Matt’s Road & Track Coupe - Dec-25 update: Cobra Nogaro chairs

A little update, unfortunately light on Z4 progress, but no doubt some of these things will help me to nudge the Z4 forward in the long run...

Fitted some bucket seats in the MX5 at long last (a pig of a job as there's little room in the cabin and you have to get them as low as possible for helmet clearance) and did a few trackdays in that, great fun!
Tried some Yokohama AD09s on it... and I'm still on the fence about them, perhaps a little less grip than I'd anticipated. More seat time needed on them, but I'm already wondering if some of the published testing on them was on a non-EU compound. We shall see...

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Unfortunately had a bad day in the MR2, came out a corner on the last session of a TD... clack, clack... 'oh no!!! get it out of ge.... BANG!!!'... flames in the rear view and a suddenly very hot back... GET IT STOPPED AND GET OUT... QUICK!
Thankfully I was able to do that, stopping by a marshall's post, he couldn't get the pin out of the fire extinguisher so I grabbed it off him and put the fire out myself. This was all in a very short space of time and the heavily cut out rear of the MR2 meant I could get to the base of the fire very easily and put it out very quickly. A scary experience and a real pain to lose an engine, but the rest of the car survived and I was completely unharmed. I think I would have been fine anyway, but I was very glad of my nomex top and gloves!

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(the removable bulkhead has been removed here)

Having partly stripped it down, we're not sure what's happened yet, I thought it was a bottom end bearing and Dan thought it had dropped a valve, but it doesn't look like either. It was equipped with a nice Clockwise motion gated sump baffle and piston uprated pump to give it every chance, but these things happen.
As my Dad always said... 'when there's a hole in the block, you know where you stand'... :lol:

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On a brighter note, I finally bought myself a scissor lift, which will make working on the cars sooo much easier, the garage is an absolute mess at the moment as I'm sorting through everything and selling the CRX, but once I get everything where it needs to be and my bench and racking in place I'm sure it will be terrific!
First time I tried to use it it tripped the circuit breaker, so I couldn't use it for a few days whilst I waited for a D curve MCB... followed by another few days when this idiot didn't think about the in-house MCB for the garage!... :roll:

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Another addition that should make Z4 life easier is a spare car... the missus and I share a (my) daily, and I take the Z4 when I want or she has the other, but I would rather not subject the Z4 to the winter and salt, especially now with the rear subframe refurbed. Not to mention the times I've been left with a Z4 and the need to transport wheels or tyres....
So I give you... Graham, the Civic in all his 150k, 1.6 diesel splendour...

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A full service history and a meticulous and mechanically sympathetic previous owner mean it presents and drives like a well-kept 60k miler, I'm sure it will come in very handy indeed and mean I only use the Z4 when I want to. :)

Finally to the Z4, but first a diversion via the little CRX... I have been readying the CRX for sale for some time, running into a braking issue I can't get to the bottom of. Without going into too much detail, under certain circumstances (low-speed maneuvering usually), there are no brakes and I have been trying to solve this for months! New master cylinder, brakes have been apart a number of times, bled, bled, bled and bled again... can't figure it out! Has been driving me mad!...
Back to the Z4... it did the same!! :-o

First instinct was one of 'I completely hate cars, they're all dickheads', but it's given me some hope... as I've done some investigation and I thiiink the Z4 issue is something contacting the caliper when under certain (low/no) loads and heavy offside lock. There is no issue when driving (thankfully), just like the CRX, otherwise the Hairpin at Cadwell would have been problematic!
So next decent weekend weather we have I'll investigate further, of course when its up in the air with wheels on full droop you can't see any of this... here's hoping it's the same issue on both the Z4 and CRX... they are both on aftermarket coilovers and thicker ARBs and the CRX has bigger calipers too...

Finally part two, I've got some stiffer springs to try on the front of the Z4, from 5kg up to 8kg/mm. I'm expecting them to make a nice improvement on track, but will they ruin the car on the road?... We shall see!...
 
Looks like gudgeon pin or rod failure at the little end and it's gone full flail?

An opportunity for a turbo after a rebuild. Every cloud and all that :thumbsup:
 
Quick one…

Bought some spare springs to try things:

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5kg (standard KW), 8kg, 10kg

Took the front suspension off last weekend, cleaned it up, did the maths about setting the ride height, thought it sounded wrong so guessed, fitted the new 8kg springs and it had a silly arch gap…

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The maths was right all along, now sorted.

Happily it’s taken the extra spring really well on the road, hasn’t ruined it. Look forward to trying it on track.

Also replaced the oem drop links which were way too long with some adjustables. Once I’ve settled on a length I tend to find oem drop links of that length, these are now a similar length to those for an e36 M3, so I’ll probably buy some Lemforder E36 links in due course.

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Did I do all this and then find out the Hotchkis front bar I ordered 7 months ago has now arrived with Hack… yes I did!… :lol:
 
Matt Scarbro said:
so I’ll probably buy some Lemforder E36 links in due course.

Hi Matt ,

Just curious why you would get OEM droplinks of the size you have found to work rather than just sticking with the adjustable links .
Cheers
Tony.
 
1536Z4 said:
Hi Matt ,

Just curious why you would get OEM droplinks of the size you have found to work rather than just sticking with the adjustable links .
Cheers
Tony.

OEMs can’t come loose and I’ve found the quality of the ball joints to be pretty variable. Whereas Lemforders always seem durable. :thumbsup:
 
Ordered this in May, anyway, it finally turned up:

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A Hotchkis 30mm hollow front anti roll bar, with their nice mounting solution complete with grease nipples and reinforcement plates.

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A bit of a luxury purchase in what's at least a budget conscious build, but I have it on good authority a thick front bar is particularly helpful on E46/86 chassis' and I didn't want to add a heavy solid bar. A theme that will likely emerge more as this project progresses is a desire to keep a keen eye on weight.

Along a similar theme, some replacement seats... I was keen to retain recliners, but wanted to lose some serious weight, improve support on track and hopefully improve comfort too.

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Corbeau RB, very similar, just with lower leg bolsters, to the RRBs I used in my old Clio 200 road and track car, I found them an excellent all rounder in that.

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Importantly they also have harness slots for when the rear cage goes in.

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I'm still researching mounting hardware, so any recommendations for bottom mount seats such as these much appreciated. Driver's side will need to be on a runner, passenger can be fixed and both need to be as low as possible.

Lastly some part-worn tyres for track fun when the current set are done, looking for some cheap but presentable Style 157s to go on, to save a little weight over the current heavy boys!

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Matt Scarbro said:
A Hotchkis 30mm hollow front anti roll bar, with their nice mounting solution complete with grease nipples and reinforcement plates.

Very nice Matt :thumbsup: are you going to leave the rear as standard ?
 
1536Z4 said:
Very nice Matt :thumbsup: are you going to leave the rear as standard ?

I really don't know enough about these chassis' to plan, very much a case of needing to try it and see what it needs.

Typically adding spring rate and a thicker bar at the front would dictate the need for a thicker rear bar, but I understand the reduced roll at the front helps to maintain front camber and can increase grip on these and E46s.

I hope that's what happens... hopefully I can soften off the damping too, so I'm not leaning on them to reduce roll.
I enjoy making a change trying it and working out what it needs, a rewarding journey. :)
 
It'll be interesting to see how much weight you lose with the new seats, stock electric ones are 26kg each.
 
damocell said:
It'll be interesting to see how much weight you lose with the new seats, stock electric ones are 26kg each.

Lots I hope mate, I weighed the Sport seats when I put them in... 28.4kg (maybe that was passenger complete with first aid kit and storage)...

Corbeau without rails and mounts was 11.4kg... it would be nice to think I could lose 25kg+ across the two seats without any functional compromise.

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I would love to get it sub-1300kg without ruining it... perhaps a rear cage will be the stumbling block there.
 
Sub 1300kg is a great target, i think Scoobie Dobbie hit 1316kg (or similar) with just fixed back seats and airbag removal.

11.4kg for recliners is very good. Tbf, those seats will be so much better when on track that any weight saving is just the icing on the cake. Looking forward to seeing them fitted.
 
I’ve got under 1300 with a cage, but it’s costly. Lots of design choices are compromises. Chromoly steel being one of them.
 
Vanne said:
I’ve got under 1300 with a cage, but it’s costly. Lots of design choices are compromises. Chromoly steel being one of them.

That’s impressive Vanne, I take it that’s with the exotic, trumpeted, land anchor that goes in the Z4M? You get a for bit more power to push that 1300kg too!!
 
Sub-1300kg with a cage is impressive!

Mine's1438kg with a full tank of fuel!
 
Some quick updates:

Got the Hotchkis front bar on, up to 30mm now on the front. A very short road test when weather permitted showed promising signs, I will reserve judgement for the track, but I suspect this is an important part of the jigsaw.
On the ‘softest’ setting atm, 33% stiffer than the 27mm E46 M3 bar it replaced.

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Importantly its combination with the 8kg/mm front springs haven’t ruined it on the road. :)

I’ve also saved 1.7kg over the 27mm bar, so 2kg+ over a solid 30mm bar. I’m particularly keen to pay attention to weight at the front of the car as it’s much easier to find places to lose it at the rear.
Some nice reinforcement plates and grease nipples from Hotchkis too.

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I’ll have an afternoon removing and treating surface rust in a few places soon, generally looks quite tidy though.

Secondly I mocked up one of the Corbeau seats… true to form nothing lined up with the seat / mount/ rail combination, so cutting and drilling will be required!
I hate fitting seats! :lol:
So much easier in these than MX5s though, much more room!!

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With a slider rail it will sit a touch lower than standard, with the option to remove the rail and have it properly low.

With rail:

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Pulled my finger out and edited the latest vid, returning to Cadwell late last Summer with the E46 M4 front anti-roll bar, KW rear springs and camber plates:

 
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