A Quick Suspension Question

I don't have the information in front of me, But I thought 12 inch rear springs were used.

 

http://www.ferrarichat.com/forum/308-328/441949-suspension-thoughts-3.html#post143365885

 

What I've been running QA1 on my 308 for 9 yrs now....
F shok DR5855 poly bush
R shok DR7855 poly
F spring 12-170
R spring 14-175

 

Are 170 and 175 the spring rates?

 

Correcto mate!!

 

Is that the stock rates?

 

Too soft. Must ride like a roller. That's the standard spring rate, more or less, so what's the point?

 

While we are on this topic, is does anyone know if there is a part number for the same basic shock with double adjustability--that is, adjustable for both compression and rebound damping?

 

Hi Mike,

I agree with you, the 360 wheel is one of the best looking possibilities but, there are some trade offs as we move from stock:

The 360 front wheel 7.5x18, with a 225/40x18 tire will not fit into the front spare tire compartment and you can really forget about trying to get a bigger wheel and tire in there, so that leaves us with no spare, or if we do carry one and have a flat, we are left with trying to strap the flat tire in the passenger seat or on top of the car - none of which is a satisfactory situation.

I am currently running 400/350 pound springs and 22mm front and rear bars. The car has been lowered a bit and corner balanced - BUT if I am not very carefull entering driveways, the right front tire will catch on the fender lip and pull it down, which does the fender no good at all and it sounds like hell.

With softer than stock springs, (200 is about stock I believe) you are going to see a lot more wheel and tire movement in the wheel well particularly if the car is lowered. look at the front tire to wheel well clearance on mine.

Some possibilities: roll or trim the fender lip. Use a narrower spacer and shorter wheel bolts, or live with more clearance between the tire and fender. Talk to Daniel at Ricambi about his Hill Engineering spacers and longer wheel bolts.

So, I carry a small tire pump and a couple of cans of fix a flat spray goop. The upside is that you now have some serious room for the wife's cloths in the front trunk

While I am bloviating about my ride, I would like to mention that the Hill spacers are "Hub Centric", that is, they fit snugly over the lip on the front hub and have a corresponding lip to center the wheel. This takes the shear load of hitting bumps and keeps the wheel running true. Make sure that what ever spacer you use has those recesses and lips. The photo of the disc and hat shows this well.

The comparison photo below shows (from l to r) a stock rear, a stock front and the 4 incher from Daniel.

The next two shots are of the spacer on the stock front hub and the F-50 front hat and disc. While I had the stock brakes, I constantly had the spacer falling off when trying to replace the wheel and tire. Trying to juggle the wheel, spacer and align the bolt is a fiddly process, so when I got to the big brakes, I had my machinist bore part way down in the two hles that the little pointy "alignment bolt" bolts go. This let me secure the spacer firmly through the disc hat andi nto the hub - see the little allen bolts. This is a big improvement and I recommend it.

Using the 360 front BBS wheel, (a very high quality wheel indeed), requires a spacer of about 25 mm or 1 inch thickness, (IIRC), Again, talk to Daniel. I am not sure what a 360 front wheel requires on the rear.

Argueably, the roads up here in humbug county are worse than Sonoma, but IMHO, you might be better served with a 300-250 spring rate. The lower profile tires didn't increase the road harshness nearly as much as I thought they would.
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Nice avatar bro

;-)
chris

 

I don't have your wheels and tyres, but I think you'll find you chose springs that are too soft.

I have my shocks set on 6, and the ride is very compliant. If I had your wheels/tyres, maybe I'd have them on 4 or 5...but it's not the springs that cause harshness from what I've now experienced.

Anyway, it's not a big deal because the springs are quite cheap and if you want to change them it's easy and cheap enough.

 

Good choice. This setup is the best money I've ever spent on a car.

 

Hi Mike,

The front spring needs to have a higher rate than the back spring, primarily because the shock/spring is inclined at a much steeper angle, thus putting the spring at a mechanical disadvantage compared to the rear, which is more vertical and mounts further out on the suspension. I know the rear is heavier, but the working geometry is what dictates the needed rate differential.
I think most guys are running 300 front and 250 rear.

I occasionally take the car to the track, so the higher rates and bigger bars help make the suspension work better.

400/350 for just a street car will be a bit harsh.

I am in Arcata, moved up here in 67 to go to school and decided to stay. Give me a shout if you ever get up this way,

chris

 

If you do a search, I think you'll find that some of those people say they wish they'd gone harder because the rear feels too soft. It's why I went 400/350

I appear to be getting ignored, which is fine....400/350 on a street car is NOT harsh. What makes the ride harsh is the shocker setting, not the springs....that's what my experience is.

I still think you've gone too soft, but your money, your car.