roll bar in a street car?

Do any of you get away with running mid 10 second passes at the drag strip with out a roll bar? my car is primarily a street car that i take to the track a couple times a year. what are your thoughts about roll bars in street cars. I see there are several newer challengers that are that fast and faster and are not required to have roll bars.

My Street car has had a cage in it for 23 years. I have padding all around the driver. I should always wear my full harness on the street but I don't. Your head contacting a bar in an accident is the biggest concern.

Last but not least, it won't take a lot of 10 second passes to twist the car up. My Barracuda has a bent drivers door from the countless 1.6 60fts it made before I put a cage in it. The car got raced anytime the track was open and it took its toll.

NHRA track here does not care if it's race or street, only how fast it goes.

I know a guy here who runs his street car only a few times a year at the test and tune fun events that goes 11:55 to 11:60 and they told him to put a bar in it anyway or don't come back.

New cars can run without them, but that is not smart, imo. Car goes into multiple rolls and/or gets hit in the roof by the other car and what protection is there in those types of situations? Not enough.

I wouldn't bother taking a car that runs 11.40s to a track without a roll bar. As long as you don't tell them the car runs faster than 11.49 you probably will get 1 pass. If your just slightly faster than the 11.49 that requires a roll bar you may get a warning to slow the car down. If you blast a 10 second pass they probably going to tell you to pack it up for the day. Newer cars are allowed to run 10.0s without a roll bar. I think its 2012 and newer cars but I could be wrong. This is because of the way they are designed and structured. Also once you hit the 10.99 mark you need more than just a roll bar. Aftermarket axles, flexplate, harmonic balancer, transmission shield, racing jacket and I'm sure I"m missing something else.

"get away with" is purely at the tracks discretion, neither NHRA or IHRA would condone it as it violates their Rules and has potential to effect their liability and insurability (track and sanctioning body). And to answer your question, at my local track I have seen an occasionally on the first never on the second pass. The sanctioning bodies are very concerned with chassis/roll bar with this type of infraction.

Pretty cut and dry.

If your local track allows it, that's on them.

The only thing it protects is YOU, think about that next time

I've put over 100k miles on street cars with roll bar/cage. It's not a big deal to me. Like Clark, I wear a 5 pt harness with a cage, and have it padded where my head might end up.

If you want to play at the track, you kind of have to follow the rules. Get used to buying a new harness every other year.

I have to agree with everyone here. Knock on wood never needed to find out how much I needed it but nice to know it's there. Not to hard for my fat old butt to craw across and my wife even rides with me. No swing out bars on mine either.

I had a chrome moly 5 point bar installed in my old pump gas Duster, it ran10.00 a bunch of times and one 9.993 ET at 134.8 MPH at Woodburn, OR at the Mopar race several years ago. I was told at the time slip booth to not race the car again until it had a cage in it.
I discuss that with the main tech guy and told him I would make sure it wouldn't run that quick again, I knew how to slow it down by staging a tiny bit deeper.
The drivers side door bar curve down to the floor at the front of the stock bucket seat and wasn't a real pain to get in and out of the car like having it go to the floor by the emergency brake like I had on other cars
I did not have a rear seat in that car so the rear support bars hit the rear subframe on the top of the kick up on the rear sub frames

It really depends on the track.

One we go to doesn't even perform tech and you hand your tech card out the window to a guy before entering the burnout box.

Another does thorough tech and told me not to come back until I had a rollbar after doing a few low 11 second passes.

We have a 6 pt. and it's really not that bad in a street car. I would highly recommend swingout side bars.

I do feel much safer with the bar and the 5 pt harness. We are trapping over 130 mph at times, so that gets sketchy with a lap belt.

FWIW my Camaro has had a cage in it since 2000. Never been a concern or issue for me really. Yes its paded and yes if your head hit it without a helmet it would not end well. But we can die taking the trash out too.

I've have noticed that the rules have not been enforced as far as safety equipment at some of the tracks I go to they are NHRA and IHRA tracks. I have been resisting putting a roll bar in the car because it then becomes a "race car" .... I guess you can't have your cake and enjoy it too . It is confusing with the newer cars being legal without a roll bar. Maybe that is why tracks are are not as strict as they once were.

Sort of depends on what you consider a "street car".
To me a "street car" would not require a roll bar, and be something with all the seats front and rear that you can put all your friends in and cruse around in.
On the other hand there is the "Street Legal car" which is really a racing class where the car would be "Legal" to drive on the street. The Legality of "Street Legal" varies widely.
I just don't care to have to climb around roll bars (with door bars) and cages, sit in "race seats" with 5-point harnesses, and have to wear sfi spec clothing to drive a "street car".
It is not just the rollbar/cage, but all the other regulations / certs that have to be kept up to date, like belts every 3 years, if you are going to race your "street car" at a track.

If you want to go fast at the track, it is likely better to just build a "race car".

I have a 25.5 funny car cage in my street car. Safety first... However, all of these No E.T, No time, No Prep, pour your own puddle or whatever they call these kind of events in your areas are run whatcha brung with no rules. I know of many 8 second cars with no roll bars. Dumb yes, but they do it.

My Dart is a street/strip deal and has a bar in it, I also wear a jacket, the correct up to date helmet and belts. On the street I wear the factory lap and shoulder belt.

As far as the rules being different for newer cars, they are built a lot safer than the late 60's and early 70's car most of us have.

People get enjoyment from cars in different ways. I really have no desire to own a car that I can't get in and drive wherever I want to go. If that includes running it at a dragstrip across the country, then it might as well be a fast street car, eh?

If you're happy having a car that just goes fast, that you can't drive anywhere else but a drag strip, then yeah, you should just build a race car.

I ran mid 10s for a few years w/ no rollbar or anything in my cuda. Tracks down here are very different from other places...basically no tech inspection.
When I built the hemi and aimed for the 9s, I had a 10 point cage put in the car. If they're done right, the cage isn't a big deal at all. Swing out bars are nice.

I had a 4 point roll bar in my Duster but it didn't have down tubes so it wasn't legal for 10.99 or quicker. Around here the tracks will bounce you if you aren't legal. A four point bar will stiffen up the car but it also blocks off the back seat. I wouldn't want a set of down tubes in a street car that I drove on a regular basis since it is a hassle to get in and out. Maybe some swing out bars or bolt in bars for the track day would work for you. It is really just a question of priorities.

100% disagree.

We all pile in the car and go for ice cream fairly regularly. Hell, me and 4 friends got in the car and left the track to go to breakfast at the little town just down the road because we didn't want to unhitch from the trailer! The chassis shop that built the bar made sure the back seat fit and things like the rollup knobs worked fine. The only compromises I have made with the car is the rollbar and the spool in the rear. I absolutely did NOT want a racecar that gets pulled in and out of the trailer and only runs for a quarter mile at a time! We've put over 7,000 miles on the car since I put this engine together.

Bolt it in, take it out when not at the track

I'm fairly sure my Dart is going to go faster than 11.50 when I get it to the track someday... already have homemade subframe connectors ready to weld in, and I'm considering a 6-pt roll bar too.

Are the swing-out bars legal?

The classic test for "do I need substantially more chassis stiffness (frame connector, bar, etc.)?".
With the car at race weight, level on a flat floor: open & close both doors.
Now jack it up from anywhere (try all 4 corners, diff center, K member). If the door closing is different (more, or less secure, gap irregular), you need more stiffness.

no cage leaves straight throw 5 people in and ride. see if picture took

At the local cruise night tonight, cage and all....

Consider this, nobody likes getting smacked on the head with a metal baseball bat.

If you think if I put foam on the bat it won't still do some damage to your skull, have at it.

Unfortunately, there is no good low risk solution for a non helmeted driver in a caged street car, no matter how belted.

Inches matter.

Or even easier would be an exoskeloton like the off-road guys.

Bolt it on for the track, remove for the street.

Yes I've had street driven cars with roll bars, and never really liked it.

I always thought the best way (for a street car) would be to cut away the inner structure of the roof to be able to tuck the top bars that go by your head right up to the roof skin.

this is funny but so similar to the arguements going on here in Aust .
Under ANDRA its under 11.00 - 10.50 SFI 3 layer suit SA / M helmet gloves socks shoes ( until this month it was tech rollbar etc @ 10.99) @10.50 you have tech inspection and roll bar graduating to full cage under 10.00
EXCEPT for "modern"which is factory 4 w disc brakes and air bag , in which case its good to 10.00 no roll bar no harness no safety clothing $50 helmet .Under 10.00 tech cage etc .
Under IHRA Aust they proposed "modern"to 9.00 .
Local track has gone back to ANDRA and by golly the screams from some racers .And trying to discuss it is pointless .They refuse to accept any safety arguement . Grrrr
Oh yeah i have a 5 point rollbar in my daily , its legal to 10.00 .

Tex

Are swing out bars legal? If I were to install a cage, that would be my preference.

All my street cars have at least a roll bar if not a full cage..I wouldn't own one without it. If your going to do that, then buy a Hellcat.

I wrote some ideas on my site here:
http://victorylibrary.com/mopar/frame.htm

Yes, swing-out bars are legal. Legal to 8.50 anyway. My car has swing-out door bars on both sides and NHRA cert'd to 8.50.

If you're gonna go fast, you need a cage. Not only for your safety, but to stiffen up the car. Has nothing to do w/ it being a street car or not IMO.

My local 1/8 mile track has 7.40 as the cutoff and I've gone 7.56 so far. So I'm getting close to decision time after whittling down the ET over the years starting with 8.30s.

The thing is, I like to take my family for rides to cruise nights or just a trip to the grocery store and there doesn't seem to be any safe way to do this with a bar. So I'll probably try to get it to run as close to a 7.40 as possible without going under and then stop trying to make it any quicker.

I feel more comfortable making 90+ mph passes at the 1/8 mile track with just a lap belt than I would driving around in traffic with a bar next to my or a family member's head with no helmet.

I have had both and like some said its nice not to be in the way. if you want to actually want to use the back seat how do they get in it. the cage if fine long as there only 2 of you.

Like I said, you can bolt it in, look at the rule book. 6” square plate bolted to floor for the hoop, down bars bolted at floor and hoop, side bars swing out that’s bolted. Problem solved till you go 9.99 then you have a race car, period.

Can you post a link to the page that states bolt in bars are legal?

This is taken from the 2021 NHRA rule book general regulations. It looks like the cross bars and rear bars definitely need to be welded to the main hoop. Be tough to get it in and out of the car if bolted to the plates on the floor.

4:10 ROLL BAR
All roll bars must be within 6 inches of the rear, or side, of the
driver’s head, extend in height at least 3 inches above the
driver’s helmet with driver in normal driving position or be within
1 inch of the roof/headliner in the area above the driver’s helmet,
and be at least as wide as the driver’s shoulders or within 1 inch
of the driver’s door. Roll bar must be adequately supported or
cross-braced to prevent forward or lateral collapse. Rear braces
must be of the same diameter and wall thickness as the roll bar
and intersect with the roll bar at a point not more than 5 inches
from the top of the roll bar. Crossbar and rear braces must be
welded to main hoop. Sidebar must be included on driver’s
side and must pass the driver at a point midway between the
shoulder and elbow. Swing-out sidebar permitted. All roll bars
must have in their construction a cross bar for seat bracing
and as the shoulder harness attachment point; cross bar must
be installed no more than 4 inches below, and not above, the
driver’s shoulders or to side bar. All vehicles with OEM frame
must have roll bar welded or bolted to frame; installation of
frame connectors on unibody cars does not constitute a frame;
therefore it is not necessary to have the roll bar attached to the
frame. Unibody cars with stock floor and firewall (wheeltubs
permitted) may attach roll bar with 6-inch x 6-inch x .125-inch
steel plates on top and bottom of floor bolted together with
at least four 3/8-inch bolts and nuts, or weld main hoop to
rocker sill area with .125-inch reinforcing plates, with plates
welded completely. Also, the roll bar may be welded to frame
connectors that are fully welded in place and are 1 5/8 inches
x .118-inch MS or .083-inch CM round and/or 2 inch x 2 inch
x .058 MS or CM rectangular. All 4130 chromoly tube welding
must be done by approved TIG heliarc process; mild steel
welding must be done by approved MIG wire feed or approved
TIG heliarc process. Welding must be free of slag and porosity.
6” max
All cars with an OEM frame must
have roll bar attached to frame.
Cars without frame use 6” square
1/8” steel plates on top and
bottom of floor, securely bolted
together with at least four 3/8”
bolts, or top plate welded to
rocker sill.
All materials must be 1 3/4” O.D. x .118” mild steel or .083”
4130 chromoly tubing, except A, which is
1 1/4” O.D. x .118” mild steel or .065” 4130 chromoly tubing.
5” max
4:10
A
Maximum of 6”
from roll bar to
driver’s helmet.
Maximum of 5”
from top of roll
bar to brace.
Section 21, page 22 General Regulations
Any grinding of welds prohibited. See illustration. Roll bar must
be padded anywhere driver’s helmet may contact it while in
driving position. Adequate padding must have minimum 1/4-
inch compression or meet SFI Spec 45.1. All cars running 9.99
(*6.39) or quicker, SFI Spec 45.1 mandatory.

Backseat? That's just extra weight.

WOW, they are very specific instructions. Being these are the rules for legal roll bar construction; there are ALOT of cars I compete against that are not legal. Such as wrong material and poor welding just for starters . It really comes down to the track you compete at and how seriously are they going to enforce the rule. And the risk tolerance of the driver .

Depends on the tech guy and the track. Typically they'll allow the plate to be bolted to the floor but they often won't allow the down tubes to be bolted to the main hoop. If you weld the down tubes to the main hoop to pass tech then you can't remove the roll bar from the cage. I've had a couple of different buddies get busted on this exact thing. They were told that a bolt together roll bar was legal but the get the track and the tech guy says it has to be welded together.

Crawl over the bar. Heck I can still do it. Turned 67 last Sunday.
Doug

I guess you guys crying about safety and a roll bar in the passenger compartment have never ridden in a Jeep?!

I see a lot of late models without them running well below the 11.50 requirement. Not sure how that works. Let alone have a diaper on them.

I see the part in the rules where it says the rear down bars have to be welded to the hoop.
What I don't see is anything saying they must be one continuous piece of tubing. Make it bolt together say a foot from the hoop and carry the rule book with you. Done right it may be the strongest part of the cage. For sure it will be stronger than front swing out bars.

Things sure have changed. Fifty years ago this was legal and everybody used them

Yes tube must be welded to hoop just like the side bar, the attachments. It’s all in the wording, bolt it down about 6-8” from the weld. Make-female type connector with two grade 8 bolts opposite. NHRA Tech guy said ALL they can inspect-pass is having proper bars in the right place not how bad the welds are.

Another question: I haven't installed my subframe connectors yet. If I put in a 6-pt. roll bar, are the connectors still useful?

To be fair though, the cages in Jeeps and Broncos and other similar offroad vehicles are much further away from your head than a rollbar in a passenger car, and are also padded in the critical spots.

That being said, I've had a rollbar in a fox mustang before though and I never really worried about it. It's just a risk I'm willing to accept. I may eventually put a 6pt bar in my Fury but for now I haul enough people around in it that I don't want them to have to climb around the bars to get to the backseat.

My CJ5 doesn't have padding. It is from 1980, though, long before everyone thought they had to have all the safety features in their driving appliances.

Absolutely! They make a world of difference in a uni-body car!

Make several(4+ each side ) 1/2 or bigger holes in each side of the sub frames to weld them to the sub frames, not just where they slide into the sub frames in the rear

These questions pop up fairly often and the answers are always the same. Everything is in the rulebook or the SFI spec. Other than some amendments to some of the specs, it hasn't changed in many years. Not wanting to do it doesn't change the answers. Not wanting to cut or "mess up" a nice car also does not change the answers.

It needs to be welded in or welded to proper plates on the floor and 100% welded together, except for legal swing out side bars, which have their own requirements. They still allow plates to be bolted to the floor, but I haven't seen that done by anyone in a long time. The diagonal "D" bars from the mainhoop to the floor are required if it's not welded to a frame, also on plates or welded to frame ties. Chicken s*** welds done with a fluxcore or stick welder will fail a cert.

If a track allows anything other than this to slide, it's between the "tech" guy, the track owner and his insurance company, if he has insurance. You can run there if you like. I have in the past and saw people get hurt over some dumba$$ stuff.

Years ago, we got involved with an old truck with a big motor that needed a cage before they would let him come back. He didn't want the body cut. I had similar conversations with one of the best guys at NHRA about it. He finally got tired of me asking, "well what if" and said "does he want a street car or a race car? If he wants to do that, it has to be this way." I never asked again.

Keep in mind, the rule book is a minimum. There is plenty of room for additional things to be done to improve the structure.

We had a guy at our track a few years back with an import that had a 4 point bar, seat not securely mounted, etc. He was running deep into the 9's as I recall but claimed to be much slower when teched.

He ended up hitting the guardrail broadside on the first return road entrance when he lost control (worst possible place) and it killed him.

The NHRA paid out (like they always do when there is a death) and fortunately, the family and in specific the father knew what the son was doing and knew it was only a matter of time and chose not to sue (rare in this day and age).

All it takes is one accident like this with sue happy next of kin to permanently shut down a track.

"frame connectors that are fully welded in place and are 1 5/8 inches x .118-inch MS or .083-inch CM round and/or 2 inch x 2 inch x .058 MS or CM rectangular"

I don't understand this. The connector provides vertical bending resistance.
The 2" rectangular is much stiffer than the 1-5/8" tube.

I fail to see the engineering that requires the rear tube to be welded to the hoop. A bolt-together design might be more expensive, complex, and heavy but easily made stronger than a weld. One method would be a flange-to-tube section welded to each of the main and rear, with a removable flanged tube between them. The attachment to both tubes passes already, and the shear strength at the flanges can be met by sizing the bolt area.
The welded area is the contact surface is (OD + ID ÷ 2) of the smaller tube × Pi × wall thickness. A 1-3/4" × .120" tube welded seam is .614 sq. in. 4 × 1/2" bolts provide .785".

Please: I'm OLD! Correct my errors, please.

I like it, I had 73 CJ5

It's really irrelevant who owned what jeep here IMO, its more pertinent who survived a hard crash in one, without any headrests it would be amazing if they retained movement below one's neck.
I have a lengthy history of injury free driving with limited safety measures in place over many decades, only real conclusion I can draw with certainty, I was at least lucky.

Explain that to the NHRA and let us know how it works out.

That might work at some tracks but it won't work at all of them. One of the EFI cars that I tune got bounced because the rear down bars were bolted together. He had to get them welded before the car would pass tech. His local track allowed him to run but as soon as he started towing to out of town races he got put on the trailer.

Maybe not an an error, but an omission, FC's also supply resistance to compression, tension, and twist, and depending on cross section/thickness chosen each of the the four resistances mentioned here vary as needed for the application. Meaning to me, a 3x3 tube might really best all round solution, but seldom seen.

That was so helpful.
My point is that they see no reason to discuss decisions that have been made with little input from engineers.

I agree, larger diameter is much better, but very difficult to live with in the car.
I limit my remarks to a single point of attachment, in which bending allows collapse of the adjacent tubes.

And my point is if you can build a better mouse trap go to the NHRA and get it accepted.

If you put a roll bar in a car you will actually have two.

I wrote something about a new product as sarcasm about 30 years ago, can't find it.
Ever hear of NIH? A force stronger than the hydrogen bomb, it protects important people from new ideas. Used by all car manufacturers and defense contractors.
NIH = not invented here.

A properly designed chassis is a series of triangles.

To your other comments...I'm certain engineers who are very familiar with the chassis in question, and the forces involved in accidents, are involved in the establishment of these specs and rules. Chassis builders, OE factory engineers, safety experts, sophisticated CAD and analysis, etc. Fuel cars, Pro Stock, NASCAR, Big bucks. That all filters down to the lower classes.

Unfortunately, it usually takes someone being killed to cause a serious look at the cars in question and get them updated.

He's smarter than all those people.

If they are welded to or through the floor!!

Both will work, I've used 2x2 as well as 2x3 .083 rectangular tubing for sub frame connectors in the past
It is up to you which size and how to have it installed

I used 2x2 .125” wall for mine.

You noticed that?

2 X 3 is much, much stiffer than 2 X 2, not just the obvious 50% height increase.

I agree 2x3 is stiffer, but the roll bar helps too.

Also drop the ends of the main hoop through the floor and weld them to the subframe connectors?

If you can’t bend/weld a bar in yourself, find a quality shop to install a moly 8.50 cert setup. Make sure you’re at the shop when they’re measuring/cutting and welding-in the main hoop and halo so they can build it around your actual sitting position while in the car. Not sure what belts, seats you’re using, but consider Kirkey’s or seats that would not allow your body and head to flop around a lot in the event of an accident on the street, i.e, keeping your body, head from contacting the main hoop and halo. If most of your time spent in the car is on the street, then I’d install door-side swing-out bars. Lastly, unless you’re wearing some sort of head protection, no way in hell would I ever run a car on the street with a funny car cage. I personally know two guys who died from head injuries when their heads smacked their funny car cage bars on the street. They were driving normal and were hit on the driver and passenger sides of their cars. They weren’t hot-rodding or acting like hooligans, just freak accidents. If anyone were to install or currently has a funny car cage they run on the street there is a company that makes a helmet shaped like a baseball cap that doesn’t look too goofy. It would at least allow you to live most likely.

Excellent, excellent advice!! As much as most of us do not want to hear that, it is very true. Thanks!!

I agree on using a racing seat and harness if you have a roll bar/cage. Anything lees than that (stock seats and lap belts bar or no bar) and you are at the mercy of a higher power in the case of an accident. The crash tests from the 60-60s era were brutal. One of the reasons I like beating on my cars at the track. Chances of a hard, head on front end collision are much lower with no telephone poles etc. At that point you end up abiding by the rules of where you race and add safety precautions for the street use.

A few things also come into play with design of the cage too. You don't want to be under the hoop. I have seen taller guys do this when laying the seat back or using a factory bench. It is acheived with a kicked out horizonal bar in the hoop instead of running it straight across so it does it's job. Bad place to be without a helmet, padding or not.

The other problem I see with the factory flip up seats of 67 and back is that they do not lock in position. Then you see the harness bolted to the floor behind the seat just right so in an accident the seat will fold you up as both it and you torso get intiment eith the dash. My 66 b bodies both have race seats because of this.

The rules say the hoop must be higher than you helmet so definitely check that as you put it together. For sure use swing out bars unless you are really throwing the world at it lol. I also like forward bars in our unibody mopars. Cab turned me on to the idea of running them outside of the fender apron. Way easier to work on the car with the bars out of the way.

Angling two bars that intersect the frame connectors from the main hoop( making it an 8 point) are extremely worthwhile regards chassis rigidity upgrade and making the car “ one piece”
In other words, these two angled bars would go through the rear seat footwell and weld to the frame connectors on each side.

In the drivers compartment, the only adjustment to be made to the bar locations would be fore and aft on the main hoop for leg room if using stock steering and pedals. Unless the driver is freakishly short or tall, that's pretty much a standard location. Back in the car a bit. The seat doesn't need to be against it. And the next guy to own it might want the seat to go back. The rest of it gets put in as close to the body/headliner/B pillar/ doors as possible to give as much room as possible. This usually takes some planning and effort to get it all welded up 100%. Helps to get the windshield out, Fast Super Stock and other stock body 25.x type deals or cars like a SN95 Mustang often have the roof removed to get it all done.

Frame ties are 2x3x.083, stood on end through the floor. Mopars get the back of it poked into the front of the stock frame rail, maybe half above and half below the floor. Section it up in so it fits up against the torsion bar X member, Outriggers from the frame rail to the rocker, also sectioned into the floor, provide solid mount points for the cage.

I would add the need for .125" wall FC is IMO reduced as one installs more cage components. I don't see many cases that .125" is required once one starts adding a roll bar+.. A pair of .125" 2x3 tubes are heavy for little gain.

What I did

Awesome!

Sweet CJ5! Still AMC powered?

I've had a CJ7 and 3 Postal Jeeps, one with a 350 Chevy in it. I've rolled one of the Postal Jeeps at low speed in a parking lot. FYI, don't try to do donuts with them. lol

Yep, unfortunately it is a 4 cylinder. It has sat in my 3rd garage bay for the last couple of years and I finally decided to rebuild the carb and do some maintenance. I bought it as a fix and flip but it's growing on me.

Easy fix is lay the hoop back. I do it on every one. Match or nearly match the angle of the seat back. The cross bar can be bent, but if you do, it has to go to 1.625" tubing.

In these old cars, tall guys almost touch their head on the headliner as it is. You can get the bar tight on the roof and still have an issue. Next step is aftermarket seat and seat brackets. I've had to make seat mounts to get a person down in the car far enough to be safe. Works fine, plus takes a bunch of weight out. Jaz seats and fabricated mount vs. stock mounts and buckets took 80# out of last one I did. Put them right on the original seat mount studs.

I put a race seat in my Duster and moved it back and down as far as possible so I could fit in the car comfortably. The driving position was fine but it was a little hard to get out of the car. The big problem with moving the seat down in the Duster was that it killed the rear visibility. I was thinking about putting a back up camera in the car but didn't get around to it before I sold the car. Changes like a roll bar, cage, race seats, etc. all have ripple effects and until a person has driven a car with those changes they should be a little cautious about about it.

With my Kirkeys my butt is almost on the floor, 1” or 2” at the max. Still see out the front ok. Of course my seat brackets aren’t as nice as those by a long shot.

When I did the bar in my Dart I tucked the hoop right up against the headliner. The hoop angle follows the angle of the door/rear side glass joint. It too has Kirkey seats, I made aluminum brackets to work with sliders. Once I located the position I liked a bracket was fabbed to attach the seat back to the cross bar. With the factory shoulder/lap belt I don’t see how I could get in a position to bang my head on any of the bars and with the harness on I can’t see it at all.

For those thinking about stiffening or modifying a cage, the most important factors are:
1. Tube diameter (not material, or wall thickness). Even adding 1/4" has a huge effect, far more than a direct comparison of new vs. old. Example, other variable removed: replacing a 1-3/4" tube with 2" (only 1/8" less space around it, and 1/8" closer to the interior), which looks like +14.3%, instead adds 53% to the bending resistance (and only 15% to the weight).
2. The longest unsupported tube length (between points of attachment with no intersections). Length is the enemy of stiffness, a 4' tube divided into 2 each 2' tubes (make triangles) is a 700% improvement. Even attaching a strut close to one end (making 1 piece 1' and the other 3') adds 137%.

A pet peeve of mine, is when using dual front aftermarket racing seats, is installing them effectively inline, unless I am competitively rally racing, the last thing I want in my normal field of view is a passenger bug eyed, additionally, I want their butt, weight wise as far back and as low as possible. If they buy the car, they can get driver seat. Track cars often require dual seats for check out driver/instructor.

CM, in the seat mount photo, what size is the tubing ? as for an adjuster, i was contemplating using one from a minivan. they are light, low, and have a simple lift bar in the front for adjusting. the passenger seat will be a permanent/non-adjustable mount as far back as possible, with the back attached to the crossbar, which is straight.
my only concern is the back brace for the driver's seat back will need to be [slightly] adjustable as well.
any ideas or suggestions ?
TIA as always !