Getting back on track

July 24, 2011

Life tried to get in the way for the last 12 odd months, but we’re back. The priorities this time aren’t major engineering overhauls, but reliability issues and tidying up. It’s not like us at all, but here goes.

There were some issues last year when I drove at Phillip Island (I was too lazy to blog it. Sorry) where the car would boil at the end of a run as I was coming into the pits. Solution: replace the nearly kinked rad hoses with some nice mandrel bends. Julian did the honours with his newly honed Tig welding skills.

Soon to come, a floor below the radiator to force more air through the fins and not up from under the car. Hopefully that forces enough air past the water  to keep it cool on the warm down lap and in the pits.

It wouldn’t be a Fiat if something didn’t fall off on the track. In my case,it was in the pits where I rolled the drivers side window down and it refused to roll back up. It wasn’t a race stopper at the time, but it was pulled apart after the weekend and hasn’t put itself back together yet. A job for today maybe…

The throttle cable will get some love, neither we nor the scrutineers were particularly happy with the way our exposed throttle cable spanned half the engine bay. The current setup only allows about 1/2 the pedal length under foot before the butterflys hit the stops. So we’re looking at some ways to protect the cable and adjust the pull ratio to get the right balance.

Also on the cards, a massive anderson plug to give us some more juice to crank her over. Then we go racing again!

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Solid

August 1, 2010

There have been a few days on the machine tools recently to convert all the suspension bushes to rod ends and spherical bearings. The old rear a arm bushes looked like chewing gum when they popped out, it should tighten things up nicely. Further details to come when we have ironed out the kinks and it is on the car. Cant wait!

Phillip Island…

June 10, 2010

We got there in the end…well I got there in the end. Dave was unfortunately committed for the weekend so he left if to me to do our first shakedown run in quite a while! The weather didn’t look to crash hot heading down to the Island with grey skies and sideways rain. Once the car was off the trailer, the weather had thankfully decided it had rained enough and would be happy blowing a bitterly cold wind.

A quick scrutineering session where the absence of headlights was questioned…and out onto the track.

Over the next few sessions the track dried out and I slowly remembered how to drive. Apart from a the crummy Fiat windscreen wiper coming loose when barrelling over Lukey Heights and a less than confidence inspiring brake pedal…we seem to have a bloody good car.

The motor now makes good power, pulling strongly past the redline in fourth and the grip with the new Kumhos is superb. It proved it’s corner speed against a few well prepped clubmans, just not having the same pull as a 2l out of the corner. Something to aim for.

The last session was cut short by an unfortunate ‘too many tubes in one empty thinners container’ excuse for a catch tank we had. Some degreaser and a rethink of our catchtank config will sort this for next time.

Thanks must go once again for John for lending us his trusty trailer and tyre tools and also to dad for coming down in the crummy weather with an esky full of lunch.

An afternoons work…

May 2, 2010

We better find an afternoon before May the 30th to complete the following, Phillip Island is beconing!
  • Bleed Brakes
  • Header Wrap
  • Carb Heatshield
  • Boot Lid Pins
  • Change front Towhook to fabric loop
  • Battery and Tow stickers
  • Pump Jets – Downsize
  • Swap Ignition system?
  • Wash
  • Nut and Bolt Check
  • O2 Sensor

Research, then trial and error.

Research was teh crucial part, and the reason why it has taken us nearly a year to progress to the point where the car will start and idle successfully. I haven’t written on this blog for many months because it has been just too embarrassingly disheartening. For a while I lost faith, thought we’d spent too much on some crappy leaky sidedrafts which didn’t bloody work. Research shed some light. Here’s the saga as it unfolded.

Synch Carbs

Juice Synching Carbs

Possibly as far back as 12 months ago, some reading on Guy Croft’s excellent forum turned up the holy grail of 40mm Weber sidedraft jetting for our particular application. Some careful fudging of these figures to allow for a smaller displacement went on in Julian’s head, and we came up with a theoretically perfect jet combination. The carbs were already rebuilt, the world’s sexiest airbox was welded up so all that was left was to insert textbook jets and race.

Not quite.

To cut a year-long story short, we found out that there are many different series of Dellorto DHLA carburetors (See this article, possibly originating from the Sideways Technologies forum). Our particular ones came off an Alfa, so were probably emissions, meaning that the progression circuit was designed to meet the US emissions laws, and thus less tunable than earlier non-emissions (and most Weber) carbs. Thus the textbook idle jets we forked out for were way too lean (we’d planned on 47, currently running 60) and air correctors were too small (details to follow soon!).

The Interrogator

Pross, 'The Interrogator'

This much we now knew, so we booked in to see Pross at Enhanced Motorworks in Fairfield. After 5 or so dyno runs, and a consultation by a talking computer called the Interrogator, we had eliminated the lean idle, synch’d the throats, discovered the rich spots and dialed the advance. It took a morning, but Bianca is finally dialled for race. The final figure was about 60kW / 80 HP at the wheels. I guesstimate that the whole package weighs less than 800 kg wringing wet, which brings us close to 100HP/ton. I’m off to the Alfa club website to book us in for 14 March. Watch this space!

P.S. Thanks go to Woppy for his thoughts on why it wouldn’t hold idle, and Peter at Thornbury Carbureters for being so conveniently located.

sumps up

November 9, 2009

The weather have been fantastic for the garage lately, a night or two throwing the spanners round after work and Bianca is all but buttoned up again. Last week the super special sump went on to save the main bearings from our sticky kumhos.

<sump

Thanks once again go to John for letting us know this had to be done!
Dyno bloke will have be called upon shortly.

A quick aside

April 23, 2009

I was reading “The Grapevine” at Autosport.com and came across this story. It’s second story the article.

http://www.autosport.com/news/grapevine.php/id/74664

Apparently we’re not the only ones naming our race car (Not that I’m claiming that we invented the phenomenon). Let’s hope we don’t total Bianca and have to contend with building Bianca’s Dirty Sister. Although if we built up a Motec fed 1600…