Spacers vs Handling ?

I posted this over on the 997 forum but it was suggested I post this here too. Hopeing to hear fronm the track day guys. OK, I searched the forum for my question and all I can find is some posted were people have put various sized wheel spacers on to help give the car a more agressive look. So far nothing has been said about what wheel spacers do for the handling or ride of the car. Do spacers change the geometry of the suspensions to provide any good or bad handling traits for the car? How much extra weight do spacers add to the suspension? thanks, Mike

I don't think you notice any difference in driving...I got 15mm in the back since a couple of weeks...makes the P look much better, but no handling difference...and I love to corner hard and make the car drift a little while doing this....and no difference...maybe guys that track have another opinion??

I run 5mm/F and 17mm/R. No noticeable difference in handling.

I have 15mm in the front...no differences noted...

Newport - where did you get the 15mm and how much did you pay for them?

wheel enhancement....with all the hardware i think it was about $250 for the pair.

7mmF 15mmR. No noticable change in handling. I really like the subtle enhancement to the look of the car. The only minus with the the mod is you need extra long lug bolts which means I gave up the security (keyed) bolt. I didn't look too hard but maybe there are long security bolts available?

So 19in rims changes the geometry of a 996 but spacers don't? Come on fellas which is it?

Thanks for all the reply's. I posted this on some of the other Rennlist forums hoping to get a track guys point of view too. I will let you all know what I learn. Dealer say's anything much over 5mm or more puts undue stress on the longer bolts. I do not want that!

Personally, I dont agree with 19's changing geometry, but the theory is the 19" wheels have larger diameter so it puts more load on the suspension...all spacers do is emulate more witdh on the wheel. So nothing changes. In simplified terms thats what I think is going on....But the question was does it affect handling...19's handle BETTER on my car, but that does not mean there isn't mor load on my suspension. The spacers dont have any effect on my handling that I have noticed.

In theory 19 inch wheels the same width and same offset as 18s don't change anything as long as the tires are of similar diameter. As for spacers, the best way to envision what they are doing is to imagine two foot spacers. Imagine the extra stress they would put on your wheel bearings, how they would change your suspension geometry and where the wheel pivots when it turns. The same is true for 15 mm spacers. Just less. I sure wouldn't worry about 5 or 7 mm spacers on the track but I don't think I would use too much more. Having said that, I have 7 mm f and 15 mm r on my street 996 just to make it look good. Jim

Widening the track on your car will actually help the handling. I know in time trials it's considered a 'mod' over 5mm so it must be helping. Wider is better. Look at the cup cars, they have molded fenders and super wide wheels. It's not for looks in their case. Go for it. However I think there is a limit where it will be helpful I wouldn't go over 15mm. My 19s have the correct offset so I don't worry but if I ran the stock 18s I'd want the spacers for racing.

Increased track width = less weight transfer = increased road holding at that axle. Increasing track by the use of wheel spacers changes the steering geometry (Ackerman I think?) and also like JimB said puts more load on your wheel bearings.

Actually cup cars have the same fenders as our cars and don't have super wide wheels. I think they are 9s and 11s. Usually they race on what amounts to about a 235-245 in front and 285 on back. A wider car is theoretically better but a modern Porsche suspension is a tricky thing. Also, adding spacers is adding extra stress to a street suspension that is already under extra stress on the track. At the end of the day, it is unlikely that you will have any trouble with reasonably sized spacers on the track. It is equally unlikely that you will see any advantage. Jim

thanks...these are the type of post's I was looking for.

I thought that the MKI 996 GT3 cars came with 5mm spacers on them (front and rear) to improve track handling? It surely can't be a bad idea. That said, I'm running them all around and it definitely 'feels' more excited to turn 'into' and drive hard 'through' corners than it did before.

Exactly!

The only reason cup cars would run with these tire widths is because anything wider would be illegal.

Perhaps although not dramatically wider. I think the fastest tires for those cars are the Supercup series slicks from Michelin which are about those sizes. I don�t pretend to have any meaningful knowledge in the area though. Just what I pick up from friends in the pits. This I do know. You can�t say a cup car is wider and therefore wider is better so adding spacers to a 996 will make it handle better. Neither can you say a GT3 comes with 5 mm spacers and a GT3 handles better than a 996 so adding spacers will make a 996 handle better. Neither can you say that a rulebook for an autocross series says that spacers progress you to another class so spacers are good and will make a 996 handle better. I�m not saying you shouldn�t put spacers on your 996. I have 7mm and 15mm spacers on my street car just to make it look good. I�m just saying that Mike asked how spacers will impact handling. Don�t tell him that it will improve handling unless you know that to be true and I�m pretty sure nobody here knows that to be true. I�ve spent more time and money changing and testing suspension parts on my 996 than anyone this side of Grand Am Cup and I don�t know the answer. Ok, I�m climbing off my soapbox and going back to work now. Jim

JimB, thank you for you honest answer.