RE: Flyin' Miata Twincharged MX-5 in development

[mybrainhurts]

Shame Mazda made this model look like a dog.

[RBH58]

PunterCam said:

Over the last 10 years or so I've come to the conclusion that all turbocharged cars are ste. Rubbish throttle response, sluggish engines, crap power curves that make just pulling into traffic a fking lottery.. Shove this ruined mx5 up your arse.

A little inclined to agree. My wife has an Abarth 124 and I have an MX5 RF and I drive both regularly. The thing I prefer about the MX5 is its immediate engine response which, combined with a very mobile chassis, make it extremely easy to steer with the right foot. It also pulls strongly from as little as 1500rpm in ANY gear. The 124 is quite laggy and it’s really got nothing until the turbo spools up. It’s fun in its own (wait for it....whoosh) way, but it’s not as good a “sports car” as the MX5.

[hornmeister]

mainaman said:

I loved mine,probably the most characterful small four pot around.VAG axed it for cost reasons(cheaper to build turbos only) and over a sort of owners backlash-the type of drivers,who are not bothered to check the oil level every week,leading to in-warranty failures.

I loved mine too, when it worked.Great little engine/car combination.

I'm please you;re one of the lucky ones, however I take issue with your allegation of miss care. I suggest you spend some time on the Polo or cupra forums to get an idea of the propblems. My car suffered 9 breakdowns in 9000 miles from new. Oil never dropped below half way as I was fully aware of it's thirst and always fed super unleaded. It was completely stock unmodified, driven with care, always warmed up before pushing etc.

It melted 2 sets of sparkplugs, 3 sets of turbo pressure sensors and VW couldn't understand why it kept burning out wiring so their "master engineer" installed 2 sets at the same time to "solve " the problem.

All despite me telling them exactly what the well know fault was and what they needed to do to fix it. This was on the updated revision of the engine with the well known issues supposedly fixed. At the end I threatened legal action and they bought the car back off me. Was sold on to someone else who then sold it on 8 months later so obviously still not fixed. The amount of hassle I had to go through to get any sort of decent service and them not holding their hands up and fixing it properly are the reasons I'll never touch another VAG product Maybe I was unlucky or bought a lemon, but there does seem to be a lot of us considering the relatively low volume sales.

In theory having a supercharger for the instant punch until the turbo kicks in later and at higher revs is a great idea. In practice however unless it's a big heavy and solid engine and turbo the added complexity is a price not worth paying in my opinion. Not sure a turbo on an MX5 is going to be big and slow enough to need a supercharger, but if it works then good luck to them, I'll pass thanks.

Edited by hornmeister on Friday 26th January 11:34

Edited by hornmeister on Friday 26th January 11:53

[mgrays]

So what was VAG's problem?

Sounds like too much heat from bad ECU map running lean/pinking/over pressure.

If you want over 200 hp/litre you end up with the oversized turbo IMHO which is hard to manage. It also tends to drive you to lower compression ratios.. that in turn makes them inefficient off boost so they become thirsty and poor low rpm response. The engineered response to that is to add the supercharger to fill in that lack. A 400 bhp MX-5 is fun idea but you run out of tyre width so kind of pointless and driving it in town is a pain if you have not power below 3,000 rpm. Hence nice for track days or a marketing exercise (Keith and Bill doing a what the heck moment in Grand Junction!) but a 220-260hp level is more sane and you can just about keep the gearbox together! So I stopped at the 220-240 hp level .. so far one engine, one gearbox in 100k which is peanuts in terms of cost, and I now know what makes them break (do not lift off throttle at 110, ease it off or conrods undergo inertial pull test ... plus do not take red rags from hot hatch and sports bikes (nice to leave them behind but maybe not clever)).

[RBH58]

I think (maybe) 200hp is fine and more than enough in an MX5. Otherwise you start getting into diminishing returns. The OEM gearbox is probably marginal for long term durability with high torque, and you start needing bigger tyres and brakes and before you know it your MX5 is a 370Z.

If you want a faster MX5, why not just buy a Boxster?

Edited by RBH58 on Saturday 27th January 01:58