Why does my ride height look so high even though it's lower than spec

[jwakil]

I measured my front ride height (center of wheel to center of torsion bar cap) to be ~4.75in which means my car is 0.5inch lower than even the Euro spec. Yet it looks very high as seen from the wheel well/tire gap. I have 15inch wheels and my tires are 215/60R15. Does this look normal?

[boyt911sc]

Originally Posted by jwakil

I measured my front ride height (center of wheel to center of torsion bar cap) to be ~4.75in which means my car is 0.5inch lower than even the Euro spec. Yet it looks very high as seen from the wheel well/tire gap. I have 15inch wheels and my tires are 215/60R15. Does this look normal?

jwakil,

You got a smaller diameter wheel!!!! Most people use the 16" diameter wheels. Look at someone's car with 16" wheels and compare.

Tony

[gduke2010]

the 15" tires with 215/60 tires. I think 50 sires are more common. Try looking up different tire sizes on Tire Rack. You can look at how the different sizes look on your car.

[Joe Bob]

What is the height from the top of the wheel arch to the floor?

[Schumi]

Originally Posted by gduke2010

the 15" tires with 215/60 tires. I think 50 sires are more common. Try looking up different tire sizes on Tire Rack. You can look at how the different sizes look on your car.

50 tires would be even shorter and thus fill up the wheel well even less, making the wheel to fender gap increase.

[aigel]

Most people go a lot lower than that. And they may have larger diameter wheels / tires.

George

[Oh Haha]

Here's mine at 25 rear, 25 front on 16 inch wheel, 205/55 and 245/45(yeah I know it should measure higher in front)

At certain angles I think it looks too high, compared to others.


Then I take a pic like this and it looks pretty slick-

[Bill Verburg]

Originally Posted by jwakil

I measured my front ride height (center of wheel to center of torsion bar cap) to be ~4.75in which means my car is 0.5inch lower than even the Euro spec. Yet it looks very high as seen from the wheel well/tire gap. I have 15inch wheels and my tires are 215/60R15. Does this look normal?
........

If this picture shows what was measured then you are not measuring correctly.

the correct way to do it is to measure from the floor to the center of the axle and from the floor to the center of the torsion bar
(this is under the car and harder to do). Then subtract the 2 #s.

alternately for a less precise but easier to get #, measure from the floor to the wheel arch at the axle center.

[wildcat077]

Originally Posted by Oh Haha

Here's mine at 25 rear, 25 front on 16 inch wheel, 205/55 and 245/45(yeah I know it should measure higher in front)

At certain angles I think it looks too high, compared to others.


Then I take a pic like this and it looks pretty slick-

Wayne,

Your car is real lucky,it gets to sleep on a nice warm carpet ... lol

Cheers !
Phil

[R_Builder]

Remember the math here folks.... a 215/60R15 tire is 25.2" in diameter, which is actually BIGGER in diameter than what we are used to dealing with/seeing on SC's (stock = 205/55R16 = 24.9" diameter).

Since the OP shows a picture of the front left tire, I will assume that is corner that was measured. Unfortunately, that corner varies the most based on how the car is loaded (driver/no driver and amount of gas in the tank). It is always tricky, in my opinion, to get the right "look" with the car just sitting there AND have the numbers "in-spec"...

As a footnote, something that I find interesting is that Porsche really didn't mess with the STOCK overall tire diameter much through the years. It hovers right around 25" pretty much from '65-'89. Again, in my opinion, it almost seems like they were more worried about aesthetics than performance as, on the whole, the fender archs didn't really change all that much through the years (flares excluded)... they had holes to fill and a 25" diameter circle looked best to them!? Certainly performace came into it as the tires got better and the wheel diameters could increase, but in the end they just swallowed up the 25" diameter tire with bigger wheels.

Anyway, got side tracked there... my advice to the OP would be to get 1/2-5/8 of a tank of fuel onboard, have someone of similar weight sit in the driver's seat, make sure the front trunk isn't too full of junk, then measure the fender lip to the ground for a quick check. Stock Euro height would put that number somewhere around 25 to 25.5".

[ossiblue]

jwakil, please clarify this statement: "I measured my front ride height (center of wheel to center of torsion bar cap)" as it does not correspond to the picture you posted and it's causing confusion. Did you, in fact, measure as shown below?:


I ask because if the 4.75" you mention is measured as in the photo, it is incorrect.

[jwakil]

Originally Posted by ossiblue

jwakil, please clarify this statement: "I measured my front ride height (center of wheel to center of torsion bar cap)" as it does not correspond to the picture you posted and it's causing confusion. Did you, in fact, measure as shown below?:


I ask because if the 4.75" you mention is measured as in the photo, it is incorrect.

I measured the height correctly: Center of wheel height minus center of torsion bar height from ground (a-b in the drawing). So the 124mm in the drawing would be ~120mm in my case, and the Euro spec is ~108mm I believe. The picture I showed is just to give you an idea of how much gap there is between the tire and fender. If I put it at the Euro spec, the gap looks even more outrageous.

[Wil Ferch]

I never, never found the spec measurements posted by Porsche as shown in the preceding diagrams to make sense...and I've posted on this factoid before on this board and others... never getting any satisfactory answers.

R_builder is absolutely correct...do the math... a 215/60-15 is 25.2" rolling diameter and a 205/55-16 is just under 25". Also true....from the 185/70-15 days and before...all Porsche rolling diameters for tires were about 25" (+/-).

We are admonished NOT to use the 25.5" from-floor-to-top of wheel arch measurement ( front) and 25" basis-rear.... but trying to do it the supposed "right" way never made any mathematical sense using Porsche's a, b and c dimensions....wonder why?

Show us lower A-arm at static ride height.....should be slightly angled-down toward ball-joints....some of us lower to get the A-arms near "parallel" to ground...but never go lower with the ball-joint-end being higher than the inboard pivot.

[tcar]

15" wheel is stock for an SC, the 16" were optional (but almost all US cars had 16's).

Peter Zimmmerman (posts on Pelican) who wrote "The Used 911 Story" actually prefers the 15 inch wheels on the SC - much nicer ride, etc.

Lower the front, another 1/2 inch or so, it's easy, and see if you like it. You may want a bump steer kit.

Is the other front wheel the same?

How are the rears?

[Wil Ferch]

If its "too high"....then getting it "back down" will not necessarily require a bump steer kit. True enough....even factory correct ride height may beg for bump-steer correction, but it won't be bad and is usually not necessary. To the original poster, let's see lower A-arm angularity.

[Oh Haha]

An alignment will be necessary if you lower it more than .25. Probably best to get it done if it's been a while.

[steely]

jwakil, can you provide the actual numbers (a, and b)?

[ossiblue]

Originally Posted by jwakil

I measured the height correctly: Center of wheel height minus center of torsion bar height from ground (a-b in the drawing). So the 124mm in the drawing would be ~120mm in my case, and the Euro spec is ~108mm I believe. The picture I showed is just to give you an idea of how much gap there is between the tire and fender. If I put it at the Euro spec, the gap looks even more outrageous.

Okay, somebody correct me if I'm wrong but this is what I see (using the drawing as a reference.)



If you are trying to lower the car body (point B in diagram) relative to the center of the wheel (point A), then the gap measurement that results should be larger than the 124mm indicated, not smaller. So according to your measurements, you actually raised your car. Remember, measurement B is from the ground to the torsion bar and you want to get that measurement smaller--closer to the ground. The measurement A is from the ground to the center of the wheel hub and it does not change no matter what you do to the adjuster. Therefore the gap between A measurement and B measurement would increase . Am I missing something?

[kach22i]

It looks high for being lowered to lower than Euro. I have no idea why - sorry.

My height (I think) is stock USA.

My old 50 series looked like golf cart tires.


My new 60 series are about 1-3/4" taller in diameter and make parking lot maneuvering much easier.


There is a surprising variance in the actual heights/diameters of 205/60 and 215/60 tires between different manufacturers. Tire rack is one of the few sites which list them. You should be almost 25" diameter, but could be less than 24" from what I've seen in the charts.

From memory, Hankook tires run small on some models. What brand tires are you running?

[jwakil]

Ossieblue.... The Euro height (A-B) is 108mm instead of 124mm in your drawing. (I don't know where the 124 came from, I've never seen that in any spec). If I'm at ~120mm, I'm lower than the Euro spec by ~12mm=~0.5inch.

my exact details:
My dimension A = 11.75inch
My dimension B = 7.0 inch
A-B = 4.75inch = 120.7mm
Height from ground to top of tire is ~24inch (tires are pretty worn)
Height from ground to top of wheel well arch =26inch


I've very confused by something else now. My tires are definitely 215/60R15s. However, when I measured the wheel rims, I got 16inch for the outer lip. Do you measure the wheel as shown by the red arrow or green arrow? If its the red then I have 15inch tires on 16inch wheels!!



My bottom line is that I expected the gap between top of tire and wheel well to be less than the current 2 inches if my ride height is lower than the Euro spec. Do any of these dimensions explain why this is or is it normal. I'm not interested in going too far below spec because the steering effort becomes too much. I've already been there and done that and understand all the alignment implications and bump steer ..blah..blah..etc..etc... Would also like to know if I have 15 or 16inch wheels!?