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Car setup question

Posted: Sun Mar 18, 2018 5:19 am
by Helge Tielker
Guys, I was looking for more information on setting up the car with regard to the wheels.
I am lucky to have a Kronprinz set dated 12/1959 same as my car, but those are 4,5 x 15.

I can remember to heave read about 5,5 or even wider back and 4,5 in the front.
For along time I enjoyed the standaard with our chromed 4,5x15 (not original if I remember good for a 1959 BT5) but now my kid (working on his 1st engine, 14 years old) is getting older I guess the car should be look "more" Porsche ;) (as my son would say - he loves the BT6 outlaws, down and wide).

Can you experienced guys give us an advise what to use front and back on wheel size combination, to keep it drivable but with a more sportive (;)) character.
Does it make sense to lower the car?

We habe a BT5 (4.12.1959).

cheers from Holland and thanks to any advice already

PS: does anyone has an instruction video (youtube, selfmade or something like this) how to change the rubber seal from the back window

Re: Car setup question

Posted: Sun Mar 18, 2018 7:41 am
by Doug McDonnell
4.5 x 15 was standard. And about the only thing that will fit in the trunk as a spare. Going wider to 5.5x15 is done by many. Lots of discussion here: viewtopic.php?f=1&t=27101

Re: Car setup question

Posted: Sun Mar 18, 2018 2:05 pm
by Edwin Ek
356 cars are tail-happy, so oversteer is always nearby, even at relatively low speeds. That is either good or bad, depending on your perspective.

I have posted this a few times before, and here it is again:

One thing I am doing on my car which may be of interest to you is to run 4.5" rims with 165-78 tires on the front and 5.5" rims with 185-70 tires on the rear. There are several attractive aspects to this approach:

Improves handling and cuts down on oversteer, and Porsche itself started doing the same thing itself a few years later when it figured out what was going on.

Doesn't screw up the delightful light mechanical steering feel, which is one of the best characteristics of a 356.

Reduces the on-stilts look at the rear.

Is a subtle modification which can be reversed in a few minutes.

Of course the accuracy of the speedometer and odometer is unaffected.

Half the time the 165 spare will be the right size for use and can be rotated with the front tires.

Vredestein and Pirelli make tires in both sizes.

Re: Car setup question

Posted: Sun Mar 18, 2018 2:57 pm
by Helge Tielker
Guys,
thanks ... read the discussion topic link .. guess I will go and search 2 5,5 wheels ... since when 5.5 x 15 have been available for our tubs? I mean, is there a chance to find 12/59 from 5.5?

cheers from Holland

Re: Car setup question

Posted: Sun Mar 18, 2018 3:02 pm
by Doug McDonnell
Helge 5.5 rims are a 911/912 rim. They were never available for 356s. The only way you could have 5.5 rims dated like that would be to have a Vendor remove the outer rim and replace with 5.5 outer rims using your dated inner rims. My Outlaw uses aftermarket rims with wheel spacers. Minilite 6.5x15 rims. Rear end is decambered 1 degree to aid in fitment.

Re: Car setup question

Posted: Sun Mar 18, 2018 3:38 pm
by Edwin Ek
Helge,

When I bought my early 1962 car, there were widened 5.5" rims at all 4 corners. Two of the centers are Lemmerz stamped 1-62. I figured those centers must be original to my car. That kick started the idea in my mind to run them in the back and use Lemmerz 1-62 4.5" rims in the front.

As Doug says, there weren't 5.5" rims fitted to any 356. You can easily have 4.5" rims modified with 5.5" outers. People do it all the time. If you want to do things to a high standard, you can look for 12-59 4.5" KPZ donor wheels and have them modified. Or you can ignore the dates and use any donor wheels. Just be sure to use the same manufacturer (KPZ or Lemmerz) for left and right, because the centers no doubt have different weights. I say that because whole rims definitely do.

There were Empi Porsche 5.5" rims in the late 1960's and early 1970's. If memory serves, our own Jim Perrin was involved in bringing them to the US. There were versions for both drum-brake and disc-brake cars. They are very hard to find these days. So it's easier and more straightforward to just modify rims.

Re: Car setup question

Posted: Sun Mar 18, 2018 7:06 pm
by Mervyn Hyde
Edwin Ek wrote:Helge,


There were Empi Porsche 5.5" rims in the late 1960's and early 1970's. If memory serves, our own Jim Perrin was involved in bringing them to the US. There were versions for both drum-brake and disc-brake cars. They are very hard to find these days. So it's easier and more straightforward to just modify rims.
My 63 car had these (Empi Sprintstars) on when I bought it. They were date stamped 1967 and were 5.5" as the original owner liked to do rallies and gymkhanas.They are much sought after and I sold then for good money to a guy with a Karmann Ghia. I refitted the original rims and hub caps which were packed in boxes. They are 4.5" and are Lemertz and all stamped 9/62 as I recall. I am more than happy with the original wheels which seem to grip well if the suspension geometry is right.

Re: Car setup question

Posted: Sun Mar 18, 2018 7:30 pm
by Martin Benade
Actually new 5.5 wheels are quite easy to buy new. I know Sierra Madre among others has them, pretty cheaply, in silver or chrome. Handling is an opinion thing, my feeling is that my B understeers a fair amount until you really push it, at which point it certainly oversteers. My preference is 5.5 on all four corners, that is the most common upgrade that everybody does, although some like the staggered idea.

Re: Car setup question

Posted: Sun Mar 18, 2018 8:26 pm
by Edwin Ek
Martin, you are right on the money that rear-engined cars push until the rears lose traction. Modern 911's (991's) miraculously don't do that; they have great turn in.

Re: Car setup question

Posted: Sun Mar 18, 2018 8:46 pm
by Martin Benade
Especially if you follow factory tire-pressure numbers, they dialed in extra understeer to try to keep us out of trouble. Of course like any safety device, us guys love to defeat it because we are so skilled and tough!

Re: Car setup question

Posted: Sun Mar 18, 2018 9:03 pm
by Ron Dohmeyer
Will 5 1/2 15's fit in rear of '59 coupe?
How about 5 1/2 16's?
Thought I've read that they won't?
I'd like some more rubber but don't want to buy wheels I can't use!
Thanks!

Re: Car setup question

Posted: Mon Mar 19, 2018 7:13 pm
by Helge Tielker
Thanks guys so far - a lot of information - I guess step 1: buying aftermarket 5,5x15 for the back combined with my original 1960 4,5 in front .. what tire size should I tase back? If I like it I keep it like this and keep the original 4,5 set kronprinz for originality ;) .....as is.

Re: Car setup question

Posted: Mon Mar 19, 2018 7:53 pm
by Edwin Ek
165-78-15 in the front and 185-70 in the rear. Vredestein (home country for you) and Pirelli make tires in both sizes.