Advice on Normally Aspirated BP Engine Build

[CrazyRacer]

Well being the impulsive guy I am, I went and looked at the SE that SS11 is selling in this thread...

http://mx5cartalk.com/forum/viewtopic.php?f=73&t=70501

Seemed to be a nice clean car that drives and goes well (but I'm comparing it to a stockish NB8A). Its got a few decent mods on it including a NitroDann exhaust, bigger FMIC and piping and a MBC. YellowSpeeds and a few other goodies too.

But no, I haven't bought it, but considering it. He's asking $13250. A decent stock NB8B seems to be $9500+ (I know people keep telling me they go for $8000, but I haven't found one that I would call decent for that money yet).

So given the mods it already has, is it on the way to being SP decent, or there's still miles to go and I would be better doing a build from scratch.

What are the main issues with the SE that everyone seems so negative on them.

I've already got a 4.3 1.5 way LSD that could go into it, so does that solve the gearing problem?
I also have a rebuilt HKS GT2510 turbo which are pretty popular on CA18 nissan engines. Commonly used to make 180rwkw on 98, but I've seen dyno sheets of some hitting 215 on E85 at 17psi. Supposed to be pretty fast spooling too, so thought this might be a good future upgrade. Who does decent manifolds and dumps to fit the garrets?

[davekmoore]

Still need exhaust, manifold, ECU, tune.

Whether that works overall compared with a non-SE depends on what you'll use the car for.

[CrazyRacer]

Its already got a decent looking NitroDann exhaust.

But yes, manifold, ECU and tune.

Looking to use it as a fun weekend road and track car, not as a daily.

The fact that its a factory turbo appeals. How legal are after market turbo kits seen as being in Victoria?

[Nevyn72]

How legal are after market turbo kits seen as being in Victoria?

Well there's your answer, looks like an SE or SP if you want to go for turbo without major headaches then!

[davekmoore]

Forgot about the ad mentioning the exhaust. And it's a 3" one, which is what Dann would suggest with your Garrett.

Yup, simpler to put a proper turbo on a car that came from the factory with a turbo, however weedy the OEM one was.

If you do this, invest in a proper combo of ECU and a tuner who knows the ECU inside out and will guarantee results.

[Ned Loh]

if you want a fast car car turbo is the way to go. Lets face it, even moderately modded naturally asipated mx5 don't have much HP. To legally drive the car on the road, and go fast on the track, the simpler option is to buy the car you linked to.

Looks like very good value to me (no association with seller!). and yes I agree good NBs are closer to 10k than 8k.

Good luck!

[hks_kansei]

The fact that its a factory turbo appeals. How legal are after market turbo kits seen as being in Victoria?

Easy answer, they aren't.

Basically Victoria has oddly strict EPA rules compared to other states, while I havent read the EPA stuff for a while when I read it last the big hurdle was the ECU, there was a clause in there that basically said if you have the ability to change the tune to not pass emissions then it's an instant EPA fail (yes, regardless of if it actually passes emissions or not)
The rule covered Standalone ECU, piggybacks, and even chipped OEM ones.

If you want a 100% Legal turbo MX5 in Vic you have 4 options:

Buy an SE
Buy an SP
Buy an NA6 and have AVO install their legal kit (not that cheap)
Buy any MX5, have a turbo installed, then contact an engineer and discuss your options for making it legal (note: none likely to be particularly cheap)


The last option is to buy an NB8A or NB8B and install all the SE parts into it (engine, ecu, brakes, gearbox, etc) and then fill out the Vicroads forms for adding engine combination offered by the manufacturer... this option might still need engineers approval though. (not to mention you have to gut an SE in order to make a replica SE and end up spending a lot more than just using the SE)



The basic premise here is, either turbo and try to stay hidden, or rego the car at an address in Albury and not worry about Vic rules at all.

[CrazyRacer]

It sounds like having a quick, legal car for both track and road is not really a viable option. I'm starting to think a dedicated track car is really the best way to go.

I had a look at the car that Owen Boak has for sale at them moment, which has some nice stuff on it, but only a standard SE engine and does require a bit to be spent on it to get it on the track as he's keeping some of the goodies on it for another car he has. I'm considering it, but it might be a bit impractical for me just at the moment.

I do have another track car project that is in the very early stages of a build, but is held up at the moment. It is turbo , but not an MX5 .

I might be better to stop being so impatient to get back out on the track and just finish that off, or just track the stock NB I've got while I finish that build. My main problem with that is that my daughter has claimed the NB for herself when she turns 18 and gets her licence, which is only a few months off.

[madjak]

I think it's hard to balance out a track car with a street car especially if you have to keep it legal for the street use. Most of the modifications that are required to make an MX5 work on the track like modifying the brakes, power increases, full cage etc aren't legal on the street. Either way you end up with a very compromised track car or an illegal street car.

[Magpie]

I went down this path and have a quick road car but a compromised track car. However at WTAC what is considered 'road registered' probably can't be legally dríven on the streets, but that is another story. Decide what class you want to compete in and build to those rules.

You can have a full cage on the street provided the mod plate was done previously. It is not possible, at least in QLD to have a full cage mod plated now.

[davekmoore]

It would be brave to drive a car with a full cage on the road with just an inertia reel belt and no helmet. For any degree of protection from hitting your head on the cage in an accident you'd need to use your harness, helmet and HANS device. That would be inconvenient and would be like waving a red flag at Plod, especially with the roof down.

[sailaholic]

Depends. Ever dríven on the road with a harness? It's a pain in the ass. Shoulder checks are all but impossible if the belts are done tight. I think I'd take my chances with a 3 point in traffic.

Chance of hitting the roof bar also depend on its position and your seated height.


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[zossy1]

Owning a dedicated track car is a liberating feeling - you can go nuts with it (within your chosen rule set) and it's a lot of fun.

[Magpie]

This thread has been the epiphany for my next journey... how to have your cake and eat it (have 2 cakes).

[madjak]

Yeah two cakes, a trailer and a towing vehicle.