drag shocks

by 73ss Tue Jul 11, 2017 5:53 pm

Anyone have any experience with drag shocks? I installed a set of 3-way competition engineering shocks on the back in an attempt to get the car to hook. I set the to the soft setting and the car rides stiffer than it did with gas charged kyb's. I set them on the extra firm setting and it rides like an F-250. I was under the impression they should be softer to allow the car to squat down on the tires. It blows the tires off worse now than it did before with the old kyb's. I installed MT 275 drag radials and have been playing with pressures & found they do not like much of a burn-out. It hooks better than with the BFG TA's but is still not where it needs to be.
Rear suspension is stock with Poly bushings and adj upper arms set to -1 degree pinion angle. I've tried running with & without rear sway bar installed. no difference.
Any thoughts?

by Joe73 Tue Jul 11, 2017 6:05 pm

I ran them for a while. Same CE 3 way you have. I kept the rears set at 50/50 and the fronts set at 80/20. I worked fine. I'm now running Monroe gas-matics after reading guys running quick quarters with them. I believe they are a 50/50 shock. I havent driven the car with them yet.
As for a sway bar. I removed my rear bar back in the 80's. And I removed the stock SS bar and replaced it with a regular stock 7/8" bar. And spaced it about an inch from the frame up front. Definitely helped with weight transfer but really road like junk. VERY sloppy in turns on the street. I put all the stock bars back in and Im running the Monroes.

by 73ss Tue Jul 11, 2017 6:29 pm

Thanks for the feedback Joe. I went to summit and looked at the lakewood 50/50 shocks and they are alot softer than the CE's set on the 50/50 setting, cycling them by hand anyways. I haven't done anything with the front, other than removing the bar. I have kyb's on the front. Car is more bouncy in the front than it is in back with the ce's installed. I was expecting the back to be more bouncy with the CE's. I'll stop by a store tonite and have a look at the monroes.

by bigredlaguna Tue Jul 11, 2017 11:39 pm

Have you tried bringing the ride height down a bit in the first place? Lowering the rear ride height brings the Instant Center back toward the middle of the car. That should help with the traction issues if the geometry is trying to lift the whole car instead of just the front bumper. If that helps, then the stiffer shock might keep the more advantageous geometry in place.

by fasrnur Wed Jul 12, 2017 1:04 am

Back in the late 70's Moroso made drag shocks. The front ones were 90/10's and the rears were 30/70's. They worked great together to get My Elky to hook. Doubt they still make them today though.

by bracketchev1221 Wed Jul 12, 2017 6:11 am

Ok, first leave the rear sway bar in. It doesn't hurt anything and actually helps. You need to keep the rear lower bars parallel to each other as much as possible. And as far as REAR shocks go, 70/30 means just it takes 70% force to compress it compared to 30% extension. The shocks are stiff on compression, for the fact you want the rear to SEPARATE from the body, not squat and then the shocks to hold it there. Soft compression means the car is pulling the rear into the body and applying no force to the tires. Have you ever seen the famous Chevelle, cutlass etc, wheelstands? the car will pick the driver side front tire WAY up and the passenger side front tire stays on the ground. And when the car leaves, it goes to the right. That is because the driver side tire is planted and the passenger side rear tire is being sucked into the wheel well. This is why Moroso rear trick springs actually have a heavier rate for the passenger side spring to counter this force. And why everyone put an airbag in the right rear corner. The front end you want soft on extension to get it up quicker to transfer the weight to the rear. This is the 90/10 split, 90 to compress it and 10% extension.

Now with all that being said. Powerbraking the car is usually a big deterrent to getting traction. The suspension has to be able to help the tires get traction. And weight transfer is how to do it. If you have the car torqued up against the brakes and the suspension already extending, the only thing to take the hit is the tires and they just spin. Its better to leave as close to idle as you can without having a carburetor bog. Leaving at idle can also fool the converter a little by giving the engine a running start at what little stall speed it has and make it stall a little higher.

by 73ss Wed Jul 12, 2017 9:05 pm

Thanks for the feedback guys. As far as lowering the rear it probably wouldn't be a bad idea, but ground clearance is tight with the headers & X pipe setup I have.

bracketchev, you are saying I want the rear to be stiff? maybe try an airbag on the right? You are right as far as powerbraking, If I leave by "rolling" into the pedal it will hook, for the most part. Usually a high 1.8 60'. Anything more than rolling into to it and it breaks loose. If I stab the pedal, it breaks loose. I don't see why I shouldn't be able to cut a 1.6 60'. I've been trying to sort this thing out for years. I did call MT and they said one small burn out for the first pass, and none for following runs. They also said to avoid the water. My tires look to be the same as on the back of the "ride of the week" car. Same tread pattern.

by Joe73 Wed Jul 12, 2017 9:31 pm

Ray is right on the money.

I also know the more parallel the lower control arm is to the ground, the better.

by bracketchev1221 Thu Jul 13, 2017 5:45 am

You need the shock to allow the body to separate from the rear and push the rear to the ground. So it would be soft on extension to allow this separation. But the shock needs to be tighter on compression to resist the tire wanting to bounce the rear back into the body after the separation has occurred. Higher hp cars will get to a point where it will separate the rear from the body and completely flatten the sidewall of the tire. Here is where it either needs a stiff sidewall tire or tighten the shock extension to slow this motion.

by bracketchev1221 Thu Jul 13, 2017 5:52 am

Joe73 wrote:Ray is right on the money.

I also know the more parallel the lower control arm is to the ground, the better.

Basically this is a rule of thumb trying to set ride height. If the bar is higher at the front, the car is too high. Then in connection with this it usually requires raising the rear of the top bar off the rear. If you've never heard of instant center think about if you drew lines from the ends of the bars following the bar angle to see where they would intersect. This point would be known as the instant center. This is the point the rear is trying to leverage around to push the rear down. Factory bars have it so far out in front of the car there is almost no force on the tires. By raising the rear of the top bar, it moves the instant center more towards the rear and it shortens the lever and applies more force on the tire.

by BBMALIBU Thu Jul 13, 2017 10:56 am

First...everything that bracketchev1221 said.....X2.

Second.....Read through the post titled " Rear Frame Supports" by Joe73.
Particularly the info regarding DickMiller Racing.
Limey posted the DMR articles from Popular Hot Rodding (thought there was a Sticky with this info).

Third...More info on the car and qtr mile times?

Forth...everything that bracketchev1221 said.....X3. Very Happy

by 73ss Thu Jul 13, 2017 8:02 pm

The lower arms are far from being parallel to the ground. Whats the best method to get them parallel? Springs? I should be able to bring it down some without exhaust clearance issues. Is this why the drag shocks did nothing as far as hooking? It got worse with them, at least on the street. I take it im fighting a loosing battle until this is addressed?

Ray are you referring to those relocation brackets that bolt to the top of the rear and move the arms up? I don't think those are made for the G3's.

I couldn't find Joe73's post. I did pick up DMR Millers book. (The site won't allow me to post his first name) Shocked

As far as the car, nothing fancy, basic 10:1 454, 781 oval ports with 2.19/1.88 valve package. Performer RPM intake with Q-jet. 200 4r with 2500 converter and 3.73 out back. I do think the converter is a little on the loose side which is probably contributing to hitting the tires too hard.

Best et: 12.85 @ 107 with a 1.86 60'. That was achieved by gently rolling into the pedal off the line. Anything more than that and it's wheel spin & 13's. Still will trap 106-107 with the crappy et. That was on a well prepped sticky track.

by BBMALIBU Fri Jul 14, 2017 11:42 am

I think a few minor changes will allow you to reach your goal.

Without a current picture of your car, how high is the rear sitting (also the front)?
If the car is sitting too high in the front or rear......replacing the springs is the fix.

Since you already have the CE Drag shocks, keep them and set to 50/50.

Recommended option: since you mentioned the rear upper control arms are adjustable (factory has been replaced),
consider replacing the rear lower control arms too (with non adjustable).

Last but not least...the most important tip of all.......PRACTICE LAUNCHING THE CAR.
Driver skill is a huge factor.....period.

by Joe73 Fri Jul 14, 2017 12:22 pm

http://www.g3gm.com/t7899-rear-frame-supports

by 73ss Fri Jul 14, 2017 5:50 pm

Thanks for the post Joe & advice BBmalibu. much appreciated. the rear is slightly higher than the front

I got to thinking about this and it's starting to make sense now. A few weeks back I went to the summit racing "super summit" They allowed fun runs & passengers down the track. My friend wanted to ride along. My first pass with a passenger, spare tire, tool bag was a 13.19 with 1.88 60'. That surprised me that it did that well with the extra weight and 90 degree hi humidity day. I figured I could click off some easy 12's without the weight. Made 2 more passes without the extra weight (250-275 pounds) and couldn't get out of the 13.40's, kept blowing the tires off. I even got the car moving & then nailed it, spin. This was the first time using the drag shocks. MPH went up 2 without the weight.

I figured with the extra weight, it made the car lower, making the lower arms more parallel to the ground and that's why the first pass was the best?

I'll see about getting a pic. I haven't tried anything since the photobucket mess...

by bigredlaguna Fri Jul 14, 2017 10:36 pm

Do you know what springs are in the rear now? You could use some of those spring compressors that clamp one level to another to lower the car temporarily for testing purposes and see what ride height works best for you.

by 73ss Sat Jul 15, 2017 5:27 pm

bigredlaguna wrote:Do you know what springs are in the rear now? You could use some of those spring compressors that clamp one level to another to lower the car temporarily for testing purposes and see what ride height works best for you.

I'm assuming they are original. I removed one and it's 14 1/8" tall, and about .570" wire diameter. I replaced the front ones with the correct BB springs when I swapped the BB in. The car does sit about 1 1/4" higher in the back. Rear tires are about an inch taller than the fronts.

by 73ss Tue Jul 18, 2017 9:31 pm

I've been looking at the moog website and it looks for the rear springs, the shorter they are free height the heavier duty they are, the more pounds per inch. I measured mine and they are 14 1/8" tall, .657 wire diameter which looks like a wagon spring (part # 6381 14.34" , .65" wire). regular 2dr coupe constant rate is part # 5391 15.4" tall, .59" wire.

It's looking like a PO might have put wagon springs in the rear. I've had the car since 1990 and haven't replaced them.

If anyone has some rear springs out would you be so kind as to measure the free height and what they came out of?

Are springs known to loose some of their free height over time?

by Joe73 Tue Jul 18, 2017 9:37 pm

I dont think they lose free height over time but I know front springs "settle in" and sag a bit over time. I'm sure the rears do the same but not to the extent of the fronts since the fronts have all the weight up there.

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