Lowering Springs and Drag racing

[karolko]

I would like to know if any of the you faster 9 second guys are running for coil springs and how much you have lowered you vehicle

28" tall tires are what i am running, so something comparable would be great.

Also what type of spring rates are you guys running, and how does that spring rate feel on the street. My car is a street vheicle, but it i have not built it to be a road coarse vehcile, just a straight line monster.

Thanks guys

Adrian

 

[Nick Micale]

Not sure of your question?

Our build for a GN suspension into the low 9's is about the same for a 11 sec street build.

The springs are Regal non-AC in the front and stock replacement GN in the rear.

Shocks do vary, but KYB or Edelbrock up front are good, rear is usually a 50/50 from Summit or the like. Some guys get crazy and go with adjustable shocks, but I use the above and do as well as they can.

No front sway, and HR anti-roll bar in the rear. Pinion angle needs to be set, and a good idea to upgrade upper and lower rear control arms.

Dropped spindles or lowering springs will kill launching the car properly.

 

[karolko]

Hey Nick,

So you keep the factory ride height for you drag vehicles? I would of thought that a slightly lowered vehicle with the right spring rate of course would work well on the track.

This is what i have been fearing, if i lower the car even 1" i will be hurting the launch. Can you even fit 28" tall tires with a 1" lower car with a frame notch and rolled fenders?

 

[MSDGN]

Listen to Nick...I had my car lowered and the 60fts suffered...I have since put it back to stock height and slowly getting it dialed in...I just had some of my lowest 60fts on some recent back to back runs...1.53...launching around 10 lbs PSI...when car was lowered I struggled on the 60ft...the numbers were all over the place from 1.55-1.65...now I know some will say they have had great success with the car lowered...could be but it didn't work for me...if you look at most of the fast guys the cars aren't lowered...

 

[chikn305]

if you lower your car you will need the adjustable uppers to set pinion angle and you will need relocation brackets for the lower control arms to get the angle of it right that is the biggest thing people overlook when lowering their car. If that angle is not corrected it will cause the rear axle to push up thus causing your new found traction problem. The lower control arm should parallel or angled slightly down at the rear mounting point.

 

[GNRick]

Not sure of your question?

Our build for a GN suspension into the low 9's is about the same for a 11 sec street build.

The springs are Regal non-AC in the front and stock replacement GN in the rear.

Shocks do vary, but KYB or Edelbrock up front are good, rear is usually a 50/50 from Summit or the like. Some guys get crazy and go with adjustable shocks, but I use the above and do as well as they can.

No front sway, and HR anti-roll bar in the rear. Pinion angle needs to be set, and a good idea to upgrade upper and lower rear control arms.

Dropped spindles or lowering springs will kill launching the car properly.

I have factory replacement springs all around and am searching for shocks now. I like the looks of the Edelbrock Classic series as they are grey with a black boot. However, they are $85 each and the Summit adjustables are $23 each. How would the Summit shocks perform on the street and highway? Is 50/50 the soft setting? I have Bilsteins on my other car and they are kind of firm. I'm also considering the Monroes sens a trac for a soft ride. Car sees the track 2-3 times per year. So am I asking too much for a shock to work ok at the track and be acceptable on the street?

 

[charlief1]

Some interesting info. Thanks guys.

 

[malibuick231]

I have the following with a best of 1.55 60ft on a 275/60 MT drag radial. I dont have the trans brake in it yet and I am leaving on a 175 shot out of the hole untill i get 10 psi then I let the boost take over. My cat is a single turbo sbc with a 4l803 trans and 373 gears. I am going to change the gears to 308 soon which shouldnt hurt me. I ran 308 gears in my old car with the v6 and the same suspension minus the bmr anti roll bar and on a 9x28 slick I had a 1.40 60 ft.
bmr anti roll bar
bmr billet lowers in the stock location
edelbrock adjustable uppers
eibach 1in springs all the way around
2in spindle up front
3 way adjustable shocks in the rear
lakewood 90/10 up front
Here is a picture of the way the car sits now.

 

[malibuick231]

Let me try it agine.

 

[Alky V6]

I don't know if this will help. I'm a rookie with suspension.
Best 60' has been 1.28.
Stock front and rear springs.
Aftermarket 90/10s up front, New off the shelf 50/50s in the rear.
No front sway bar.
ATR rear sway bar. Soon to add an anti-roll bar too.
Adjustable uppers. Set at the same length as the OEM uppers.
Moser 12 bolt axle housing which has a raised upper control arm mounting point. Location is 1" higher. I think this causes less squat and more tire plant?
Tire was a 28x10.5-15 slick.

 

[oldtimer]

I don't know if this will help. I'm a rookie with suspension.
Best 60' has been 1.28.
Stock front and rear springs.
Aftermarket 90/10s up front, New off the shelf 50/50s in the rear.
No front sway bar.
ATR rear sway bar. Soon to add an anti-roll bar too.
Adjustable uppers. Set at the same length as the OEM uppers.
Moser 12 bolt axle housing which has a raised upper control arm mounting point. Location is 1" higher. I think this causes less squat and more tire plant?
Tire was a 28x10.5-15 slick.

ATR rear sway bar. Soon to add an anti-roll bar too.

Very interesting Don. I have thought of this dual combination in the past but was concerned about the two systems working against each other causing suspension bind. How do you see the two working together ??

George

 

[oldtimer]

Let me try it agine.

Very nice ride

George

 

[Alky V6]

ATR rear sway bar. Soon to add an anti-roll bar too.

Very interesting Don. I have thought of this dual combination in the past but was concerned about the two systems working against each other causing suspension bind. How do you see the two working together ??

George

The rear sway bar controls the rear suspension in a couple different ways. Being attached to the lower control arms, it controls body sway, roll and also helps the control arms (upper and lower) maintain the axle position side to side. Similar to what a panhard bar does for the common racing 4 link setup.

The anti-roll bar controls only body roll or sway. It does nothing to help maintain side to side position of the axle to the undercarriage.

I really don't know. It may be too much body roll control with both bars on there. I don't know if you can have too much or not. We'll find out, I guess.

Like I stated, I'm a rookie at this suspension stuff. If anyone has a good reason why it won't work, I'm all ears. Thanks.

Oh! And I do plan to put air bags in with light pressures. I had one only on the right side at about 20 psi. It popped a little while back.

 

[V6UnderPressure]

The rear sway bar controls the rear suspension in a couple different ways. Being attached to the lower control arms, it controls body sway, roll and also helps the control arms (upper and lower) maintain the axle position side to side. Similar to what a panhard bar does for the common racing 4 link setup.

The anti-roll bar controls only body roll or sway. It does nothing to help maintain side to side position of the axle to the undercarriage.

I really don't know. It may be too much body roll control with both bars on there. I don't know if you can have too much or not. We'll find out, I guess.

Like I stated, I'm a rookie at this suspension stuff. If anyone has a good reason why it won't work, I'm all ears. Thanks.

Oh! And I do plan to put air bags in with light pressures. I had one only on the right side at about 20 psi. It popped a little while back.

If you go with the Anti-Roll bar, I don't think you need to worry about getting Airbags.

 

[Alky V6]

If you go with the Anti-Roll bar, I don't think you need to worry about getting Airbags.

It would help to take some of the stress off the roll bar though, yes? Or, a good backup if something were to happen to the roll bar. Rod end break or something.

 

[V6UnderPressure]

It would help to take some of the stress off the roll bar though, yes? Or, a good backup if something were to happen to the roll bar. Rod end break or something.

Probably, but it also depends what type of anti-roll bar. If you get a weld in one, then I believe there is no give. However, the HR Anti-Roll bar, has the poly bushings so it has at least a little give. I would think that with an HR Bar, the air bags would be useless. I'd be curious to see how many people on here using anti-roll bars are using air-bags. I would say most are not, but hey I could be wrong.

 

[Alky V6]

Probably, but it also depends what type of anti-roll bar. If you get a weld in one, then I believe there is no give. However, the HR Anti-Roll bar, has the poly bushings so it has at least a little give. I would think that with an HR Bar, the air bags would be useless. I'd be curious to see how many people on here using anti-roll bars are using air-bags. I would say most are not, but hey I could be wrong.

I would think that the air bags give you some adjustability to the springs basic spring rate. If you have a critical tire to fender lip situation, it would be nice to have the air bags.

And again, if for whatever reason something happened to the roll bar system, the air bags would be there to help. A little bit, anyway. I like backup systems when they're that simple.

 

[V6UnderPressure]

I would think that the air bags give you some adjustability to the springs basic spring rate. If you have a critical tire to fender lip situation, it would be nice to have the air bags.

And again, if for whatever reason something happened to the roll bar system, the air bags would be there to help. A little bit, anyway. I like backup systems when they're that simple.

True, backup systems are nice. Depends on how fast you're going as well that truly determines if you would need it. Getting that bag in there is no fun though, unless of course you got the spring out.:biggrin:

Then again, I guess I really don't care about having a backup of anything since I removed my spare tire.

 

[Alky V6]

My opinion, a sway bar is fine up to the very high 8s. If the plan is to go deeper into the 8s, you need something stronger. My experience, so far.

 

[karolko]

Hey Don, I think the reason you are putting down some serious times is that your uppercotrol arm mounts are 1" higher. Does your car launch pretty hard? Is the car getting a little squirrely on you at the end of the track?

I am of the opinion that if you are running an HR bar, then bags are noto nessessary for mitigating the twist effect from the rotational torque. I however like you idea of using them as insurance for your tires.

I think proper suspension tuning with our cars will involve proper spring rates, adjustable shocks and altered Instant centers.

Don, why are you running stock height anyways?