Hillman Avenger Turbo

You mean by machining the wheel mounting faces? Yes probably, but I'll see how they go on first. Otherwise I'll end up with a pair of wheels specifically for the back of the car, or I'll have to get all 5 done.

Always an option, although I do like the current wheels.

I do think it would look amazing on a set of these Tvr wheels though, although they're 15" and the wrong pcd.

IMG_20230713_151124 by Chris Witkowski, on Flickr

Well I still haven't built the back axle, although I did paint it along with the arms.

I've also been messing with an idle valve. Up to now, the car hasn't had any idle control, other than setting the throttle stop to give a sensible idle. I had the warm idle speed set to about 850rpm, which meant the cold (summer) idle was very slow at about 500rpm. It's not a major problem as I only use the car in the drier months, but it would be nice if it started and idled perfectly in all conditions.

It is possible to control cold/warm idle speeds by having fairly retarded ignition timing at idle. This means that the throttle has to be cracked open a fair bit, as retarded timing at idle slows the idle speed. By then using more advance when cold, the engine makes more torque and speeds up. The problem with doing it this way, is that Tunerstudio's cold advance feature adds timing everywhere during warmup, meaning if you command an extra 20 degrees advance to bring the idle speed up, the entire table will have that extra 20 degrees until warm.

Besides, when messing with the idle timing, I've found it makes the most torque at about 35 degrees of advance, and it picks up and generally feels 'better' with the high advance. So I've left it at 35 degrees.

So anyway, the idle valve. It's a Bosch 3 wire PWM unit, which I've tied into the intercooler piping and the existing vacuum manifold like so:





I've opened out the hole in each manifold runner from 3mm to 5mm, although the barbs are 4mm bore. The vacuum manifold is fed via the idle valve through a barb with a 7.5mm ID. This combo gives me the ability to idle over 2000rpm or so, so it's plenty.

I only plan to use the idle valve during warmup, and once warm it will be closed. It does leak a bit of air through though, even when closed, so I had to back off the idle screw on the throttle bodies to account for this. For now it idles warm at about 950rpm, which is the lowest I can get it without retarding the idle timing as mentioned above.

I had to add an upgraded transistor to the ecu, as the standard one can only carry about 0.8 amps. It's the one stuck to the lid on the left. The other is boost control.