So I am just begining to see why people always sa race cars are never done. I just ran my first autocross on track tires (Nitto NT-01s) and now my previously perfect handeling car lifts front wheels way into the air. Corner workers were saying as high as six inches!!! Now I am NO expert but this leads me to believe that there is still a considerable amount of time to be had if I can keep the wheels on or alot nearer to the ground. My question is how stiff to go in the rears. I currently have #140 Weltmeisters on the back and stock front torshens with a H&H 19mm ajustable front sway bar set one hole from soft leaving two stiffer settings (four holes total). I am thinking #175 or #200 2.5inch springs on ajustable perches. Any suggestions? Will ajusting the front bar to full stiff be enough to counteract springs this stiff? This is for a strictly autocross car that only gets driven to events and on the occassional sunny day. Also it has a six pt. cage.
Any input will be appriciated since I would only like to buy one more set of springs.

The way it was explained to me was "if a corner lifts up, push down from the opposite diagonal corner". I use Goodyear slicks and the other vintage racers that use the various brands of race tires use 250# to 300# rear springs. I tried 250# but ended up with 300# to make the car sit flat and it does on high G-force turns. Since you went with much stickier tires, the changes to your suspension are just beginning probably......

What does one do about the front if #300 springs are used? I think #300 is probably too mutch for my car as it only has 205 tires and a 125ish hp 1911.

Well I just jumped up to 300lb rears, This is up from 200's
I have much better shocks and much stickier 11" wide slicks Than ever before.

22mm front weltmiester bar and 21mm T bars.
We have stopped the front wheel lifting thing and seems we are lifting the inside rear tire in corners less.

125HP 1911cc NICE!!!!!!

It's not the HP, it's the cornering ability. I have seen 120 HP 914-4s outrun a 3L 914 because they had better setup suspension and a faster driver. Which brings the point that when you change the car it will take some time to get comfortable with it too.

I know all about beating "faster" cars. At the last autocross out here at El Toro I turned in the fastest time for a 914 and placed 15th out of 100 on times alone. I would like to improve the handeling of the car without changing the front except for stiffening up the sway bar. Has eneyone succesfully run #200 springs without adding stiffer torshenbars. I think that these stiffer springs would really help keep the car flat but I do not want the car to push or have uncontrolable overstear because it goes very neutrally the way it is set up now with the same air pressure front and rear.

front:
- stock 911 ('84 carrera) T-Bars
- 22mm adjustable sway bar
- koni adjustable shocks
- turbo tie rods

rear:
- 250 lbs eibach springs
- adjustable perches (threaded)
- mueller roller bearings
- stock swaybar

goodyear R250 9" slicks on all 4 corners


the car feels very nice and balanced!
Andy

The only way you'll keep the car balanced with those is to put a really immense sway bar up front. Which will increase the tendency to lift the inside front wheel--though not by as much as the stiff rear springs will reduce it...




If you like the way the car is set up now, I suggest leaving it that way. Lifting a front tire isn't necessarily good, but frankly it isn't hugely bad either. Lots of cars do, except of course for the front-wheel-drivers which assume the "pissing dog" attitude...

If you really want to cut down on the wheel lift, you will probably have to go with stiffer rear springs and stiffer front torsion bars. You might even want to be able to back off the sway bar to its softest setting...

--DD

I think you could get away with 175, Try it and if you have to just jump to a bigger bar in front. Are all your bushings in and your shocks in goog shape? Often wheel lifting can be caused by bad shock or bushing too.

I looed back in my log books, For a brief time I had stock 17mm front torsion bars. and 200lb rear springs.
Weltmiester front bar set 1" from full soft.
Koni Off the shelf sports. Running Hoosier A3S04 205/50-15

Car was fast on new tires. but had body roll and would lift the inside rear around corners. and was loose everywhere.

21 T bars and 200 rears was better but with the added grip of the slicks I just needed more rear spring as I was again lifting the rear inside tire at about 1.4 lateral G's

Right now I am running probably the cheapest suspention upgrades that one could do. The rear shocks are red Konis, the ones that you have to remove the spring and fully compress to ajust, that came on the car when I bought it about four years ago. When I put on the #140 rear springs I ajusted the Konis to full stiff because I figured they would need to be firmer to compensate for the stiffer springs. When get new springs I will definatly buy new shocks because I found out the hard way why they reccomend using three of the skrew type spring compressors instead of two. Dentist bills cost way more than a new set of Koni Sports. The rear bushings are Elephant Poly Bronz so they sre probably not the problem. By the way if any one is considering these bushings I highly recomend them. They inproved the ride quality over worn stock bushings and I was able to install them without disconecting the brake lines. The only downsides are that the grease fitting holes a hard to drill, broke about five, and tap and the new bar bolt thing that the bushings rotate on is not hollow like the original one so it is about twice as heavy.

From the sounds of things I should save my money and get 21mm front torshens #250 ish springs and a full set of Koni Sports to replace my questionable rear shocks and my front KYBs. By the way I found 3.75 inches at the front jack points to be to low. I blew out the drivers shock and even now with new KYBs, were new in the box left over from another project not my first choice but made it easy and cheap, and 4inches at the front jack points I only have about .75inches of travel before my shortened bump stops start to work. Thank you guys for all of your imput on the black art of suspention tuning.

same problem here ...

i'm running out of shock travel on my yellow konis in the front.
i cut off one section from the rubber stops as i was told that was save to do with the konis.

but still ...


for the street, i have both swaybars disconnected and the koni's on full soft. makes it much better and almost bearable ...

thank god the tracks are usually not quite as bumpy as the CA roads ...
Andy

I drive my car so infrequently that I do not even bother to but the seat bottoms in for driving around. This may be my youth but even with the seat bottom out and a modified limited travel suspention the ride quality of my 914 is far superior to the new Mini Coopers that I have ridden in.

Are those Nittos the ones with all the curvy grooves as tread patterns? With a tread wear rating of ~100?

My 914 is a lot like yours, but with 195/50 Dunlop Sport tires that I bought before I knew would be such an AX junky. New tires are in my future, hopefully some that allow me to drive to events (10-70 miles freeway cruisin) w/o worries and still get good stick. I looked at the Nitto photos and info and they seem pretty good. Any comments on ride noise, value, fit vs. other 205/50s etc are appreciated

I have only run one event on them, 11 runs of a 1.1 mile course, but they were good for about 3 seconds over my yoko avs es 100s. It makes the car completely different feeling, way more fun that the 3 sec would indicate. The car feel much faster with them on but this may have to do more withe the wheels than the tires. I have them mounted on Mahles and the combination is about 5 pounds lighter a wheel than the yokos on Empi knock off eight spokes. I really like the tire but cannot comment on how it compares to the likes of a 710 though I beat a very fast CS car that was running them. Verry predictable and they make noise at the limit. Cannot comment on highway noise because I change wheels at events and have NO interior, NO sound dedening, and scraped floors with all of the seam sealer removed coupled with not the quietest exaust and LOUD carbs. When I am on the throttle whch happens to be most of the time when I am driving the car I cannot hear much other than the carbs sucking. Maby that is why I only get 11MPG. Tires cost me a little over $700 mounted and ballanced and say on the side wall Recomended For Compotition Use Only. If they wear like they do on my dads 912E I should get about 8-10 autocrosses out of a set but that is pushing it to the limit on every run and four wheel drifting out of and through many of the courners. At El Toro they set up the courses fast!!! Last Sundays was a Fourth Gear course with me hitting somwhere in the neighbor hood of 100mph. Great fun breaking from 100 to 60 in 50 feet with toe out:)

I hve to run a .25 inch spacer in the back and am running -2.5 degrees of camber in back with -1.5 up front. Need more up front but cant get any back is almost perfect.

Hmm nice braking. 100 to 50 in 50 feet. I am almost sure I can't do that. and I pull over 1 G braking.

Assuming my physics classes from thirty years ago haven't failed me......

100mph-50mph at 1g will take about 83'

@1.5g about 55.5'
@2.0g about 42'

I would think that braking at 1.5 g's is possible with all 4 tires braking to the max.

That is some heavy duty braking with alot of other variables, Surface must be smooth, have a high grip texture.
Tires are probably THE MOST IMPORTANT
Slicks are tough to control at least for me. I don't normally do stupid stuff on the street with street tires. (I said normally)

Oh and car wieght, wheel wieght.

The braking distance and speeds stated are just my estimates. Between being on the edge of out of control and having a speedo that reads 8-10mph fast I dont really know how much speed I was shedding in how many feet. I seriously doubt that the car will break at 1.5G though. You can make your own guesses as to what 5500 in 4th to 3800 in 3rd is. Besides sticky tires it is fairly stock. Maby 50 pounds under weight, no carpet, back pad, floor tar, sound deadening, radio and related components but a very heavy 6pt cage.

give him bad advise...he's going to catch me

I think you need to improve all 4 corners together to retain the workload balance. steve has 22mm up front. I run 21mm torsions with 175 springs. George runs 21mm & 200. Jess runs 21mm and 200 I think with a 19mm bar