ideal lowering for handling

[thornclaw]

has anyone determined the ideal amount of lowering to improve handling? most of the discussion re: springs and handling centers on the rates, with minimal discussion of what the ideal amount of lowering would be-if such a thing could actually be ascertained

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[Egparson202]

Interesting question. I haven’t seen anything definitive, but I’ve seen a number of people recommending lowering no more than 1 inch.

 

[Jonyxz]

Iirc correctly, 3/4"max to avoid messing with suspension geometry.

 

[Louk]

I would look at what something like a cftp gt500 or gt350r and would think those would be lowered the optimal amount? I’m no expert if they have different suspension pieces that would make the drop different from a regular GT.

 

[S550 Recon]

When looking at the static height and it's effects on the geometry change, from static to dynamic bump and rebound, for the S550 chassis the best ride heights (generally) for all around performance is approximately 14.25 to 14.50" when speaking wheel centers to fender edge.

 

[TeeLew]

has anyone determined the ideal amount of lowering to improve handling? most of the discussion re: springs and handling centers on the rates, with minimal discussion of what the ideal amount of lowering would be-if such a thing could actually be ascertained

Yes, it could be ascertained. You'll need a stopwatch and a racetrack.

I personally think that lowering the rear *more* than the front is very important in producing a stable car on corner entry. There are no factory style aftermarket springs that I'm aware which do this. Most people want looks more than limit handling performance and/or this is a product of my personal driving style

 

[Angrey]

The correct answer would be with the belly to the ground if you can return the suspension geometry to proper. So I would think the question (for me) is more appropriately framed, "How far can you lower the car before adversely affecting the suspension geometry" or "How much adjustment does the factory suspension have in correcting lowering before it becomes detrimental to grip and stability."

The ideal handling would be for it to be nearly flat on it's stomach with the fenders chopped to handle the 26.5" diameter wheel/tire articulation. Obviously that's not a tenable option. I'm betting it "geometries" out before it wheel contacts out.

One of the things I like about the Steeda K member is it allows for both adjusting the roll center height and also widening of the track slightly.

 

[Angrey]

Yes, it could be ascertained. You'll need a stopwatch and a racetrack.

I personally think that lowering the rear *more* than the front is very important in producing a stable car on corner entry. There are no factory style aftermarket springs that I'm aware which do this. Most people want looks more than limit handling performance and/or this is a product of my personal driving style

It would be a dynamic evaluation against the affects of lift/pressure. Driving around with a Carolina squat might be better for suspension dynamics but it's probably detrimental to aero. I'd imagine it would create even more lift in the rear. Maybe that can be overcome with more wing or more aggressive front splitter angle. It would be an interesting evaluation.

 

[TeeLew]

It would be a dynamic evaluation against the affects of lift/pressure. Driving around with a Carolina squat might be better for suspension dynamics but it's probably detrimental to aero. I'd imagine it would create even more lift in the rear. Maybe that can be overcome with more wing or more aggressive front splitter angle. It would be an interesting evaluation.

I'll take my chances.

 

[NightmareMoon]

I think Vorshlag settled on 3/4” for a balance between lower center of gravity and still having travel to let the suspension work.

Mine is lowered ~3/4” all around and I also have the geometry correcting bits. Steers great.

@TeeLew yeah IDK about that reverse rake idea. Is your car unstable on entry? Never had that issue myself.

 

[TeeLew]

I think Vorshlag settled on 3/4” for a balance...

@TeeLew yeah IDK about that reverse rake idea. Is your car unstable on entry? Never had that issue myself.

That 3/4" sounds reasonable.

It's not 'reverse rake'. It's just less rake than stock. If we look at the bottom of the car, it's still slightly tail-up.

I am entry loose, but a lot of it is me and my personal tendencies. I tend to over-charge entries, which often induces my problem, but, done correctly, it also loads the front end and gives better rotation entry-to-apex.

My whole philosophy is to get the rear of the car stable on entry. I can carry the brakes into the corner combining braking and lateral loads and keeping tire load forward in the car to help it turn. This pretty much requires a stiff-ish front spring to make happen. Once the car is turned, I want to be able to apply the throttle quickly and put power down. That pretty much requires a soft-ish rear spring. It also means my car will understeer a bit mid-corner, which is just part of my compromise.

Here's the deal with the understeer I've created. To this point, it all allows me to be more aggressive in my driving. I always want to be driving with my fists on the wheel. If I ever find myself doing the fingertip thing, I know the car isn't stable enough. When dealing with the inevitable mid-corner understeer (which isn't nearly as bad as you might expect, because I'm generally able to do a lot of turning early in the corner) I *must* be patient. Going back to throttle too early in the corner, or worse, doing the maintenance throttle thing, will just compound the push. But, If you have the discipline to just stay off the pedals and let the car turn, then you'll be able to put the power down almost all at one time.

Here's another thing to remember. My car is significantly lighter on the nose naturally than almost everyone else's and I have the battery in the trunk. I have more rotation in my car just due to weight distribution.

TeeLew-ism #1: The point at which one initiates throttle is meaningless. The point at which one reaches full throttle is vital. It's rare to sacrifice the latter for the former.

 

[NightmareMoon]

TeeLew-ism #1: The point at which one initiates throttle is meaningless. The point at which one reaches full throttle is vital. It's rare to sacrifice the latter for the former.

sure, less rake (but still some rake) makes sense.

I coach a lot of novice autocrossers, and its pretty funny when they goose the throttle in a 180 turn at the actual midpoint. Car pushes and shoots perpendicular to the direction they needed to be going. Its counter-productive and slows down how quickly they can actually get the car rotated to face down the straight. Let the car turn a bit longer, then add gas when you can start unwinding the wheel.

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