Floor brace on 1st gen

B

benracin

New member
I'm in the process of fitting my seat to the car and I'm finding that the perfect place for the seat puts it right over the cross member that runs from driver side to the trans tunnel. I have to put the rear of the seat on the floor to keep my head off the roof. Due to that cross member ending up in the middle of the seat, this puts the front of the seat about 2 inches up in the air. It's a comfortable position but I don't like the idea of running a bolt from the seat through the air 2 inches and then through the bottom of the car.

Could I cut out that cross member? This would allow me to put the seat right on the floor of the car and make the whole mounting process MUCH easier and probably safer. But is this cross member an integral part of the car? Could I cut it out and fab a new lower cross member out of flat iron to replace it? Do I need to replace it? Am I insane?
 
If you like the position, (I do....), I would get some good stock, and weld some bracketry OVER the crossmember. (I'm presuming you are nervous about crushing the crossmember) Then bolt thru the new bracket. Remember to reinforce the floor area generously to displace the loads.

If I had the choice I would leave as much material as possible.

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Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]
 
Thanks Jake. My concern isn't so much that I would crush it, just that with out it there, mouting the seat would be a piece of cake. So it sounds like you think that member is an important part of the cars structure and should stay there.

Part of me was thinking that the member is only there to mount the original seat to and that was it's only purpose, meaning I could take it out.

Thoughts?
 
Originally posted by Benracin:"Could I cut out that cross member? This would allow me to put the seat right on the floor of the car and make the whole mounting process MUCH easier and probably safer. But is this cross member an integral part of the car? Could I cut it out and fab a new lower crossmember out of flat iron to replace it? Do I need to replace it?"

Benracin,
I have the same problem. The previous method I used included this crossmember. The front part of the seat brackets were bolted through it. Although I was below the rear hoop, I am not happy with where my helmet is in relation to the side bars and front hoop. When I sit in the car with the seat removed, I am low enough but, that cross member will most likely be in the way. I also want to cut it out but I have reservations since the RX7 is of unibody construction.(When I installed a fuel cell, I even was concerned about cutting out the spare tire well)
My thoughts were to replace the cross member with two one-inch box steel pieces, one welded in front of the seat and another behind. Place the seat on the floor and use the box steel as a place to bolt the steel pieces that are bolted to the sides of the seat. I am also considering welding plate steel under the car to strengthen this section.
I also would welcome any thoughts or opinions on the removal of this crossmember and mounting the seat.

Originally posted by Benracin:"Am I insane?"
Most likely- insanity helps to make this sport enjoyable. I have had friends and acquaintances ask me "how can you race" after hearing about all the work and effort it takes to put a car on the track. My reply is generally "how can you not race".

Bill Emery
Glen Region
ITA#23
 
I like your idea Bill with the box steel in front and in back. I got my seat with the brackets already so I would just need to run some bolts straight down. With your idea, I might then run two pieces of flat iron from front bracket to the rear for my seat brackets to sit on making a nice flat surface. Is the bottom of your car kind of arched up in the middle?

I think welding some reinforcement under the car is a really good idea. When I first put the seat in I just had large grade 8 washers under the car and after yanking the seat back and forth and watching the car floor flex I re-thought the idea. I'll probably run a thick sheet down each side of the seat leaving the center clear so I can still get to the brake lines.

Ben Harding
 
Oh, and I usually get the question "are you insane" after telling my non-racing buddies about sitting in the car for hours trying to get the seat in JUST that right spot each night with my helmet on. (I leave out the part about making car noises and shifting gears.)
 
Don't forget about the sub strap attachment!

(And I'm assuming that you have the cage in there already...makes a BIG difference!)

------------------
Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]
 
Orginally posted by Benracin:"Is the bottom of
your car kind of arched up in the middle?"

Ben,
I took a look at the floor last night while grilling dinner. I not quite sure what you mean by arched up in the middle. I have several rectangular plateaus in the floor that make the surface uneven. It seems to me that this cross member could be removed although I would like to hear from anyone who would not recommend it. I cannot not get under this section of the car right now since it is in its winterized state. (dry rotted tires and antifreeze) Jake makes a good point regarding reinforcing the area where the sub strap attaches. Also, how are you connecting the seat to the cage? I/O Port Racing Supplies markets an ajustable system that works well.

Bill Emery
Glen Region
ITA#23
 
Hey love the idea. But I`m not sure but please tell me I`m wrong cause i would like to fix my head trama 2 I`m 6`2 and I know Jake is like 6`9 or Something. But Is it a NO NO to strenghten the frame. Please let me Know/
Scott Haven
99 ITA Rx7 NER
 
Scott you raise a good point. I'm unable to find the part about the frame in GCR in my quick scan, but I'll try to tell you what I've decided to do. So far I have cut out that cross member, it came out fairly easy actually. Tonight I welded some 2" wide flat iron, about 3" long on two sides infront of where I'll mount the seat, and the two sides behind the seat. I'll then run 2 pieces of square stock from side to side, one in front, one in back. A keep wondering if this is actually necessary, but if that cross member actually did something this would take care of that.

Part 3 of my plan is then to run some flat iron from the rear "new" cross member to the front one on each side of the seat for my seat brackets to sit on. My seat already has brackets attached. They curve under the seat and then are able to bolt to the floor. So I've basically created a square that not only gives the seat a nice flat strong surface, but hopefully made the floor a little stronger. Maybe it would help if I was hit towards the bottom of the door???

Then the final part of the plan would be to put in some reinforcement under the car to run the bolts through and create a really strong seat mount.

Does this classify as strenghtening the frame? Am I going over the top? It sure has been a lot of work. I'm getting better at welding though!
 
OK, first of all, I'm only 6'3" on a good day!

Secondly, page 18 of the ITCS (you do have a 2003 GCR, don't you??
wink.gif
), discusses this point. It sounds as though you are good to go. The point about "no other function" is a gray one, and when it comes to safety, you will have to be pretty overboard to raise a red flag. Who will protest your seat mount because it is strengtening your floor??

As I remember, my sub strap ended up right between the fuel and brake lines. I gingerly eased them to the sides to do my installation, then eased them back. Your strap kit should include reinforcements that the manufacturer deems appropriate. Always a good idea to add a larger plate between the floor and the hardware in addition to what the supplier provided.

When in doubt, read the good book, and check the manufacturers instructions, esp when it concerns straps! (The final story on Dale Earnharts death was inproperly installed straps, and everyone knew it.....)

------------------
Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]
 
It one respect this thread is somewhat comical with a bunch of tall guys trying to fit in the first gen. RX7. I am also about 6'3".

Ben,
It always amazes me the amount of time fabrication takes. How did you remove this cross piece? A closer examination of the one on the passenger side looks like it is spot welded into place which means it should come out with little difficulty and maintain the integrity of the floor. I also do not see a competition advantage to your reinforcements.

Originally posted by benracin:" Maybe it would help if I was hit towards the bottom of the door???"
You are right in regard to this point. When I was turned sideways and T-boned, the damage was sustanined to the lower third of the door.

Originally posted by lateapex911:"As I remember, my sub strap ended up right between the fuel and brake lines."
Jake, is this because of where you located a brake propotioning control? Also what type of seat do you use and how did you mount it?

Bill Emery
Glen Region
ITA#23
 
I think what is even funnier is that I'm 5' 5"... how am I having such a hard time with my helmet hitting the top? Probably because I need to sit up straight in order to see over the wheel. Feel free to use any phone book jokes you can think of.
smile.gif
 
I used a grinder to cut out most of it, the rest is held in by spot welds and using the claw part of a hammer along with beating the crap out of it with the other side it comes out pretty easy. Some of the welds broke, some put a tiny hole in the bottom of the car. It looks good now that it's out though. I think it's going to come together pretty slick.
 
The pics are in! I'd be interested to know what everyone thinks. Sure the welding is a little elementary, but what about the over all idea. It does look pretty cool in person and not having that brace in the middle of the floor as made putting the seat in and placing it much easier.

Thanks for the help.

[This message has been edited by benracin (edited March 25, 2003).]
 
Looking awesome Ben! Looks like We are going to get alot more done this weekend now that You got that seat mounted!
smile.gif



This weekend will be a blast! Up all weekend working on the car, You ready for that?
 
You're right Ben, that floor looks strange to me. Have you looked under the car in that area for scuffs or other tell-tale signs? I don't think that is the normal floor profile, but I wouldn't jump off a tall building because of it! Just make sure it's sound and the lines that run under there are sound.

Bill- I use a Momo Rookie, and I will have to check out the mounting....it's been awhile! My memory is also sketchy on the whole substrap mountig thing...I do not have a proportioning valve installed as yet. I will check things out soon and report back asap!

------------------
Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]
 
Ben, what is your plan so that the lap belts do not travel over or near the black rear seat support brackets & that you also have the belts at the correct angle with reference to the seat & your body ?

David
 
I was using the cars mouting points for the lap belts which are a bit further back then the supports I put in. Those supports are near touching the floor so they are actually quite far away from the path of the lap belts. I don't think there will be any problem.

And to jakes comment, does the floor look strange? It really bows up in the middle running the length of the seating area. I've always thought it was just how things were but it's seemed odd to me. I've smacked it with a hammer a couple times and it doesn't move easily. Is your more flat?
 
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