onebad928s

ok i have a 84s and i want it lowered for performance not so some kid can say "can you scrape it" I called eibach and nothing, H&R i heard nothing good about in the import world.Im looking to go about 1.25 to 1.5 inches. I checked on the bilsteins but they would only go to .75.And i dont want to get the coil overs and let the spring tension out.Remember this is for performance mostly straight aways.

Lou
soon to be finished!! supercharged 84 928s
<img border="0" alt="[bigbye]" title="" src="graemlins/xyxwave.gif" />

Ed Ruiz

The Eibach and Weltmeister springs will usually cause the car to ride about an inch lower.

However, keep in mind, that lowering the car below the factory specs will likely cause a situation where it cannot be properly aligned, which may lead to excessive tire wear. Also, I've seen lowered 928s that suffered catastrophic engine damage because either the alternator or the AC belt adjustment bracket made hard contact with the road or road debris. I sure hope you'll be driving on perfect roads. YMMV.

Mike LaBranche

As Ed said, the Eibach's etc will lower you an inch or so. You'll have some adjustability on the shocks as well i.e. to go lower. Factory says 190 +/- 20 mm on the front so 'officially' 170 is as low as it should go. The racers are running around 100-110mm but there's no speed bumps on racetracks. On the street, I think you'll be happy with stiffer springs and better shocks and 1" lower. Too low and you're going to prang the engine/alternator/compressor. You might also start to see bump steer and other unwanted behaviors.

Brent 89-GT

I don't understand the statement about not wanting to get coil overs. That car came from the factory with adjustable hieght coil overs didn't it?

I also think you misunderstand what happens when you adjust coil overs. You are not letting the spring tension out, whatever that means. Unless you change the wieght of the car, the springs are under the same amount of pressure no matter where you set the height adjustment.

Next, if you want straight line performance, drag racing? , stiffer springs are the last thing you want. Drag racers want wieght transfer to aid in rear tire hook-up. That means soft springs and flabby shocks, not really Porsche type stuff.

Lowering the car may look cool but it kills the way the car drives when you apply it to a 928. Like mentioned above it also risks some expensive parts.

If you want it lower, for whatever reason, and want it more for straight line running, the best option is to keep the softer stock springs and screw the coil over perches down.

I am just a little confused as to what exactly you are trying to accomplish. You claim you are not doing it for the look so, why do it? It will negatively affect the cars performance if that is your real concern. Good Luck

deltaP

Ditto on some of the posts.

Lou, you may want to check the archives on this topic. Lowering will open a can of worms.

The 928 suspension designers were some of the best in the biz. Their work has been copied for the last 2 and a half decades.

I'm sure it can be done, but there is a lot to it (for instance, dropping the steering rack to avoid bump steer). You may want to have a chat with Mark Anderson and the likes who have lowered their cars for racing and am sure they are intimately familiar with the ins and outs of what should be done to maintain proper geometry.

BTW, the first car I lowered many years ago when I was in high school, was a Ford Escort. It was a huge success. More than one car went into the ditch trying to keep up with me (one was a beemer, he he!). The last car I lowered, a Benz 190E, was a complete disaster. I bought a kit from H&R and it was a total piece of crap. I had to fabricate custom parts to get the car to a resonable setting. It was a waste of time and money.

bergstsm

Lou,

I can speak from experience, and have a picture to back it up if you want it. If you lower it, and the alternator makes hard contact with anything, say (in this order):
Goodbye Engine Block
Goodbye Alternator (po
Goodbye Wallet
Goodbye Wife (just a joke)

The previous owner of my car did not heed that advice, and bounced the alternator off of a speed bump (or something hard), cracking the engine block at the point where the alternator mounting bracket bolts to the block. NOT PRETTY, NOT CHEAP. Lowering it only makes it a greater possibility.

Shawn

Bryan

I'll chime in on the opposite side of the spectrum - I want to raise my 928. Its spoiler scrapes on the entrance and exit to my driveway, and just about everywhere else. It rides like it has iron bars in place of shock absorbers. It eats rear tires like popcorn. I'm tired of having to recite a list of excuses for what first-time passengers are about to experience. It's positively terrifying handling-wise on anything other than a smooth, dry road (where it's acceptable but not great).

Yes, yes, yes. It's an '85 with its original suspension. I know. I just gotta get around to ordering up new shocks and springs and getting it dialed in and aligned. No big mystery here. It's sitting at about 155mm right now - going to set it to 175mm on Bilsteins and CS front/GTS rear springs.

I just got a kick out of the idea of lowering a 928.

Bryan

Jim bailey - 928 International

Bryan try adjusting your nuts ....the lower spring perch sits on a large nut which allows you to raise/lower the ride height . New springs will not be softer than old ones , new shocks will be firmer than old ones (unless you have Koni shocks adjusted full hard) . Tire wear is always 95 % an alignment issue not suspension . 928s handle GREAT something is radically wrong with your car / alignment and it is not springs or shocks !

Brent 89-GT

Bryan, It really shouldn't ride hard if it is on the stock springs still. My GT rode pretty darn smooth on stock springs, I fixed that . I still have my stock springs if anybody is interested.

Bryan

My car has the stock Boge suspension, so I can only adjust the rear ride height. The problem is that if I raise the rear the ~20mm it needs to be raised, then it'll lower the front spoiler by ~2mm and it already scrapes on everything. My logic being that the distance from the tip of the front spoiler to the front axle is about 1/10th the distance from the front axle to the rear axle.

I'm sure that sagged original suspension messes the alignment up real good. As far as wear of other components - bushings and so forth - I'll definitley check all this stuff. The rear suspension seem to be in worse shape (judging with my ear and butt) than the front. There aren't that many links and bushing to check in the rear suspension, are there? Kidding. Sigh - I've been putting off the suspension work, and thereby putting off an alignment because there's no point aligning it then ripping the suspension apart to rebuild it. Seems like I have to grit my teeth and do it.

Bryan

V-Fib

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Sigh - I've been putting off the suspension work, and thereby putting off an alignment because there's no point aligning it then ripping the suspension apart to rebuild it. Seems like I have to grit my teeth and do it.
</font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">I just ordered the parts to change out my aluminum ball joints and steering rack bushings. I have been buying parts along the way in an effort to spread out the cost. I already have the tie rod ends ect, ect. I'm going to do the front first, then tackle the rear. If you do the rear first, let us know how it goes.

Anthony Tate
79/928 Silver Metallic

Jim bailey - 928 International

Bryan all 1985 stock front suspension had adjuster nuts they are not as obvious as the rear look for a funny castle type nut under the lower bell shaped spring perch .

onebad928s

As for the security of the parts under the car use a belly pan.
Delta- as for lowering different cars it has been for looks as well as performance.Less of a body roll even if you do upgrade sway bars.And i have also had my share of lowered and have lowered cars from vettes,trucks(4x4 and 4x2)911s to the everyday rice burner.
The 928 is known for the suspension but to the point of its independence.At higher speeds you dont want air to run under your car causing lift as go GT2 and GT3, drag cars and basically any car in racing format except a offroad rally car.I understand the little spoiler on the earlier cars is suppose to keep the rear down but it doesnt do a good job

Brent 89-GT

Well, I guees you must know more about it than Porsche did. As the 928 evolved into the S4 series, the front spoiler dissappeared. It was replaced by a smooth undertray that managed the airflow under the car. The S4 cars use a belly pan that starts under the nose and extends nearly to the rear wheels. Air going under the car is fine as long as you plan for it as the 928 engineers did. The S4 was hearalded as the most stable supercar out there, it was the one Car and Driver magazine didn't mind running inches from the wall at top speed. It doesn't need to be lowered to be stable at speed.

You are also wrong about roll reduction simply based on lowering the car. Roll center is designed into the suspension. The 928 suspension is very well designed. It was designed to work very well at stock ride hieght. Just because you lower it does not mean that you have lessened the body roll. The rules you assume to apply to all cars do not necessarily apply to the 928.

Go ahead, count on a the flimsy little belly pan to protect your engine. You might want to contact the off-road shops for a 1/4" steelplate if that is what you expect to save you.

Good Luck

Jim bailey - 928 International

the 928 body shape was wind tunnel tested during development (unlike the 911) the result was a body shape which at top speed had almost NO LIFT so all 3400 lbs of weight was still riding on the wheels with no spoilers or wings ! Air under the car does not cause lift at all but does incur some potential drag from the turbulent air bouncing off suspension arms , mufflers , rear suspension crossmembers etc. . 928 suspension does follow the same "rules" as most other cars ; it is hard to get away from the laws of Physics . If you lower any car it lowers the center of gravity which is a good thing . One important consideration however is that any suspension system is designed to function at a particular ride height with the suspension arms typically at or near horizontal . With unequal length double A-arm suspension lowering it too much gives too much negative camber ; too much change as it compresses further plus the effective spring rate DECREASES as the spring shock moves toward a more horizontal position . It also causes the toe to change too much the wheels are not pointing the same direction etc. those can be bad things . The most important issue still remains the potential to break the engine block by hitting the A/C compressor , alternator oil pan or starter . Adding a belly pan strong enough to protect those bits would add too much weight . Weight is our enemy it compromises acceleration , braking , and cornering . Lower the car far enough and the "protective bracket "(tie down hooks) which bolt to the front of the lower A-arm mounts to the chassis will begin to start hitting the road when cornering this starts to unload the tire and a steel bracket has a poor coefficient of friction . wings spoilers flairs hood scoops red calipers drilled rotors 18 inch rims big exhaust pipes and very low cars have much in common ........it is done for the LOOKS not because of any necessity or improvement in efficiency .