Hi all,
My '74 is original in appearance except for the tire size and I think it sits too low. I have on 195/65/15 Bridgestone’s. I know 914's sit low but when I see pics of other ones, even with the same tire size I have, mine seems lower. I know that the original tire size made the car sit up higher. I‘d like to get closer to that original "look" w/o buying the original size tires which are very expensive.

I think the PO may have lowered it. I read where the front end can be adjusted with the torsion bar. Could my back end have lower/shorter than original springs?

What is a good estimate as to what a 914 should measure off the ground if everything is original spec except the 195/15/15 tire size? I measure 22 ¾ “ to the where to body starts above the rear tire and 23 ¾ “ at the front. Should they be the same?

Do I need to adjust the front bar and put on different rear springs to get off the ground more? What is the proper size/ part no. rear spring?

Thanks
Steve

While not a direct answer, you don't mention how old your rear springs are. It seems to me ALL 914s sag in the rear with age. I think the rear springs are rated at 70psi. That's not a lot. Over time, folks usually lower the front to match the sag in the rear.

I have been curious about ground to fender lip measurements so I hope someone with that info will chime in.

When I looked into this, I found two sources of information. The factory manual specifies the adjustment of the front suspension geometry, which is only related to the chassis and is independent of tire dimensions. It says “the accurate height adjustment of the front axle is the basis for measuring the vehicle.” This statement indicates that adjusting the front torsion bars, is the only adjustment to ride height the factory intended, the only other possible variables are factory determined – rear coil springs, rear shock absorber travel extent and tire outside dimension.

The factory manual describes the process to set the ride height by adjusting the geometry of the front suspension at the torsion bars to a specified dimension. So the geometric relationship of the front axles to chassis is fixed. Note that to adjust this correctly, the car must be loaded to its DIN weight, which means empty but ready to drive, full fuel tank and spare wheel mounted. The only parameters given for the rear suspension are a few specifications of the rear coil springs, including the unloaded dimensions, there are no factory rear suspension components that are adjustable. Through 1972, the rear springs specifications include 461mm unloaded length. That specification changed for 1973-76, to be 471mm length with no mentioned resulting change in chassis height. The full extended dimension of the stock factory rear shock absorber with the spring installed would determine the rear ride height, and would not be adjustable using factory parts.

Marketing brochures for each year also indicate general dimensions but they are only helpful as a guide. Only one undercar dimension parameter is given. The under car dimension for 1970-74 914/4s was indicated as 120mm (4.72 in.). For 1975-76 914s, the dimension was increased to 140mm (5.51 in.) which may be a result of the changes related to safety bumper design requirements for those model years. There are no revised or supplemental front axle adjustment specifications for the 1975-76 years in the factory manual so it is not clear how this increased dimension was achieved.

The location to measure the undercar dimension is not clear. At one time I had thought it was a specified dimension to the lowest surface at the bottom of the chassis. If so, the dimension measured at the 4 chassis support ‘doughnuts’ might be a good place to measure to. I quickly measured my own stock 1974 2.0L with stock rear springs and tires awhile back – it is about 7 inches to the doughnuts, its sits level, the engine bar clearance is of course lower but I did not measure it at the time. But I am not convinced it is a measurement to the chassis because people looking at marketing brochures probably would not care about this dimension. It could also be an undercar clearance dimension and if so I would think it should be measured to the lowest part of the car (which could hit an obstruction) which might be the engine support bar. If this is an undercar clearance dimension, which seems more likely, then it is dependent on tire sizes, which because it is in marketing brochures, we have to assume are the OEM tire sizes. Another measurement related to ride height to verify is the overall car height, 48.4 in., but this would also depend on tire size.

With only one fuzzy undercar dimension given we might assume that the chassis should ride level and is not raked, but this is not clear and may not be correct. Its is clear that the front suspension is adjusted and the rear is fixed by factory component dimensions. Whatever chassis rake angle or flat level condition that combination results in is the answer…which I don’t have and would be interested to know.

Pages from the factory manual and brochures attached for reference.

Anyone have other information?

Jeff, thanks for all the good info.
Steve

Not if you get them from me. I have the stock size tires that were my teener when I purchased it, available for sale here. PM me if that's of interest to you...I just don't have room to store them any more.

So, is 90mm the consensus as to what others are running for the front axle differential height? Sure looks high to me.

My car (which is just got a couple weeks ago) was set to 105mm.

Comments?

Thanks,

Steve G

Whatever spring you choose, REAR ride height can be easily be adjusted by using adjustable perches....so get shocks that use these.

The front height can be adjusted by dialing the torsion bars up or down. Remember that this will change alignment and should be done with a shop that can check this....also consider corner balancing.