A broken ebay record

I hate to sound like a broken record but I am sick to death of seeing Chinese rubbish here in the workshop. I know it is cheap and Ebay make a fortune from selling it but if it doesn’t work then it isn’t cheap. Take this superbly anodised fuel pressure regulator, a direct replacement for the original. On the face of it, it works. But when you apply a vacuum, or pressurise the unit, the fuel pressure does not move. Any turbocharged car must have a rising rate regulator, this one does not even respond to vacuum, let alone boost. So how cheap is it when you have to buy another one and have had a wasted journey to the rolling road?

1.8 Turbo

I see an awful lot of VW 1.8T engines here and we regularly do this little mod to the throttle body. The stock ECU does the idle, (even though it is a cable throttle), through the drive-by-wire motor on the body. The way it works is that the throttle is almost closed and then the VW ECU adjusts the throttle to give the desired idle speed.

When you fit any aftermarket ECU you then find that the car idles at about 500 rpm. We drill out the body and use an Allen bolt as a throttle stop. I don’t bother with a lock nut; I just put a dab of Loctite on the thread and wait for it to go off. With engine heat this is only a matter of less than a minute. This allows you to set the throttle with very low ignition advance on idle. That way when the engine is cold the idle stabilisation system, using the ignition advance, has some air to work with and you have half a chance of the cold idle holding up.

Filters

We do a fair bit of testing on the rolling road; it isn’t all just mapping. One of the things we have looked at in the past is air filters. Just to give you an example we tried several different filters on a certain bog stock K Series engine and could not find one that gave more power than the original stock filter. The aftermarket filters can come into their own once you start modifying the engine though. But you have to think about how you install them.

We had a Zetec 1600cc engine on the rollers and when we fitted the filters over the intake trumpets the power held up no problem. Not quite job done though. When you shut the bonnet it looks like the air filters are somewhat restricted. Sure enough, a power run with the bonnet closed resulted in a loss of 5 bhp. If you look at the power curve you can see how the bonnet-down flow started to restrict air flow from 6000rpm onwards. Below that there was no real change.

While we are talking about filters, do bear in mind that the filtering agent in all these filters is the oil that you coat the filter’s surface in. The medium, be it cotton of foam is just there to hold the oil. No oil on the filter means it will not filter much beyond the odd passing brick!

Turbo Pipe

Young Jono here has sold his Fiesta and replaced it with an Audi A3 Turbo. Naturally, being young and having a pulse, he wants to play with the engine. The 1.8T engine is very tuneable but like all engines you do need money if you want the best from it. Our own Golf has a KO4 turbo and big bore exhaust and it makes over 280bhp – too much for the car (on the road) if we are honest.

A big part of getting power from a 1.8T is the exhaust system on these cars. The stock outlet pipe is pretty mean in terms of diameter so Jono has “invested” in a Piper Exhausts’ outlet pipe. You can see the difference in the pics. With no other mods this gave him a power gain over stock and we are regarding it here as an investment for when he does get the bigger turbo.

Lotus Elan

It was always a bit of a small car in its day but when you look at the original Elan now against a so-called “Super-Mini” it is tiny. This example was re-built by Spyder Cars and they fit the Ford Zetec engine in place of the original twin cam. A stock Zetec with throttle bodies makes anywhere from 160 to 170 bhp with perfect road manners. The original Twink made 105 to 115 bhp and has all the bad manners of a competition engine. This was the car of my dreams when I was a lad; it still looks perfectly proportioned to my aging eyes!

Superflow engine dyno

It has been a long haul but the Superflow 902 engine dyno here at Emerald is finally up and running! We have a 2.3 Duratec in place and are using it as a mule to gain experience with the kit. I have to say that I love it. You can sit in comfort and map away without ear defenders for a start. I keep looking at the water temperature (after all the years on the rolling road it is a habit I can’t seem to break) but the temperature hardly moves. That’s one advantage of a 1000 gallon radiator! We can see the water temp going into the engine at 70 degrees and coming back at about 75 degrees - when the engine is making something like 40 bhp.

It was the throttle control that took some time to sort out and held things up. The system comes with an hydraulic throttle on the console but initially we had problems with it not staying on the arm’s brake. You put on some load and the lever creeps back, reducing the throttle setting. I fixed that by routing the throttle cable from the lever to the bodies but then it did not respond to snap throttle closing. You could see from the software that snapping back the throttle did not result in the butterflies closing straight away. If something does go wrong I want to be able to shut off the power a.s.a.p. so I wasn’t happy with the hydraulic throttle.

A super long cable would not work so I looked into Drive-by-Wire. I found a motor from a BMW M3 that basically linked to the BMW throttle bodies via an arm. It was a simple matter to extend the arm and then have that work a very short throttle cable. The K6 ECU has the hardware to run drive-by-wire throttles but it isn’t released yet. We have a test ECU now on the dyno operated from a throttle pot that we mounted the Superflow hydraulic throttle arm. It works perfectly; you can’t move the arm faster than the throttle bodies respond no matter how fast you push or pull on the lever. It also stays exactly where you put it, making mapping a lot easier. At the moment the dyno is just for us to play with and we plan to use it to develop new features for the K6 ECU. Think of it as Dave’s early Christmas present to himself!