Seating/Roll Bar Height Concern - Need Some Help

[Xusia]

OK. Wow. If bolt on is an option, that will make this much easier (and make me very happy!). My father-in-law is an awesome fabricator, so any roll bar addition would be completely custom [over] built.

[BC Huselton]

What I was envision was the "Mating Method" as you describe it here. There are bolt in roll bars throughout the SCCA that meet standards. This should be doable by a savvy structural designer...I am not. My motive was to surface it as an alternative to having to reconfigure so many other things to get our seating position below the S hoop. I will check with Maximum to see if they could configure something. Are there other competent designers to contact that might make this work?

"The main hoop shall be one continuous piece with smooth Mandrel bends with no evidence of crimping or wall failure." Does this mean it cannot be bolted to or effectively secured in some fashion to the lower hoop structure?


BC

[Santiago]

Maximum Motorsports is strictly Mustang focused. Couldn't hurt to ask, but I would bet they'll take a pass on such a project.

For any safety project that you need to pass a specific rule, you really should get in touch with the organization writing the rules. Someone there will be in charge of the series you want to run, and they are the definitive answers to what does or doesn't meet the requirements. For something like HPDE most of the race-series rules just don't apply.

Personally, seems like the big challenge for some sort of add-on raised bar is going to be getting it to fit within the available body openings. Looking forward to seeing what folks come up with.

Best,
-j

[Goldwing]

My father-in-law is an awesome fabricator, so any roll bar addition would be completely custom [over] built.

I guess you'll have to decide how much he likes you first, lol.

[Grintch]

So what about NOT racing - just HPDE? Is an add-on generally permissible?

The quoted rule WAS the HPDE rule. So no welded on or especially bolt on extensions. While track day rules get you out of a full cage, being 2" under the main hoop, and the broomstick test. They don't avoid the one piece main hoop requirement. The NASA TT safety requirements are the same as HPDE, but the SCCA ones are a bit stricter.

Basicly you need to modify the driving position so you fit under the main hoop, or you need to cut off and replace the stock roll bar with a taller one. Even for autocross, in the Modified classes, you need a proper, 1 piece main hoop. Although this probably wouldn't be enforced at many local events.

[Xusia]

I'll keep my eye open for "less safe" HPDE events (<-- joke here, people!), but for me that effectively means "bye, bye track!" I guess I'll have to settle for tracking my "much safer" sportbike...

[Grintch]

This is why I have been questioning the height of the roll hoops since the prototypes were built. Especially for a car that was supposed to be "wookie" compatible.

[Canadian818]

I really hope the broomstick rule isn't strongly enforced here. This pic is with no cushion/foam on the seat.



And the seat couldn't possibly be lower without cutting the bars.

[Santiago]

The quoted rule WAS the HPDE rule. So no welded on or especially bolt on extensions.

Basicly you need to modify the driving position so you fit under the main hoop, or you need to cut off and replace the stock roll bar with a taller one. Even for autocross, in the Modified classes, you need a proper, 1 piece main hoop. Although this probably wouldn't be enforced at many local events.

You need a proper 1-pc main hoop 2" over your head. That doesn't mean you MUST cut off the stock bar. You only need to do this if you cannot package an additional bar (basically another 4-point bolt-in bar) that meets the requirements. That is, if you can manage a different hoop that can be bolted into the car and removed for street duty, then you can leave the existing bar alone (and run a FFR soft-top, or whatever you're into on the street). What you cannot do (and I wasn't recommending) is that you try to bolt on an extension to the existing hoop. So if that's what Xusia meant by "add-on" then no, that won't fly. My point was simply that a bolt-in bar satisfies HPDE rules, not that a bolt-in appendage does.

The difficulty with what I suggested (also stated earlier) is that you need to be able to fit this additional bar around the existing body work. For many S-car owners, that's going to be a challenge as they may not want to modify their bodies, and I suspect they'll need to do so in order to allow another 4-point bar to bolt in. My thought was that another 4-point bar could be easily added just behind/outside the current bar - but you would need to clearance the area around the upper intake vents. A creative person could do this in a fashionable way - a quick and dirty way would be a carbon panel that matches the factory lines but easily unbolts for installing the bar. A harder way would be to recess a panel into the existing lines and paint to match the car.

I do agree, however, that preserving the body as-is means cutting the existing bar and welding in a new one that's high enough to pass tech. I also agree with Grintch that you'll likely pass tech anyway at many events - not that you should, just that you probably would.

For reference, how tall is Canadian818?

Best,
-j

[Canadian818]

6'2 in the morning

[gioguy21]

Hi guys, (extreme newbie here) i'm doing research before pulling the trigger and have been wondering about my height. i'm 6'3" 225. how hard is it going for me to fit in this thing?

[Xusia]

I'm not sure if you've read this entire thread, but the answer to your question depends on how you define "fit." It depends somewhat on where your height is (leg vs. torso), but if you are "average" I'd say you are likely to find a way to be physically able to drive the car, albeit the position probably won't be comfortable.

[Goldwing]

Try to get to factory five and sit in one of their cars or watch for their auto show circuit (I caught them at Carlisle, PA for the kit car show). At your height & weight, you're probably like me in that most sporty cars don't fit well, and I'm 3" shorter, just broad shouldered. There are mods that will help starting with a thinner fuel tank, moving to a thinner low profile seat, and finally some are looking at moving the pedals forward as well. The tank and seat are easy, but cost money. The pedal box will be more difficult, but inexpensive if you're good at fabricating. You'll laugh, but use "wookie" as a search term to find threads and posts on the topic.

[gioguy21]

lol @ "wookie"...thanks guys for the input

[Grintch]

You need a proper 1-pc main hoop 2" over your head. That doesn't mean you MUST cut off the stock bar. You only need to do this if you cannot package an additional bar (basically another 4-point bolt-in bar) that meets the requirements. That is, if you can manage a different hoop that can be bolted into the car and removed for street duty, then you can leave the existing bar alone (and run a FFR soft-top, or whatever you're into on the street). What you cannot do (and I wasn't recommending) is that you try to bolt on an extension to the existing hoop. So if that's what Xusia meant by "add-on" then no, that won't fly. My point was simply that a bolt-in bar satisfies HPDE rules, not that a bolt-in appendage does.

The difficulty with what I suggested (also stated earlier) is that you need to be able to fit this additional bar around the existing body work. For many S-car owners, that's going to be a challenge as they may not want to modify their bodies, and I suspect they'll need to do so in order to allow another 4-point bar to bolt in. My thought was that another 4-point bar could be easily added just behind/outside the current bar - but you would need to clearance the area around the upper intake vents. A creative person could do this in a fashionable way - a quick and dirty way would be a carbon panel that matches the factory lines but easily unbolts for installing the bar. A harder way would be to recess a panel into the existing lines and paint to match the car.

I do agree, however, that preserving the body as-is means cutting the existing bar and welding in a new one that's high enough to pass tech. I also agree with Grintch that you'll likely pass tech anyway at many events - not that you should, just that you probably would.

For reference, how tall is Canadian818?

Best,
-j

Is there room to bolt in a new roll bar without cutting off the old one? I can't think of a case where there was a good mounting point available with a non compliant "style bar" already in place.

[metalmaker12]

Hi guys, (extreme newbie here) i'm doing research before pulling the trigger and have been wondering about my height. i'm 6'3" 225. how hard is it going for me to fit in this thing?

I am 5'9 so no big help, but if you mount a thin seat to the floor ( kirkey style) and use the Boyd tank and push the firewall back to the tanks edge you will fit no prob. Tom (Wallace) is pretty tall ( like 6 something) and he fits

[AZPete]

Gioguy21, I'm 6'3" with 32" inseam, 235 lbs. and I fit, but I made a few adaptions. Installed the Boyd tank and moved the rear firewall back 3". I cut the bottoms of the OE seats to get them lower, which works for me but you could get even more space with Kirkey seats. Also, there's a very important improvement over the FRR roadster that is key. In a roadster there's no way I can get out while seated because the door hinges are by my knee. In the 818 the door hinges are much more forward, almost to my ankle, so I can get out with my butt in the seat. Why is that important? Because in the 818 I don't have to raise my body straight up to get my left leg out, as in the roadster, which means I can buy the 818 soft top, drive in any weather and have air conditioning. Foot room and head room are good but the length of the door is also very important for tall guys! Yes, you'll fit.

[mekohler]

I am 6'3" and I went with a fixed NRG seat, Boyd tank. I took the brackets on the seats and made the rear of the butt of the seat as low as possible, and tilted the front of the seat up a couple of holes. I now have several inches of clearance. I had to elongate the mounting holes to allow the recline angle I am using. I might of even flipped the brackets to get the rear lower.

[Santiago]

Is there room to bolt in a new roll bar without cutting off the old one? I can't think of a case where there was a good mounting point available with a non compliant "style bar" already in place.

I can't speak to other cars, since I wasn't looking over those candidates. However, for the 818S I do think one could fabricate a mounting base just to the side of the existing bar. The S-car's main hoop bars land right at the end of the frame, so if you were so inclined you could readily fabricate a flat base just past that (i.e. further out laterally) to which you could bolt in a bar (properly gusseted). Of course, this sends the bar through the plane of the horizontal section of the forward quarter panel. The down bars heading back would also land you afoul of the same area (only further back), so you'd end up having to come up with a removable body panel that might look something like the carbon fiber one that the early Blue R-car had in that area.

Definitely not an option to everyone's liking, but do-able.

Best,
-j

[Goldwing]

Well, I finally relented and accepted that the stock seat won't work for me. The cockpit is too small. I'm experimenting with Procar sportsman Pro 1615. I'm using the Boyd tank, and I'll modify the firewall to help. For the firewall, my plan is to bend the lower portion of the upper piece further about 12*, then cut the "shelf" in half and overlap the pieces to thin the shelf. At this point, either my legs are happy or the recline is about right. Still not enough room for both, but it'll have to do unless I get ambitious enough to follow others with a pedal box mod. I'm trying to decide between mounting the slider level or at an incline. I need to use a spacer under the front of the seat to tilt the seat bottom, if I put the spacer under the track, I can lower the rear portion of the track, just a bit more. Has anyone had experience with the NRG seats and Procar's to compare them and offer an opinion? I'm lucky to have a Summit Racing close by to play with the Procar. Here's the Procar just thrown on the floor for reference:

image.jpg

I sit just barely below the roll bar. I didn't look at adjusting the cushioning yet, as I'd like to keep this seat returnable.
Here's a pic of the planned firewall profile:

image.jpg

Opinions? Foreseeable problems? Thoughts?

EDIT: Oh, for reference, I'm just shy of 6' with a 32" inseam.

[wleehendrick]

I'm about the same size as you and went with NRG seats mounted on the floor. I was able to use the sidemounts to give a good recline and fit similar to your first photo, if not a touch lower; the harness holes are right at the level of the square tube. BTW, I bent the upper piece of the rear firewall an additional 16deg in a press-break, IIRC. I also found that the steering wheel was too high, so I used some slightly longer SS spacers to drop it a bit more. I'm using a 320mm wheel, BTW, so knee clearance isn't a problem.

[flynntuna]

I'm curious, what is the measurement from the pedals to the front of the seat, from the pedals to the seat back and from the steering wheel to the seat back? At just under 6' myself, it doesn't seem that anyone over 5'6" will fit with the WRX seats and fuel tank.

[RM1SepEx]

I'm curious, what is the measurement from the pedals to the front of the seat, from the pedals to the seat back and from the steering wheel to the seat back? At just under 6' myself, it doesn't seem that anyone over 5'6" will fit with the WRX seats and fuel tank.

5'8" fits... but no bigger with stock seats. And I did lower the FFR brackets, they were waaaay higher than they needed to be.

[TahoeTim]

I'm late to the party but what was FFR thinking? I get the Cobra needing to look correct but why didn't they stretch the 818 a couple inches and/or raise the rollbar an inch? I never built a GTM for the same reason.

I don't get it.

[Xusia]

We are ALL asking that question...

I'm hopeful this will be addressed in a future update. Or perhaps a version that's 3" longer: 2" in the cockpit, and 1" in the engine bay (for the EZ engines). 818L?

[Goldwing]

I'm curious, what is the measurement from the pedals to the front of the seat, from the pedals to the seat back and from the steering wheel to the seat back? At just under 6' myself, it doesn't seem that anyone over 5'6" will fit with the WRX seats and fuel tank.

Brake pedal to seat front (in modified position): 19-1/2"
Brake pedal to rear seat cushion ("): 39-1/2"
Top of steering wheel to seat back: 29"

On the last measurement, I have a pretty good fit here. With my arms straight, I have a good hold of the steering wheel, it's a good fit in this position, one where I likely won't shorten the steering wheel. This Procar seat has a pretty deep lower cushion, so take the first measurement with a grain of salt. Without modifying the firewall or tank, those numbers would be 3" smaller. I have a nice clutch pedal feel in this seat position, but I may move the gas pedal a bit forward for long drive comfort.
Taking a few measurements, the uncompressed Procar seat is giving an extra 2" rearward at the bottom, and 3" at shoulder level. It's less drastic sitting in it due to the factory seat being very compliant while the Procar seat is much firmer. Still noticeable, just not 3" drastic, the seat height going to the aftermarket seat is much better IMO. I'm going to check the height on the NRG seatback, my head is close to the rollbar, while the crown of my head sits even with the top of the seatback. The factory seat gives my head and neck pretty good protection from the roll bar and from whiplash.

[Goldwing]

Wleehendrick, can you measure the seatback from the bottom cushion to the top of the seatback on your NRG? The Procar is 31-1/2", I could use a bit more height ideally. On the firewall. I had planned on doing just as you did, but wanted to be sure the seat didn't get blocked by the shelf, so I'm grabbing an extra inch. I'm hoping stuff on the other side of the firewall is flexible on mounting position, lol. The steering wheel is factory, but has the height adjusters, so I have the movement I need. It would be nice if it truly tilted though.

[flynntuna]

Brake pedal to seat front (in modified position): 19-1/2"
Brake pedal to rear seat cushion ("): 39-1/2"
Top of steering wheel to seat back: 29"

On the last measurement, I have a pretty good fit here. With my arms straight, I have a good hold of the steering wheel, it's a good fit in this position, one where I likely won't shorten the steering wheel. This Procar seat has a pretty deep lower cushion, so take the first measurement with a grain of salt. Without modifying the firewall or tank, those numbers would be 3" smaller. I have a nice clutch pedal feel in this seat position, but I may move the gas pedal a bit forward for long drive comfort.
Taking a few measurements, the uncompressed Procar seat is giving an extra 2" rearward at the bottom, and 3" at shoulder level. It's less drastic sitting in it due to the factory seat being very compliant while the Procar seat is much firmer. Still noticeable, just not 3" drastic, the seat height going to the aftermarket seat is much better IMO. I'm going to check the height on the NRG seatback, my head is close to the rollbar, while the crown of my head sits even with the top of the seatback. The factory seat gives my head and neck pretty good protection from the roll bar and from whiplash.

Thanks for taking the time to measure, those measurements are nearly identical to what I've got my DD adjusted at. The only difference is the brake pedal to seat back, where it's at 41.5". Looks like most people will be making the firewall mod.

[philly15]

Just out of curiosity, what seats have people had the best luck with? I've held off ordering to see what works best. I myself am contemplating the corbeau fx1 pro, but wanted to get some last second opinions first. Pretty much anything should work for me I'm only 5'9" 180.

[wleehendrick]

Mine are NRG FRP-300. I was leaning towards those Corbeaus, until I got a great deal on NRG seats from Erik. I would think they would fit similarly; pretty much any fixed back bucket with sidemounts that let you drop the butt down just above the floor, and tilt it backs seems to work well. For those around 6', moving the firewall back is also necessary for leg room, but you may not need to depending on if your height is in your legs vs torso.

[Xusia]

I'm still working on my stock 2003 WRX seats, and I've made some progress. I've mostly solved the legroom problem, and have a plan to address the height problem.

I've completely disassembled the seat (not as difficult as it seems!), and believe there is actually room to get the seating position much lower. As always, I will post pics - and probably a video - when I get it worked out.

[CU9DZ]

Yes I would vote for the 818L also. I have two sons who are 6'3" so need the car to fit tall people. I am 6' even. Have been reading all your comments about moving the seat back.

[Xusia]

Also posted in my build thread; making progress on the seats: https://plus.google.com/107272488473...ts/d4jbg8vNPSz

[Xusia]

Wow. I really expected more folks to be excited by this.

[AZPete]

Xusia, I appreciate what you've done. I also tried to make the WRX seats work so I cut lots of metal off the seat bottom, modified the FFR mounts and removed some foam. I got the drivers seat low enough that even with the head rest raised it's below the roll bar. I bolted directly to the frame and also put in a Boyd tank. But, a lot of guys want the seats to be adjustable or just want to buy aftermarket seats. The main reason I wanted to make the WRX seats work is that I can buy nice leather upholstery made for these seats. Maybe with your video (and cute daughter!) other guys will make the Subaru seats work. This photo was before I did the passenger seat. Quite a difference, eh?
DSCN3066.JPG

[ehansen007]

I would say that if you're over 6-0 , you're going to have to have to get kirkeys or glass seats (where you're sitting no more than an inch off the floor) in order to get your head below the roll bar with a helmet on. Broomstick will be tough. There's a reason why the roll bar on the challenge car looks like a swing set; because it works!!!

challenge-2.jpg

[FFRSpec72]

I would say that if you're over 6-0 , you're going to have to have to get kirkeys or glass seats (where you're sitting no more than an inch off the floor) in order to get your head below the roll bar with a helmet on. Broomstick will be tough. There's a reason why the roll bar on the challenge car looks like a swing set; because it works!!!

challenge-2.jpg

What bugs me is about 80 percent of the sedans would not pass test as peoples heads are right up against the roof but the roadsters get the scrutiny

[Santiago]

Xusia, I just got a chance to check out the video - very cool mods to the OEM seat! I think this will be a major help to folks. The fact that an ultra-cute daughter is cheering you along only makes it better. =)

Best,
-j

[FFRSpec72]

I have been playing around with the rear firewall for a fuel cell design and here are the measurements and angles that I came up with, these should also work with the Boyd tank (not sure of the slant on the Boyd tank though). This should work well with a 10 degree layback on the seat (as you can gain 4" over a 20 degree layback).

FuelCell Layout1 (1).jpg

[AZPete]

Wow. I really expected more folks to be excited by this.

Xusia, many guys are like me and take only a brief note of suggestions, or ignore them entirely, if they are not ready for that part of the build. I'll bet you've done that, too. Later, however, I go back and read it carefully when I'm into that part and understand what's happening. You'll find some guys months from now pasting in a link to your video to help somebody asking about making the OE seats work. It's all just a big ocean of info that we dip into when needed. Keep posting your innovations, please.