Knockhill race circuit track day 5/5/2008

 

The Glenrothes Car Club track night gave me the opportunity to give the Abarth it's first proper test since it's rebuild in October last year. As such it was the first chance to test out the modifications made to the suspension and engine and see what difference they make to the car. The weather was sunny and dry and track conditions were good. The evening lasts two hours and it's an open pit lane so you can just do your own thing, come in and out when you like. The night was quite busy and there was a mix of cars on the evening, some very quick which meant you had to keep a close eye on the mirrors. It does compromise times as you have to come off line to allow faster cars to pass but the standard of driving was good. Below are the list of modifications carried out during the restoration. The aim was to give more power and increase front end grip - to reduce the understeer

 

Modifications Made

 

Suspension

Uprated dampers and Springs

Modified geometry

Increase in rim and tyre width on the front

 

Engine

Ported head

Carb bellmouths added

Manifold matched to the head

Increased choke size and re-jet of carbs

Larger radiator

 

 

I opted to do 15 minute stints and then take 15mins for cooling down which meant I got about an hour of track time in total. During cooling down I could check the car over to make sure nothing was getting damaged. I have to say that I'm quite happy with the overall improvement from the modifications. Lap times were a best of 70 seconds and is an improvement of about 3-4 seconds. It might have been possible to break into the 60's with a banzai lap.

 

The handling in much better with much more grip from the front end resulting in more neutral handing. Lift off oversteer is now possible and the tyre wear is now even across the tread, previously wear was concentrated to the outside edges. Front end grip is so much improved that the rears are now working quite hard, the rear tyres having rubber scrubbing off like the fronts. The movement from the rear is now quite noticeable so a great improvement. The engine never missed a beat and temperature stuck dead on 90 the whole time. The only thing concerning me was oil temperature which rose to around 3/4 on the gauge, a larger oil cooler might be invested in to solve this. I was a little disappointed with the power increase, I am expecting more from the engine, it is quick for an Abarth but I'm going to go back and look at the jetting.

 

What now?

Well overall the car went well for basically a road car. It's not really a track car although it is fun to drive on track. I'd like more power so I'm thinking about a change of cams and carbs to extract more from it although that would be some way off. The handing is now nice so just a change of tyres to something grippy would be good. With these changes I'm sure it would drop it well into the mid 60's which is pretty good.