Track spec NB 1.8 Turbo build advice

[Hjt]

I would love a 120kw na vehicle. Stock SP made roughly 125rwkw w/ the gt2560r

Your whole braking system, tyres, bushings will wear at a higher rate with more output.

The turbo itself is $1200 new plus fitment. They do die at times.

[timk]

I have no idea of your driving history but the car sounds like it is pretty well developed and would be making good power as it is.

A proper race car takes many hours of driving to really get the absolute maximum from especially if it is highly developed. I think you should get more seat time and really learn to get the most from it...you might be surprised by just how quick it can go.

+1 to this. I took a stock naturally aspirated NB (sans interior) out to an MX-5 Club track day and it was awesome out of the box. People were asking if it was an SE or an SP!

[davekmoore]

Your car seems to have everything a normally aspirated car could have and more. So even if you're already a quick race driver there's no certainty a turbo will make it quicker rather than slower. For someone such as me who is not a quick driver a turbo can make for less speed as the car's more of a handful when the boost comes in so more care is needed with the throttle in the first half of corners.

What a turbo will do is eat up more fuel, lubricants, pads, rotors, tyres, drivetrain components and yet more development time and $$$$ to deal with the extra under-bonnet and transmission heat.

Also bear in mind that a 174rwkw turbo car will feel different but will almost certainly not feel quicker than a 120rwkw normally aspirated one either. Let me know if you're ever likely to be in Bendigo so you can try mine.

[RaceTech]

Thanks all for your time and opinions on this ...

As I mentioned earlier the whole focus on purchasing this car was too have a shitload of fun in something I can push 100% on track with and get out to Bathurst, Lakeside, SMP etc and just really enjoy it in a car that I can afford to rebuild if I had a big off, compared to the Lotus.

Having owned a large variety of track focused cars all highly modified I just presumed the little MX5 at 200rwkw would be quite a competitive little car at a open sprint/TimeAttack meet.

This particular car is very well setup going of the spec sheet, I think the large overbore in NA is a positive as capacity would be increased to 1950cc or there abouts but in turbo form all my searching leads to cracked blocks etc on med-high boost setups.

I think after reading all this I may be best to just work on refining the current setup and gets some track time in the car first before I jump the gun.

The ITB's from Jenvey are only 650gbp Ive read good reports on these and quite a good increase in mid/top end power ...

Cheers !

[MrsB]

Hi there

Firstly if you are going down this road you need to read the CAMS 2B rulebook if you want the car to have any value at the end of it and if you want it to be eligible for anything other than club sprints and time attack. There are basically two turbo set ups you can run the SE and the SP. Both have their own for's and againsts as do quads

[CT]

Having built a 210rwkw turbo class 2B MX5 before - I recommend u save some money before you commit to turboing that car. Here's some stuff my car had which made it race ready and reliable and lapped bathurst in a 2:32, wakefield in 1:04s and 1:46 at PI:
- Custom PWR intercooler
- electric water pumps, coolant re-routes and higher pressure cooling system, 50mm custom radiator
- 550cc injectors, bosch 044 primary pump, walbro 190 in tank pump, 949 dual fuel rail and dash 6 fuel lines and surge tank
- GT2560 turbo on SP manifold
- extensively ported head, oversize stainless valves, double valve springs
- Carillo rods, FM wiseco pistons
- modified baffled and gated sump
- Nissan GTS 5 sp gearbox conversion
- Boznjak Front Hubs
- Billet Boznjak rear axles
- AP 4 Piston front calipers
- Colster Engineering rotor hats
- 296mm rotors
- Haltech ECU with over 50hrs dyno time

[Charlie Brown]

Having built a 210rwkw turbo class 2B MX5 before - I recommend u save some money before you commit to turboing that car. Here's some stuff my car had which made it race ready and reliable ......

Like that word CT..."some".

You forgot to say that "some" translates into "buckets of money" on top of the "hours of work".

I love "some" of the comments on this site about turbo charging and how much power their motor is putting out and how they’re surprised when the motor ‘pops’ or gearboxes, diffs and axles break.

I remember Chris G saying to me a couple of years ago that he can run a team of three NC’s over a season for the cost of one turbo'd NB.

[NitroDann]

Build a 400hp NA and then see if you can go back.

It's not easy. Everything is a compromise in life though.

Part of why you can run an nc cheap is becaise you can buy then cheap and resell for cost.

Dann

[Charlie Brown]

Build a 400hp NA and then see if you can go back.

It's not easy. Everything is a compromise in life though.

Part of why you can run an nc cheap is becaise you can buy then cheap and resell for cost.

Dann

It's not the cost of the NC that makes for cheap racing; it's the cost to replace worn and broken parts, especially gearboxes. Put down more than 230rwkW and you’ll be looking for a second hand 6 speed gearbox that will set you back $1200, when you can find one.

HP or kW is a drug. As you said 'see if you can go back', but if you want to find out the real cost of running turbo power on the track in an NA or NB, then speak to those with experience who have been there and done it. Ask CT, Greg (Turbo Boy/Girl), Matilda or Nick, Brian A, Daniel, Chris G, etc. You'll get similar answers, we've sold our cars.

[NitroDann]

I understand, what I don't understand is why none of the yanks have driveline problems.

Dann

[CT]

I understand, what I don't understand is why none of the yanks have driveline problems.

Dann

They do, but they don't often admit it. Plus, most never run on slicks. Slicks increase the load on everything multiple times over R specs. I blew a rear CV joint to bits off the start line at Oran Park once. Billet axles and modified CVs fixed that.

Nemo was the best MX5 I could have built; reliable, fast and fun. Exactly what a race car should be. I only ever blew one gearbox and it was after 3 years of racing so hey, not too bad. Even my race engines lasted 3 years before a refresh and the only issue on teardown was one piston had a cracked skirt. If you do it right, they can be reliable.

[Sean]

Build a 400hp NA and then see if you can go back.

Not many genuine 400hp NAs around, I had over 300, went back to a sub 100hp NB - Loving it!

Everything is a compromise in life though.

So true.

[mazmad]

Build a 400hp NA and then see if you can go back.

It's not easy. Everything is a compromise in life though.

Part of why you can run an nc cheap is becaise you can buy then cheap and resell for cost.

Dann

It's not the cost of the NC that makes for cheap racing; it's the cost to replace worn and broken parts, especially gearboxes. Put down more than 230rwkW and you’ll be looking for a second hand 6 speed gearbox that will set you back $1200, when you can find one.

HP or kW is a drug. As you said 'see if you can go back', but if you want to find out the real cost of running turbo power on the track in an NA or NB, then speak to those with experience who have been there and done it. Ask CT, Greg (Turbo Boy/Girl), Matilda or Nick, Brian A, Daniel, Chris G, etc. You'll get similar answers, we've sold our cars.

Amen sister.