DINOmobile

Last year I installed Steeda Ultralite springs and D-spec shocks. I have not been happy with this combination. In particular, the only way to stop the car from lurching forwards and back whenever I hit the gas (even when I do so gently) is to set the shocks to the firmest setting. That is to firm for daily driving.

Does anyone think that I would see an improvement if I replaced the shocks or the springs or is there any other parts I should look at replacing?

Thanks,

Dino

jahudso2

If you want to keep the car from squatting during hard acceleration, you can install rear lca relocation brackets. By lowering the rear mounting point of the LCA, it creates "anti-squat" which basically takes some of the load transfer out of the rear springs and places it in the control arm which effectively limits the squat during acceleration.

Garyalpusa

I dont think the problem is really the shocks fault. Springs are the main force to help with antisquat and the front of the car moving around during acceleration and brakeing. The shocks, struts are there to control the springs. By going to full stiff on the D-specs you are using them to make up for the springs. I have D-specs with Voigtland GT-500 Lowering springs and I do not get the body movement you describe. I also have them set on full soft for the street and have a nice comfortable, controllable ride. I also have front and rear relo brackets that help with a lowered suspension so that may have something to do with it. Suspension is a black art and its tough to piece together parts that really work well together. GA

Philostang

+1 to Gary's experience. I have a similar suspension set up (Vogtland leveling springs, Koni Sports, Steeda relocation brackets, and their comp. upper control arm w/bracket). I get nose dive on very hard braking, but not like you describe.

There's a spring thread here that was active recently. Check it out. Your Ultralite springs are a linear rate spring, which lots of folks like for tuning purposes. The leveling springs I have are progressive, and their spring rate values are close to the GT500 version Gary has. Here's a comparison of published specs:

Vogtland GT leveling springs (PN 950394)
FRONT: 152 lb./in. - 250 lb./in.
REAR: 121 lb./in - 225 lb./in.

Steeda Ultra-lite (pn 555-8206)
FRONT: 195lb/in
REAR: 175lb/in

You can see that you start out a good deal firmer (making the street ride adjustments only minimally effective) and never really get into heavier rates on compression. It's a compromise spring that many folks are happy with...

What's odd is that at that starting rate I'm surprised you have so much movement that disturbs you. I would think you would be unhappy at the far end of compression, not at its onset. Just thinking through things...I'll stop rambling now.

Best,
-j

Sleeper_08

Here is a thread showing the various spring rates

https://mustangforums.com/forum/s197...g-allowed.html

DINOmobile

Thanks for the replies guys...

So from what I'm hearing, I should be OK on shocks but could do better on springs.

I can try out the relocation brackets first before anything else. As far as the Vogtland springs go, what are the benefits of a progressive spring?

Philostang

First, I think you'll be quite happy with the relocation brackets; assuming that you've already moved up to aftermarket lower control arms (yes?). The arms would take care of most of your wheel hop, and the brackets will address the squat on acceleration.

Now, "what are the benefits of a progressive spring?" Ooooh, that's a loaded question. There's not just one type of progressive spring, so this gets messy.

From what I understand (in theory) you can get a softer street ride as the spring spends most of its early compression under a low rate, but then as the spring is compressed more (you go in a turn hard or you hit a bigger bump in the road, like a pothole, etc.) it "progressively" increases spring rate, making it less and less easy to compress (i.e. a higher spring rate). That (in theory) gives you the best of both worlds, a soft street ride and the capability to handle cornering duties.

From what I gather, most folks think it's usually a compromise. The emphasis is on "usually" as not every manufacturer winds the coils the same to be "progressive." You can wind them in two segments, effectively making progressive mean "2-stage" or you can wind them in gradually increasing tightness (making them, oh I don't know..."progressive"). Now, here's the pinch, each manufacturer is frequently winding a generic spring that they'll assign to a car - they don't always (nor I think typically) design a spring specifically for that car. What this means is that the cool idea of a progressive spring doesn't always pan out, as the car it goes into may weigh enough to either never get itself into the higher ends of the progression or conversely to already be in it at ride height (or really close to it, so that your "soft" portion of the spring compression is sucked up once you run over a pebble).

(*deep breath*) Things get worse once you try to tune with the damn things. Because few of us have the equipment to really know where in the spring's travel (and thus rate) we are with our car, it can be really tricky to figure out what the heck the spring is doing (while we are trying to fiddle with the shock settings). Mostly it becomes a (harder than usual) guessing game with lots of checking...if we can manage it. If you've got the 2-stage type, you can also find your car having 2 very different characteristics with an abrupt attitude change in the middle (from a driver's perspective, this is just not cool; which means it's not confidence inspiring, which means its a hard car to drive at the limit).

So there you have it. When it works, it rocks. When it doesn't, who knows why it doesn't in our specific case, it may offer little of the claimed benefits, and it can be really frustrating to tune.

All that to say I'm actually really happy with my Vogtlands.
Hey, I got lucky (read: I called Sam and just listened to him. He should be along shortly, I suspect.)

Best,
-j