Eric's NA8

[ericson]

Hi everyone,

So I found out that my 1996 NA8 was previously owned by a forum member 'broady' and wanted to keep the story of this therapeutic machine to live on.
Broady's garage chat thread: http://www.mx5cartalk.com/forum/memberlist.php?mode=viewprofile&u=3297.

It ticked over 217,000 kms recently and it's been my joy (and few headaches) since July 2017 and done one motorkhana event hosted by MX-5 Club of NSW.

Stock NA8 bottom end
Head had port and polished when it was rebuilt 2 months ago
IL Motorsport fan shroud kit with Spal VA09-AP12/C-54A fans
OEM spec 26mm radiator
Yellowspeed Racing Dynamic Pro Sport Coilovers
SSR Star Shark 14x7
Coolant reroute delete (previous owner had it installed, but I didn't find it necessary)

Logs:
11/07/17 Bought the car with 207,000 kms on it.
18/08/17 Installed Yellowspeed coilovers, replaced gearbox, fuel pump, coil pack and leads replaced.
24/06/18 Head rebuilt and assembled with ARP head studs, coolant reroute deleted, timing belt service done.

Cheers
Eric

[Custardtart]

The link sends me to Broady’s profile not the thread.

[ericson]

Oops my mistake, the link to thread: http://www.mx5cartalk.com/forum/viewtopic.php?f=57&t=39496

[ericson]

After nearly a year of ownership I noticed the engine was pinging under load, especially in hot summer days -- I couldn't drive the car properly as it would ping going up a steep hill or give a little push with AC on. My guess is it was probably caused by increased compression due to 0.048" head shave done by the previous owner. So I had a spare stock NA8 reconditioned, port and polished by mx5mania.



And cleaned the hydraulic lifters.



Maruha 86mm was too large and been told it might drop the compression so went with Cometic headgasket standard bore size and thickness (83mm x 1.00mm). Also previous owner must've lost few washers for OEM head bolts; so got some ARP head studs.

Piston tops were also cleaned and scrubbed to get rid of built-up carbon deposits.



eBay 52mm alloy radiator started leaking some time ago, so went with 26mm OEM replacement paired with IL Motorsport fan shroud and two Spal VA09-AP12/C-54A fans.



Head finally went on after a month of wrenching. While everything was out, replaced the hoses, water pump, valve cover gasket, intake and exhaust gasket, timing belt, fuel filter, spark plug, oxygen sensor, ECU temp sensor (it had incorrect one from NA6 with grey connector, not green one), coil pack and air filter

Made a rookie mistake of not installing the fuel injector seals correctly and fuel went everywhere when I primed the fuel system. So got a new injector seal kit from Repco for $24!!, it was on discount for some reason.

Also I had Supermiata coolant reroute kit installed, but removed it and went back to stock cooling system configuration. Had to get new water neck (BPE8-15-170A).



And relatively healthy(?) compression, ranging from 160 to 180psi.

[ericson]

About a year and half ago, a set of 10-yo Tein coilovers that came with the car was replaced with brand new Yellowspeed coilovers. At first I enjoyed the lowered ride and sharp turn-in feel, but eventually the car being a daily driver I slowly found Yellowspeed to be bouncy and harsh (started to feel pain on my lower back when going on a long road trip).

So ordered a set of Koni adjustable shocks with H&R springs to make the ride more compliant, along with KYB shock top mount and SACH dust boot with built-in bump stop -- I didn't know where to source FCM or Flyin Miata bump stops without paying premium for shipping ($100 I believe).

Package arrived not long ago from the UK, also had to pay hefty tax on these and ended up costing about the same as buying these locally.



Shock mount drilled to fit Koni's 12mm diameter shaft, perch set to middle front and rear and ready to go in.



Also ended up getting the plastic gasket that sits between the shock mount and chassis, part number is G030-28-013A.



Front shocks in,



Rear shocks in,



Entire installation took around 7 hours wrenching by myself, it would've help a lot to have someone pushing down on the control arm, holding the shocks while threading the nuts etc.

Drove the car around the neighborhood, it definitely is more comfortable. Doesn't feel like I'm being shaken like hairspray can, but on the other hand it feels slightly numb-er than Yellowspeed coilovers, less sharp and bounciness is still there -- will try different damper settings in coming weeks leading up to a track day in October.

Also the ride height is near-identical when I had Yellowspeed, I hoped it'd be slightly higher Might move the perch to highest setting after I get different bump stops.

[ericson]

Forgot to post a photo of how it sits.

[Custardtart]

What spring rates did you go with? My neighbour has the konica on his NA8 and it seems a good shock for road and track.

[ericson]

What spring rates did you go with? My neighbour has the konica on his NA8 and it seems a good shock for road and track.

These springs are supplied by Koni if you get this shock as a complete kit, and I wasn't able to find any definitive spring rate probably because they are non-linear, progressive springs.

But according to 5xracing, estimated spring rate for front is 240-270 lbs/inch (4.3-4.8 kg/mm) while rear is 220-260 lbs/inch (3.9-4.6 kg/mm).

Front coil 11.0 mm diameter, 7.5 turns, 245 mm length
Rear coil 10.5 mm diameter, 8.5 turns, 260 mm length

Hope it somewhat answered your question

And yes, they seem pretty good for street use so far. Got a track day coming up in early October, will see how they feel compared to Yellowspeed.

[cookie]

Looks like it's in good hands. I found the Konig good also. I'm baffled why you removed the reroute. I'm sure you're aware of the problem it's trying to remove, the radiator will be adequate but I'd reconsider the reroute.

[Custardtart]

I’m not sure the reroute is necessary for a car that sees occasional track use with shoet sessions. Plenty of cars out on track with out them doing just fine.

[ericson]

Looks like it's in good hands. I found the Konig good also. I'm baffled why you removed the reroute. I'm sure you're aware of the problem it's trying to remove, the radiator will be adequate but I'd reconsider the reroute.

Custardtart answered it At first I jumped on the "reroute is a must" wagon after doing some research as to why it's needed or desired but after a while I felt that reroute is not needed for daily driving. I don't drive the car 'hard' anyway.

Instead of keeping the reroute I went with upgraded Spal fans with shroud, survived a track day at Wakefield Park last week with ease. I don't think the thermostat even opened (the aftermarket temp gauge was reading 60 C while oil temp went up to 115 C).

[ericson]

Lower radiator hose link pipe was corroded to a point where it started leaking pretty badly. Now it's been replaced by Maruha stainless steel replacement.



It's considerably heavier than the stock link pipe though.



Also got myself a hard top from later NB model in Supreme Blue, didn't check the latches are worn and had to get replacement as well. Along with required electronics; relay, fuse block, pig tail and dash switch.

Side latches (NA02-R1-310G):



Then fuse block (N008-66-730), relay (LA40-67-740) and dash switch (N007-66-460):



Haven't installed the pig tail yet on the demister as I wasn't able to get the NB pig tail disconnected, don't want to break it.

[apsilon]

Haven't installed the pig tail yet on the demister as I wasn't able to get the NB pig tail disconnected, don't want to break it.

It should be simple but in reality it's a real PITA. The release tabs (at least on mine) were on the inside, ie up against the hardtop/glass which made them difficult to see and almost impossible to reach. I was able to get to them with some small picks but I still couldn't get them to release (I'm guessing after being attached for so many years they didn't want to slide off). To make matters worse the demister tabs that they connect to are a very soft material so even with the tab released any pulling to encourage it to slide off would just bend the tab.

In the end I decided the lesser evil was cutting away the plastic on the pig tail so I nibbled away at it with some side cutters. Once the plastic was out of the way I was able to again release the tab but could now get a second pick in to help separate the pieces. Given I was unlikely to reuse this pigtail and it could still be used with some heatshrink or similar to provide any insulation, as opposed to risking breaking off the demister tab from the glass, I figured this was acceptable to me.

[ericson]

Fitting a custom 4-2-1 header and Magnaflow 100 cell high flow cat with stock catback made the car a little louder, but I wanted it to be more louder. So after a 2-month wait, I finally got my hands on a Magnaflow catback exhaust. They were bit heavier than I expected; but they sure sounds good.

4-2-1 header ceramic coated in black:



The Magnaflow catback didn't sound raspy nor rice-y. Will post a video once I film it



Underbody shot:



The tip is pretty close to the bumper, I'm thinking whether it'll start melting the rear bumper on a hot track day?



Also, got myself a set of Enkei RPF1 in 14x7 +19 to replace the SSR Starshark (I plan to get them restored). It will be wrapped with Falken Azenis RT615k+ in 195/60R14 (they were $150 per corner). I went to Wakefield on the Labour Day with street tyre with 50% tread left and keen to find out how it performs.

[Custardtart]

Lots of goodies there, should sound good with new exhaust and you can’t go wrong with RPF1’s