Are aftermarket subframes safe?

[Decline]

Yes it's been installed for a little over a year. The car handles like a real sports car now. I have a TCI torque arm in the rear with TCI bolt on subframe connectors. Non mini tub
I saw your other post regarding not cutting up the floor for a quadra link. I assumed you had a nice car to start with like I did. This setup all bolts on, no cutting required.

[another69]

That looks pretty clean in your car - do you have enough clearance in the front down low for your motor accessories or did you go with a high mount setup? Did you go with the 20:1 or 15:1 rack, and are you happy with it?

I was leaning heavily toward a torque arm rear, just weighing my options. My trunk pan and frame rails are brand new, and the rails seem thicker than stock so I really don't want to cut them up. I don't want to do the standard mini -tub, but I may go to the frame rail. I can fit a 275 in there now no problem.

[Decline]

That looks pretty clean in your car - do you have enough clearance in the front down low for your motor accessories or did you go with a high mount setup? Did you go with the 20:1 or 15:1 rack, and are you happy with it?

I was leaning heavily toward a torque arm rear, just weighing my options. My trunk pan and frame rails are brand new, and the rails seem thicker than stock so I really don't want to cut them up. I don't want to do the standard mini -tub, but I may go to the frame rail. I can fit a 275 in there now no problem.

It's a 350/350 sbc no a/c ..no clearance issues. No LS(yet) ran out of $$$..lol
I do recommend getting the AME headers. Some others might fit but these fit for sure and have good ground clearance. Notice the first tube going up and over to get around the steering shaft and past the lower control arm. The above underside pic was not these headers. Those were right on top of the LCA bushing.
Rack is 20:1..seems fine. Great around town, feels fast enough on all but the tightest autoX course(del mar)
I run 275s on all 4 corners. There's still room. I'm thinking of bumping up to run 10" wide rims and 285 RS3s on all four since the hankooks have a round shoulder and are fitment friendly.

[TheJDMan]

That header looks like it would make changing plugs a challenge.

[Decline]

That header looks like it would make changing plugs a challenge.

Its definitely a PITA. I need an assortment of extensions, swivels, and wrenches. Each one requires a different method, and they get more difficult to reach towards the rear which is nice cuz space is already limited towards the firewall.

I think I read somewhere that stainless works has/had headers that work too but I've never seen them.
After having fitment issues on the car with all these custom parts I was done screwing around and just bought what I knew would work. They're mild steel and kinda heavy but they go on and off easy and they clear stuff

[another69]

Did you use the stock column? Any bind when you turn the wheel lock to lock?

[Decline]

Did you use the stock column? Any bind when you turn the wheel lock to lock?

Stock column. No bind.
When you first get the subframe there will be two spacers in each side of the steering rack and your turning radius will horrendous. I pulled back the boot and they pop right off. I'm only running 9s with 275s in the front with like 6.25 backspace but it doesnt touch the frame on full lock with the spacers removed.
The newer frames have a lot more room now. I think speedtech quotes a 315 in the front stock wheel well

[another69]

They advertise a 265, I wonder why they include the stops if you can get a 275 without stops & no rubbing?

[RobNoLimit]

It's all been said but here's a bit more. First, all of the aftermarket subs for these cars are stronger than the OE sub (with the notable exception of 'Drag Race' inspired lightweight clips). We do 'Twist' or torsional flex tests on all of our frames and subframes, as well as the OE components they replace. - Many of these are on You-Tube. With 1000 lbs force applied, the OE sub will twist about 13 degrees (this is being held only by the very rear two mounts and the front two mounts, with force applied to one front horn) Our Sniper IFS gives up about 3.5 degrees. Now, in a car, with all six mounts in place, this will be less, but 1000 lbs force on one corner (above the other corner) is no big deal, as this would only be appx .92G on the average weighted F-body. BUT, this doesn't matter that much in the safety department. Look at the six mounting bolts. The front two are holding up the core support and fenders, which act as the 'crumple zone' so there are really only four bolts holding the subframe to the car. And these are in 40+year old fatigued metal. - at best. So, additional strengthening devices pay off big time in the handling and safety department. The best front suspension geometry will suffer if the subframe/shell is moving around. Subframe connectors, roll cages, pinch rail stiffeners, full rails, Ride Tech's Tiger cage, Hotchkis Handle Bars, and the like will all increase the handling AND safety of the car. Add those into the equation for the real answer.

[another69]

A roll cage would be great, I just don't know of anyone local who can do it. I've always imagined that a hidden cage would be a really unique way to do it, but it would be tough. Bars hidden in the A and C pillars, and above the headliner and behind the kickpanels. Really make it part of the unibody... but that's another subject. Looking at the stock sub it looks pretty beefy, but good to know that the aftermarket ones should be stronger.

Never heard of pinch rail stiffeners - can you elaborate?

[Ron Sutton]

While I did NOT design the frame for Speedtech's new clip (just the suspension & steering geometry) ... the strength of their clip is pretty impressive. Using new laser cut & weld technology ... the clip is not completely hollow instead, like all other designs are. The Speedtech clip has stiffening structure welded INSIDE the frame rails to increase stiffness & rigidty of the front frame clip.


Video for RSRT Designed Speedtech eXtreme Subframes & Chassis





To watch this In-Depth Video on YouTube ... Click HERE.

[Samckitt]

Stiffer isn't always better, yes better in terms of handling. But what happens when you hit something head on? A stiff frame means the car stops quick & you take all the forces. A frame built with crush zones will do much more damage to the car, but will stop gradually dissipating the energy slower and be easier on the driver.

[Ron Sutton]

Stiffer isn't always better, yes better in terms of handling. But what happens when you hit something head on? A stiff frame means the car stops quick & you take all the forces. A frame built with crush zones will do much more damage to the car, but will stop gradually dissipating the energy slower and be easier on the driver.

I agree Scot. Stiffer is not always better.

I have experience with crush zones too. For anyone following along, that wants to learn more about increasing safety in their cars for track duty, you may want to check out my safety thread HERE.

In my race cars & Track Warrior cars we use a 5-zone concept, where we look at the car as Very Front Zone - Mid-Front Zone - Cockpit - Mid Rear Zone - Very Rear Zone. The very front & very rear zones are designed for high crush to absorb the most energy of impacts. The mid front & mid rear are designed for medium crush to absorb energy from the highest of impacts. The cockpit is designed as a low crush zone to protect the driver. I used to say "no crush zone". But in 200 mph head on crashes into the wall, the cockpit cage will deform some.

In my experience, the front frame rails from 60-70's production cars are too weak. When we raced in classes requiring stock clips, we've ran Camaro, Impala, Chevelle & other clips. When you hit something ... what we would consider to be low impact ... the frame rails would fold up quicker than a Politician on a polygraph. LOL

It is my belief that the front frame rails need to be stiffer in these 60's-70's muscle cars ... for both performance & safety reasons. I think several Pro-Touring manufacturers have done that with their replacement clips. I like how Speedtech did theirs with the internal braces inside the frame rails & crossmember. It is my opinion that stronger front frame rails & crossmembers ... will do a better job of keeping the engine out of the cockpit & in the engine bay where it belongs ... in hard head on crashes.

[JEFFTATE]

The DSE Hydroformed subframe is very strong. I've seen a DSE equipped car that was crashed pretty hard and the subframe, the car, and the driver faired well , considering the severity of the crash.
This car had all the DSE equipment , cage, harness,etc..

[Buryingthesun]

First of all. . . We all should agree these cars were not built for safety.

Second, I don't know if my 67' frame was built any different than the rest of the frames out there but it looks like a complete toilet with the worst coat hanger welds possibly done by a drunk on the assembly line. So if you think thats going to save you in a reck you are sadly mistaken. . . Let alone the 4 body mounts are more likely to just tear off the body flinging the from and you in opposite directions

[JohnUlaszek]

Here is a link to an article I wrote on the Detroit Speed subframe. I know most of us are pretty familiar with the product at this point, but Its worth checking out to see how dramatically different the design and manufacturing of Detroit Speed's part is compared to OEM.
Detroit Speed Subframe Story

[FANTM58]

If your n the market, check out Chassis works,Chris Alston. That's the oneI have. Love It !!

[Anthony k]

Subframe / crash test safety means nothing unless your driver safety restraints are improved upon.

We sometimes get asked this as well regarding our chassis.

Bigger brakes, stronger suspension parts, better tread compounds, wider tires...
These are safety additions that will assist in collision prevention.

I can assure you any major brand subframe you buy isn't flimsy.
However I have to pitch our chassis and mention they're a stronger option than just a subframe.

-Dale

If if your chassis fit without completely redoing 40% of it I'd be impressed.

"your" subframe was stronger after being serverly cut up and re-engineered to fit

[Hex]

Don't buy a subframe from Checkered Racing.
Safe? Try life-threatening.

So while restoring my Nova a couple of years ago, I noticed my stock subframe was shot. All of the body and suspension mounting holes were rotted out and it was falling apart.



Not having $4500+ to dish out for a TCI or similar front subframe, someone pointed me to Checkered Racing. Only an hour or so drive from me, and made what appeared to be quality, heavy duty products at an affordable price. I started researching and found hundreds of people with their subframes or 4-link kits that seemed to love them.

So I spend $2500 or so, and bought a subframe, control arms, shocks and springs, spindles, disk brakes, rack and pinion, and crossmember.

The problems started from day 1.....

1. A friend of mine was going to be in their area of offered to pick it up for me. He delivered it, and I noticed that I didn't have any shocks. After a phone call with Checkered Racing, they didn't have them in stock and were drop shipping them, but I would need to buy a spring compressor to install the springs on them. (Sure, I'll just spend $100 more, no big deal).



The body bushings they sent me were solid aluminum. I knew this before hand. They were supposed to be 'precision cut on a lathe'. Let the pictures show you how precision cut they are. Oh and converting to stock style poly bushings would require LOTS of measuring and drilling on the subframe to make sure they were centered. I decided to try the solids.

Btw, these are the small ends of 2 different bushings. As you can see, they are extremely tapered. They measure as large as 1.12" on the big ends.





3. The springs themselves were supposed to be QA1 400 lb springs. They didn't have the QA1 label on them, and weren't the color of normal QA1 springs. They appeared to be knockoff springs.

4. I get the springs installed on the shocks and get them installed. I let the car down. The springs bottom out just sitting in the driveway, not even moving. I hadn't driven the car yet, but I was pretty sure this wasn't good.



5. I go to install the brake lines. The flexible lines that bolt to the caliper they sent me were completely wrong. They had a rectangular head on them, and the calipers have a round indent where the brake lines are supposed to bolt up. I call them up, "Sorry I didn't realize we had stopped using the other brake lines, I'll send you the correct ones. Just send yours back". I send them back, a month goes by. I call and he gets an attitude with me on the phone, but mails out the correct ones.

6. The 'correct' ones show up. Here are the banjo bolts that came with them. Needless to say, I had to buy new ones.



7. They were supposed to send everything needed to hook the stock steering column to the new steering rack. It included a U joint that was splined on one and a smooth on the other for the rack (this was fine), a piece of pipe for the shaft (still okay), and another U joint that was smooth on both ends. Nothing to connect it to the stock rag joint. I had to buy a smooth to splined U joint, and a splined Rag joint adapter (another $70), and then welded up the steering shaft.



8. So I go to bolt on my core support and front bumper after dealing with the brakes. The bracket holes in the front of the subframe are setup for a Camaro front bumper, not a Nova. I had to strap the bumper in place and then drill out the brackets to match the subframe.

9. I went to install the crossmember for the trans, which I asked them NOT to drill for for the trans mount, and they did. I had to redrill one hole and oval out another to get my trans mount to bolt to the crossmember.

10. I go to put the wheels on. The press-in studs for the front weren't working so good. 2 of the studs would spin when I tried to put a lug nut on them. Have to impact them on and then finish tightening by hand.

11. I go to get an alignment. The guy looked at it and said "Heim joint control arms"? That'll be $250 and 3 days, if I even feel like doing it. He was the only shop in town that would touch it.

12. First drive. Everything is fine. Go to hammer on it (Turbo 5.3) and when I let off, the car is all over the road. After that, I have steering wobble. Back to the alignment shop ($).

13. Next drive? Guess what happens. Steering wobble. Not sure whats going on. Take it to the house and get under it. This is what I find. The hole for the lower control arm mount was oval, and the control arm would just wobble around loosely.

https://www.youtube.com/watch?v=ThVU_o2VlLc

He sent me some new weld on plates that are part of their 'updated design'. I have to weld on these new plates with new washers and bolts. Then? Alignment.

14. I go to put it all back together and I notice that my ball joint boots are already shot. Oh and both of my lower ball joints have taken a crap on me, you can grab the bottom of the wheel while they are torqued down and wobble it back and forth on the ball joint.



15. The 'upgraded' brakes I ordered from them sucked. The calipers didn't have very much clamping force and there was brake dust everywhere in no time. I took them off to lube up the sliders and stuff on the brakes to quiet them down, and the steel backing plates on the pads had already come loose.

16. The ride was EXTREMELY rough from the bad springs. They DID send me new springs. Guess what? Real QA1s. They tried to argue the first set they sent were also QA1s. They also wanted to send me 450 lb springs to help with the collapse. I asked for 550s. The 550 lb springs work perfect.

17. After a few thousand miles, I lost brakes. I went to slow down from a pass and couldn't. Both feet jammed onto the pedal, it rolled to a slow stop. I get home, and the brake pads on both sides had shattered. I sent them a message and ask if they're trying to kill me. They reply with "No, but I'll send you new pads if I can find any laying around the shop". No thanks, I went and bought new Ceramic pads.



18. This morning I was working on the car a bit. Swapped intake/throttle body and went to go for a drive. Started up the car, pulled it into reverse. BANG. Oh crap, I tore up the trans maybe? No smoke, and couldn't find any other issues. Got back in, started up, put into reverse. Car wouldn't move. Looked under car and noticed the issue. A control arm had snapped. THANKFULLY it snapped in my driveway and not during a pass, or I would have been in serious trouble.



This isn't a drag car. There is a pink carseat in the back at all times. We take it everywhere. On cruises, to car shows, to the mall. I drive it to work all of the time. At this point, I don't feel safe driving it. I contact Checkered Racing. "We can just send you another control arm". No thanks. I don't feel safe with your stuff. A control arm was the best I was getting. I told them I may have to contact my lawyer. Their reply? "OK".


If any of you consider buying from Checkered Racing, I STRONGLY urge you not to. Your life isn't worth it.

[raustinss]

terrible when one person lacks morals , puts money over someone elses lives . this seems to be the perfect example of one person giving other good people a bad name