of time in the 997cup and the car used its tyres noticeably quicker. The 996cup carried 40kg in the Porsche Open and it cost nearly half a second at Brands Indy.
Steve Rance said:
Stay flat and wait for the engine to hit the limiter, when the limiter kicks in keep flat, button the clutch and shift as quickly as you can. It’s worth a decent chunk of time but it’s hard on the box and will half your rebuild hours. I used it only on a quali lap.
Steve,yes i know that in a race car,but a road car! I thought may be the new gt3 has some sort of ignition cut on the shifter,as it aint going to look to good on warranty and 1 to 6 ign, bouncing off the limiter.I also wondered if they had change the gears to semi helical or similar to allow a reliable gearbox.
Re weight,race cars are so differant,a cup is on average what 1120/1140kg,thirty kg will make a difference ,but on a lardy 14/1500kg!
Steve Rance said:
I noticed a big difference - even a small passenger. The GT cup used to give weight penalties in the next race for the podium winners. From memory it was 35kg for the winner with slightly less for second and third. I found that the 35kg cost a lot of time in the 997cup and the car used its tyres noticeably quicker. The 996cup carried 40kg in the Porsche Open and it cost nearly half a second at Brands Indy.
And you have taken a fair few passenger rides .......Yellow491 said:
Steve,yes i know that in a race car,but a road car! I thought may be the new gt3 has some sort of ignition cut on the shifter,as it aint going to look to good on warranty and 1 to 6 ign, bouncing off the limiter.
I also wondered if they had change the gears to semi helical or similar to allow a reliable gearbox.
Re weight,race cars are so differant,a cup is on average what 1120/1140kg,thirty kg will make a difference ,but on a lardy 14/1500kg!
Ah. Sorry, thought that you were referring to the 996 CupI also wondered if they had change the gears to semi helical or similar to allow a reliable gearbox.
Re weight,race cars are so differant,a cup is on average what 1120/1140kg,thirty kg will make a difference ,but on a lardy 14/1500kg!
I guess the 'magic' here is that this isn't 'full-bore' flat-shifting, but rather it's a modulated power-shift where activation of the clutch (and probably other parameters) brings in some electronic intervention over engine speed, so that input/drive loads into the transmission are controlled and shock-loading kept at manageable levels through the ratio-change sequence. And the box is still fully synchro'd, of course.
I imagine that it's the absence of severe shock loads into the transmission (such as you might get with full-bore flat-shifting and/or the use of dog engagement instead of synchro's) that ensures adequate durability with helical gear sets, rather than needing to move to wider and stronger straight-cut gears - which would bring all sorts of other issues (largely refinement, noise and vibration related) on a road car.
My best guess...
James
I imagine that it's the absence of severe shock loads into the transmission (such as you might get with full-bore flat-shifting and/or the use of dog engagement instead of synchro's) that ensures adequate durability with helical gear sets, rather than needing to move to wider and stronger straight-cut gears - which would bring all sorts of other issues (largely refinement, noise and vibration related) on a road car.
My best guess...
James
Taffy66 said:
Took my GT3 for a nice long drive this afternoon and ended up driving from Sennybridge down to Brynaman on the A4067 and back across the mountain road A4059 to Llandovery..This mountain road is fantastic with no hedges and very well sighted plus no sheep at this time of year.
I drove up to Holyhead through Snowdonia this afternoon....there were sheep everywhere! Cheib said:
Taffy66 said:
Cheib said:
I drove up to Holyhead through Snowdonia this afternoon....there were sheep everywhere!
Try your best to not let them distract you..;)
Just want to add a couple of notes on some of the things said.
1) GT3 RS .2 power increase reason over the .2 gt3.
It's very simple, more air in, more fuel = power. It's not possible to emulate on the 991.2 gt3, as the side intakes create a proper ram air, it has bigger tubes than the .1 rs, possibly the intake manifold is bigger too. And obviously a tune to adjust afr.
The titanium exhaust doesn't make power, it doesn't work like that and it's only the muffler that is titanium on the rs (s).
2) muffler delete doesn't make power and actually it's more probable that you lose mid-range than gain anything. And the weight savings are minimal vs side muffler delete.
The proper way to make power, is bigger and longer primaries, with a 3 inch junction with side muffler delete and a proper 3 inch internal tubing reinforced muffler (side muffler delete increases pressure on the central muffler and it will blow out eventually).
A tune might be needed, but these latest ecus adjust nicelly their afr.
If the ss is a good one you could ceramic coat it, delete heat shields, that will improve heat dissipation and avoid heat spots as they do oem.
So, you will save a LOT more weight (heatshields and side mufflers weight a LOT), and make tremendous power, torque and increase reliabilty (given afr adjust to oem values).
3) Suspension isn't really that hard, plus you have proper masters of it in UK gravitycentre being one, if needed a little trip to the ring and getspeed, schirmer, raeder/manthey will sort your car, but it's a bit irrelevant until one is lapping close to the 'record' laps.
4) Reduction of rotational weight and ceramics not only improve brake distances, but tire wear, accelaration and brake fade enough to be noticeable (mag wheels with iron disks improved brake wear).
Ceramics are just better, not only they brake the same, they last lomger with track pads, and the leader and actually the best ceramic disks are made in the UK, they are rebuildable, almost as strong as iron in brittleness, and cheaper than oem pccb and they brake the exact same used as they did new, this is a major pro on confidence and obviously on times.
Best mod for anyone with either iron or pccb.
I can't remember the name but it's the disks movit sell with their calipers (not worth it by the way, just improve pucks to metal ones, as soon as brakes get major heat, the rubber ones are f
ked, brake coolant will need to be improved as it will transfer a bit more heat, but it will brake better).
I think it is all.
Edit: not all, lol
5) Pdk cars don't really pull on mt cars, saw this in 1st hand, as long it's a rolling start and mt driver uses flat shift it will be pretty much neck and neck, pdk should pull away tho, better gear ratios, idk the losses of the pdk but it's much less than any other gearbox from vague memories of a tech table talk I heard from a zf engineer, might be totally wrong on this one, but cumulative with weight savings, spec (manual had lighter driver, pccb, no lift) and the fact it has less losses, and he shifted well. On track pdk in auto will 'win' but manual, if personality is a fit, will always win on fun and not be far off if everything is done well.
6) Just some tips for mods for track rats that will actually improve your times and save your money on pointless other mods.
6.1. Ceramic disks mention above paired with good track-day or fast road pads for ceramics
6.2. Either rebuild your calipers on regurlar basis (learn to do it yourself, not hard) or upgrade the pistons/pucks.
6.3. Brake cooling ducts, cheap, easy and make a difference everywhere braking
6.4. Cup 2 n2, trofeo r or cup r tires.
6.5. Remove the nets from the front fenders (rs)
6.5. Proven alignment, mostly for tire wear.
6.6. Dot 5 brake coolant
6.7. .2 don't really need much suspension mods, but .1 rs and gt3 will benefict tremendously from upgraded springs and a damper with internals paired with stiff springs, tractive is my favourite, but kw manthey or ttx will be great.
All models might improve from dsc controller if proper tuned and if one knows what it wants to improve specifically.
6.8. If anyone is in the mood to spend more money, reducing rotational weight will help a lot, and proper headers like the setup mentioned above will throw any gt car into another play level.
Any of these mods can be done in isolation, but brakes and tires are always my priority (and adress any possible reliability problem), followed right after by setup / suspension upgrade if really needed, then all the rest.
1) GT3 RS .2 power increase reason over the .2 gt3.
It's very simple, more air in, more fuel = power. It's not possible to emulate on the 991.2 gt3, as the side intakes create a proper ram air, it has bigger tubes than the .1 rs, possibly the intake manifold is bigger too. And obviously a tune to adjust afr.
The titanium exhaust doesn't make power, it doesn't work like that and it's only the muffler that is titanium on the rs (s).
2) muffler delete doesn't make power and actually it's more probable that you lose mid-range than gain anything. And the weight savings are minimal vs side muffler delete.
The proper way to make power, is bigger and longer primaries, with a 3 inch junction with side muffler delete and a proper 3 inch internal tubing reinforced muffler (side muffler delete increases pressure on the central muffler and it will blow out eventually).
A tune might be needed, but these latest ecus adjust nicelly their afr.
If the ss is a good one you could ceramic coat it, delete heat shields, that will improve heat dissipation and avoid heat spots as they do oem.
So, you will save a LOT more weight (heatshields and side mufflers weight a LOT), and make tremendous power, torque and increase reliabilty (given afr adjust to oem values).
3) Suspension isn't really that hard, plus you have proper masters of it in UK gravitycentre being one, if needed a little trip to the ring and getspeed, schirmer, raeder/manthey will sort your car, but it's a bit irrelevant until one is lapping close to the 'record' laps.
4) Reduction of rotational weight and ceramics not only improve brake distances, but tire wear, accelaration and brake fade enough to be noticeable (mag wheels with iron disks improved brake wear).
Ceramics are just better, not only they brake the same, they last lomger with track pads, and the leader and actually the best ceramic disks are made in the UK, they are rebuildable, almost as strong as iron in brittleness, and cheaper than oem pccb and they brake the exact same used as they did new, this is a major pro on confidence and obviously on times.
Best mod for anyone with either iron or pccb.
I can't remember the name but it's the disks movit sell with their calipers (not worth it by the way, just improve pucks to metal ones, as soon as brakes get major heat, the rubber ones are f
ked, brake coolant will need to be improved as it will transfer a bit more heat, but it will brake better). I think it is all.
Edit: not all, lol
5) Pdk cars don't really pull on mt cars, saw this in 1st hand, as long it's a rolling start and mt driver uses flat shift it will be pretty much neck and neck, pdk should pull away tho, better gear ratios, idk the losses of the pdk but it's much less than any other gearbox from vague memories of a tech table talk I heard from a zf engineer, might be totally wrong on this one, but cumulative with weight savings, spec (manual had lighter driver, pccb, no lift) and the fact it has less losses, and he shifted well. On track pdk in auto will 'win' but manual, if personality is a fit, will always win on fun and not be far off if everything is done well.
6) Just some tips for mods for track rats that will actually improve your times and save your money on pointless other mods.
6.1. Ceramic disks mention above paired with good track-day or fast road pads for ceramics
6.2. Either rebuild your calipers on regurlar basis (learn to do it yourself, not hard) or upgrade the pistons/pucks.
6.3. Brake cooling ducts, cheap, easy and make a difference everywhere braking
6.4. Cup 2 n2, trofeo r or cup r tires.
6.5. Remove the nets from the front fenders (rs)
6.5. Proven alignment, mostly for tire wear.
6.6. Dot 5 brake coolant
6.7. .2 don't really need much suspension mods, but .1 rs and gt3 will benefict tremendously from upgraded springs and a damper with internals paired with stiff springs, tractive is my favourite, but kw manthey or ttx will be great.
All models might improve from dsc controller if proper tuned and if one knows what it wants to improve specifically.
6.8. If anyone is in the mood to spend more money, reducing rotational weight will help a lot, and proper headers like the setup mentioned above will throw any gt car into another play level.
Any of these mods can be done in isolation, but brakes and tires are always my priority (and adress any possible reliability problem), followed right after by setup / suspension upgrade if really needed, then all the rest.
Edited by luigisayshello on Thursday 1st November 11:20
luigisayshello said:
the best ceramic disks are made in the UK, they are rebuildable, almost as strong as iron in brittleness, and cheaper than oem pccb and they brake the exact same used as they did new, this is a major pro on confidence and obviously on times.
Best mod for anyone with either iron or pccb.
I can't remember the name but it's the disks movit sell
Surface Transform.Best mod for anyone with either iron or pccb.
I can't remember the name but it's the disks movit sell
ETA: Trouble is, the 997 GT3 PCCB replacements are nearly £11k fitted, as opposed to £4k for a set of Alcons that are only 13kgs heavier for the full set of four. My pockets aren't that deep.
Digga said:
urface Transform.
ETA: Trouble is, the 997 GT3 PCCB replacements are nearly £11k fitted, as opposed to £4k for a set of Alcons that are only 13kgs heavier for the full set of four. My pockets aren't that deep.
Not opposed, plenty of reasons steal can make sense. ETA: Trouble is, the 997 GT3 PCCB replacements are nearly £11k fitted, as opposed to £4k for a set of Alcons that are only 13kgs heavier for the full set of four. My pockets aren't that deep.
But if you think long term, ceramics will outlast 3 sets of Alcons or around that, save on tires, at least a couple of sets by the end of their life, brake performance is always constant, money suspension will have to work less, performance (response mostly) will increase, and rebuilds are as expensive if not less than a set of 4 steel brakes. Besides the original money it's a win in every aspect vs steel.
But on 997, my money would be on coolant pipes pinning, guards lsd or drexler, 3.89 gearing and manthey kw or a set of used/well priced ttx and do a rebuild on them. Plus a couple of bits and bobs but that alone would make it another car. Lwfw but in my opinion ot would need a crank damper but they are expensive as hell.
And these were thinking on 991 gt cars and giving an argument to save the money on pccb and retrofit proper ceramics after.
P.S. Some of the improvements on ceramics can be slightly improvements, some aren't, but the cumulative improvements make quite a difference, especially on the ease of getting good times repeatedly and edging out similar cars with similar skilled drivers.
An important note is that coaching and skills are the best mod by far, followed by reliability and consistency upgrades, in my opinion.
Gassing Station | 911/Carrera GT | Top of Page | What's New | My Stuff