GlennB
Silver Level Sponsor
I am transferring this conversation from the SAOC Motorsport FB group as I think it will be useful to others and be properly archived here.
History: in 2009 I acquired the car in rallying setup with a nicely running but tired 1600 with the Weber DCOE40's. Lack of garage, tools and physical health meant I left all major matters to others and was happy to pay for it. In 2014 I bought a custom full race engine but left the DCOE tuning to the engine builder - the engine failed after 500 miles running-in and only 8 race laps. In 2016 I got tired of waiting for the engine to be fixed and bought a stock running 1600 which only needed a change to the idle jets for smooth operation. I also decided to build my own 1725. Eventually the 1600 full race engine was returned and I fitted it early 2019 and it ran nicely without changes to the DCOE's. It dyno'd at 97 BHP but was not re-jetted as there appeared to be an ignition misfire. On the track I was out-gunned by all the other cars but my main problem was actually a sticking servo plus rear suspension handling where I had severe difficulty controlling the car in the corners and probably lost as much time in cornering as I did from lack of top end. Lay-off and early retirement and an improvement in health meant I started to take on all aspects of the cars preparation, buying a hoist and a welder. I swapped the race engine for my fast road 1725 - using the same DCOE setup as before just to see if it was any good. The engine is a stock 1725 lower end, lightened flywheel, fast road cam 07097 and a vizard modifed head, skimmed heavily. Compression is 182 psi on all 4 cylinders so the skimming has retained reasonable compression. I decided to work on the rear suspension and found the shock absorbers had effectively failed (one seized and one very weak) and both had broken the custom made lower mounts. I replaced the shocks and welded up the mounts, also lowering the lot by 3cm. The race 2 weeks ago was the first one with the repaired suspension and the first time I was able to corner with confidence gaining back some of my lost performance. The engine runs really well, and smooth, a bit rich, but seems to limit after 5KRPM. I was still outgunned with no more power after 5KRPM and it is at this point I have started looking at the Webers.
I have 30mm chokes, 130 main jet, 165 air correctors, and 45F9 idle jets. This runs well with the 1725 albeit rich. I am sure I need bigger chokes. I have two objectives, firstly to have a good road setup which might mean a small tweak to the current configuration. The second objective is to have a major improvement on the track - but not to the ultimate as this 1725 engine is not internally balanced. Also it would be useful for the setup to accommodate the full race 1600 if I decide to put it back. Where do I go next is the question?
I was thinking 32mm or 34mm chokes with whatever other jets are appropriate and perform a complete swap from road to track for any track action.
The manifold is a Chris Draycott special, 8.5cm deep and I use gauze covers without a plenum or filter.
History: in 2009 I acquired the car in rallying setup with a nicely running but tired 1600 with the Weber DCOE40's. Lack of garage, tools and physical health meant I left all major matters to others and was happy to pay for it. In 2014 I bought a custom full race engine but left the DCOE tuning to the engine builder - the engine failed after 500 miles running-in and only 8 race laps. In 2016 I got tired of waiting for the engine to be fixed and bought a stock running 1600 which only needed a change to the idle jets for smooth operation. I also decided to build my own 1725. Eventually the 1600 full race engine was returned and I fitted it early 2019 and it ran nicely without changes to the DCOE's. It dyno'd at 97 BHP but was not re-jetted as there appeared to be an ignition misfire. On the track I was out-gunned by all the other cars but my main problem was actually a sticking servo plus rear suspension handling where I had severe difficulty controlling the car in the corners and probably lost as much time in cornering as I did from lack of top end. Lay-off and early retirement and an improvement in health meant I started to take on all aspects of the cars preparation, buying a hoist and a welder. I swapped the race engine for my fast road 1725 - using the same DCOE setup as before just to see if it was any good. The engine is a stock 1725 lower end, lightened flywheel, fast road cam 07097 and a vizard modifed head, skimmed heavily. Compression is 182 psi on all 4 cylinders so the skimming has retained reasonable compression. I decided to work on the rear suspension and found the shock absorbers had effectively failed (one seized and one very weak) and both had broken the custom made lower mounts. I replaced the shocks and welded up the mounts, also lowering the lot by 3cm. The race 2 weeks ago was the first one with the repaired suspension and the first time I was able to corner with confidence gaining back some of my lost performance. The engine runs really well, and smooth, a bit rich, but seems to limit after 5KRPM. I was still outgunned with no more power after 5KRPM and it is at this point I have started looking at the Webers.
I have 30mm chokes, 130 main jet, 165 air correctors, and 45F9 idle jets. This runs well with the 1725 albeit rich. I am sure I need bigger chokes. I have two objectives, firstly to have a good road setup which might mean a small tweak to the current configuration. The second objective is to have a major improvement on the track - but not to the ultimate as this 1725 engine is not internally balanced. Also it would be useful for the setup to accommodate the full race 1600 if I decide to put it back. Where do I go next is the question?
I was thinking 32mm or 34mm chokes with whatever other jets are appropriate and perform a complete swap from road to track for any track action.
The manifold is a Chris Draycott special, 8.5cm deep and I use gauze covers without a plenum or filter.