The Mustang Forum for Track & Racing Enthusiasts

Taking your Mustang to an open track/HPDE event for the first time? Do you race competitively? This forum is for you! Log in to remove most ads.

  • Welcome to the Ford Mustang forum built for owners of the Mustang GT350, BOSS 302, GT500, and all other S550, S197, SN95, Fox Body and older Mustangs set up for open track days, road racing, and/or autocross. Join our forum, interact with others, share your build, and help us strengthen this community!

FRPP LCA Relocation Brackets with stock LCA's?

Sesshomurai

JScheier said:
darreng505 said:
Can you elaborate on this please? I have around a 1.5-1.8" drop and have my adj. LCA's mounted in the lowest hole of my BMR relo brackets. This has greatly improved rear end stability during high speed braking (especially on declining straights).

I do not consider 1.5" an extreme drop. 2" or greater, yes, extreme, and then you run into other issues (pinion angle, damper range of movement & lack of travel, roll centers, instant center, etc. Will moving the arms from the OEM location to 'a' lower location on the axle increase rear stability when lowering the rear of the car 1.5", yes. Will moving them to the lowest hole with this drop help more, I'm not seeing it.
EDITED (I was on my phone and driving earlier. lol)

I see it however. But I recognize a lot depends on the driver, and other car suspension changes, etc. Generally, the angle of the LCA with respect to the chassis and rear axle is "one" determining factor in the affect of traction and axle stability. So it shouldn't be a subjective thing.

At VIR earlier this month I tested my adj. LCA's in the bottom and middle hole (they are not that far apart actually) on a wet track (VIR full) and the second day on a dry track (VIR grand). I noticed slightly less traction in the middle hole (compared to the bottom), but I only based that on two occurrences: 1) The rear end got loose coming through/down turn 10 on VIR full and 2) Coming out of turn 12 on the back stretch, I lost traction pressing the accelerating. Both times in the middle hole (and in the rain). But it's not really a scientific experiment and there are too many variables to conclude anything from my situation due to track conditions.

However, on dry track, in either the middle or bottom hole, the high speed braking situation I had prior to the new LCA's and relo brackets was gone (see thread https://trackmustangsonline.com/boss-302-technical-forum/heavy-braking-situation/ ) so I know that at least in the lowest hole configuration it improves brake handling significantly. So much so, that I'm amazed how the car handles now compared to before. As a previous Porsche owner, I feel its now "in the game".

My curiosity with your earlier post was with regards to this comment:

That lower location is too low for a 1.5" drop. For short term use, it will be fine (IE: safe).

I am still new compared to you and others here with all this, so I want to know what safety issues might the lowest hole pose to a lowered car? And why is it 'too low'?

Thanks for your time btw!

D
 

JScheier

Too Hot for the Boss!
Dude... don't drive angry (or text)!!! ;D

darreng505 said:
My curiosity with your earlier post was with regards to this comment:


That lower location is too low for a 1.5" drop. For short term use, it will be fine (IE: safe).
I am still new compared to you and others here with all this, so I want to know what safety issues might the lowest hole pose to a lowered car? And why is it 'too low'?

My comment was meant as Safe as in... installation of the OEM arm into the lowest hole of the relocation bracket will not cause any unsafe issues. Some internet sites like to think that if you do 'X', then you will spin-off into a wall and destroy the world... this isn't the case here. It is 'safe' to run the OEM arm in the lowest relocation hole... just not overly desirable. The upper hole, with the OEM arm will cause issues as the arm and relocation bracket will contact (if you can even get it installed) and thus would not be considered 'safe'.

There is actually a point of being too low on these S197 cars. Mainly with reference to the front suspension, but the rear is affected as well. Dropping the car 2"+ you should start look at the following:

1. Center link to chassis clearance
2. Amount of travel (compression in particular) in your rear shocks
3. Amount of spring compression available until coil-bind

In the front, the main issue is bump steer (mostly correctable with bump steer correction kits and/or longer ball joints), but you will also get into strange camber curves if you go too low. Keeping the front LCAs as close to parallel with the ground and not having them point up (up = higher at the wheel end vs. the chassis) is a good rule of thumb.
 

Sesshomurai

JScheier said:
Dude... don't drive angry (or text)!!! ;D

darreng505 said:
My curiosity with your earlier post was with regards to this comment:


That lower location is too low for a 1.5" drop. For short term use, it will be fine (IE: safe).
I am still new compared to you and others here with all this, so I want to know what safety issues might the lowest hole pose to a lowered car? And why is it 'too low'?

My comment was meant as Safe as in... installation of the OEM arm into the lowest hole of the relocation bracket will not cause any unsafe issues. Some internet sites like to think that if you do 'X', then you will spin-off into a wall and destroy the world... this isn't the case here. It is 'safe' to run the OEM arm in the lowest relocation hole... just not overly desirable. The upper hole, with the OEM arm will cause issues as the arm and relocation bracket will contact (if you can even get it installed) and thus would not be considered 'safe'.

There is actually a point of being too low on these S197 cars. Mainly with reference to the front suspension, but the rear is affected as well. Dropping the car 2"+ you should start look at the following:

1. Center link to chassis clearance
2. Amount of travel (compression in particular) in your rear shocks
3. Amount of spring compression available until coil-bind

In the front, the main issue is bump steer (mostly correctable with bump steer correction kits and/or longer ball joints), but you will also get into strange camber curves if you go too low. Keeping the front LCAs as close to parallel with the ground and not having them point up (up = higher at the wheel end vs. the chassis) is a good rule of thumb.

Thanks again for the info. Very helpful. Coincidentally, I have a steeda bumpsteer and ball joint kit on its way from a couple days ago (20% off even!). Front adj LCA's next summer perhaps.
 

Sesshomurai

JScheier said:
darreng505 said:
Front adj LCA's next summer perhaps.

Let us know how those work out for you... and definitely keep an eye on them if you run the curbs!

Funny you mention curbs. I've had some scary oversteer conditions when experimenting with curbs - and in the boss I only recommend clipping them if you are going in a straight line. Otherwise, its a crap shoot and not worth the disruption to one side of traction in my limited experience (for the risk of totally losing it 1 out of a 100 tries). Also, off-camber curbs are strictly a no-no in my book (which is different from others preferences).
 

TMO Supporting Vendors

Latest posts

Buy TMO Apparel

Buy TMO Apparel
Top