To Build or To Buy? Advice Appreciated

[StanTheMan]

I can also confirm the MSPNP2 is around 1500 landed. I purchased about a month ago 76 us cent for the dollar. PayPal conversion was 72 cents
799 ECU
25 USB plug
25 pig tail
20 temp sensor
65 shipping
11insurance
That's 1277 direct conversion at today conversion. PayPal will add another 2% and your bank may add another 30 odd for foreign transactions
5% import duty. That's around $60. 10% GST $115

[Skifey]

NA8 is a better base. Believe me I've owned a NA6 for 20 years.....almost

for you it seems all about straight line speed & the acceleration?

You can beat most motorbikes around the twisters with 100 HP good suspension set up, good tyres , Torsen or LSD of your choice & good brake pads.

You have to be a bit of a nutter though. And if the motorbike still beats you. That rider must be totally insane.

Having power makes me (personally) lazy in shifting.
Having power is great for the racetrack
Having power is awesome for overtaking on country roads.
You don't need power for impressive performance

My 02

haha thanks for the 02
But nah, I'm not at all about straight line speed, but I AM all about acceleration. Torque especially. Nothing I love more than being able to haul ass out of a corner. Straight line speed is fun, but I'm not really one to go speeding on public roads, so in my mind, it's practically useless. I'd much rather get to the speed limit blindingly fast rather than be able to do 250km/h

[Skifey]

I purchased an na8 for $6k. It was very healthy with low kilometers. I spent two years researching and buying parts from nissan, rx8, Suzuki and Mitsubishi forums. All in I would've spent over $15k, and I got everything at an absolute steal. The ECU, the wideband and the manifold/dump I got for next to nothing and it still blew your budget.

Sent from my LG-H815

Fair enough, I can't argue that. Thanks kindly for the succinct advice everyone. You've been brilliant - as always

For future reference, is there any places I can be looking to buy an NA8 that arent obvious? i.e gumtree, carsales? I've found a facebook group or two but nothing much is going.
And also, whats some good places to source refurbished/used/new turbos, intercoolers etc... the whole shamboozle basically again not so much referring to gumtree etc. Anything and everything mx-5 basically is what I'm after. Hit me with 10,000 sites, stores preferably in brisbane but I really don't care, I'll take anything

[billybunter]

only 250kph I bet mine would run 270/275kph that is IF you were game enough to hold onto the wheel and it would still get there very quick unfortunately I never did but could have....if only

[Magpie]

Having developed a NA6 I would head the advice of others and get yourself at least a NB8B first as this would be a better platform to start off from. If you have the chance pop out to the dodgy day on 04/12/16 and there maybe some forced induction MX5's there not to mention other MX5's (and their owners).

However, if mind is set on your chosen path, then keep an eye on all the sites you have looked at for the right bargain, they do come up, you just need patience. Whilst waiting for the right bargain you can start to procure the other parts for the build.

Turbo - cannot help on that as I'm naturally aspirated (and staying that way). Miata turbo is a great (brutal) resource as is NitroDann...

Fuel - E85 or 98?

Brakes - If not using NB8B there will be issues with getting ADR approval. But if a track only car then irrelevant and you may want to read this http://www.miataturbo.net/general-miata-chat-9/anyone-have-any-brake-questions-81577/. Do you want to run a booster or pedal box?

ECU - are you going to self tune or use a professional shop? If going professional choose your tuner and what an ECU that the tuner supports.

Acceleration - is the rate of change in velocity. You actually want Newton's second law (F=ma). Therefore an alternative to improving acceleration force is to reduce mass.

As an example a car with a mass of 1,100 kg in 10 sec goes from 0 -100 and needs 56.9hp, reduce the weight to 900kg and you only need 46.5hp. Now if the 900kg car had 56.9hp it would do 0-100 in 8.2 seconds. Conversely a car with a mass 0f 1,100 and 46.5hp goes from 0-100 in 12.2 secs. Don't think that just increasing HP is the solution to increased acceleration force.

On going support - make sure you factor into your budget the ongoing running costs. Consider that rotors/pads/tyres/fluids all require more frequent replacement/changing when the power levels are increased way above stock.

[chrons_rotary]

Cheap 1.8L NAs are out there, just need to spend time waiting and watching.

Like everyone else says, if you want more power out of it, go the NA8 (bigger brakes, bigger diff, easier to turbo compared to the NA6) or NB8B (stronger gearbox, even bigger brakes than the NA8).

I picked my NA8 Clubman 3 years ago for $4k, with some rear quarter damage.
The damage didn't bother me, and doesn't make the car any slower, so still has the same damage to this day ( I would rather spend money on new race tyres than spend it on fixing the damage).

The car has spend many hours and thousands of dollars in Danns workshop, and I believe he knows what he is talking about when it comes to the real cost of turbo charging an MX5.

The end budget of 10-12k is doable for a reliable, quick, turbo-charged NA8, if you spend time searching for good 2nd hand parts, and deals on new ones, though you probably won't have enough to get it engineered.

Best place to look for 2nd hand parts is this forum itself or the MX5 Facebook groups, with several 2nd hand parts being posted up here on a daily basis, it won't take too long to find the right parts you need.

Finally read up on this : http://www.miataturbo.net/diy-turbo-dis ... post-4288/
MiataTurbo is a great resource for turboing your Miata (who would've thought?)

Good luck

Ken.

[Magpie]

Adding to my previous post on improving acceleration (rate of change in velocity)

In general at QR on the Sprint layout I'm at Wide Open Throttle (WOT) about 25% of a lap, this in itself is not a good statistic. Consider that a car accelerates at its best at WOT, therefore it stands to reason that just by increasing the time the car is at WOT should translate into a better lap time (cetrus paribus).

The attached picture is the MX5 accelerating out of T6 to the start/finish line at QR. Note I have removed some outliers in the data when a gear change happens. The car is in 3rd for 3.75 seconds, 4th for 16 secs and 5th for 3.5 secs.

The graph suggests that I should hold 3rd for a little longer, whilst it is decreasing it is still is better than any of the acceleration available in 4th. The 4th to 5th gear change looks about right, albeit it could be held a little longer as well.

Irrespective of when the gear changes are made, if the car was 10% lighter then it would accelerate 10% faster. Provided the grip is available, 10% improvement in acceleration at WOT could equate to about 1.5 sec improvement in lap times at QR Sprint!

Now to work on using WOT more and the brakes less as well as adding lightness

Acceleration by Eipeip, on Flickr

[Skifey]

So I've been a little busy guys, sorry I haven't responded to everyone's mad advice and help!
I might as well come out and say it though; I went out and - heeding everyone's advice - bought an NA6 with a 1.8L conversion, Megasquirt ECU and suspension already all done. Suffice to say, I PROPERLY BELONG ON HERE NOW! I've had no disappointment thus far owning it and god, does it make me smile

On that note; you guys do not disappoint. Thankyou everyone for all the mad advice thus far. You've all been awesome!

And I suppose I'll just move on to the next problem if you guys are still all for pitching in useful words!

Important questions...
- The car has been tuned at home by the previous owner and is running rich. Wheres the best/cheapest place in Brisbane that I can get this fixed?
- The car is a little sloppy/delayed/half asleep on throttle from idle. Is this normal? Can i fix it easily?
- The handbrake is weak as piss, the previous owner provided me with a new handbrake cable, whats the install process? link me?
- When the aircon is turned on the car drops in idle, not just a little, a fair bit. Enough to make it borderline stall at idle. Whats the fix? ECU related?
- The previous owner supplied me with a spare set of used injectors. Not sure what size or from where. He says there's 1.6L injectors in the 1.8L engine currently. Is there any reason for that? Should I be swapping them out for something else?

Not so important questions...
- Is it a dumb idea to put 15" low profile 225 width tyres on the rear and something thinner on the front?
- This forum has led me to believe that NA speaker size is 6.5" but theres conflicting information. Can anyone confirm? Because mine are rooted and need replacing
- Are coilovers on this car unnecessary for ultimate circuit performance? I've currently got king springs and bilstein shocks front and rear
- Is there any shop online or retail (preferably australian and not mx5mania.com) where I can source knicks and knacks like clear front indicators, aluminium trim pieces for interior?

HIT ME WITH SOME KNOWLEDGE PEOPLE

[StanTheMan]

Best & cheapest may possibly be indirectly related or totally unrelated.

Sounds like you have a crap tune when you say sloppy/delayed/lag from idle to throttle

Handbrake needs adjusting on the back of the caliber . There is an Alan key bolt which probably need tightening

I get a lot of my stuff from UK. Serious performance parts you may have to find in the USA but the Americans can be painfull to deal with. Postage costs a bomb and goes via Pluto to get here.

eBay , Amazon are also your friend and check out the forum sponsors obviously. they are on every page.
Mania
Mx5 plus
Mx5 parts & so on

[NitroDann]

It needs a good tune, by a patient tuner.

Expect to pay at the very least 600 dollars.

Dann

[Alex 2550]

Congrats on the purchase, Due to your location probably be worth getting in touch with Automotive plus (MX5 plus) the forum sponsor.
they are in Aspley. they could have a good look over your car, adjust handbrake ect but also give you a bit of an idea of things that may need attention sooner rather than later (if any). Also they may be able to have a look at the tune on your megasquirt as im sure they would of seen a few with there popularity in this community or point you in the direction of a good tuner.
alternatively (and i hope you don't mind me saying Mark) chat to Magpie on the forum about attending a dodgy day or social gathering, this forum is a very friendly group where we tend to look out for each other, you may even be able to find someone on here to look at your megasquirt maps and tell you where it can be improved till you get the time/money to get it on the rollers and tuned properly.
i wish you all the best with it, they are an awesoem car.

[manga_blue]

Congrats and good luck with it.

There's a cable tension adjusting screw near the base of the handbrake handle on the driver's side. Most problems with poor handbrakes on NAs comes from overtightening this. Basically the self adjusters in the calipers only ever adjust themselves when the cable is completely slack. If anyone tightens up the cable enough to stop it from ever being slack then these adjusters don't work automatically and you have to get into the calipers and do it manually with an allen key. Just slack off the tension adjuster at the handbrake until the cable goes slack, make sure all the little pivots underneath the car along the handbrake cable route are free, press the brake pedal hard for a few secs to let the self adjusters do their thing then tighten up the tensioner again until the handbrake is full on after 6 or 7 clicks AND NO LESS.

[Magpie]

- Is it a dumb idea to put 15" low profile 225 width tyres on the rear and something thinner on the front?

If tracking the car most people will say that 225 tyres (on 8" rims) are optimal for a MX5. AT the moment I'm running on 205/50/15 AD08R's and still have not found the REAL limits of grip that this combination has. Personally I will stick with 205's until such time as I can do consistent low times and cannot find the 1/10ths. Then and only then will I move to wider rubber.

- This forum has led me to believe that NA speaker size is 6.5" but theres conflicting information. Can anyone confirm? Because mine are rooted and need replacing

Speakers not needed in a track car and even if it remains road legal you cannot here the stereo (or passenger complaints) over the noise of the fuel pump/exhaust and gravel hitting the floor

- Are coilovers on this car unnecessary for ultimate circuit performance? I've currently got king springs and bilstein shocks front and rear

This is a decision based on class running in. There are some very fast OEM MX5 drivers without coilovers so are they needed? However if wanting to tweek the suspension coilovers add this ability (springs, height, rebound/bump, corner weights).

- Is there any shop online or retail (preferably australian and not mx5mania.com) where I can source knicks and knacks like clear front indicators, aluminium trim pieces for interior?

Again a budget decision. Keep an eye on the forum and Gumtree for MX5 parts that are for sale. MX5 Plus can 'find' most parts that you may need, give Dave a ring and discuss. By the way I do have Automotive Plus stickers on my car I use Motorsport Brakes for pads (rumour is there maybe a group buy on these with prices up to 15% off retail).

Important questions...
- The car has been tuned at home by the previous owner and is running rich. Wheres the best/cheapest place in Brisbane that I can get this fixed?
- The car is a little sloppy/delayed/half asleep on throttle from idle. Is this normal? Can i fix it easily?
- The handbrake is weak as piss, the previous owner provided me with a new handbrake cable, whats the install process? link me?
- When the aircon is turned on the car drops in idle, not just a little, a fair bit. Enough to make it borderline stall at idle. Whats the fix? ECU related?
- The previous owner supplied me with a spare set of used injectors. Not sure what size or from where. He says there's 1.6L injectors in the 1.8L engine currently. Is there any reason for that? Should I be swapping them out for something else?

Hopefully people with a similar ECU will provide you with some advice on a place near by who can tune your car (Lokiel/G). The idle/injectors/air con are all tune related. I use Haltech and GT Auto and in general this is where most cars tuned by Automotive Plus go.

Handbrake manga_blue already answered

Alex 2550 thanks for the Dodgy day plug. At the moment no more Dodgy days are planned, at least for the next few months however if demand is sufficient happy to host another one.

[93_Clubman]

car is a little sloppy/delayed/half asleep on throttle from idle. Is this normal? Can i fix it easily?
He says there's 1.6L injectors in the 1.8L engine currently. Is there any reason for that? Should I be swapping them out for something else?

As it's an NA6, check the accelerator pedal arm isn't separating from the firewall - it's not uncommon on NA6s.
NA6 B6 injectors were blue tops & NA8 BP injectors were tan tops - given you're running an MS, & it's a BP motor as opposed to B6 motor, no good reason to run the B6 injectors, but as Magpie says all tune related, so check the tune. Btw, there some MS base maps freely available for the BP motor:
http://www.megasquirtpnp.com/gen1/mspnp_downloads.htm
http://www.megasquirtpnp.com/mspnp2_maps.php