newbie needs help with seat install

[clinkster]

hey all you pros, got a question for ya. I am installing some new bucket seats in my 70 nova and am having hard time deciding how to install them properly and safely. my problem is the car didn't come with buckets seats from factory so I only have two mounts per side on outside. my planted seat brackets are meant to be bolted in place of stock buckets, im missing the inside brackets. I know I could go buy stock brackets and weld them in, I guess, but.......so my question is this: if I make my own brackets what is the safest and best way to mount, welding in brackets to floor pan? if so what thickness do you use for brackets? drilling holes in floorboard with plates underneath? I don't know, what do you guys do? I want to be safe and secure as this will be an autocross car. :thankyou:

[Sieg]

The floor pan is only 18-19 gauge metal so welding thicker plate to that does gain anything. A thicker plate on the underside should spread the load and increase strength. Do you have pictures of the pan/seat area?

Here's the driver side of a '69 Camaro which has a U-channel welded into the saddle from rocker to tunnel. Seat mounts bolt in to nut plates welded on the underside of the top of the channel.

http://photos.smugmug.com/photos/i-BMCMhMg/0/XL/i-BMCMhMg-XL.jpg

AMD may have channels for the Nova???

[clinkster]

thanks for the reply and advice. mine is similar to your Camaro but I will try to get pics loaded. I have an idea on how to proceed. seems as though the seat belt anchors are way more critical. thx again I will try to get some pics of my battle.:thankyou:

[Sieg]

seems as though the seat belt anchors are way more critical.
Think of the seat back as a big lever. Serious force can be generated. If a seat mount fails belts are pretty much worthless. :thumbsup:

[DRJDVM's '69]

In a head on collision... Or near head on... There is no force on the seat... Your body isn't attached to the seat. The forward movement of the car stops and so does the seat... Your body keeps wanting to go forward and the belt takes that force

In a rear end collision your body is going to put force on the seat back and drive the back mount into the floor and try and pull the front mount up ... At that second the belts aren't doing anything... A split second later they are just keeping you from flying forward and out of the seat

Bottomline is that you don't want anything weak when some massive force may be applied to it

[DRJDVM's '69]

I would have a decent wide base to the bracket inside the car and a plate on the underside where the mounting bolt passes through... That will spread the load out over the relatively thin sheetmetal of the floor. Personally I wouldn't have the seat bolted to a bracket that is welded on the inside of the car unless it was put there by the factory

[Sieg]

In a head on collision... Or near head on... There is no force on the seat... Your body isn't attached to the seat. The forward movement of the car stops and so does the seat... Your body keeps wanting to go forward and the belt takes that force

In a rear end collision your body is going to put force on the seat back and drive the back mount into the floor and try and pull the front mount up ... At that second the belts aren't doing anything... A split second later they are just keeping you from flying forward and out of the seat

Bottomline is that you don't want anything weak when some massive force may be applied to it
Losing it out of a corner and backing it into a vertical obstruction is my primary concern.

[clinkster]

wow, you guys make very valid points....I will make sure I have sufficient brackets on the underside of the mounting points. now the question is what is sufficient? will a two inch diameter by 3/16" thick work? again guys thanks for keeping me safe.:thumbsup:

[Sieg]

wow, you guys make very valid points....I will make sure I have sufficient brackets on the underside of the mounting points. now the question is what is sufficient? will a two inch diameter by 3/16" thick work? again guys thanks for keeping me safe.:thumbsup:

thx again I will try to get some pics of my battle.

Are you sure there isn't factory mount positions?

You could call Wedge and ask them: http://wedgebrackets.com/chevrolet-nova-68-74-seat-brackets.html

[BBC71Nova]

I've been dealing with this same issue with my Nova as well. To make matters worse, my floor pans were replaced and the new pans didn't have even the bench seat mounts.

I've been working on it off and on for months. I don't want to have exposed/visible fasteners under the car. I've build some brackets that position the attachment point to the floor pan where the floor braces are. That way the fasteners will be hidden in those channels.

I still haven't come to agreement on how to attach the brackets to the floor pan. I took some weld nuts and welded them to slightly larger squares of sheetmetal. I was considering welding those to the floor pans from the top. The larger size spreads the load a little but I'm not a huge fan since ultimately the perimeter weld would be all that is holding them in.

I've been contemplating posting this same topic for weeks so this is very timely. I'll try and get some pics maybe this weekend.

[clinkster]

OK guys so I finally got some pics of my seat issue. I finally decided to modify the seat brackets to sit flat on floor boards. I will use the two outer existing holes with longer bolts and follow up with thick washers underneath with an additional nylon nut. On the inside I will drill hole through floorboards and follow with same thick washer and nylon lock nuts as well. I will use all grade 8 hardware as well. if you guys see anything further needed please let me know. thanks

[RECOVERY ROOM]

your on the right path, Make sure your welds are GOOD !!