993tt

Hi all!

I'm in the process of buying a new set of wheels to my 993tt. I'll probably go for RUF wheels but now I'm having trouble deciding if I should buy 18" or 19", it's a tuff job but someone's gotta do it

Application: Mainly street, town and some long distace driving. I will drive on track three/four times a year.

My car is Euro stock but I will buy a front strut brace and change the camber in front to something between -1 to -2 to get rid of the understeer.

The wheels, regardless of diameter, will be 8,5" front and 10" rear. I will put 245/285 rubber on them.

Now, I've been doing some calculations at http://www.powerdog.com/tiresize.cgi and found that the side wall difference between 18" and 19" is very small if I allow a slightly larger diameter than stock on the 19". Look below (sorry about the metric, 1" = 25,4mm).

Spec Sidewall Diam. Rev Difference
225/40-18 90 mm 637 mm 500 / km 0.0%
285/30-18 86 mm 628 mm 507 / km -1.4%
245/35-19 86 mm 654 mm 487 / km 2.7%
285/30-19 86 mm 654 mm 487 / km 2.6%

2.7%(front) and 4%(rear) increase in diameter will mean 86mm sidewall instead of 90mm. As you also can see, I will get a better balance between front/rear diameter.

Am I correct in assuming that the comfort/level of grip will be about the same with the 19" wheel, given the tyre sizes above!? Btw. these tyre sizes is what RUF recommend on a 993tt.

Can you see anything wrong with this?

I know that the weight of the 19" will be more than with 18" which will lead to less acceleration, braking and poorer suspension characteristics. The question is how much will the weight punish the handling... will I ever notice!?

So... why even think about 19" considering the above (nobody wants to make their car perform less, right!?) Well... The difference in looks between the 18" and 19" is quite stunning (I will try to post pictures) and maybee sometimes the show is worth it, me thinks

Please help me out here. Am I getting into deep water?

18"


19"

993tt

Please forgive me, being a new member of this list, I should of course introduce myself.

My name is Erik Phersson. I´m Living in Northern Sweden, just below the Arctic Circel. Member of Porsche Club Sweden, hence the PCS remark in my footnote.

Vehicle owned:
Porsche 993 Twin Turbo, 1996 (my pride and joy)
Volvo V70 AWD, 1999 (for those cold winter days)
Aprilia RSV Mille R, 2000 (awsome track tool)
Honda Africa Twin, 1999 (great for touring)

That's me, I wish you all a very nice Christmas and a happy new year!

Greg Fishman

Erik,
I don't have any personal experience with the 19" wheels you refer to so I can't comment on their weight, etc. Unless they are a ton heavier I don't imagine you will notice the difference. You may notice a bit of difference in acceleration due to the 19" pkg's larger overall diameter. My opinion is the biggest drawback to the 19's are that your choice of tires is limited. I am a track junky so most of my choices are based around that, if you don't track your 911 then that may not be a concern. If I were getting 19's I would look at the BBS LM wheel, I think they are one of the best looking wheels out there.

I don't know that this helped you out much but thought I would try. Good Luck
Greg

E. J. - 993 Alumni

This is my favorite wheel - PERIOD!



If I were to put new wheels on my car, it would be these - even if it meant going to 16s.

E. J.

993tt

I just learned from RUF that the rear wheels are 28,66 Pounds and the front is slightly lighter. Does anyone know what the stock Hollow Turbo 18" weighs?

Also, RUF recommends Michelin Pilot Sport to these wheels. Apperantly Pirelli doesn't make any tires in the right dimension though Bridgestone S-03 can be found. I thought it was strange that they didn't recommend S-03 instead, so I asked why. The only thing they said was "We recommend the 19" wheels from Michelin because they are running very well"

I'm currently running S-02's and are very happy with them. I had Asimmetrico but I think the S-02 are superior in dry grip (haven't tried them so much in the wet)


E.J.! I think those wheels are awesome too. In fact, I was going to buy those but, when I saw the 19" wheels fitted on a 996, it just blew me away!!!

Viken

Front: 19.95 lb
Rear: 25.13 lb

The Pilot Sport is a pretty good tire

I disagree. I switched from Asimmetrico's to S-02's and lost quite a bit of dry grip and feel.

Ran

Thanks for the introduction. I wish you the same.

The RUF wheel, even in 18 size, has a tendency to look larger than some 18 inch wheels because it extends all the way to the outside edge so if you find your due diligence on the 19s leaving you in two minds, consider the 18s too. I have not seen an AWD 993 with 19s (aside from RUF BUILT cars) and cannot comment on their desirability since I dont know if RUF does some modification but my obvious concern is the lack of sufficient sidewall. Because of the seeming paucity of data, basically it looks like once you find out by trying 19s, it will be your thesis to contribute here

I have the Pirelli Asim all around on one car and SO2 on the other. Of course I cant compare diff cars but I also had an older version of Michelin Pilot on before. Price wise, Asim is a good bet I thought. SO2 looks best but cant say that its looks match its performance though it is not bad. Hard to judge since a newer tyre always seems better simply because it is newer. The Michelin was great when I first got it.

Larry T.

Erik,

Personally, I prefer the 18". I actually think the 19" look a little over the top. Here is a picture of the 18's on a black c4s. In person, these wheels really make a statement! They are very "bright" and look very large in this size.

ps sorry for the large picture size!

Larry T.

Sorry, try this again

993tt

It's kinda hard to see from the pictures at RUF's site which ones are the 18" and which are the 19", looking at the pictures of the cars that is... I've asked RUF for some pictures when the wheels are mounted on a 993. I'll post them when/if I get them.

Another thing. I was wondering why Porsche put tires on a 200Mph (nearly, anyway ) car that differs in diameter from front to rear. I mean, isn't that exactly what they shouldn't have done!? The stress on the differential must be enormous when approaching 200! But then I (actually my brother helped me out) thought, Wouldn't the rear tire expand more, given the 60mm extra width, than the front when driving so fast!? Maybe it should be a 1.4% difference so that at higher speeds, when the stress is most, the wheels have basically the same diameter...

If this is true, then the difference of diameter should be less if the difference of witdh is smaller...

thoughts, people?

Larry T.

Larry T.

E. J. - 993 Alumni

Thats what I am talking about. Cant beat the looks of those wheels.

993tt

Hi Larry!

Kind of hard to read the postings when the pictures are so big

If you remove your messages I will put som smaller versions of your pictures up instead. First thing tomorrow morning, have to get som sleep now!

How to remove:
Click the "document with the pen" icon in top of your posting(s) and then select the "Delete Post?" check box in left/top corner. After that, just click the "Edit Post" button.

cheers!

bet

Ok, I have to ask. What is the orange/yellow car in the show room in front of the 993tt? Panoz? Lotus?