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      06-17-2019, 01:43 AM   #1
eggman51
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Adding a 4 or 6 point harness to a Roadster - possible?

Hey Folks,

Did my first track days with my daily driven Z4M Roadster - absolutely loved it!

Two minutes flat at The Ridge with tons of sloppy driving!

I dislike the brakes, but can see a way through that with upgrades I've looked into. I absolutely hate being on a track with the stock seats and 3 point belts.

I've tried researching options for mounting a harness, but end up getting lost in threads that look promising, but end up being coupes or cars with roll bars that are no longer daily drivers (or at least give up the soft top).

I would prefer to keep the OEM seats, but am open to the possibility of a seat replacement.

Any pointers would be much appreciated - cheers!

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      06-17-2019, 03:38 AM   #2
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Wow. Awesome time for first time out with the Z4MR at the Ridge.

How did the car feel to you? What wheel/tire setup are you running? Did you have DSC off? Great heel n toe down shifts.

How did you mount your camera at that angle? It's great and I cannot get to that some how. Can you share? Not many of us track with a roadster. Roadster track-specifics are not very well documented.

From my researches the last few years, I've leaning toward getting a bucket seat for track days. Have them off after the track for cruises is the preferred solution for me. A bucket with a 3 point will keep you more secured on the track than keep the OE seat and run harness and cut off parts of your interior.

A bucket with less than 560mm in max shoulder width will clear the door panel without trimming. Once setup, getting the seat off are just few bolts. I think that's liveable.

HTHs,
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      06-17-2019, 11:51 AM   #3
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Quote:
Originally Posted by ZeD4Mr View Post
Wow. Awesome time for first time out with the Z4MR at the Ridge.

How did the car feel to you? What wheel/tire setup are you running? Did you have DSC off? Great heel n toe down shifts.

How did you mount your camera at that angle? It's great and I cannot get to that some how. Can you share? Not many of us track with a roadster. Roadster track-specifics are not very well documented.

From my researches the last few years, I've leaning toward getting a bucket seat for track days. Have them off after the track for cruises is the preferred solution for me. A bucket with a 3 point will keep you more secured on the track than keep the OE seat and run harness and cut off parts of your interior.

A bucket with less than 560mm in max shoulder width will clear the door panel without trimming. Once setup, getting the seat off are just few bolts. I think that's liveable.

HTHs,
I agree that this - a bucket with the stock 3point belt - is the best option if you do not want to cut/drill any of your interior. If you use Bray Krause seat hardware you can probably swap the driver's seat in 30min or so.

Everything with a street/track car is unfortunately a compromise...
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      06-17-2019, 04:16 PM   #4
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The car generally felt great except for the brakes. Good handling and balance, amazing mid-range grunt and top end power from the lovely S54 engine.

My past track experience is 90% with formula cars. I've never driven a street car on a track extensively (a few laps here and there). A single seater formula car brakes *way* differently than a road car hehe. I burned through a set of DS2500 fronts in 2 days. I am not sure what is wrong with my braking setup, but the pedal feel is terrible - long travel, soft through 80% of the travel, then form at the end; not at all confidence inspiring. And it does make heel 'n' toe downshifting much more difficult than it should be because of the radi ally different "bite height" for the brake pedal vs the gas pedal position.

I bought it with 19" CSL knockoffs and some Hankook Ventus tires on the front, and General Tires on the rear. I swapped those out for 18" Apex ARC-8 and Michelin PSS 4 tires in a staggered setup.

I left the DSC on. I will likely try it off once I get more comfortable. I kept forgetting to turn on the Sport button, but that seemed to help with throttle response. One day I will do an ECU hack to have that remember it's setting.

I will find a pic of the camera setup - RAM suction cup mount on the rear console (the part that doesn't open). Very basic. Ran an external mic into the engine bay to get that amazing S54 sound

You can kinda see the mount in this pic:
https://photos.app.goo.gl/cfQBjDadr9tmRAv67


The 3 point seatbelt is problematic. At these speeds a 4 point harness seems like the only thing that will keep you firmly planted in the seat so you are not over exerting to brace yourself into position.

The Bray Krause or Macht Schnell hardware and a seat swap (likely for the summer / season for me) with a competition seat seems like a good idea, but I would really like to have a 4 point or 6 point harness.

I just can't figure out where to safely mount that shoulder straps? Seems like there are solutions for the lap belts and the ASM straps, but nothing I have seen for the shoulder straps that does not involve a roll cage.

Thanks for the ideas and insights Gents!

Cheers!
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      06-17-2019, 04:33 PM   #5
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Re Belts - If you look at how Vanne has them mounted, this might work for you. I believe he is using eye bolts that are mounted in the rear bulk head. I also used a similar setup in my Toyota MR2. Keep in mind that most clubs will also require you to use a HANS device if you have a 4+ point harness; so bake that into your cost.
https://www.zpost.com/forums/showpos...&postcount=201



With regards to your brakes: Based on your last post, it seems like your using Hawk HPS street/track pads. Your description sounds like you have serious fade and are probably boiling your fluid. Definitely swap in a true track pad for your track days (like Hawk DTC60) and flush with any 600+ DOT4 Race Fluid and you should be good to go.
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      06-19-2019, 11:19 PM   #6
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Problem is even if you could retrofit a 4/6 point with proper harness bar, a lot of clubs still won’t let you run without a roll bar. And on a roadster that’s really tough...
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      06-20-2019, 02:42 AM   #7
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Quote:
Originally Posted by Azeka1 View Post
Re Belts - If you look at how Vanne has them mounted, this might work for you. I believe he is using eye bolts that are mounted in the rear bulk head. I also used a similar setup in my Toyota MR2. Keep in mind that most clubs will also require you to use a HANS device if you have a 4+ point harness; so bake that into your cost.
I sent Vanne a note - thanks for the heads up. Concerned about safety of that mount point, but that does seem OK.

Noted re: Hans, thanks.


Quote:
Originally Posted by Azeka1 View Post
With regards to your brakes: Based on your last post, it seems like your using Hawk HPS street/track pads. Your description sounds like you have serious fade and are probably boiling your fluid. Definitely swap in a true track pad for your track days (like Hawk DTC60) and flush with any 600+ DOT4 Race Fluid and you should be good to go.
I didn't use the Hawk HPS 5 on the track based on advice here and from others. I went with Ferodo DS2500 pads front and rear. I ate through a set of fronts in 2 days and a set of rears in 4 days. I think the rears were mostly burned out by DSC, so I will switch that off - by end of day 1 I should have switched it off, I was just being (too) conservative.

I put in Castrol SRF fluid. I bled the brakes a couple of times at the track. The mechanic at the shop says the brakes were not bedded in properly and, as a result, this was causing the electronic braking system (??) to modulate the braking pressure. At least I think this is what he said, it kinda sounded odd to me, but he's a very experienced mechanic and has been spot on with other things, so - if that sounds weird - this is likely my lack of understanding of his explanation.

In my view the brakes on the Z4M are the most inadequate aspect of the car. I plan to change out the front brake system, probably to an AP Racing PRO 5000 R based kit. Engine great, handling great, transmission ok, brakes are for a road car imo.

Quote:
Originally Posted by 3002 tii View Post
Problem is even if you could retrofit a 4/6 point with proper harness bar, a lot of clubs still wonít let you run without a roll bar. And on a roadster thatís really tough...
The ones I currently care about do allow it. Perhaps in the future a roll bar is required, but that starts to seem silly on a daily driver roadster given that, as I understand it, you give up the convertible.

I made another lil video of me and my daughter out for a rip - slower lap times on purpose, but lots of fun

https://www.youtube.com/watch?v=Dn3UeSqd5Gs

Cheers!
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      06-20-2019, 03:33 AM   #8
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Quote:
Originally Posted by eggman51 View Post
I sent Vanne a note - thanks for the heads up. Concerned about safety of that mount point, but that does seem OK.

Noted re: Hans, thanks.




I didn't use the Hawk HPS 5 on the track based on advice here and from others. I went with Ferodo DS2500 pads front and rear. I ate through a set of fronts in 2 days and a set of rears in 4 days. I think the rears were mostly burned out by DSC, so I will switch that off - by end of day 1 I should have switched it off, I was just being (too) conservative.

I put in Castrol SRF fluid. I bled the brakes a couple of times at the track. The mechanic at the shop says the brakes were not bedded in properly and, as a result, this was causing the electronic braking system (??) to modulate the braking pressure. At least I think this is what he said, it kinda sounded odd to me, but he's a very experienced mechanic and has been spot on with other things, so - if that sounds weird - this is likely my lack of understanding of his explanation.

In my view the brakes on the Z4M are the most inadequate aspect of the car. I plan to change out the front brake system, probably to an AP Racing PRO 5000 R based kit. Engine great, handling great, transmission ok, brakes are for a road car imo.



The ones I currently care about do allow it. Perhaps in the future a roll bar is required, but that starts to seem silly on a daily driver roadster given that, as I understand it, you give up the convertible.

I made another lil video of me and my daughter out for a rip - slower lap times on purpose, but lots of fun

https://www.youtube.com/watch?v=Dn3UeSqd5Gs

Cheers!
Eamonn

Just curious which clubs allow harnesses with bucket seats and no roll bar in a vert? If they have a regional chapter near me I’ll have to take a look as that’s the only reason that’s prevented me from going that route.
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      06-20-2019, 09:27 AM   #9
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Quote:
Originally Posted by eggman51 View Post
I didn't use the Hawk HPS 5 on the track based on advice here and from others. I went with Ferodo DS2500 pads front and rear. I ate through a set of fronts in 2 days and a set of rears in 4 days. I think the rears were mostly burned out by DSC, so I will switch that off - by end of day 1 I should have switched it off, I was just being (too) conservative.

I put in Castrol SRF fluid. I bled the brakes a couple of times at the track. The mechanic at the shop says the brakes were not bedded in properly and, as a result, this was causing the electronic braking system (??) to modulate the braking pressure. At least I think this is what he said, it kinda sounded odd to me, but he's a very experienced mechanic and has been spot on with other things, so - if that sounds weird - this is likely my lack of understanding of his explanation.

In my view the brakes on the Z4M are the most inadequate aspect of the car. I plan to change out the front brake system, probably to an AP Racing PRO 5000 R based kit. Engine great, handling great, transmission ok, brakes are for a road car imo.
It's your pads save your money because stock brakes are more than adequate.

According to Ferdo's website, these 2500 pads fall off a cliff and begin to lose their coefficient of friction at 350* C / 650*F. You need to be using something like the 3.12 or Hawk DTC60/70 that maintains a stable and much higher level of friction all the way to 800*C/1500*F. Never used Ferdo which is why I keep drawing comparisons to Hawk, but the data they provide here seems pretty helpful.
https://www.ferodoracing.com/product...e-pads/ds3-12/

Keep us posted!
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      06-20-2019, 12:18 PM   #10
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Quote:
Originally Posted by 3002 tii View Post
Just curious which clubs allow harnesses with bucket seats and no roll bar in a vert? If they have a regional chapter near me Iíll have to take a look as thatís the only reason thatís prevented me from going that route.
Maybe we define clubs differently, but there are groups that run lapping days in my region. They allow a convertible without a roll bar, and will allow a 4, 5 or 6 point harness. One of those groups requires a HANS device for any car using a 5 or 6 point harness.

These are pretty informal groups, the most organized would be Hooked on Driving. They have a published policy on convertibles.


Quote:
Originally Posted by Azeka1 View Post
It's your pads save your money because stock brakes are more than adequate.
I'm not convinced they are adequate, but I will run them again, likely a few times. I'm not too experienced with different pad compounds, and the 4 days I did in the Z4M recently are the most time I have spent with a road car on a race track. However, the design of the very basic brakes and small pads seem out of alignment with other aspects of the car.

In terms of pads, I will likely try some DS1.11. And I need to get used to changing pads regularly (to swap from track / road pads).

So much fun in this car, hoping to get back at it this weekend, but my cooling fan died and I need to get a new one in =/

Cheers,
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      06-20-2019, 04:40 PM   #11
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Plenty of track groups would permit running a convertible without a rollbar, basically, once you sign the wavier you really are on your own.

For running my Z4MR on the track, I am leaving everything stock, and just use like CG locks or the old autocross trick to lock myself in place. Stock works and is tested, either you have a custom rollbar made, mount a proper 5-6 point harness and a proper FIA race seat in the car, or leave it stock. Personally safety is a do none or do them all sorta deal.

DS2500 is a dual purpose pad, a good dual purpose pad, but still not a proper track pads. Just remember, the more capable the brake pads are, the faster the pad eat rotors, and the more corrosive and dusty brake dust comes out.
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      06-20-2019, 08:09 PM   #12
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I think I will try some Ferodo DS1.11 pads on the front and 2500s on the rear. I will swap out the DS1.11s for some 2500s as my street pads.

I'm gonna use the 2500s as street pads so that in the event I need trackable pads in a pinch they will work.

I am also thinking of doing a seat, harness, HANS device and mounting the harness the way Vanne has his mounted (as per the linked thread above).

The CG Locks are interesting, I will try one of those out, if I don't like it, I can use it in the passenger seat for when wife and kids come along for a ride

Cheers,
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      06-20-2019, 10:01 PM   #13
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Quote:
Originally Posted by kyriian View Post
Plenty of track groups would permit running a convertible without a rollbar, basically, once you sign the wavier you really are on your own.
Thatís definitely not the norm. CCA wonít even allow Z4 roadsters in stock trim. National policy is all verts (even those equipped with factory rollhoops) require roll bars and hard tops. NASA and PCA will allow verts but any harness needs to be equipped with rollbar unless youíre using Quickfits with factory seats and even thatís not a guarantee. But at least in that scenario you still have the option of running your stock belts.

As for smaller organizations (advanced only or open track days), Iíve actually found the rules to be even more strict. Not saying the above is absolute but in the northeast itís usually more often the case youíd fail tech if you showed up with 5/6 points and harness bar only. Auto-x is an entirely different story...
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      06-21-2019, 10:37 AM   #14
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Originally Posted by 3002 tii View Post
Thatís definitely not the norm. CCA wonít even allow Z4 roadsters in stock trim. National policy is all verts (even those equipped with factory rollhoops) require roll bars and hard tops. NASA and PCA will allow verts but any harness needs to be equipped with rollbar unless youíre using Quickfits with factory seats and even thatís not a guarantee. But at least in that scenario you still have the option of running your stock belts.

As for smaller organizations (advanced only or open track days), Iíve actually found the rules to be even more strict. Not saying the above is absolute but in the northeast itís usually more often the case youíd fail tech if you showed up with 5/6 points and harness bar only. Auto-x is an entirely different story...
Oh I am not saying that its the right way, but there are also track organizers who are more about $$$ than safety, and ultimately that will bore organizers who would just have you sign your name down and shake themselves of all responsiblities by offering a far lower price, which on paper at least, they aren't wrong. Hell I used to run and help with a group like that (I get in for free, so don't judge me).

Sadly with the Z4MR, it leaves many of us with very few options for safety, only reliance I have is to just run stock belts and believe BMW did their testing to ensure that if a tire fails on the track, I'll still be in one piece and the stock bar will hold me up long enough for me to crawl out.

I stand by my view though, with any car the owner wants to make safe for track, do it all, or do none at all.
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      06-21-2019, 11:17 AM   #15
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Quote:
Originally Posted by eggman51 View Post
Perhaps in the future a roll bar is required, but that starts to seem silly on a daily driver roadster given that, as I understand it, you give up the convertible.
Rollbar and harness installed, the owner said it still allows the top to go fully up and down.
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      06-21-2019, 10:55 PM   #16
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Quote:
Originally Posted by eggman51 View Post
I think I will try some Ferodo DS1.11 pads on the front and 2500s on the rear. I will swap out the DS1.11s for some 2500s as my street pads.

I'm gonna use the 2500s as street pads so that in the event I need trackable pads in a pinch they will work.

I am also thinking of doing a seat, harness, HANS device and mounting the harness the way Vanne has his mounted (as per the linked thread above).

The CG Locks are interesting, I will try one of those out, if I don't like it, I can use it in the passenger seat for when wife and kids come along for a ride

Cheers,
Eamonn
The DS2500 compound falls between Hawk HP Plus and Street/Race, neither of which is really adequate for the Z4M on the track. I had to move to the Hawk DTC60s (front and rear) on my 3.0si to get satisfactory brake performance. If you want to stay with Ferodo pads, find a compound that matches up with the Hawk DTC60 heat range. You might find Raybestos in same heat range also.
The CG lock will go a long way to addressing your issue with being stable in the seat. I've used it for years for autocross and track and it makes a huge difference. Cinch it down till it almost squeezes out a little bit of pee-pee and you'll feel fine once you get out on the track.
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      06-22-2019, 02:49 AM   #17
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Quote:
Originally Posted by schobyb View Post
Rollbar and harness installed, the owner said it still allows the top to go fully up and down.
Wow... do you by any chance have any contact details for the owner or shop that did the work? Would be much appreciated - that is an ideal set up for me.


Quote:
Originally Posted by dc_wright View Post
The DS2500 compound falls between Hawk HP Plus and Street/Race, neither of which is really adequate for the Z4M on the track. I had to move to the Hawk DTC60s (front and rear) on my 3.0si to get satisfactory brake performance. If you want to stay with Ferodo pads, find a compound that matches up with the Hawk DTC60 heat range. You might find Raybestos in same heat range also.
Gotcha - was thinking to keep the DS2500s as my street pad just in case I run out of pads while at the track. Will switch over to a track pad. Don't care about brands, but the DS2500 seems fairly unique in that it is a trackable street pad. Will probably try DS1.11 Ferodos as the track pad.

Quote:
Originally Posted by dc_wright View Post
The CG lock will go a long way to addressing your issue with being stable in the seat. I've used it for years for autocross and track and it makes a huge difference. Cinch it down till it almost squeezes out a little bit of pee-pee and you'll feel fine once you get out on the track.
I ordered one to try it out, but having been cinched up in dedicated race cars, I have a feeling I will lean toward the full harness / seat set up.

If I can track down some info on the rollbar that allows use of the soft top and the price is reasonable I'd be quite happy =)

Cheers!
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      06-30-2019, 10:21 AM   #18
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My take on the whole thing is regardless of the rules, youd have to ask yourself a question. Is it a good idea to run 4/6 points with out a roll bar, pretty sure the answer to that is a definite no.

Same goes for the HANS device, can you run without it? Sure, but is it a good idea? Again, answer to that is probably no.

Mod it fer sure, but do it safely.

Eamonn, if needed mate, I can send you pics of how I went about it, I'll need to dig em up or take some new ones. Car is under 3 tarps ATM, hiding from the heat/sunlight.
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      06-30-2019, 12:28 PM   #19
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This thread has got me thinking if our factory roll hoops could serve as a roll bar that's required for harnesses but maybe the trick is to run non-fixed back seats. In that case maybe I can run a Profi II ASM FE's (DOT legal, anti-submarining tech, HANS compatible) with seats similar to this owner.

And then use eye bolt back plates welded to bulkhead, nice and clean like this. Entire setup is basically 95% reversible, not too crazy of hit on wallet doesn't appear to compromise safety. I may reach out to HMS to get their take...
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      06-30-2019, 01:50 PM   #20
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Quote:
Originally Posted by Vanne View Post
My take on the whole thing is regardless of the rules, youd have to ask yourself a question. Is it a good idea to run 4/6 points with out a roll bar, pretty sure the answer to that is a definite no.
This is where I am sot sure I understand all the safety related issues. If it's OK to run a convertible with factory roll hoops (as some groups have determined) - then I don't understand how 6 point harnesses or fixed back seats make it any less safe.

It seems to me that if you are going over, the type of seat or seat belt has nothing to do with safety, it's over to physics and geometry that would be constant regardless of seat or harness type.


Quote:
Originally Posted by Vanne View Post
Eamonn, if needed mate, I can send you pics of how I went about it, I'll need to dig em up or take some new ones. Car is under 3 tarps ATM, hiding from the heat/sunlight.
Don't put yourself out, but if you have some pics handy that are not already posted, they would likely be helpful. I am pretty sure I will end up mounting my harness the same way you did yours - strongly reinforced into the bulkhead, at the correct height, but not directly mounted onto a roll bar.

I will probably end up putting a roll bar into this car, but I need to do more research on a roll bar configuration that preserves the soft top. Based on the earlier post in this thread it can be done! Have reached out to that owner through the interwebz, but no response just yet.


Quote:
Originally Posted by 3002 tii View Post
This thread has got me thinking if our factory roll hoops could serve as a roll bar that's required for harnesses but maybe the trick is to run non-fixed back seats. In that case maybe I can run a Profi II ASM FE's (DOT legal, anti-submarining tech, HANS compatible) with seats similar to this owner.
Still not sure I understand the relationship between seat type and safety - I must be missing something (not being sarcastic there) - I just don't understand how fixed back vs reclining has anything to do with safety?

In the linked thread above, the angle on the shoulder straps would not conform to best practices for mounting a harness. The shoulder straps should be flat, or angled down up to 25 degrees, but not angled up.

The seats in the M - lovely for spirited road driving - are not usable with a harness because of the fixed headrest (and they do not have a hole for anti-sub straps, so afaik can only be used safely with the Schroth ASM capable 4 point belts). However, they should still follow the guidelines for mounting positions and angles.

I notice the owner of that car said he would use the 4 point harness for Autocross, and the 3 point belt for track and daily driving. Not sure I understand why unless it's a governing body / approval issue.


Quote:
Originally Posted by 3002 tii View Post
And then use eyebolt back plates welded to bulkhead, nice and clean like this. Entire setup is basically 95% reversible, not too crazy of hit on wallet doesn't appear to compromise safety. I may reach out to HMS to get their take...


This is what I am planning to do, and appears to be how Vanne mounted his shoulder straps behind the fixed back racing seat. I just ordered the parts for this from HMS.

I am going to use a "proper" race seat - a Sparco QRT Performance - and a Schroth 6 point harness with Brey Krause mounting hardware and mount the shoulder straps into the rear bulkhead with Schroth FIA approved re-enforcing plates on the back side. I will mount these in a way that conforms to harness mounting guidelines.

I believe this should be as safe as any roadster with factory roll hoops, and should provide a much better seating arrangement for track driving (which I could argue improves safety).

Totally open to the idea that I may be missing something, this is safety so I am not wanting to mess about, but I can't get a roll bar into the car yet. However, I don't see the relationship between racing seats, 6 point harnesses, and factory roll hoops being less safe than factory seats, 3 point belts, and factory roll hoops.

Cheers,
Eamonn
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      06-30-2019, 08:18 PM   #21
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Quote:
Originally Posted by eggman51 View Post
Still not sure I understand the relationship between seat type and safety - I must be missing something (not being sarcastic there) - I just don't understand how fixed back vs reclining has anything to do with safety?

In the linked thread above, the angle on the shoulder straps would not conform to best practices for mounting a harness. The shoulder straps should be flat, or angled down up to 25 degrees, but not angled up.

The seats in the M - lovely for spirited road driving - are not usable with a harness because of the fixed headrest (and they do not have a hole for anti-sub straps, so afaik can only be used safely with the Schroth ASM capable 4 point belts). However, they should still follow the guidelines for mounting positions and angles.

I notice the owner of that car said he would use the 4 point harness for Autocross, and the 3 point belt for track and daily driving. Not sure I understand why unless it's a governing body / approval issue.

This is what I am planning to do, and appears to be how Vanne mounted his shoulder straps behind the fixed back racing seat. I just ordered the parts for this from HMS...

Totally open to the idea that I may be missing something, this is safety so I am not wanting to mess about, but I can't get a roll bar into the car yet. However, I don't see the relationship between racing seats, 6 point harnesses, and factory roll hoops being less safe than factory seats, 3 point belts, and factory roll hoops.

Cheers,
Eamonn
The M sport seats definitely cannot be used with harnesses, including Quick Fits since the headrest is integrated. The shoulder belts might slip off regardless of the angle which you install them.

And regarding the link I posted, I was not suggesting by any means that's a good setup. I was merely showing you the seat I was considering since the fitment was spot on. Therefore I posted the picture of the eyebolts showing how I would address the deficiencies in that other setup.

Regarding fixed vs reclining, fixed back seats have high side bolsters so it's not meant to be used in conjunction with a factory 3-point setup as the lap belt would never get tight around your legs. For a track-only car ditching the 3-points is fine but strapping into a 5/6-point every time you're on public roads can be a hassle. Yes you can retain the factory 3 points but you still have the issue of the lap belts not securing you. Personal preference but not something I want to deal with (read not a safety decision but matter of convenience for me).

Reclining seats don't have this issue but most reclining seats also don't have the hole on the seat bottom to run a 5/6 point, usually limited to 4-points. 4-points are generally at disadvantage because you run risk of submarining so that's why they're only allowed at low speed events like auto-x, unless you find a harness that has anti-submarining (ASM) tech. The harness I linked not only has ASM features but is compatible with HANS and both FIA / FMVSS 209 certified (so should be good for road courses).

Separately during rollover, [the theory is] a fixed back seat will not give meaning the driver will stay upright if secured via harness. That's why a roll bar is crucial since you don't want the roof to collapse on you. Ironically if what I'm contemplating above "works", roadster owners wouldn't have to worry about this as the roll hoops would suffice for rollover protection.

FYI I am by no means a safety expert so you should do your own due diligence but this is what I gathered when I researched the issue for my previous track car (and ultimately settled on "half" cage, fixed back and 6 points with HANS).

So to recap, for my proposed setup, I *think* it checks all the boxes with respect to "street friendly", ASM, HANS, and rollover protection. A fixed back, aftermarket rollbar and 6 points would probably be safer but its not the direction I want to take the car in. Been there done that and I'm looking for something milder, easier on my wallet, and street friendly.

Picture below is my old coupe for reference...
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Last edited by 3002 tii; 07-01-2019 at 10:54 AM..
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      06-30-2019, 09:04 PM   #22
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Much more clear - excellent reply - thanks. Apologies if my written form tones as dickhead, your thoughtful response is much appreciated. Keep us posted on how you go, I will make an effort to do same.

Cheers,
Eamonn
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