HPDE Seat Height Issues
2 Attachment(s)
I'm sure this has been handled many many times, however the only solutions I can see require cutting seat mounts or custom brackets.
I want to try a HPDE, however I am unsure about the broomstick test. Normal driving position yields I am above the roll bar, with the seat slid super far forward and the back leaned as far as I can, I barely fit under. When I swap in a Corbeau Forza Seat I gain maybe 1/4" more headroom. This still has me barely a half inch below the top of the roll bar. Obviously more room is safer, but the SCCA time trial rules state "The top of the roll bar must be above the top of the driver’s helmet when the driver is in normal driving position." My question is... am I in the clear with a half inch of clearance? I have already done a foamectomy, my race seat doesn't gain much more room, I would really like to avoid any permanent changes to the car as I don't know if I will every do this type of racing again. The pictures show normal seating position as well as seat slid forward as far as possible. I am only 5'10" which makes me wonder if something is amiss? Normally these threads deal with people who are over 6' tall. If there is a specific thread that has other ideas besides cutting seat mounts or custom brackets let me know, I would hate to buy a $1000 hardtop or a $400 new seat just to try out a single track event. Thanks. [IMG]http://i62.tinypic.com/xbxxl5.jpg[/IMG] [IMG]https://www.miataturbo.net/attachmen...ine=1429628409[/IMG] |
What kind of rollbar is that?
|
2 Attachment(s)
I am not positive.... I bought it with the car. Here are some pics for reference.
[IMG]https://www.miataturbo.net/attachmen...ine=1429630535[/IMG] https://www.miataturbo.net/attachmen...ine=1429630535 |
How much clearance is there between the bar and the soft top? If there's extra space there then swapping roll bars is probably the best solution.
If it's as tall as can be done, then you need to lower the seat. If you've done a foamectomy and tried race seats, then the next step is to cut out the rear seat mounts, omit the sliders and bolt the seat to the floor. It sucks from the perspective of driver compatibility, but you'll gain a TON of room. I went from 1.5 inches above the roll bar (sitting on my stock seats) to 2 inches below by doing this. --Ian |
I was really hoping to avoid cutting mounts. Once you bolt the seat to the floor don't you lose the durability of the mounts? Aka, crash and your seat rips out of the floor. I assume I would need something to help support the load.
I will check clearance to soft top. Any input on SCCA regulations with the roll bar height? |
Originally Posted by Swanpuppy
(Post 1225256)
I was really hoping to avoid cutting mounts. Once you bolt the seat to the floor don't you lose the durability of the mounts? Aka, crash and your seat rips out of the floor. I assume I would need something to help support the load.
I will check clearance to soft top. Any input on SCCA regulations with the roll bar height? --Ian |
Originally Posted by codrus
(Post 1225249)
... cut out the rear seat mounts, omit the sliders and bolt the seat to the floor. It sucks from the perspective of driver compatibility, but you'll gain a TON of room. I went from 1.5 inches above the roll bar (sitting on my stock seats) to 2 inches below by doing this.
--Ian Yes, you'll need to sandwich the seat mount around the floor pan and create a hard-point to retain anything resembling safety. Of course, not a single vendor makes anything resembling plug-n-play mounts, which makes sense given how rare these cars are. =P I took AWR mounts and cut them up because they don't mount anything but a Sparco Sprint low enough. Don't even bother with the Kaze mounts, they mount everything higher than stock because they're forgot to engineer them after they made them look pretty. |
more foamectomy. I have NB seats so it may be different, but I did a foamectomy, it wasn't enough, did more, seat actually got more comfortable and I got low enough Total drop from start to finish was about 1.5".
|
I am a little confused. You seem to be clearly passing the broomstick test there which means you're in the clear for HPDEs and unless you think you're going to roll the car your first time out on the track with street tires then you should be just fine. If you want to be lower than that it will likely involve permanent modifications to the car that you can commit to if you feel that tracking the car will become a much more common occurrence.
|
Originally Posted by Ryan_G
(Post 1225320)
I am a little confused. You seem to be clearly passing the broomstick test there which means you're in the clear for HPDEs and unless you think you're going to roll the car your first time out on the track with street tires then you should be just fine. If you want to be lower than that it will likely involve permanent modifications to the car that you can commit to if you feel that tracking the car will become a much more common occurrence.
2nd picture he does pass, seat all the way forward, uncomfortable, not livable for the track. |
Originally Posted by humming
(Post 1225324)
First picture he doesn't pass, his preferred seating position.
2nd picture he does pass, seat all the way forward, uncomfortable, not livable for the track. So to answer the question he asked, Yes. A quarter inch of clearance is within the rule set and you should be fine for the event. If you find yourself wanting to track more often and are uncomfortable with that amount of clearance as you get faster then you can change the seat or make permanent modifications to the floor pan to sit lower in the car. |
1 Attachment(s)
Originally Posted by Ryephile
(Post 1225309)
This, the rear mounts and sliders obviously have to go, however I wouldn't go as far to say "a ton" of room is gained. It very much depends on what exact seat you have.
https://www.miataturbo.net/attachmen...ine=1429658343 --Ian |
Originally Posted by Ryan_G
(Post 1225333)
He mentioned that if he swaps in a Corbeau Forza (fixed back seat) he still sits 1/4" below the roll bar. I assumed this seat would be used for the track anyway.
|
Originally Posted by codrus
(Post 1225352)
Fair enough. I have Recaro Pole Positions, and I dropped my seating position by about 4 inches from stock doing this.
.. --Ian I'd love to be another 1/2" lower than what I ended up with; perhaps Recaro's are a better "low" buy than 1-piece Sparco's. |
1 Attachment(s)
I tried this and got me a low as I could without cutting things up. I need to tilt it back a bit more though.ProCar Innovations Race Spec Seat Mount Version 2 | KazeSpec Engineering
Got me this far. https://www.miataturbo.net/attachmen...ine=1429673012 |
Originally Posted by Ryephile
(Post 1225362)
Good data point, thanks for sharing. Are your race-shop fabbed mounts in your build thread?
I'd love to be another 1/2" lower than what I ended up with; perhaps Recaro's are a better "low" buy than 1-piece Sparco's. I dunno if it's true of Recaros in general, or just of the specific Pole Position model. There was some kind of problem discovered with the PPs last year, and the FIA certification was pulled. I dunno why -- I've heard from a couple people that it's really a big deal over nothing, but you can't buy them right now. My certs were expired anyway (5 years for FIA), so it doesn't really matter to me. Supposedly Recaro is working on fixing whatever the issue is and new Pole Positions are expected in a month or two. --Ian |
Im not sure which version Kazespec mount Ryephile had but my Kazespec V2 seat mount with my Recaro replica(yes flame on) seat sits me with a good amount of clearance for the "broomstick test". Im 5'10" with a good amount of torso length. Your roll bar looks to be of a decent height so i would look into the mounts that your bucket seat is mounted too. If you have the coin, go with a custom mount if you really do like sitting in that Corbeau Forza seat.
|
Originally Posted by Ryan_G
(Post 1225320)
I am a little confused. You seem to be clearly passing the broomstick test there which means you're in the clear for HPDEs and unless you think you're going to roll the car your first time out on the track with street tires then you should be just fine. If you want to be lower than that it will likely involve permanent modifications to the car that you can commit to if you feel that tracking the car will become a much more common occurrence.
I should then be just fine with the Forza seat and my 1/4-1/2" clearance. Time to sign up for HPDE :vash2: |
While on this topic..... One other question, padding the roll bar. Must it be covered with an official brand or style of padding? Or are people able to slap something together to get through an event?
|
While I would highly suggest SFI padding I have seen multiple people at Sebring with absolutely no padding. You should really talk to people who attend your local events as each region is run slightly different.
|
My permanent modifications to the car are all under the carpet the way I did things.
Sprint seats and custom brackets, no sliders. The front mounting points connect to the OE point. The rear OE points were shaved and re-welded to allow for the custom bracket to sit lower. The rear bolting points for the custom bracket sits further back than OE and have a backing plate and bolt welded to the floor of the car. Then, when bolting in the race seat, you bolt from the bottom, using another backing plate that is not permanent. When not in use the holes are filled with a simple rubber plug. The OE seats bolt in as usual. The mounts for the harness are of similar design. I can bolt in and out the racing seats and harness attachments and belts for the OE seats in about 30min for both sides. Sliders would be ideal, but with the OE front hump on the NB and being 5'10" with a helmet I can't pass a height test using the blackbird bar...b/c that bar works with both the hard and soft top. Also, I got a roll bar cover from harddog with no slitting and made the cuts myself to work with my bar along with the padding. It was a lot of custom fab work I paid a local rally shop to do, but the end result is such an easy seat swap there is nothing to complain about. And, you can't tell any of it is there with the OE seats in place. |
Originally Posted by Swanpuppy
(Post 1225432)
While on this topic..... One other question, padding the roll bar. Must it be covered with an official brand or style of padding? Or are people able to slap something together to get through an event?
Our local club requires SFI padding anywhere where your body may hit the roll cages. Two of NASA mid atlantic tech guys suggested that SFI padding is still better than pool noodle padding for your hands, knees, etc. (ie non-helmet body parts that could hit a roll cage). I haven't been able to research this, but SFI padding does give with a big enough impact...so maybe. We put SFI around most places, then pool noodle around the nascar bars, but we are discussing changing that before our Sept. race. |
2 Attachment(s)
good ideas and products to think about.
https://www.miataturbo.net/attachmen...ine=1430415344 foamectomys are good way to get lower but a aluminum seat is the best way to get lower. at 250 a seat these are inexpensive. make sure you brace it. https://www.miataturbo.net/attachmen...ine=1430415344 for roll bar padding on a street/race car the bsci padding is the way to go. it's dual foam density makes it a less of a headace if you knock it while entering or exiting the vehicle. i made a thread that covers it. FYI one stick was enough to cover the important parts of the roll bar. https://www.miataturbo.net/race-prep...-racing-79356/ |
Thanks for the padding info, ill look into that and pick some up. Signed up for the Milwaukee Mile Track Night in America. Should be a good time.
|
According to SCCA for a HPDE with a hardtop there is no broomstick test, in fact, they don't even require a rollbar. I'm not saying I agree with their position but it is the way it is.
Mounting a race seat to a Track Dog mount and swapping for track days is a good idea. Then swap your stock seat back in for street driving. |
All times are GMT -4. The time now is 06:00 AM. |
© 2024 MH Sub I, LLC dba Internet Brands