Originally had Gabriel suspension with stock a-arms and 2 inch drop Intrax springs. Had the shocks replaced with Koni yellow sport adjustables front and rear. OE a-arms replaced with BMR tubular a-arms. And left the Intrax springs in. Thats when the issue occurred where the front seemed to bottom out but the rear was fine. Had the stock front springs put in the front. The car is now leveled but the front is a little bit higher. And the car is taller than before :\ . wondering what springs i should go with to drop the car one inch in front or anyone have an idea as to why my front bottomed out after replacing the shocks in front?

 

I don’t have any experience with Intrax springs, but maybe the design of the bmr arms had the suspension sitting differently in the front. Im running Eibach Pro springs all around. Koni yellows, stock A arms. No rubber isolators in the front, and replaced the thick rear isolators with heater hose on the top two coils.

 

Exactly what i was thinking. Thinl maybe the eibach pro will give me that 1 inch drop all around? The fronts now are stock spring and rear are 2 inch drop intrax spring.

 

What measurements do you have in front and back from the ground to the wheel well on the edge? I loke the height you have in the front .looks closest to how i had it a week ago.

 

Man what color is that?! It's beautiful!!

 

Thanks, it’s Hyper Blue Metallic. It comes on the new 6th gens.

 

You may want to check the settings on the shocks, they are usually shipped full soft and I believe the compression side is the only adjustment. Firm that up and they may not bottom out.

 

Rebound side is the adjustable. Compression is fix valved. Not his issue.

The issue has to be the BMR A-arms causing the bottoming out. If these same springs where int he car with a Gabriel shock they ride lower then with the Koni Yellow because the Koni is a high gas charge shock that will lift the front about 1/4 to 1/2" over the Gabriel. So the thing that was the game changer was the BMR arms. Probably built wrong.

 

im thinking of getting bmr 1.25 drop and eibach pro kit 1 inch drop springs and testing to see what drop i like.

 

Seeing what drop you like is a very subjective look and a non-performance goal.
Why not pursue both, rather than picking a spring rate by how it looks?

Pic of your car? How do you use your car (application, application, application)? Budget? Suspension knowledge?

You should think hard about how you want the car to be sprung. Next, match the bars to the spring rates. Then, work on drop (ride height) - this should be adjustable (may not fit your budget).

Post up the Intrax spring specs (HEIGHT, RATE, WIDTH) and your sway bars. I agree that the a-arms seem to be the culprit, but they can be overcome. With that 2" drop, have you adjusted the PHB or roll centers?

 

i will post pictures of the car tonight and will try to figure out how to determine the spring rate . i have adjustable PHB and Rear control arms with relocation brackets since the car was lowered by the previous owner. I got a wonder bar for the front and replaced all the steering and added camber caster plates/ strut bar/ koni sport yellow adjustable and wonder bar. But i have no clue how to match the bars to the spring. The car is a daily driver and my budget isnt a problem if im looking for springs to make it sit back to how it was. I really appreciate you reaponding to this thread. I dont have knowledge on springs and their rates and how to match other parts to them so i appreciate that thank you.

 

Contact patch is the highest priority. This is the overarching theme.This is why dampahhs (shocks/struts) and rubbahhs (tires and their compounds) are critical. You just have to pay the price. Shocks help keep the contact patch.
The front tires need force, from weight transfer on corner entry, to provide front tire grip. Too little & the car pushes (understeer), too much & the car is loose on entry (oversteer). The rear tires need force, from weight transfer on corner exit, to provide rear tire grip. Too little & the car is loose, too much & the car pushes on exit.
So how do you work a tire more?
The further the suspension travels … the more weight is transferred TO that end or corner of the car, putting more load & grip on the tire(s) at that end or corner. And more weight is transferred FROM the opposite end or corner, reducing the load & grip on the tire(s) at that end or corner.


Leaving aside discussion of Roll Centers, we can focus on springs, shocks, and sway bars as tools to control the weight transfer and keep all four contact patches optimal. We tune a car to find the optimum balance of grip. Grip equals speed.


For cars to handle well, the suspension needs to travel or work (it can’t be flat). It has to roll (side-to-side) and pitch (front-to-back). It is dangerous to have a car that rolls a lot, and pitches a lot. So we need to find a balance. There are two common strategies: let the car roll a lot and pitch a little (conventional), OR, pitch a lot and roll a little (modern). The conventional route has stiff front springs and soft rear springs; and small sway bars to allow the car to roll: low travel/ high roll. The modern route has soft front springs and stiff rear springs; and big sway bar in front with smaller one in rear: high travel/low roll. Both these strategies are effective. Soft and stiff are relative terms: total difference in dive could be as little as 2” or less; total difference in roll angle 2*.
Now the conventional or modern approach needs to be decided upon. High roll/ less pitch (conventional), or low roll/more pitch (modern). Again, these are relative to each other, not extreme positions by themselves. The modern approach puts the nose on the ground (more weight xfer on the front) to provide grip to turn. The conventional approach uses more roll angle to help turn (not that it doesn’t have some pitch). The modern approach can carry more corner speed, but the conventional approach can out-brake going into the corner = two different driving styles.
The conventional will use heavier front springs and lighter sway bar; modern will use softer front spring and bigger sway bar. With a bigger sway bar, you can’t just lock up the front suspension – you need independent wheel movement. Limiting roll helps preserve tire life – better for long road courses. Softer bar with more roll heats up the tires more – better suited for AutoX. But personal driving style/preference will really dictate which to choose. Remember, you have to match the rear with the front choice.


For the average TGO member, the conventional is best because our cars suffer from:
- the static roll center height is too low, causing too much roll angle
- the dynamic roll center height in dive and roll is very low, causing even more roll angle
- front suspension geometry has a jacking effect and a higher front roll angle vs. rear
- rear roll center was too high

In stock form, high roll is built-in. With a V8, you should get the biggest front sway bar you can find, regardless of approach. If you’re willing to adjust front and rear roll centers, then a more modern approach can be applied, BUT, driving style can still dictate which is best for you. Pick an approach, and we’ll go from there.

 

these are photos of how it was about a week ago. I will take pics tomorrow of how it is now from a side view. I measured the distance from the center of the wheel well to the ground of the front and rears. Front is 26 5/8 inches. Rear is 26 1/4 inches.

 

Nice color; I like it.
What are the wheels - make, size, weight? - this does affect spring rate choice. Stock brakes? Does it have SFC?

In choosing a conventional set-up, a stiff front spring is desired. This keeps the car nose up with less suspension travel. If the nose goes down, the front roll center could actually go below ground. As a daily driver, you want something softer, so we are going to have to make some compromises (it's all about compromises). And all advice is ballpark as each car is unique along with driver preference. Testing is the only way to get it right, and few go through all the work to do that.
With all this said and not knowing your previous specs, I would say that #700 - #850 front spring rate will meet your goals. 700 is mild firm and 850 is medium firm. For the rear, #200-#225 with a 21 or 19mm sway bar. This is with the understanding that you will be lowering the rear RC via the PHB adjustments.

Now, to adjusting the ride height:
I prefer front weight jacks for height adjustment. Detroit Speed is supposed to have some that work with other a-arms (BADNBLACK), but I haven't heard of anyone actually doing it. Do a search on makes. I have never heard of anyone not liking WJ's once they have them. You can cut springs (I don't like this method) and many people go this route. But it's cut, install, check, remove, cut, install, etc. til you get it where you want it (who knows what happens to spring rate?). And if you ever decide to do an LS Swap, then you have to do it all over again. Keep the Koni yellow struts.
On the rear, I prefer the newer mono-tube coil-overs. New shock tech is showing up on these, and coil-overs give you ride height adjustment (1"-1.25" adjustment). Don't let a sales guy tell you more adjustment than that. Get the right shock for the intended range from the beginning. A 2" drop in rear goes from stock 16" range down to 14" range. For example, I have RideTech HQ 6110 w/#250 and 19 mm bar in the rear. Sell the Koni rears - they're not bad, just not contemporary tech and no ride height adjustment.

How bad do you want to educate yourself, spend money, and do mods that will continue to produce benefits into the future? You'll need to purchase: front weight jacks and front springs, rear coil-over kit (plate and mounting hardware) and find a smaller junkyard swaybar (new bushings for bar). You've got some good stuff on the car, already.

OR, if you just want a "look," put heater hose on top and bottom of spring, put in the rubber isolater, and you might get back the inches lost with the a-arms. OR, buy new front springs and cut to desired length.

 

wait are you LSXmatt? if so i like your vids with the painting the car and the ls engine swap. i plan to go that route but leave the LS stock.

 

So i found rhe thread that mentioned the stock ball joints vs the aftermarket ones on the BMR a arms could be the issue. What you guys think? Should i measure the length difference and see if that is the problem?

 

oh man yes you are right about that. And i think i may have found the issue where in another thread someone had said the balljoints seemed to be different on the BMR a arms from stock. Would that be the culprit? And if so would it be recommended to get different ball joints same as stock or just go change springs to compensate the ride height issue?

 

https://www.thirdgen.org/forums/susp...-bmr-arms.html

 

Ha yea thats me. Thanks for the support 👍

 

the wheels are 18x7.5 Milanni and ill check tires once im home. The brake system is stock. I am thinking of grabbing SFC after i get this resolved. And no i wont want to go the route of cutting springs. I do like the rear coilover idea and the weight jack on the fronts. So would any of the eibach pro kit or bmr spring be a good combo with the weight jack to adjust the front and then just have rear adjustment with coilover? I have rear drum brakes so unsure if the coilover would transfer well to a disc brake conversion down the road? Oh and did you see what i found about the ball joints? I definitely want to learn and do testing with different products for first hand experience like you mentioned

 

Are weight jacks adjustable when in the spring? Or would i have to pull them out and reinstall over and over?

 

Wonder if UMI weight jacks would work with the BMR a arms? Hmmmm

 

Yes, they are adjustable on-car.
For mine, I just open hood and turn the bolt. I welded a plate inside the k-member spring cup, cut a hole through the frame rail so the bolts go up into the engine bay. This is a lot of work. You should get the UMI that SlickTrack mentioned - they are easier to install.

 

They should work with their a-arms since the spring sits in them like a normal arm. I know the BMB k-member causes issues, they use a larger than stock ID for their spring center and since our weight jacks are tight tolerance it doesn't mesh well.

Hope that helps!