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    Re: New C4 and C4S - check our NEWS

    I'm confused about it needing to be wider to fit 305mm wide tires. I've seen 997 Carerra & Carerra S owners running 20" wheels with 305's on the rear who have posted pics on the various forums? Am I wrong?

    Re: New C4 and C4S - check our NEWS

    Quote:
    TerryR said:
    I'm confused about it needing to be wider to fit 305mm wide tires. I've seen 997 Carerra & Carerra S owners running 20" wheels with 305's on the rear who have posted pics on the various forums? Am I wrong?


    The wheels that will come on the C4's must have a different offset than the 19" wheels that come on the C2's. The C4 body is .87 inch wider on each side, yet the 305/30-19 tire that it comes with is only .4 inch wider than a 295/30-19 tire that comes on the C2.

    Phil

    Re: New C4 and C4S - check our NEWS

    Quote:
    STRADALE said:
    LOVE the size of the rear tires. Definately looks meaner then the 997S.
    Looking from the back with those monster tires all it's missing is a wing to comlete the bad look!
    Bring on the TT



    Based on a tire comparison calculator I used, the 305/30-19 tire is .4 inch wider than the 295/30-19 tire that comes on the C2 (12.01" verses 11.61"). That is only a little over 3% wider.

    Phil

    Re: New C4 and C4S - check our NEWS

    i'm happy and i'm not happy...

    Before my dream was to buy the 997 Turbo..so i dream a wide car,a car with a lot of power,with a big wing etc..so i wait a 4S WIDE..and i'm not so happy

    Now,the 4S is not SO wide..we need some instruments to see how wider is near to a "base" 997...so i'm happy becouse the NON 4S 997 are not slim..and if i go with a 997 Gt3 instead of the Turbo is good the same..becouse is only less wide that the turbo..

    Is not easy to explain...but in my mind is clear..

    Understand?? no.. hahahhaha

    Today i will call my dealer and i tell him to change my order from the 997 Turbo to a 997 Gt3 that will be less expansive, not slim,rear weel drive,with a big wing,and fun

    ciaooo

    Re: New C4 and C4S - check our NEWS

    mitico Dario!!!!!
    Good choice!!!!!
    I'm not sure that the 997 Turbo will beat the F430

    Re: New C4 and C4S - check our NEWS

    My biggest disappointment with the C4/C4S is the 4wd system.
    I don't really understand why they have decided to make them "widebody" either, but I do think I will like the looks once I see more pictures/see it live.

    Since we don't have very much info about the 4wd system in the 997 yet, I won't be too harsh, but it certainly looks like it's a carryover from the 996. Since the 997 is quite a radical departure/improvement from the 996, I expected the same to be true for the 4wd versions as well. And that they would fit an electronically controlled system, like Haldex, in the 997 C4/C4S.

    The viscous system is not a bad system, but it is not great either. The biggest problem IMO, is that it's a "dumb" system relying purely on speed-difference between the axles and the heat generated by that to work. This makes it slow, it can take about one quarter wheelturn before it reacts, unlike Haldex which reacts almost instantly, less than 1/8 wheelturn. And when it's -20 C/F outside it can be difficult to get enough heat in the viscous oil to make it lock the axles properly.

    And under braking, when you don't want the 4wd system engaged, it is slower to disengage than Haldex, which disengages instantly because it is electronically controlled and is working together ABS, ESP and all the other 3-letter safetysystems.

    These are some of the reasons why Volvo and Audi changed from a dumb, analog if you like, system like viscous to a smart, electronic, system like Haldex and I was expecting Porsche to do the same.

    Porsche uses a electronically controlled centre differential in the Cayenne (PTM), which works in basically the same way as BMWs X-Drive and M-differentials. Which would make the 997 C4/C4S about the only cars out there that still uses the viscous system.

    But as mentioned earlier, I will reserve my final judgement until we have more in-depth information about how the 4wd system in the 997 works.

    Please prove me wrong Porsche!

    Re: New C4 and C4S - check our NEWS

    Wanted to send the order but my dealer says that it is not possible yet. Does anyone know when Porsche is going to take orders?

    Re: New C4 and C4S - check our NEWS

    Quote:
    temm said:
    Since we don't have very much info about the 4wd system in the 997 yet, I won't be too harsh, but it certainly looks like it's a carryover from the 996. Since the 997 is quite a radical departure/improvement from the 996, I expected the same to be true for the 4wd versions as well. And that they would fit an electronically controlled system, like Haldex, in the 997 C4/C4S.




    The 997 is not a radical departure from the 996 at all, in Porsche's words, it's an evolution!
    Just look at them, they look so similar!
    However the 996 was a radical departure from the 993, I don't think anyone will deny that and guess what, the 4WD was identical (almost).
    As you wrote yourself, wait and see.

    I think mostly due to costs, they did not bother with electonically controlled system similar to the 959.
    Maybe on the 997 Turbo.
    But re Haldex, isn't the system predominently FWD?
    It certainly is on Audis, and hence, after having tried an S3, it's efficient, but boring.
    Can you make a haldex system RWD.
    On the Lambos, I think it's a viscous coupling mechanism, similar to Porsche but minimum split is 30% to the front wheels whereas it's 5% on the Porsche giving it a more RWD nature most of the time.
    And finally, I was very impressed by the Subaru sti, what 4Wd system does it use? Electronic one like the Mitsu EVO 8?
    I personally believe that the Japs are a step ahead when it comes to 4WD tech with all their fancy YAW control and stuff.
    Bar the mythical 959 of course.

    I do not have your technical knowlegde on 4WD tech Temm, that's for sure.
    But have you ever tried a 996 Turbo?
    The last thing that came to my mind was that the 4WD system was slow to react, same for my C4 actually.
    That's what this car's all about, grip, grip and more grip!
    Never tried a 959, wonder how it defers.
    RC,
    I think you're one of the lucky few, any major differences?

    Re: New C4 and C4S - check our NEWS

    Quote:
    Fanch said:

    The 997 is not a radical departure from the 996 at all, in Porsche's words, it's an evolution!
    Just look at them, they look so similar!




    The 996 mkII and the 997 are similar yes, but if you compare the 996 MY01 to the 997 MY01, I would say that the difference is borderline radical

    Quote:

    But re Haldex, isn't the system predominently FWD?
    It certainly is on Audis, and hence, after having tried an S3, it's efficient, but boring.
    Can you make a haldex system RWD.




    From the Haldex website:
    "Haldex LSC is installed in the drive-train of the vehicle to distribute the torque between the front and rear axles.
    In a basically front wheel driven vehicle, Haldex LSC will transfer the torque to the rear axle, and vice versa for a rear wheel driven vehicle."

    Quote:

    I think mostly due to costs, they did not bother with electonically controlled system similar to the 959.
    Maybe on the 997 Turbo.




    I don't think the Haldex system would increase the cost that much, and there have been many (unconfirmed) reports in the swedish motorpress that Haldex has a deal with Porsche.
    I think they just didn't bother to change it
    My prediction is that we will see an electronic system in the 997 Turbo, and that the C4/C4S will get it when it's time for the 997 facelift.

    Quote:

    And finally, I was very impressed by the Subaru sti, what 4Wd system does it use? Electronic one like the Mitsu EVO 8?
    I personally believe that the Japs are a step ahead when it comes to 4WD tech with all their fancy YAW control and stuff.




    The EVO and Impreza uses 3 full-time mechanical diffs on the front, centre and rear axle. (Electronically controlled - they are Japanese after all )

    Quote:

    I do not have your technical knowlegde on 4WD tech Temm, that's for sure.
    But have you ever tried a 996 Turbo?
    The last thing that came to my mind was that the 4WD system was slow to react, same for my C4 actually.
    That's what this car's all about, grip, grip and more grip!




    No, I have never tried the 996 Turbo. And I agree with you, under normal circumstances and temperatures the viscous works just fine, but in very cold weather, like Norway in winter, it might not work as well as it should. I remember reading a swedish roadtest of a 996 C4S where the tester could not get up the slight incline in his driveway because the front wheels did not drive at all after being left outside a cold night. And don't get me started on the old Golf Syncro my uncle used to own..

    Re: New C4 and C4S - check our NEWS

    Ron

    can you post a picture of a 997S and a 997 C4S in the rear..like what you have done with the 996 4S and 997 4S


    thanks

    Re: New C4 and C4S - check our NEWS

    The new C4 and C4S are good for the driver that wants the 4WD within the style of the 997 and 997S. I respect the design decision to make them visually similiar to each other. I am not certain whether the C4 and C4S power has been enhanced to keep them at the effective performance levels of the C2 and C2S (lap-times, standing start, rolling start, etc.) If so that is a good thing to provide the 4WD without performance penalty. Of course the cost penalty is debatable; does it really require that option amount - if you really want 4WD from Porsche there is no choice.
    For me that means waiting for the 997 GT3, 997 TT, or taking the 997S with performance options. Right now my leaning is for the 997 GT3.

    Re: New C4 and C4S - check our NEWS

    sorry, couldn't find a good press picture for CS in the same positions as the C4S. In this shot C2S looks wider .

    Re: New C4 and C4S - check our NEWS

    hahaha

    no problem thanks !!

    Re: New C4 and C4S - check our NEWS

    everything has been commented, only one comment from me ,whic i think it has not been mentioned.

    4WD is mainly for those who suffer a heavy winter, rain, snow etc...

    BUT 305/30/19 is not at all a plus for this kind of weather!!!

    Cannot fit chains and believe me aquaplanning is BIG..!!!

    Aquaplanning can be fatal, and if you remember an accident posted a while before here with a 911 showed aquaplanning to be the cause even that the car had PSM....


    Aquaplanning from a huge tire cannot be eliminated even with the best computer system...i am afraid...


    So one less reason to purschase a C4S now..

    Re: New C4 and C4S - check our NEWS

    Quote:
    Ron (Houston) said:
    sorry, couldn't find a good press picture for CS in the same positions as the C4S. In this shot C2S looks wider .



    At least in this pic, the difference in width is hardly noticeable at all. I really what it looks like in real...

    Re: New C4 and C4S - check our NEWS

    Ron,
    From your 2 pictures, if you look and compare the side mirrors, you can tell the rear are wider on the C4S.

    Re: New C4 and C4S - check our NEWS

    Quote:
    Dilinger said:
    everything has been commented, only one comment from me ,whic i think it has not been mentioned.

    4WD is mainly for those who suffer a heavy winter, rain, snow etc...

    BUT 305/30/19 is not at all a plus for this kind of weather!!!

    Cannot fit chains and believe me aquaplanning is BIG..!!!

    Aquaplanning can be fatal, and if you remember an accident posted a while before here with a 911 showed aquaplanning to be the cause even that the car had PSM....


    Aquaplanning from a huge tire cannot be eliminated even with the best computer system...i am afraid...


    So one less reason to purschase a C4S now..



    Yes you're right, but in mine (the guy who had the aquaplanning crash ) they are 285 and on the C4S, they are 295.
    So I don't think 1 cm more is gonna make a huge difference, not better for sure, but considering your argument, then it's also valid for the 996 C4S.

    And now to quote RC and I agree with him 100%,
    As opposed to what Porsche says actually, I see more 4WD carrera as a sporty feature than a safe one, the device helps accelerate earlier in corners, aquaplanning as you wrote Dillinger prevents the car from being driven fast in heavy rain (remember aquaplanning occurs only when you encounter big patches of water, not on wet roads) and on snow, forget it, same as 2WD drive.
    For the winter, put winter tyres on.
    As for snow chains, they are available, last winter, I saw an Enzo in Courchevel (brit one with license plate SUG4R) and the Enzo was fitted with rear chains.

    Re: New C4 and C4S - check our NEWS

    fanch i beleive the car for bad weather was the 996 C4 only!!!


    no other it had the best proportions.


    Now your car has 285?? Which car do you own?

    Re: New C4 and C4S - check our NEWS

    Quote:
    Dilinger said:
    fanch i beleive the car for bad weather was the 996 C4 only!!!


    no other it had the best proportions.


    Now your car has 285?? Which car do you own?



    996 Carrera 4 Cab (the 320 hp one).
    Great car BTW!
    Re your comment, yes the C4 has a more planted feel than the C2 on the wet, but 4WD can give false confidence, because, trut me, once you lose it, it's usually too late!

    Re: New C4 and C4S - check our NEWS

    Guess what, given the same PSI, the contact patch on two different size tires will be the same. So having wider tires won't really make a difference if you have the same tire pressure. It will only make the shape of the contact different.

    Re: New C4 and C4S - check our NEWS

    Quote:
    colonel said:
    Ron,
    From your 2 pictures, if you look and compare the side mirrors, you can tell the rear are wider on the C4S.



    I think it's the angle of the shot. Based on the mirrors and side that looks way more than 44mm to me.

    Re: New C4 and C4S - check our NEWS

    Quote:
    Texas911 said:It will only make the shape of the contact different.



    Yes, but that difference leads to decreased ability of the tire to evacuate the standing water (given same thread design and compounds) on the road which is what leads lower hydroplanning threshold of the wider tires. The wider contact patch shape is not able to "dig" as well, the water needs to be channeled/displaced further to the side to be evacuated, and tends to "float" over the water more easily at higher speeds.

    However grip on wet and hydroplanning are two different things and while hydroplanning characteristics will be affected, grip on wet may no be affected.

    The problem with hydroplanning/aquaplannig is that one minute you are doing fine and have all the grip and the next without warning if you encounter a suficient puddle of standing water at sufficient speed that the tires can't evacuate, you loose control completely, like Fanch sais, when its gone its gone. All you can do is maintain all your inputs costant (steering/thottle) and hope that you regain traction in time to recover, sometimes if you see the standing water you can brake before you enter it and then resume constant inputs when you enter it at less speed.

    I do lots of highspeed driving in the highways here and it rains a lot in winter so aquaplanning if frequent, but never been enough to loose control. I don't need prescription glasses but I find that night driving glasses not only increase contrast and perception in night driving with their filters, but really help in differentianting normal wet safalt and standing water parts when it rain, specially at night but also in daylight. I highly recomend them if you drive at night or in rainy days in highways. If its sunny I use polarised grey-lense sunglasses for driving.

    Re: New C4 and C4S - check our NEWS

    FIRST OF ALL BIGGER TIRE IS WORST IN AQUAPLANNING REGARDLESS TIRE PRESSURE


    Second, Carlos you dont have this problem beause you owned a carrera 4 with 265 rera tyre, the best size option,proved to be...


    But now with your 997 S and rear drive, plus 55 Hp and 295/30 19 in the back...well this is another story man!!! So watch out ...:) Plus you ll have that PSE sound pushing you to press the gas pedal all the way down!!

    Re: New C4 and C4S - check our NEWS

    Quote:
    jfraser said:
    From the photos the changes are subtle enough as to be indistinguishable from a C2, C2S (just as well that there's a badge on the back).....I had anticipated the resale value of the C2S to take a bit of a hit once the C4S came out.....I' don't think that will be the case....from a personal point of view I would have considered a C4S if it had been differentiated the way we all expected. As it currently stands I prefer my C2S....Living in CA I don't have dodgy weather to contend with (although it is raining today ) I find the C2S has mountains of grip, so for me AWD and extra weight are not a compelling story.....I'm really surprised the car doesn't have some additional styling cues. I'm sure it will be excellant, but it just feels like Xmas day, when the gift you really wanted isn't the one you got



    Very well said

    Exactly my thoughts

    Re: New C4 and C4S - check our NEWS

    I'm interested in hearing the experience of others, but I'd imagine, C4 or not, PSM or not, if one wants to drive a 997 in the winter, winter tires are required. If true, it makes the tire width in summer irrelevant, except for the aquaplaning issue in the rain during the summer. My comment about aquaplaning would be that one should simply slow down on wet roads. I doubt anyone would have any problems with large puddles at reasonable speeds, even with the tires on the C4 and C4S. If you're out there driving at the limits of tire grip and risking aquaplaning in the rain, then you're pissing me off because I or my loved ones might be out there too.

    Am I wrong? If you drive slowly enough, you give the tire more time to clear the water right? So just slow down in poor conditions. And don't tell me that a big puddle can sneak up on you. Wet conditions are wet conditions.

     
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