Posted By: A70Runner
Stock seats with 5 point harness - 03/31/09 10:45 PM
I just put a roll bar in my 70 Roadrunner and was wondering if anyone has modified the stock hi-back bucket seats to work with 5 point belts? Any pictures? Thanks 
Stock seats with 5 point harness
Posted By: dizuster
Re: Stock seats with 5 point harness - 03/31/09 10:48 PM
I'm in the process of doing it right now. I bought an extra yard of material from Legendary when I got the trim covers.
Make sure that if you cut a hole in the structure of the seat frame, that you find a way to protect the belt from any sharp edges. I just used a 1/2 piece of tubing bent to fit around the sharp edge opening.
Make sure that if you cut a hole in the structure of the seat frame, that you find a way to protect the belt from any sharp edges. I just used a 1/2 piece of tubing bent to fit around the sharp edge opening.
Posted By: Hot 340
Re: Stock seats with 5 point harness - 03/31/09 11:08 PM
So you are saying they need a hole hacked into them to work?
Posted By: A70Runner
Re: Stock seats with 5 point harness - 04/01/09 12:23 AM
Quote:
So you are saying they need a hole hacked into them to work?
Yes to make the shoulder belts meet the cross bar.
Posted By: DennisJ
Re: Stock seats with 5 point harness - 04/01/09 12:37 AM
What about the part in the rule book,that says the seat has to be attached to the roll bar? How do you do that with a factory type seat?
Dennis Jokela
Dennis Jokela
Posted By: Cab_Burge
Re: Stock seats with 5 point harness - 04/01/09 05:17 AM
I have stock high back seats in my Duster(10:40 ET), it has been through tech at a bunch of different tracks for Pro ET and I have never been bounced or informed that I had to change the way my shoulder harness is mounted or used. It mounts to the bar behind the seat and drapes over the seat with no holes in the seat and no bracing to the seat 
I wish sometimes that I had made a hole in the upper cushion for the shoulder harness to feed thru but I didn't 
If yours is a stock seat in a car that does not require a racing seat then check with your local tech before cutting the seat up 
I wish sometimes that I had made a hole in the upper cushion for the shoulder harness to feed thru but I didn't If yours is a stock seat in a car that does not require a racing seat then check with your local tech before cutting the seat up
Posted By: Scamp408
Re: Stock seats with 5 point harness - 04/01/09 09:52 AM
The rule book states if you use a stk seat you do not need the seat attached to the bar . It also states that you donot need the crotch belt through the seat. My shoulder harness does not go throught the seat.BUT DOUBLE CK THE RULE BOOK.
Posted By: Quicktree
Re: Stock seats with 5 point harness - 04/01/09 10:45 AM
I wouldn't drive a car with the seat not attached to the bar. Monte posted a while back about how unsafe a stock seat in a race car is. get a race seat if you want to race.
Posted By: Cab_Burge
Re: Stock seats with 5 point harness - 04/01/09 03:14 PM
The stock seats that have the latch for the upper part of the seat are probally not as bad as those that don't, the key to my using the stock seat not attached to the bar is that I always tighten the shoulder harness and seat belt tight enough so I have a hard time moving forward in the harness before the burn out. IHTMS. Bill Bagshaw told me about one of his wrecks in his old Pro Stocker when the crotch strap hurt him more than anything else in the crash 
You don't want your body to move in a crash, especially forward or to the sides
You don't want your body to move in a crash, especially forward or to the sides
Posted By: cudarex
Re: Stock seats with 5 point harness - 04/01/09 03:32 PM
What I was told about the dangers of stock seats with no shoulder harness hole thru the back (harness looped around the top), is if you ever have a wreck where the forces cause a downward movement of your body because of the cushing of the bottom seat then that will cause slack in the harness around your shoulders and the shoulder harness could then slide off of your shoulders. And there are all kinds of forces on the body if the wreck is bad enough.
Posted By: cudarex
Re: Stock seats with 5 point harness - 04/01/09 03:38 PM
Here's a e-body done nicely.
Posted By: BradH
Re: Stock seats with 5 point harness - 04/01/09 03:44 PM
Quote:
I have stock high back seats in my Duster(10:40 ET), it has been through tech at a bunch of different tracks for Pro ET and I have never been bounced or informed that I had to change the way my shoulder harness is mounted or used. It mounts to the bar behind the seat and drapes over the seat with no holes in the seat and no bracing to the seat...
Same thing w/ my Challenger.
Posted By: dizuster
Re: Stock seats with 5 point harness - 04/01/09 06:32 PM
I've been a seat engineer/test engineer for more then 10 years. Here is my opinion.
First, the shoulder belts absolutely should come through the seat. Wrapping them around the sides is very unsafe, because as mentioned they could slip off your shoulders during a crash.
Second, the crotch strap is very important also. The reason it is there is to keep you from "submarining" as we call it. The lap belt needs to stay accross your hips. Some impacts can cause you to slide down under the lap belt. When that happens your internal organs take all of the load instead of your hip/pelvic bones. Not good. On modern seats we do a lot of testing to ensure that the occupant does not do this, but I wouldn't trust 40 year old technology to keep you from going under the lap belt.
Last. I feel that there is nothing wrong with using a factory seat in a race car. The seats are heavier then an aftermarket race seat, however the attachment is much more robust also. The lap/shoulder belts take the large majority of the load that the seat see's.
When there is a crash, the floor deforms quite a bit in an un-occupied seat. With the belts/driver in the car, the belts actually hold the seat in place. It never gets near the deformation of floor needed for seperation.
Anyway, just my
First, the shoulder belts absolutely should come through the seat. Wrapping them around the sides is very unsafe, because as mentioned they could slip off your shoulders during a crash.
Second, the crotch strap is very important also. The reason it is there is to keep you from "submarining" as we call it. The lap belt needs to stay accross your hips. Some impacts can cause you to slide down under the lap belt. When that happens your internal organs take all of the load instead of your hip/pelvic bones. Not good. On modern seats we do a lot of testing to ensure that the occupant does not do this, but I wouldn't trust 40 year old technology to keep you from going under the lap belt.
Last. I feel that there is nothing wrong with using a factory seat in a race car. The seats are heavier then an aftermarket race seat, however the attachment is much more robust also. The lap/shoulder belts take the large majority of the load that the seat see's.
When there is a crash, the floor deforms quite a bit in an un-occupied seat. With the belts/driver in the car, the belts actually hold the seat in place. It never gets near the deformation of floor needed for seperation.
Anyway, just my
Posted By: Cab_Burge
Re: Stock seats with 5 point harness - 04/01/09 07:41 PM
Quote:Bob Lambeck crashed his 1972 Pro Stock Duster at Orange County Raceway in CA. in 1972, the car met all of the tech requirements at that time. It had a four point harness in the car and a fibreglas "race"seat that was properly braced in the car, he slid out of the seat(submarined) and harness and was push up under the dash and trapped thier. He broke one of his hips as well as other dameges
I've been a seat engineer/test engineer for more then 10 years. Here is my opinion.
Second, the crotch strap is very important also. The reason it is there is to keep you from "submarining" as we call it. The lap belt needs to stay accross your hips. Some impacts can cause you to slide down under the lap belt. When that happens your internal organs take all of the load instead of your hip/pelvic bones. Not good.
, I thank that accident may have help make NHRA start requiring five point harnesses instead of the four point ones I owned and flew a small airpplane for several years, the aircraft industry is very active in making passneger seats in commercial aircraft very safe, not so in the private aircraft produced up to around 1991 when the goverment passed a liability law reforming how long the aircraft manufacturers are liable for parts the make and sell 
The new small airplanes sold now have 22 G impact rated seats for all passengers and pilots
Posted By: dart_73_br
Re: Stock seats with 5 point harness - 04/02/09 01:34 AM
Ok guys,
I was going to post a similar topic...
I want to know if could do something to put a 5 point or 4 point harness on my Dartīs stock bench style seat ?!?
Dangerous ?
I want to keep it as stock as possible... will run 11s.
Posted By: dizuster
Re: Stock seats with 5 point harness - 04/02/09 02:21 PM
Good info Cab.
Does your sons car have a cage? If not I would not put shoulder belts in because in a roll over it could pin him in an upright position when the roof crushes. Actually a stock shoulder belt would be better.
What year is the car? '73 and up should have a shoulder belt.
Does your sons car have a cage? If not I would not put shoulder belts in because in a roll over it could pin him in an upright position when the roof crushes. Actually a stock shoulder belt would be better.
What year is the car? '73 and up should have a shoulder belt.
Posted By: Gearbox
Re: Stock seats with 5 point harness - 04/02/09 04:52 PM
I'm also at the point of buying and installing a 5 point harness into a stock bench seat application. I was going to weld tabs to the crossbar, just behind my shoulders, as for the crotch strap have not figured that one out just yet, should I weld a plate to the stock floor with a Tab, then wrap the belt up the front of the bench seat? or have a hole cut in the upholestry. Any suggestions on the best belt to buy for a NSS type application. Thanks.
Posted By: an8sec70cuda
Re: Stock seats with 5 point harness - 04/02/09 07:13 PM
I have factory buckets, 5 point harnesses, and a 10 pt. cage in my '70 'cuda. I do NOT have the seats attached to the crossbar and the harnesses go around the back of the seat, not through it. My crotch belt does NOT go through the seat, it loops up in front of it.
I am big guy, 6'5" tall and 320 lbs, I have broad shoulders (ex college O-tackle), so the belts are less likely to slip off my shoulders. Is this safe? Probably not, but it has passed NHRA tech inspection at a couple tracks and has been cert'd to 8.50 like it sits. At the time I recovered the seats, I couldn't find an upholstery shop locally that would cut the seat for the belts to pass through them and I didn't trust myself to do it. Not saying it's the right way to do it, but it's what I did and it passed tech inspection. CHIP
I am big guy, 6'5" tall and 320 lbs, I have broad shoulders (ex college O-tackle), so the belts are less likely to slip off my shoulders. Is this safe? Probably not, but it has passed NHRA tech inspection at a couple tracks and has been cert'd to 8.50 like it sits. At the time I recovered the seats, I couldn't find an upholstery shop locally that would cut the seat for the belts to pass through them and I didn't trust myself to do it. Not saying it's the right way to do it, but it's what I did and it passed tech inspection.
CHIP
Posted By: cudabunch
Re: Stock seats with 5 point harness - 04/02/09 08:21 PM
Quote:
I have factory buckets, 5 point harnesses, and a 10 pt. cage in my '70 'cuda. I do NOT have the seats attached to the crossbar and the harnesses go around the back of the seat, not through it. My crotch belt does NOT go through the seat, it loops up in front of it.
I am big guy, 6'5" tall and 320 lbs, I have broad shoulders (ex college O-tackle), so the belts are less likely to slip off my shoulders. Is this safe? Probably not, but it has passed NHRA tech inspection at a couple tracks and has been cert'd to 8.50 like it sits. At the time I recovered the seats, I couldn't find an upholstery shop locally that would cut the seat for the belts to pass through them and I didn't trust myself to do it. Not saying it's the right way to do it, but it's what I did and it passed tech inspection.
If I was a tech and saw you crawl out of your car,I would pass it also
You look taller in a photo 
Posted By: Quicktree
Re: Stock seats with 5 point harness - 04/02/09 09:01 PM
Quote:
I have factory buckets, 5 point harnesses, and a 10 pt. cage in my '70 'cuda. I do NOT have the seats attached to the crossbar and the harnesses go around the back of the seat, not through it. My crotch belt does NOT go through the seat, it loops up in front of it.
I am big guy, 6'5" tall and 320 lbs, I have broad shoulders (ex college O-tackle), so the belts are less likely to slip off my shoulders. Is this safe? Probably not, but it has passed NHRA tech inspection at a couple tracks and has been cert'd to 8.50 like it sits. At the time I recovered the seats, I couldn't find an upholstery shop locally that would cut the seat for the belts to pass through them and I didn't trust myself to do it. Not saying it's the right way to do it, but it's what I did and it passed tech inspection.
passing tech doesn't mean it's safe. do you trust your life with it? I wouldn't.
Posted By: an8sec70cuda
Re: Stock seats with 5 point harness - 04/02/09 10:58 PM
Quote:Quote:
I have factory buckets, 5 point harnesses, and a 10 pt. cage in my '70 'cuda. I do NOT have the seats attached to the crossbar and the harnesses go around the back of the seat, not through it. My crotch belt does NOT go through the seat, it loops up in front of it.
I am big guy, 6'5" tall and 320 lbs, I have broad shoulders (ex college O-tackle), so the belts are less likely to slip off my shoulders. Is this safe? Probably not, but it has passed NHRA tech inspection at a couple tracks and has been cert'd to 8.50 like it sits. At the time I recovered the seats, I couldn't find an upholstery shop locally that would cut the seat for the belts to pass through them and I didn't trust myself to do it. Not saying it's the right way to do it, but it's what I did and it passed tech inspection.
passing tech doesn't mean it's safe. do you trust your life with it? I wouldn't.
Did I say it was safe? No. In fact I said it's probably not safe. Do I trust my life with it? No. I don't trust my life with anything I drive, even if I'm surrounded by airbags. You're still gonna die if the crash is bad enough. CHIP
Posted By: Quicktree
Re: Stock seats with 5 point harness - 04/02/09 11:05 PM
Quote:Quote:Quote:
I have factory buckets, 5 point harnesses, and a 10 pt. cage in my '70 'cuda. I do NOT have the seats attached to the crossbar and the harnesses go around the back of the seat, not through it. My crotch belt does NOT go through the seat, it loops up in front of it.
I am big guy, 6'5" tall and 320 lbs, I have broad shoulders (ex college O-tackle), so the belts are less likely to slip off my shoulders. Is this safe? Probably not, but it has passed NHRA tech inspection at a couple tracks and has been cert'd to 8.50 like it sits. At the time I recovered the seats, I couldn't find an upholstery shop locally that would cut the seat for the belts to pass through them and I didn't trust myself to do it. Not saying it's the right way to do it, but it's what I did and it passed tech inspection.
passing tech doesn't mean it's safe. do you trust your life with it? I wouldn't.
Did I say it was safe? No. In fact I said it's probably not safe. Do I trust my life with it? No. I don't trust my life with anything I drive, even if I'm surrounded by airbags. You're still gonna die if the crash is bad enough. CHIP
sorry Chip but if I didn't trust my life in it, I wouldn't drive it. 9seconds is way to fast to be taking any chances.
Posted By: dizuster
Re: Stock seats with 5 point harness - 04/04/09 03:36 PM
Quote:
I'm also at the point of buying and installing a 5 point harness into a stock bench seat application. I was going to weld tabs to the crossbar, just behind my shoulders, as for the crotch strap have not figured that one out just yet, should I weld a plate to the stock floor with a Tab, then wrap the belt up the front of the bench seat? or have a hole cut in the upholestry. Any suggestions on the best belt to buy for a NSS type application. Thanks.
Plate the floor is fine. But make sure that you cut a hole in the seat for the crotch strap. The point of it is to keep you upright in a crash. If it's too far forward, it will allow you to slip down and you could get hurt as mentioned above.
Quote:
Did I say it was safe? No. In fact I said it's probably not safe. Do I trust my life with it? No. I don't trust my life with anything I drive, even if I'm surrounded by airbags. You're still gonna die if the crash is bad enough. CHIP
You are right if the crash is severe enough, there is always a probability that you could die. The idea is to maximize your chance at life under all circumstances.
What about a less severe crash? What about the broken axle 90 degree turn low speed head on starting line crashes? Even if you hit the wall at 35mph you might see a 20g load. 320lbs x 20 g's is 6400lbs that the belts see.
Wider shoulders certainly helps, but coming aroudn the side, I doubt it's enough in a crash. I bet you could pull the belts off your shoulders with your hands.
Not trying to tell you how you have to live your life, just trying to open your eyes a little to something other then the "if the crash is bad enough you're gonna get hurt anyway" mentality.
Posted By: Quicktree
Re: Stock seats with 5 point harness - 04/04/09 03:39 PM
Quote:Quote:
I'm also at the point of buying and installing a 5 point harness into a stock bench seat application. I was going to weld tabs to the crossbar, just behind my shoulders, as for the crotch strap have not figured that one out just yet, should I weld a plate to the stock floor with a Tab, then wrap the belt up the front of the bench seat? or have a hole cut in the upholestry. Any suggestions on the best belt to buy for a NSS type application. Thanks.
Plate the floor is fine. But make sure that you cut a hole in the seat for the crotch strap. The point of it is to keep you upright in a crash. If it's too far forward, it will allow you to slip down and you could get hurt as mentioned above.Quote:
Did I say it was safe? No. In fact I said it's probably not safe. Do I trust my life with it? No. I don't trust my life with anything I drive, even if I'm surrounded by airbags. You're still gonna die if the crash is bad enough. CHIP
You are right if the crash is severe enough, there is always a probability that you could die. The idea is to maximize your chance at life under all circumstances.
What about a less severe crash? What about the broken axle 90 degree turn low speed head on starting line crashes? Even if you hit the wall at 35mph you might see a 20g load. 320lbs x 20 g's is 6400lbs that the belts see.
Wider shoulders certainly helps, but coming aroudn the side, I doubt it's enough in a crash. I bet you could pull the belts off your shoulders with your hands.
Not trying to tell you how you have to live your life, just trying to open your eyes a little to something other then the "if the crash is bad enough you're gonna get hurt anyway" mentality.
well said