Suspension ideas?

Cpjetmech

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2013 GT, mostly sees normal driving but I enjoy going faster at the track. I’m in Texas and roads are a little rough. Currently car har just an eibach lowering spring, other than that suspension is stock. Problem currently is that I can’t even pull in the driveway without scraping and the car doesn’t 60 foot well at all even with a drag radial. I’m thinking about adjustable coil overs like bc racing for an affordable price on coilovers. My thoughts are, will the coilovers help or hurt the 60’ and also can coilovers be used with other products like bmr control arms to help launch? I’d like to have a decent ride quality on street but still not look like a 4x4. Any set ups that people have good success with? Thanks
 

07 Boss

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I second the call to BMR. I even went with them on my current F-body build.
 

sportinawoody

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If you’re n/a, the formula is really simple and basic. Upper arm and bracket (since you’re lowered), lower arms, panhard brace and bar and an adjustable shock. Doesn’t really need to be a double. A good single adjustable will work fine for low tq cars. You need to set your pinion angle if on a one piece driveshaft and center the rear end with the panhard since you’re lowered
 

sportinawoody

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If you’re trying to launch above 4500, I would suggest welding the axle tubes and doing the lower control arm mounts as well to get the cars instant center moved back some from factory
 

Sky Render

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You need to adjust pinion angle regardless of what driveshaft you have. Otherwise you will get driveline vibration at certain speeds. This adjustment should be accomplished with an adjustable upper arm so it can be done without affecting wheelbase or anti-squat geometry.
 

sportinawoody

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I did not know 2 piece shafts suffered as importantly as one piece shafts. Good info.
Instant center from the factory on all s197’s is too far forward. That’s the whole point of upper and lower arm brackets to allow you some leverage to move it back to where it works better for weight transfer. This is in consideration of drag racing. I know nothing about road course setups or cone killers.
 
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Sky Render

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The OEM 2-piece shaft will not become damaged like the CV joints on a 1-piece, but there is a harmonic vibration if the pinion angle is off. My car had it at around 70 MPH after I lowered it until I put an adjustable UCA on.
 

Norm Peterson

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2013 GT, mostly sees normal driving but I enjoy going faster at the track. I’m in Texas and roads are a little rough. Currently car har just an eibach lowering spring, other than that suspension is stock. Problem currently is that I can’t even pull in the driveway without scraping and the car doesn’t 60 foot well at all even with a drag radial. I’m thinking about adjustable coil overs like bc racing for an affordable price on coilovers. My thoughts are, will the coilovers help or hurt the 60’ and also can coilovers be used with other products like bmr control arms to help launch? I’d like to have a decent ride quality on street but still not look like a 4x4. Any set ups that people have good success with? Thanks
I'm guessing you have 'Sportlines', which are too low for anything other than some appearance preference. They may or may not be too stiff for what you're looking to do, though they sort of need relatively high stiffness to keep you off the bump stops at least half of the time.

How much more ride height do you think it would take to clear your driveway entrance?

The rear of the S197 is not that well suited for using coilovers, as putting the springs around the shocks will eat into room that would be much better used for wide wheels and tires. That said, I think you can get adjustable-height lower perches that will work with coilover springs at the axle's existing lower spring seat locations. It is also possible to space the existing rear Eibachs up if you know what you'd be getting into (and have access to metal cutting and welding equipment).

If you're getting wheel hop, you need to look at rear control arms with firmer ends than OE rubber. Start with the LCAs (because they're much easier to install) and do the UCA only if some wheel hop remains. Beyond that, you're probably looking at engine and transmission mounts.

If it simply spins the rear tires too easily/too quickly, you need to look into LCA relocating brackets and adjust the LCA inclinations for more anti-squat. This will plant the rear tires more quickly. It may be possible to load street tires too quickly, so just throwing the most aggressive (lowest hole) setting at the problem may not be the hot tip here.


There is no need to replace the panhard bar brace unless the OE brace is damaged, or possibly if you're running serious R-compound road race tires or real road-course slicks. Since you're more interested in the straight line, you're never going to put much load into it so don't bother swapping that one.


Norm
 
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Norm Peterson

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I'm skeptical about using coilovers in street duty. You pretty much get what you pay for, really good ones tend to need occasional rebuilding, and the damper shafts generally aren't protected as well against dirt and the elements as regular struts and shocks with conventional "big springs" are.


Norm
 

sportinawoody

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We bent a 2 stock panhard braces launching at 5500 only making 650 tq at the wheels on the same car. I see op isn’t making that kind of power but those flimsy stamped steel panhard braces do take a lot of abuse in hard straight line launching but that car wasn’t setup with an arb so it didn’t distribute the weight evenly either
 

sportinawoody

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Truth be know, bare minimum of a good lower arm and a good single adjustable shock would all but eliminate wheel hop on close to stock powered cars. Isn’t going to be optimum by no means but having a shock that can better control the load will do wonders. Stock shocks just have nowhere near enough rebound control to combat wheelhop
 

Cpjetmech

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Yes whatever spring is currently on the car is an eibach, not sure which spring but it’s pretty dang low. It has factory shocks still, bought it like this. It rides pretty bad like this but would probably only need it to be about another 1/2 “ higher to clear driveway bc sometimes I can angle it in without scraping. Thanks for all the comments, I think I’m going to call bmr and see what kind of package I can put together.
 

Pentalab

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We bent a 2 stock panhard braces launching at 5500 only making 650 tq at the wheels on the same car. I see op isn’t making that kind of power but those flimsy stamped steel panhard braces do take a lot of abuse in hard straight line launching but that car wasn’t setup with an arb so it didn’t distribute the weight evenly either
The BMR panhard braces are so cheap to buy, it's really a no brainer, just toss the oem stamped steel PHB brace. I used the brace in conjunction with the BMR 'on car adjustable PHB'. DOM tubing, and bigger diam vs oem. The adjustable portion is made from chromolly steel..and resides inboard a bit on the pass side. Easy to adjust with a couple of wrenches. I slithered underneath, and tweaked it with the aid of a helper..who told me when to stop tweaking. Car was lowered 1.25" at back end too. Worked superb.

BMR PHB and mating brace was later replaced with a whiteline watts link. The whiteline watts link pair of arms are made from chromolly steel..and ditto with their version of a brace.


The BMR PHB brace is rectangular DOM steel tubing. Like apples and oranges compared to the oem brace.

The oem PHB, with one end cut off in the bandsaw... has either lead shot..or sand inside it, for 'nvh'.
 
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Norm Peterson

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The BMR panhard braces are so cheap to buy
It's still money that the vast majority of people don't need to be spending.


The BMR PHB brace is rectangular DOM steel tubing. Like apples and oranges compared to the oem brace.
Sure, the OEM brace is "flimsy" if you pull down on it in the middle (the usual way people picture it being flimsy). But it should never be loaded like that, not even at the drag strip.

If it buckles under compression, that would imply that something is structurally deficient around where the pedestal on the passenger side attaches. I don't know if that could come from unusually hard launches on a prepared drag strip, but I do know that I'd have looked at more than just a PHB brace that somehow became bent.

Exactly where a bent brace actually bent probably matters - I do think the OE brace could have been designed with a better local load path to its connection on the driver side (its neutral axis is not straight where the shape transitions from a channel section to flat, presumably for bolt access).


The oem PHB, with one end cut off in the bandsaw... has either lead shot..or sand inside it, for 'nvh'.
That's actually a pretty good engineering solution. Ford wasn't allowed to build Mustangs with exhaust systems so loud that you couldn't hear anything else. It was certainly an improvement over the channel-section PHB design that GM used on the 3rd and 4th gen Camaros and Firebirds.


Norm
 

Cpjetmech

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I’m pretty newb with suspension but is the panhard bar what centers the axle left to right under car? My left rear tire sticks out a little farther from quarter panel than the right rear tire.
 

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