BBR turbo NC - 3 top gotchas?

Had my NC3 for almost a year now, love it overall and can’t stop thinking about the BBR stage1 turbo conversion.

Having exhausted searches in forums etc, I wish I had the top 3 ‘gotchas’ from those with real-life experience of these conversions.
Maybe underbonnet temps now become excessive, support is substandard (subjectively of course!), a new std clutch lasts very little, insurance companies take the mickey – whatever the issues happen to be.

My first road bike was a Kawasaki 750turbo, so ain’t a turbo virgin. Also have a ZH2, so still into forced induction - but at this age I value reliability and peace of mind above all

Hopefully this will talk me out of spending the car’s current worth on an 11-year old car :rofl:

I cant help much but i have just bought a Honda S2000 as i really fancied an NC but just wanted something with a little more sparkle.
This isnt an advert for the Honda but just to say i looked and looked at the tuning packages but just could not justify the cost of the forced induction ones.
The super 200 package looked interesting and not terrible value really for the gains on offer but what i did read about the company in general kind of made the decision for me.
Not sure you will get the answers you want online really as there is what seems a 70/30 split on happy/unhappy customers.
As for the clutch it would be madness not to upgrade it but thats another expense to add on.
I did think that there was a little less to worry about on a Turbo conversion done properly but that may be wishful thinking.
I did read insurance could be an issue, never looked into prices personally.
A rather nice looking red Turbo converted car appeared online about 3 months ago for close to £10k, i was interested but the car i was selling took longer than expected or i may have taken a punt on it.

Had a typeR FN2 and the lack of midrange was hard to swallow.

Not keen on changing the cams, all sorts of issues can arise in the process, let alone the cam profile could easily shorten the drivetrain life. Oh and the bearing mating surfaces will never match with the original cams that wore together from the factory. Oh, you also take from below to add above. I really don’t want to compromise any of the very-low down pull, I find it suits this car very much for leisurely rides.

‘uprated clutches’ can be a can of worms in my experience, I’d love to stick with std if possible.

After-sales support is indeed extremely important, but on a public forum people might be reluctant to be frank (sadly)

Why would that be?

I know what you mean about the midrange, I did find the engine a little underwhelming the first time I took it to the redline to be honest but overall Im happy with the car.

Surely somebody on this forum must have had a stage1 BBR turbo NC…

The silence is deafening

I hate to suggest it, Facebook probably has a group closely related to NC Turbo.

A local member has an NC 25AE with a BBR Turbo which will be sold soon, not on the forum though.

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From my limited interaction:

I tried contacting them and had no reply, this seems to be common.

I know someone that has the throttle bodies and its been a bit of a nightmare of issues and support.

When they do the camshaft upgrade they don’t check the cam buckets, not great, what else don’t they check.

The turbo looks good, but its quite a basic setup, no electronic boost control, just on the actuator spring. The oil drain is into the sump drain below the oil level, this isn’t great. Should really be returned above the oil level. I have also heard questionable things about their tuning.

The positive is that from what I hear they can do it quickly, Looks good in the engine bay and has the BBR badge.

Negatives are Cost, its basic, communication is bad, and after sales is below par.

I’m sure there are happy customers out there, but there seems to be an above average number of people with bad reports.

Please note that all of this not from personal experience, but I have no reason to doubt the information.

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Oil drain into the sump below oil level is not a sign of careful design, that’s for sure

I have an NC1 that I’ve had turbo’d. Admittedly, not by BBR.
I wanted “super safe” so an NC3 unit was sourced, split completely into it’s bare parts form and rebuilt with 3rd party forged pistons and rods. The NC3 engine has the better crankshaft.
Clutch wise, was an RTS 5 puck organic.
Insurance was/is with Adrian Flux and went up 50 quid to around £ 550 with all my modifications declared… turbo, roll bar, wheels, MeisterR’s, brake upgrade, electronic boost control etc. I’m 58 yrs old with a clean license.
Not bad all told for a 310whp/300ft lb mighty monster.
All the above did cost more than the BBR option but I wanted the piece of mind of the whole newly built package rather than saddling my 126k NC1 unit which likely would have gone bang in little to no time.
The car gets track time about 4 times per year and the thing to watch is oil temp which rises after 12-15 laps but a cool down lap and 10 minutes in the pits sees the temp drop to normal levels. I installed a digital dash readout with oil pressure/oil temp/coolant temp which is easy to see as it changes colour (with numerals too) as it rises.

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Thanks Reggie.
Mine is from the last batch of NC3s, the 25th anniversary, forged crank, matched pistons even I’ve read somewhere. 60K engine, hopefully young enough to take the extra load.
I only aim for stage1 with an uprated clutch when needed, anything more than 7psi on a stock engine is pushing one’s luck I’d think.
Do you run stock spark plugs? I can see nothing mentioned on the BBR website.

£50 extra is quite reasonable for insurance to go up, as the online quotes can only be for stock cars.

I’d agree that 7psi is probably comfortable on standard parts hence my request for all forged from a fresh build.
The boost controller has 2 settings - 5 psi for around 250hp and 13 psi for just north of 300.
I’m very mechanically sympathetic, as much as can be, with 2k oil/filter changes and no hooning until all temps are properly up where they should be…
No, not standard plugs, hotter ones and off top of my head, not sure which brand/type.
Just to add, all the relevant bolts are ARP.

Interestingly the FlyingMiata NC turbo kit has been recently revealed, along with many design/installation details. For NC3 engines they allow 3psi more than NC1. May be a better design from what I’ve seen up to now (US product though :frowning: )

Yeah, I’d seen that. I suppose the 3psi uplift reflects the forged crank capability.

If everything else is the same (identical serial nums for cams for example) then it could be that the crank was the weakest link of the chain until NC3.

Dynamic compression ratio can be reduced with cam timing, while static CR stays the same. Bit more overlap lets some boost leak out, an old trick.

Please remember that boost is just a measurement of restriction and will be different on different turbo setups. It doesn’t really matter what boost you are making (within reason), its all about the torque and BHP. Its these numbers that break the engine.

If you have an NC3, then easy aim for 300bhp. Don’t get an exidy stage 1 clutch, complete rubbish, I’ve now gone to a Competition Stage 2 that they state holds up to 336bhp. I run Brisk RR14YS spark plugs, copper or silver produce a better spark than iridum, but don’t last as long.

My own kit made 264bhp at 6.4psi, 280 at 10psi and will be going back to take it up to about 12psi. That is on an NC2 engine, so the later one with no internal mods. I wont be going over 300bhp, as that’s about the safe limit with standard internals.

Also remember like Reggie says, if you install an electronic boost controller not only can you have up to 4 different maps, so say one at 250 and another at 300. You can also have boost by gear, so my 1st gear is set at 8psi and then from 2nd I get full boost.

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There is also the new Kraken setup
NC MZR EWG 1.8/2.0/2.5 280HP Turbo Kit - Kraken Miata MX5 Performance

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Yep, boost is simply restriction to flow. Some of us old-timers know that. :grinning_face_with_smiling_eyes:
You can restrict/heat it up and see loads more boost - but far fewer oxygen molecules to work with.

It is also interesting that the FM kit comes with a choice of two exh A/R for the turbo. Also I like their heat-management setup, it’s how I would have done it if I had the choice.

Hi.
Glad we can help with your insurance.
Regards,
Dan.