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PH Fleet

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Wednesday 1st February 2012


PH FLEET INTRO: MAZDA RX-8

A warm welcome to the car that may (or may not) live up to the name 'RX-Sub8'...


There’s no going back now. I’ve bought a Mazda RX-8. Not only that, but I’ve bought one of the cheaper ones too - only £2,800 for a 2004, 231hp six-speed manual. Stop! Don’t hit ‘comment’ just yet...

I needed to replace my turbocharged Eunos track car with something standard, modern and easy to swap between the UK and German registration systems. And my budget was capped at the £2,750 I got for the Eunos.

Sorry Chris, but an EP3 Civic Type R would have ticked all the boxes ... except I’m a snob when it comes to rear-wheel drive.

Running in process well under way
Running in process well under way
Honda S2000s  were my next favourite, decent ones were just a little bit out of my budget, and I nearly got my fingers burnt looking at cheaper examples. The next sensible choice was a BMW 330Ci. The more I looked the more I wanted to change though. A great car, no doubt, but too heavy and no LSD.

Noise test
While conducting vital ‘research’ into the S2000, I’d happened across one of the Hot VersionInternational videos. In it the S2000 was compared to the RX-8. And there was a modified RX-8, with its 9,500rpm rotary screaming through titanium racing pipes like a tin-bucket full of chainsaws thrown down a well.

This was the sort of vital information I needed. An RX-8 it would be!

Already aware of the drawbacks of rotary motors, I began doing my research. The issue of RX-8s blowing up without warning isn’t quite as dire as some would have you believe. Yes, if used incorrectly and poorly maintained, they are rotary hand-grenades simply waiting for a location to explode. One of the quirks is the fact sump oil is metered by the ECU into an injection system and sprayed into the combustion chambers to lubricate various seals. If you thrash it the ECU pumps more oil in. If you don’t check the level and let it run dry, then it doesn’t get lubricated.

Failing to maintain the ignition system doesn’t result in a typical piston engine misfire either, instead you just end up with a lack of power and a load of unburnt fuel washing away the vital lubrication. Starting from cold repeatedly, without really warming up the car, is another way to ensure poor ignition over time as the plugs get oiled. A lack of compression in the engine more often than not comes from one of these problems, and a guaranteed rebuilt motor is about £3,000.

This is where the Rex will spend its days
This is where the Rex will spend its days
Pop goes the rotary?
So the car I eventually chose didn’t just have full Mazda service history, but a recent compression check and an upgraded ignition system too. To be fair, the forums have plenty of anecdotal tales of people with engines lasting less than 50,000 miles. But I took heart in the few examples being used on track regularly with over 100,000 miles on the original motor.

And how do I intend to keep my rotary engine sweet? Even though it’s going to be thrashed around the Nurburgring every week? Through proper maintenance and lubrication. Dedicated rotorheads recommend pre-mixing a quality two-stroke oil into the fuel with ratios from between one part oil to 250 parts fuel, right up to 1:100 depending on how you’re driving the car. Indeed American firm Racing Beat dyno-tested one of their race cars with pre-mixed fuel at a whopping ratio of one part oil to only 76 parts fuel (that’s over half a litre to a tank full) and got a 4hp power increase. So better lubrication, peace of mind AND more power? I like it.

The kind of numbers we like on a rev counter
The kind of numbers we like on a rev counter
Gadget freak
Regular oil changes are one way to prevent dirty sump oil leaving carbon deposits in the chambers. Another complementary tactic is to block the automatic system’s oil intake from the sump, and instead feed it nice fresh two-stroke oil (designed to be burnt) from a separate container. One example of this is the Sohn Adaptor, which I really like.

My first opportunity to drive the ‘new’ RX-8 at full speed on the ‘Ring came recently and the experience was far from disappointing! 

Handling is like a slightly bigger MX-5, which is no surprise considering they share the same overall layout of double wishbone fronts and multi-link rear. But the balance is what really excites me. I hate understeer that can only be turned into ‘snap’ oversteer by violent methods of lifting and stabbing the gas. But in the Mazda understeer and oversteer are dictated by the driver and not the chassis. Check out the entrance to Adenauer Forst at 2min 40sec in the video below to see what I mean.

The standard car even has a Torsen limited-slip diff too, so drive from the tighter corners of the Nordschleife is perfect, no understeer at all.

The brakes, even with stock pads and knackered discs are a definite cut above the average too, with big vented discs all round (323mm on the front!) and not much weight to slow down. I can’t wait to stick new fluid, discs and pads in there. With stock power there’s no way the car will need a big brake kit.

RX-8 shows great promise as a track toy
RX-8 shows great promise as a track toy
Now the fun starts
Anyway, there’s no real way to increase the power significantly without doing crazy stuff like turbocharging (Greddy does a kit) or supercharging (Pettit Racing). Things that I can’t consider if I want to put the car on the German system this summer. I will, however, definitely be looking at an equal-length exhaust manifold and free-flowing exhaust, not to mention a de-cat (for the private trackday events only, guv) and a nice intake. But that will be more for sound and revs than overall power increases.

It would be a shame to rip out the lovely red and black leather interior, so for this season at least I’ll probably resist the urge to cage it all up.

After all the service items are done (brakes, tyres, oil), but before I blow cash on extravagant exhausts, there’s one thing I am keen to work on more; the awesome chassis. I want to drop it a little more, stiffen it up but still keep that balance. Yes, I’d like to have my cake and eat it too. Options range from the predictable (Eibach lowering springs), to the sensible (Koni Yellow dampers with H&R springs), and all the way up to the ludicrous (Ohlins track and street coilovers, costing the same as the car).

One thing is for certain, I’m already loving my new Rex and I can’t wait for summer. Nurburgring F1 track, the Nordschleife and even a few trips to Spa. Let’s just hope I’m right about the motor and the nay-sayers are wrong... and NOW you can leave your hand-grenade comments below.


FACT SHEET
Car:
 2004 Mazda RX-8 
Run by: Dale Lomas
Bought: December 2011
Purchase price: £2,800
This month at a glance: Ignored the critics, bought a Wankel, made grand plans for modification but secretly hopes the mod budget won’t be spent on a re-con motor...


Author: Dale Lomas