Grumpy Old Man.
It’s official! I am now a fully paid up member of the grumpy old man club. I had my 65th birthday last month and I am now a pensioner. Now I can complain about everything, I’ve paid my dues and I have earned it.
So, first grump this month is about wiring (yes again). People will spend thousands of pounds on building a superb engine and then save a couple of quid on the wiring loom. The stupidity of it beggars belief. The life of the engine is hanging off those few critical wires. This car came in after the first engine had melted and now it was my turn to try and sort it out.
First off there was a strange intermittent ticking noise coming from the engine bay with the ignition on but the engine not running. Looking at the live mapping screen the rpm reading was flicking up to 80 or 90 rpm and back to zero. What I could hear was the coils firing off because the ECU was being told that the engine was turning over (when it obviously wasn’t). A quick look at the crank sensor wiring showed that it was not shielded wire and there were some very dodgy looking joins on the loom. My guess was that one of the ECU PWM (pulse width modulated) signals was showing up in the crank trigger wiring. The easy test was to make up a shielded wire and run that around the engine and into the ECU. Problem solved, now on to the mapping.
Except now I had no MAP sensor reading. You can see the bodge job on the MAP sensor wires for yourself. We fitted a new plug and made proper connections further down the loom – some people have yet to discover heat shrink it seems. A quick check on the boost solenoid showed that this was not working. The car was purported to have been previously mapped to 1.5 bar of boost so it must have worked at some time. Investigation (yes, wiring again) showed that the solenoid was wired to the wrong pin in the ECU – suggesting that it had actually never worked at all. That was an easy fix, just move the pin to the right hole and it worked fine. Then finally the idle air valve wasn’t working properly but that was just a wrong setting the ECU software.
So the engine was finally mapped and it worked okay. I did hear that the people who did this installation originally wired it up for a different ECU, only to find that the chosen ECU did not do five cylinder engines! My real bitch here (now that I am officially grumpy) is that if you set yourself up as an expert and take money from people for doing a job – you really should be up to the task.
And now for some good news: for K Series engine owners. I see quite a few K Series engines here and cars like the Rover 200/25 are very popular in grass roots Rallying where the motors have to remain pretty stock. But in a series where you can run any original part there’s a new trick recently come to light. A Rover specialist who uses us measured up a lot of standard Rover cams and discovered that the VVC exhaust cam is a bit hotter than the standard Rover offering. He fitted two VVC exhaust cams to his 1600 K Series and came up to have the car mapped. Owen from The Rover Centre is no fool; he brought a pair of stock cams with him to do a quick-change operation if it all turned to the brown stuff. Happily this wasn’t needed. We gained nearly 20 bhp over the stock 1600cc engine which is pretty good when the rest of the motor was totally standard. Idle and light throttle drive were perfectly acceptable too. If you happen to have a few of these cams lying around it’s a good cheap route to extra power.
Hanger 111 Supercharged Elise.
Hanger 111 is a Lotus tuning company who recently purchased the rights to the Turbo Technics Elise supercharger conversion. Greg at Hanger 111 spent some time converting the system over to the current Rotrex blower unit which runs a separate traction fluid lubrication system whereas TT used the engine’s oil supply. We had the first one in for mapping recently. The car would have made about 230 bhp on the original TT blower so it would be an interesting comparison with the later Rotrex unit. Being old and grumpy (see start of feature) I wasn’t expecting much but the result exceeded all expectations. 260 bhp is really impressive and there’s a fair dollop of torque to be had too. The result is one quick road car that isn’t minus all the civilised road manners either.
Just feast your eyes on the Lotus 520 shown here. Colin Chapman’s idea of a family car wasn’t exactly a Ford Cortina. Cars like this immaculate restoration frighten me to death; I am scared to touch them in case I do some damage of mark the interior. When you look at the standard of workmanship in this restoration I start to wonder if you can take things too far. Personally I would be scared to use this car; it’s almost too good...or is it just me? Either way, enjoy.
A few people have been asking how we are getting on with our RX7 V8 conversion. The answer is: slowly. Part of the problem we had was that the turbos fitted in nicely exactly where they were, but that meant a slight restriction to the intake pipes. The chassis was half obscuring the rubber inlet pipe. Personally I did not see this as much of a problem; the engine would already make more power than could be used by any sane driver. However, I am only half the team on this conversion and the other half is a bit of a perfectionist so the chassis had to be modified. Being a great believer in letting people who are better than me get on with it, we enlisted some help from one the guys working at Turbo Technics. Young Tim (everyone is younger than me now) gave up his Sunday to come over to Norfolk and cut out the chassis, then weld in some strengthening plates to put the meat back into the car. It took forever with Tim working well into the dark hours. Really neat job and another major step towards breaking the diff, the drive shafts, and shredding the tyres! Cheers Tim, we owe you!
The response to our adjustable trumpets (ALI's) has been amusing to watch on the internet. There are people out there still worrying themselves to death over a tiny step in the inlet pipe. What they can’t get their heads around is the results. I think I have been around long enough for people to believe that I do not make things up. The results show massive gains, or losses, with a change of inlet length and not once have I seen a tapered trumpet give a better result than the parallel system. The step makes no difference and I have proved it on the flow bench and the dyno, but still they don’t believe it.
The potential gains from finding the right length are huge; the losses from the step are immeasurable but still, like a dog with a bone, they can’t let it go. We tried these trumpets on a full race, full Monty, K Series engine. The original trumpets were 50mm with massive intake area where the trumpet tapers outwards. Putting on some 45mm adjustable trumpets gave a good gain in mid range torque with only a small drop in peak power. The answer will probably end up as parallel 50mm trumpets. As the engine builder said at the time: “we used to have parallel trumpets on Weber and Dellorto carbs, what has really changed since then?
Let me finish this month with a brief mention of some testing I have been doing on cam timing. We have been tasked with sorting out the ECU needs of a Toyota engine which has variable cam timing on both the inlet and exhaust valves. Looking at the available duration it seemed to me that we could get all the right idle and light throttle running from having no lift on overlap, then get a big power gain from pulling the cams in and getting some proper overlap. That has been my experience with performance cams in the past. But this engine has stock cams and I was in for a rude awakening.
The engine makes best power with almost no overlap and when you pull the cams together the power disappears! It seems like Toyota use the inlet cam for power but use the exhaust cam to back-feed the exhaust gas as a form of EGR (exhaust gas recirculation) without all the valves and pipe work seen on a conventional EGR system. Tricky stuff but the question is; will we be able to use this system with a proper inlet and exhaust to get the best of both worlds from a hotter cam set up? Watch this space!