Twin Turbo Update No. 2

12 November 2001

With the car running again, and with all the new modifications that were to promise so much power, I was very disappointed at it's performance. make no mistake the thing was going a lot better than before, easier to drive (cooler and nicer convertor), but it just wasn't making the power we were expecting.

The current tune was 5-6 psi of boost, 30 degrees timing and 100 and 110 jets, and after a good hit the plugs were still white and I might have noticed some detonation going on. Something wasn't working properly so I looked into a few changes.

First a nice set of new ignition leads, as the old ones were giving strange readings on the timing light, something we still haven't figured out, but I guess I'll get over it now. Plus I was able to route the new ones down and away from the heat of the manifolds, where the old ones ran over and under them.

Shot of the new leads, they even match the paint!

Next modification was the carb hat. Although the original design was drawn from a book by a bloke who knew what he was doing, we felt there may have been a few things wrong with it. First we cut it down so that it was only as wide as the flange on the carby, this was to eliminate any 'dead space' in the hat. The other mod included fitting a 'ramp' so to speak inside the hat so that the air flows up into the hat and thenaround and straight down through the venturi of the carb.

The holes were needed for the carby stud and the fuel bowl breather tubes, otherwise this new design eliminates the chance of the air 'hitting' each other and ensures flow straight in.

With these two mods and a set of new plugs, we looked into a bit of a test drive. First round was still with the big jets and it was running very, and I mean very rich. It was surging and flooding like buggery, so we went down 16 jet sizes to 84's and 94's. This time it went, and strong, it wasn't boosting as early (a bit more jet required), but with 6 pound was still rich but running a lot better. In the past, with these jets the thing didn't want to rev, didn't boost and basically went like shit. Now, it's going the best it has, and with a week of tuning (read: more boost!), I'll be at the track on the 21st and ready to race!

In the past couple of months I also decide to update the interior of the car, to make it look half decent. Fixed up a few panels, made a set of new door trims, a new carpet as well as VHT dye the rest of the dash, kick panels etc. Doesn't look half bad for a nice backyard job eh.