Porsche 914 Suspension Type? and discussion

[olason]

Hello,

So now that I am 1000 miles away from my project car and not able to get it until basically June, I have started looking locally in the Detroit area for a project and came across a Porsche 914.

I am trying to figure out what they call the suspension type on the rear end of the car.

Here is one picture from a distance.

https://static1.pt-content.com/images/pt/2014/01/914V8bottom_detail-1.jpg

Here is an aftermarket solution picture.

https://static1.pt-content.com/images/noimg.gif

It appears that some lateral force must be transferred to the axle thus into the transaxle. I would assume that the swingarm has a dual taper bearing setup of some sort.

I am reading they make great autocross cars as well as track cars with an engine swap most likely happening.

Any input?

[vintageracer]

Done right the 914 will out handle and outperform most 911's.

I have had several 914-4's and 914-6's. The rear suspension in the car above looks basically stock with upgraded parts. Transmission "looks" like a 915 versus a 901 914 box but I am not that good with those cars.

I know I have not answered your questions just realize that with enough power 914's are GREAT cars.

A 5.3 LS in a 914 is wicked!

[andrewb70]

That type of suspension is called a swing arm. It is quite common on various German and Japanese cars.

Andrew

[olason]

Alright, I didn't know if it was more specialized than just a swing arm setup.

The green car was actually a blown 427 with a porsche g50 transaxle. I am going to ask the guys from work tomorrow who race in nasa was toned events their opinion.

[Brett W]

The 914 suspension is technically termed a semi trailing arm suspension. It is slightly different than a true trailing arm like a VW beetle. The pivot points are rotated beyond perpendicular to the centerline of the chassis. This allows the suspension to have some camber change characteristics as it rolls. There are several problems with the 914 rear suspension that can't be fixed without some fairly extensive fabrication.

It works pretty well for a street car with the four or six, but when you start feeding lots of power and lots of grip things start going bad quickly. The toe change is pretty bad once you lower the car. The car was originally designed to work with a pretty tall tire thus allowing the trailing arm to never travel past parallel, however when you lower the car to a more acceptable ride height, you get into the drawbacks of the suspension.

The trailing arms flex but its not so much in a lateral direction as more of a twisting direction. The load from the tire is fed into the trailing arm offset from center thus creating a torque moment around the axle centerline. Its not a lot, but its too much for high performance use. There are several companies selling "stiffening kits", but they don't contribute much beyond weight and bulk.

The chassis flexes quite a bit. Its a fun car to drive as I have several and have built several more for customers. They need some modernization, but they can be loads of fun. The engine bays have room for all kinds of power train possibilities. The main draw back is the expense associated with making big power is the gearbox. The transmissions that can really hold the power of a V8 are expensive, especially if you are interested in a V8. There is a four speed from a 930, but it takes quite a bit of work and the gearing is still not optimal, the G50 is the most modern option, but they are a little tougher to package because of the size. Plus there are some aftermarket options for sandrails, but they are pricey.

They use a standard dual row ball bearing setup for the wheel bearings and a standard hub. The four cylinder hubs are all drilled for 4x130 bolt pattern. They will need to be redrilled for the much more common 5x130 bolt pattern associated with other Porsche products.

Brett

[BMR Sales]

Alright, I didn't know if it was more specialized than just a swing arm setup.

The green car was actually a blown 427 with a porsche g50 transaxle. I am going to ask the guys from work tomorrow who race in nasa was toned events their opinion.

I could see it was a G50 with an Oiling System.

Yes it it a Trailing Arm Set-Up. The Boxed Strengthening kits just add more weight - if you want to to prevent the twisting flex, you can drill holes in the arms and running tubing at an angle inside the arm. The weak point is the Ear that the Arm attaches to. Chris Foley at Tangerine Racing makes an Ear Strengthening Kit as well as some other pieces, even though it looks like you have a Bar running down towards the Ear. Elephant Racing makes Poly-Bronze Bushings for the Trailing Arms.

T.C.

[Brett W]

I know Chris. Good guy. We have hung out together at some of the 914 specific events.