I was finally getting happy with the car, and I took it to my parents and gave my dad a test drive. 500m down the road, accelerating out of the village, and it started running on 3 cylinders!
We got it back, and I took off the cylinder head again. 3 of the 4 pistons looked like the one above. Disaster!
That knocked my confidence with my ECU and ITBs a bit, and after I got some new Pistons I got a kit from Webcon with some beautifully machined throttle bodies and their own ECU. I had to make a second ECU that handled just the VVT, but with that (and me running the car on premium fuel!) everything worked well.
However, Webcon ECUs don’t do VVT, they don’t ‘learn’, and they charge serious money for the interface cable and software. I took the car to get mapped, and unfortunately my VVT ECU wasn’t holding the valve positions steady at higher revs, so we mapped it without.
The end result is only 165bhp@7000rpm, and very little torque. I’ve since fixed the VVT, but don’t fancy paying another £400 to have my car’s gearshift cables fried again on an RR with inadequate cooling.
So this is where the real fun starts. I’m designing a new ECU around an STM32F4 ARM, and I’ll try and keep this blog updated with my progress…
The engine I’d chosen was an LE5, a 2.4 litre VVT engine delivering around 175bhp. The original was 147bhp.
Unfortunately the original ECU wouldn’t work in a UK car (immobiliser, CAN bus, etc) so I set about making my own (none of the affordable ones did VVT)… I mean how hard could it be?
While I was at it, I added some ITBs I’d got from a GSXR motorbike (the ITB that came with the car was electronic, so would have been even more difficult to interface). In a few months I’d got it running relatively well, however there was a lot of trial and error and it seems it took its toll on the engine!
I did some minor modifications of the inlet and exhaust, and then on eBay I saw a gas-flowed cylinder head with sport cams for a price that seemed far too good to be true. It was!
I finally plucked up the courage to fit it… Then a few months later, I was driving back home through the country roads. Accelerating out of the last corner before my village, at 6000rpm, I lost all power, and oil pressure and low coolant lights came on within a few seconds.
When I took the cylinder head off, I was greeted with the images above. If you look carefully you can see a valve seat has dropped out of the cylinder head, which seems to be what caused the destruction. This snapped the head off the valve, which was then fired down through the piston, warping the crank and putting cracks in both the block and the sump! It was a write off.
I didn’t want to go back to where I was before though, so I had a research and realised I could fit a better engine. In the US the same engine block (Ecotec) is used in 2.4 litre engines, so I ordered a second-hand one and had it shipped over from the states…
I thought I’d start off by sharing a big personal project of mine. About 7 years ago I’d saved up from my first year of work, and I bought the car above. It’s called a Vauxhall VX220 in the UK, or an Opel Speedster if you’re from Europe. If you live anywhere else you’ll probably never have seen one, but it’s basically a rebodied, rebadged Lotus Elise.
I’d made a kit car with my dad a few years before, but it wasn’t sensible enough for everyday life, and yet I missed the raw-ness of it in the MX-3 I’d got to replace it. The VX220 turned out to be more practical, and a whole lot more exciting than the kit car, and I fell in love.
I started off servicing it myself, and with some encouragement from the owners website I got the suspension geometry changed, as well as tyres, and then I started to get hooked…