92RSB4C

What angle on the LCA gave you the best performance?

KagA152

iTrader: (5)

how lowered is the car? idealy you want the lca to be parallel to the ground

92RSB4C

1-1/2" is how much it is lowered. Any pros/cons to slight angle changes?

MrDude_1

if its lowered enough that the axle half of the LCA is higher then the chasis side, then get the relocation brackets... 99% of lowered cars just need the upper hole of the brackets... only really slammed cars need the bottom hole to even them out.

camaro05

iTrader: (1)

I have sportlines and was told by umi performace (relocation bracket manufacturer) to use the lowest hole.

Mongoose

iTrader: (2)

I have the Sportlines and I use the bottom mounting hole. These really made a difference in how the car felt at speed. Before the car's rear felt like it was trembling,after it was rock solid and traction was much improved. I've never tried the upper position since I was pleased with the lower.

camaro05

iTrader: (1)

I had really bad wheel hop before installing the relocation brackest olso, now it's no more

Free Bird

iTrader: (1)

What about for drag use? Any downside to using the bottom hole? Could you get less traction by going to far?

Rabbitt

where are the different places to get LCA relocation brackets? i know Spohn sells them for $65.. what are some other manufacturers and their prices?

BretD 88GTA

Global West ($98.99) and BMR ($79.99 for weld-in. $119.99 for bolt-in.)

Rabbitt

hmm... go Spohn... lol

camaro05

iTrader: (1)

umiperformance.com

Free Bird

iTrader: (1)

that's insane. do they give you **** lube w/ that a$$ raping?

MrDude_1

two downsides..

one, if its too extreme, you could shove the wheels down really hard on the launch, and have them "spring back" and unload about 10-15 feet out of the hole.... it'll feel like a good hook, followed by a spin/breaking loose

two, if its too far off, when you hit the brakes at the end of the track, the rears will want to lift off the ground, so they just slide and your braking distance increases.



a third smaller side effect is that the farther from level they are, less efficent the LCAs can be at transmmitting movement... but honestly, ive never seen that shown in a timeslip... moving them effects too much else to quantify that....

Free Bird

iTrader: (1)

That's good information to have. thanks.

83 Crossfire TA

iTrader: (2)

Damnit, I wish I could find the video of my WS6 doing that… it seems like no one really believes it could happen, but I’ve come to the conclusion that 99% of people can’t really feel what the car is doing off the line. If they feel a hard hit that is all they need to “know” that they are working.

why would that happen?

well, more accurately, you don’t get as much weight transfer because the back can rise violently enough to prevent some of it. Really, on sticky tires it would probably be easier to tune this with adjustable shocks then LCA pivot points.

Another disadvantage is that they cause roll oversteer (on corner entry) and exit understeer which is exactly the opposite of what most people expect and what is generally fast.

My $.02:
- for road race/autox and most street use, you really want the backs of the LCA’s slightly higher then the front to give the best characteristics with turns
- compromise street/handling/dragstrip – perpendicular to the ground or _slightly_ down on the axle side. This is where you want to be if you run drag radials or street radials at the dragstrip
- on real drag tires (soft sidewalls, slicks, cheater slicks…) you want to adjust the axle end downward as your sidewalls get softer. At some point you’ll actually reach a point where you’ll actually only need the rear springs to support the car before it starts moving and under power the antisquat action of the rear suspension will actually be able to hold the back end of the car up.

91formulaSS

you really meant parallel

MrDude_1

same reason they move going forward..
when you hit the brakes, they're pulling backwards relitive to the chassis, and that makes the wheel want to go up....


im still not sure about why myself... you would think the wheel going up would let the car down, and lessen the nose pitching down, but it really just lets the rear end skid easier..

Dewey316

Because the wieght transfer is already forward, initial the torquing from the brakes, and the anti-squat will cause the rear end to lift. The LS1 cars have tons of problem with brake hop due to the better front/rear brakes they have. It all has to do with how much the front grabs, and how good the brakes are. If you have ever seen a photo of a Porsche with the tail end in the air, you will see just how much weight transfer there can be under very fast decell.

Its a really hard thing to explain in text of course, I can visualize it, and feel it though.