Installing an MX5+ twin hoop roll-bar in a 04 NB SE

[Nevyn72]

As promised, here are my thoughts and experiences on installing an MX5+ twin hoop roll-bar in my 2004 NB SE.
With this thread I hope to help others with their installs by filling in some of the missing bits and just plain wrong bits in the Installation & Parts guide for this bar.

This thread should be read in conjunction with the install guide which you will need to download and print (preferably in colour) as it isn't supplied with the bar.
Download can be found here -> http://static.shop033.com/resources/EE/162286/Other/ADE020548rev01.pdf

So to start, as those who have been following my garage thread would know, I wanted my bar chromed. I wouldn't recommend this as to do it properly is very labour intensive and also very costly!
I would estimate it would cost around $1000 to $1500 to do the job properly for the chroming alone..... I settled for a 'cheapie' solution @ $400 and you can see my thoughts on the results in this link;
viewtopic.php?f=57&t=61170&start=137

To start with, before considering doing this install, you will need the following;
- Time: It took me 7 hours in total but with what I know now I think I could do it in around 5 hours.
- Tools: You'll need a fairly good selection of workshop/handyman tools on hand.
- Patience: There are quite a few steps to be completed, including installing & removing the bar from the car at least 4 times, maybe more! (I did it 5 or 6 times)
- Creativity: The install guide is far from perfect, you will need to think things through and understand the 'intent' and 'purpose' of each step.
- A friend: While I completed this job by myself, I wouldn't recommend that, the bar is quite heavy (~20kg) and the potential of slipping and damaging your car is high.....

So let's begin.....

The installation guide is obviously written for a NA series car and there are some subtle (and some not so subtle) differences with the NB series.
The purpose of this Thread is to help those installing one of these bars in a NB to get the job done without all the head scratching I went through trying to figure things out along the way.

Proviso: This is based exclusively on my experience with a 04 NB SE but should apply to all NBs, also this is based on a twin hoop style bar but should apply to the other 3 variants of this bar with some small adjustments.....

[Nevyn72]

Before you even start the first step there's something they don't mention.

You must pre-install the backing plate for the harness bolts inside the torsion box as there's no access once installed. I added some silicone to the plate just in case, down the track, I removed both bolts at once by accident. This would release the backing plate and could only be recovered by completely removing the bar!

Here's a pic of the backing plate and bolts.



Step 1 & 2: Good

Step 3: Replace 'Cross brace' with 'Windblocker' and 'mounting bolts' with 'two screws each side'
Here's a picture.



Step 4: Good

Step 5: There are no screws on the NB sill panel so don't bother looking for them! Gently lift the sill panel and the clips will release, you will only have to release the first clip at the door striker end to remove the door rubber.

Step 6, 7 & 8: Good

Step 9: The guide says 5 'Christmas tree' clips to remove the carpet....... in the NB there are actually 18 of them and 2 screwed down conical plates!
To remove the clips you will need to pull them fairly hard, don't worry, it won't hurt them (much) but try to avoid damaging the top 'hat'.

You will need to remove the carpet so don't waste time like I did trying to avoid it!

After removing the carpet I got a bit of a nasty surprise....



There must have been some water leakage at some time in the past. Fortunately it was restricted to the plate alone and was only surface rust.
I removed the plate to clean and repair it for reinstallation later on (this was part of where I lost some time, refurbishing this plate).

NOTE: You may as well remove this plate now yourself as it will need to be removed later on to locate and install the backing plates for the rear stays of the roll-bar.

Step 10: Good - if required

Step 11: The opening in the plastic shroud to 'drop in' the spacer doesn't exist on the NB, you will have to create one yourself.



Also the NB does not have a threaded hole so you will have to use the captive nut plate and glue it in.
Because they use tapered thread bolts the captive nut plate will likely come adrift each time you install and remove the bolt, get used to re-gluing the plate in place each time!

Step 12: The bar will not slot neatly into the car with the glass rear window sot-top. You will need to firstly pre-position the bar in the space behind the seats then partly raise the roof and push the bar into position. It's an incredibly tight fit and you will scratch the plastic shrouds (I discovered why later on) this is unavoidable but the resulting scratches are largely hidden with the seats back in position. I had to 'hammer' the bar into place using the heel of my hand....

Step 13: Ensure the bar is pushed all the way down onto the spacers, it won't rock as it's jammed in place! If it's not all the way down the hole drilled in the shroud will be in the wrong place.

Step 14: You can't do this as the captive nut plate isn't in position yet!

Here's a picture of the first time the bar was positioned....

[Nevyn72]

Step 15: Good

Step 16: No bolt to remove.....

Step 17, 18 & 19: Good

Step 20: You really don't want to lose those clips!

Step 21, 22, 23, 24 & 25: Good

Step 26: The bar should slot straight in without the plastic shrouds in place as there's more clearance. Still need to raise the roof though.
This is where you may need to modify your spacers to align the holes. In my case I had to shorten one of the spacers by about 1mm. I used a bench grinder to carefully remove a small amount each time and repeatedly 'test fit' the spacer until I had removed enough.....

Step 27: Good

Step 28: The place where the mounting plate is attached in a NA is flat, in a NB it isn't!
This means that the mounting plate can't be installed as instructed..... The bulge in this location on a NB is why the bar is such a tight fit as there's less clearance by comparison.

Here's a picture of the plate as they want you to install it, as you can see the bulge will cause the plate to not sit flat when positioned on the inside later on...



Now if you rotate the plate through around 180 degrees (facing down and forwards) it will still allow the same movement required for later fitting but stay on the flat surface. Be careful with the final angle as you need to be on the single thickness plate, clear of the double inside the cavity.

Step 29: The hole and supplied rivet are 5mm not 4mm as stated.
Because the position of the hole to be drilled has changed you will not get a normal drill head in there! Fortunately I had a flexible drill extension with a much smaller head I could use.



I then temporarily re-installed the seatbelt reels to confirm the altered positioning didn't cause any clearance issues before doing the other side of the car....



Step 30, 31, 32, 33, 34, 35 & 36: Good

Step 37: There should be a small amount of movement available in the plates you have just installed to align with the lower holes in the bar. Tighten the top bolts into the captive nuts you glued in earlier before doing the lower nuts.

Step 38: You don't actually go into the boot with a NB but clear everything out anyway and remove the shroud on the driver's side rear wall for later access.

Step 39: This is where you really test your commitment as you're about to drill 8 whacking great holes in the parcel shelf!
In the guide they use a right angled air drill, not something I have or could source easily......

I was able to get a quite cheap right angled adapter for a conventional drill from Bunnings for just $15 that did the job nicely though! Here it is fitted to my cordless drill....



This had just enough clearance to do all 8 holes under the raised roof.



I used a 10.5 mm drill bit as this fitted comfortably in the holes in the roll-bar feet and gave slightly more clearance for the 9.5 mm bolt threads.
There are two existing holes that mostly line up with the required drilling locations but these may need to be widened slightly....

[Nevyn72]

Step 40: Good

Step 41: Take the time for a bit of cleaning as it's a bit messy after this step!



You can also see in this image the plastic locating tab on the demister wire that needs to be removed from it's seat before the first time you install the bar.
Unfortunately it can't edit earlier posts to put this tip where it needs to be....

Step 42: NOTE: Make sure the captive nut plates for the top spacer bolts are well glued/secured at this time!!
Everything you do now progressively seals them away, if you dislodge them when installing the bolts for the last time, you'll have to dismantle everything to re-position them again......

Step 43, 44 & 45: Good

Step 46: Be very careful when inserting the top bolts not to dislodge the captive nut plates!!

Step 47: Access to locate the passenger side mounting plate is via the cover plate I removed earlier to de-rust and refurbish. There's only room for one person to do this under the raised roof and it can be fiddly to get the bolts aligned....

Access for the driver's side is via the boot through the space created by removing the rear internal shroud. This is definitely a two person job!
(The fun I had with my helper - some blocks of wood and copious swearing! )

Next is to tighten all the bolts, do this progressively for each nut, don't tighten each nut all the way individually. There will be some slightly disturbing noises as the plate is brought fully into contact with the bar foot plate. This is because the parcel shelf surface between the two isn't perfectly flat and is 'flattened' as the plates come together.... Suck it up, you're well past committed to this by now!

Here's a picture of the bar after being re-installed for the final time! YEAH!!



You will then need to reinstall the plate on the passenger side parcel shelf that you removed earlier to install the foot plate.
Looks a lot better than it did before.....



Step 48: Good

Step 49: Take care when re-installing the carpet not to damage the rear demister wire!

Step 50: Good

Step 51: ALL DONE!!....... It should look something a little bit like this!

[Nevyn72]

Hmmmm....... Think this needs a little more Chrome......



Ahhhhh...... That's better!



And few images outside, need to give the whole car a really good clean now....





What's next?.... Well given the wind blocker with it's integrated speakers are removed with the bar install I'll look at the various options out there to replace them.

I hope this thread has been of assistance for anyone out there contemplating installing one of these bars in a NB series car.
It is my wish that you will be able to avoid some of the issues I encountered by virtue of fore-warning and hopefully avoid some of the wasted time and headaches I endured while installing this great product in my car!

And finally, what's it like on the road?
Wow! It makes a huge difference to the car's handling, even on the only short drive I did yesterday it felt a lot more rigid, stable, direct and responsive.
Well worth the effort to install!

If anyone else wants to add anything else to this thread based on their own experiences please feel free to do so.
After all it's always better to learn from someone else than to try and work it out for yourself......


Cheers,
Nev

[ManiacLachy]

Awesome post, Nevyn! Sure to be a help to many. Good job on the install, it looks great.

[Nevyn72]

Thanks Lachy!

A couple of additional bits of info I've thought of since posting.

1) You'll need a good socket set with 10, 14, 16, 18 and 20 mm sockets.

2) If you were wondering how I got the bar in and out of the car, this is how I did it.....

I set both seats as far forward as possible and tilted them all the way towards the windscreen creating a space between the seats and the rear wall/parcel shelf.
I picked up the bar in the middle and stepped into the space I had created with one foot in each floor well facing the rear of the car. I then sat down on the glovebox (gently), rested the bar in my lap and lifted the roof over my head. Easy!

[Snowmotion]

Great write up Nev. I recon you photo's and notes for the install may have added at least 1 hour to your install but it is appreciated.
I tend to get a little impatient during an install to take enough photo's to do a full write up justice.

On Step 11, this is quite variable on the NB. My NB8A 1998, had the threads in the towers and did not use the supplied ones. I only had to drill a hole in the plastic cover. So some have the thread and some do not.
On this hole drilling I used a "Christmas tree" drill bit which is a great tool to have as it drill perfect holes that can be progressively increased in size with just one drill bit.

I do not recall having the "bulge" on the tower where the rivet was to be placed and as such was able to position the bolt at the prescribed angle.

I fortunately bought an air compressor many years ago and for $44 managed to purchase the 90 degree drill from ebay that made light work of the rear parcel shelf holes.

Thank you for the write up. Really great job.

[Nevyn72]

On Step 11, this is quite variable on the NB. My NB8A 1998, had the threads in the towers and did not use the supplied ones. I only had to drill a hole in the plastic cover. So some have the thread and some do not.
On this hole drilling I used a "Christmas tree" drill bit which is a great tool to have as it drill perfect holes that can be progressively increased in size with just one drill bit.

I do not recall having the "bulge" on the tower where the rivet was to be placed and as such was able to position the bolt at the prescribed angle.

I fortunately bought an air compressor many years ago and for $44 managed to purchase the 90 degree drill from ebay that made light work of the rear parcel shelf holes.

Thank you for the write up. Really great job.

Thanks for the feedback mate, really appreciate it.

Interesting on those two points regarding the threads in the towers and the bulge.... May only be the case for the NB8b/c or even only for the SE (although unlikely given the limited production).

Must get me one of those 'Christmas tree' bits, I just used a large bit then widened using a 'saw bit', was a pretty messy process.....
I actually have a compressor and could have waited for an air drill but the $15 attachment from Bunnings worked fine, the limitation was more the cordless drill and using a plug in drill would have worked a lot better.

[Snowmotion]

I tried the Bunnings option for the 90 degree drill but all I could find were these tiny ones that would not take a drill bit bigger than 6mm.

The best thing is the MX5Plus bars look great in the cars and I agree stiffen the car nicely. Looking forward to my first track day soon.

[pepejesus]

Great post, thanks Nevyn72.

Any chance you could fix the pics up?

I'm about to install the single-hoop torque box into my 04 SE and the pictures would be very much appreciated.

[Magpie]

Great post. Agree on the time as the last dodgy day we could have had it done in about 4 hours, that excludes putting back in all the carpet etc.

At the dodgy day we were discussing about making up some short stubby drills that would fit in a die grinder instead of having to use a 90° drill. On the dodgy day we used a die grinder with a burr to make the correct hole size, very quick with the right burr.

[speed]

Awesome write up. From now on you will be known to me as 'hammer fist' ;)

[Nevyn72]

Great post, thanks Nevyn72.

Any chance you could fix the pics up?

I'm about to install the single-hoop torque box into my 04 SE and the pictures would be very much appreciated.

I was waiting on Okibi to try and restore the images via a database recovery, he told me to hold off until he could see if it was possible.
Given there is no way to edit the posts I would need to completely redo the entire thread to put the pictures back in.......

[pepejesus]

Fair enough, thanks Nevyn72.

This is a very, very useful post for me though so thank you for putting the time and effort in doing the write-up.