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Yeehaa!! Slomove is On the Road Again

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  • Yeehaa!! Slomove is On the Road Again

    After 2 months of engine upgrade work (head porting, Kentcam FZ2002 cams, high lift valve springs, alloy retainers, new tappets and vernier pulleys) I am proud to report that my engine is running again. :D :D

    I did the prescribed ritual of 20 minutes fast idle break-in and then off to 80 miles on the freeway. Everything looking good so far, that means I am O.K. for the Streets.

    No idea about the performance gain yet, I am trying to keep the revs under 5000 for now. I have also loaded a very conservative ignition map. But next week I am going to do some experiments and measurements with the Gtech and compare with stored runs.

    Let's see it it was worth the ahem, cough, oh dear, cough, well $2400 :shock: :shock:


  • #2
    I am at the very opposite end.

    This weekend I redesigned the fuel system in the engine bay in order to fit a one-to-one fuel pressure regulator that compensates for boost to get an even fuel pressure over the entire range. Bonus: Cleaner installation.

    I also enlarged my already big and ugly hole in the hood so that the air filter now can breath the fresh air instead of soaking up the heat in the engine compartiment. I really, really need to get a scoop...

    Finally I removed my windshield for a long overdue fitment of my aeroscreen plus three sexy mirrors on three sexy stalks.

    Right now my car looks like shit ( Clark, your future gearbox, which is very well sealed, can be seen at the right upper corner), and is in bad need of (yet another) remapping, but it is actually just a couple of hours of work left until it is ready for the road.

    /Magnus F.


    • #3
      If you ever need to break in or test/tune your engine stationary at higher revs (like I had to for the cams) consider my Monster Muffler:

      It does need some water sprinkling to not start smoking at the duct tape joints but it is REALLY quiet 8) No neighbor complaints at all :P

      P.S.: BTW, if you continue talking about sexy stalks you will get into trouble with the Indecency Act :mrgreen:


      • #4
        I did some drag runs today to see how the new cams are doing. Not too bad......and no speeding ticket yet :-)

        (legend: the green and blue traces are before the upgrade and the black and red traces are after. Never mind the 1860 pounds weight: I tried to compensate for rotating mass in the HP calculation.)

        I got it now under 5 sec 0-60 with the heavy 15" wheels and road tires. Using my 13" lightweight wheels with ACB10 and shedding some of the touring stuff (Sunroof, tools, sump guard) would probably end up a little better. According to the Gtech device I should have gained about 20-30 HP. This is with the conservative Zetec ignition map from Emerald. I hope I can squeeze out a little more on the dyno (and maybe bigger venturis).

        Another amazing thing: about 3/4 second are lost shifting. Is that normal or am I just a slowhand?



        • #5

          Regarding shifting. I've noticed that my clutch is slow. If I depress it all the way and quickly step off the pedal, it takes about 0.5 seconds to travel all the way back up. This is a race clutch assembly with a very strong spring plate.

          The culprit right now is the hose between the clutch piston (on top of the pedal box) and the slave cylinder pushing the throwout bearing. This hose has very small holes in its fittings, which probably restricts the flow of my DOT 4 brake fluid.

          I shall look around for another hose. Does anyone know if I can use anything with a lower viscosity meanwhile?

          /Magnus F.


          • #6
            Magnus, now that is interesting. I have never heard of that and the DOT 4 stuff is little more viscous than water. I am not sure about the clutch hose installed in my car but basically when I let go it just snaps back. That means your hose must be really tight or maybe obstructed?



            • #7
              Magnus, you should bleed it, or something. 1/2 second just ain't right.

              Gert: Where do you get your car aligned? I've got the ACB10s on now and I'd like - need - to get it all set to spec, particularly the toe.
              A day you don't go a hundred is a day wasted


              • #8
                Chris, I did it the low-tech way. Clamped some 6 foot long square ali tubes to the front tires and measured the convergence vertically and horizontally. I ended up with a compromise of about 0.75 degrees camber (because I switch to the radials for the road) and 0.5 degrees toe-in (IIRC). Last Streets track day Doug measured the tire surface temps with his needle thermometer and it was pretty even.

                The rears are not adjustable, anyway (live axle). Woody had recommended a little front toe out for the ACB10 on the track and I may try that next time.



                • #9
                  Gert, Chris,

                  The system has been thoroughly bled, dissassembled and reassembled several times. It has been like this since I got it.

                  There are no kinks or other obstructions since the braided hose goes from the slave clutch assembly to the piston on top of the pedal box in a smooth arc.

                  I've sometimes seen on old cars that their braking hoses get swollen shut "on the inside", with a similar delayed release effect on the brakes. But this hose was new when I got it and the clutch has always been slow.

                  I guess I'll have to buy a new hose and hope for the best.

                  /Magnus F.[/list][/code]


                  • #10
                    Magnus: Weird.

                    Gert: Simon at CC said 1 - 2 degrees toe out is range for an ACB10 shod Caterham car. He said measuring the temps was the only way to be sure, and I reckon that'll change some from track to track. So, explain your convergence method for toe when you have a little time.

                    After making the change to the ACB10s it feels like I have bigtime oversteer. So much so that I will not even get close to pushing things on a public roadway. The turn-in is razor sharp and the assend feels like it really wants to let go immediately. I definitely have some issues r.e .ride height & corner weights and alignment. I'm trying to get a baseline setup in place before the Shelby weekend.
                    A day you don't go a hundred is a day wasted


                    • #11
                      Chris, feel free to come along, e.g. next weekend to use or borrow my corner scales.

                      The method for the angles is to clamp the tubes vertically across to the outside of each tire and measure how much the distance from the vertical (level or weighted string) changes within 1 meter. Then you calculate arctan(distance(mm) / 1000mm). That is the camber provided you set your calculator to use degrees.

                      For the "toe in" the tubes are clamped to both sides horizontally and then again measured how much the distance changes between the tubes within 1 meter. Calculation as above.

                      This method is a little fumbly but works quite well.

                      I have no practical experience with different toe settings but 2 degrees toe-out sounds like a LOT. You car will probably look cock-eyed.



                      • #12
                        I fixed the clutch!

                        After buying a special crow feet wrench to disconnect the clutch hose from the slave cylinder withour removing the engine, I had a closer look at it.

                        Blowing through one end revealed that the hose indeed did not let much air (or DOT 4) through. Some light probing into the end of the hose revealed that the fitting seemed to have been clamped on too tight on the hose, thereby pinching it almost shut.

                        I brought the hose to my local auto tool store in order to replace it with some brake pipes. After spending 15 minutes looking at knowing guys looking at the hose muttering about SAE threading I gave up and did the only thing a desparate Swede can do in these situations.

                        I drilled up the hole at each end of the hose. As soon as the drill bit passed the end of the segment clamped by the fitting, it didn't bite anymore, indicating that the inner diameter indeed was smaller in the clamped area.

                        I checked for leaks with compressed air (there were none), and installed the hose again. This process included a nervous ten minutes fishing around inside the bell housing after a dropped bleeding tube that managed to flee when it was to be installed on the slave cylinder housing. Brass tubes are, in case you wondered, not magnetic.

                        Out on the road I discovered that the entire shifting had been transformed!

                        Earlier when I worked my way through the six speeder, there was always some fighting with each gear, resulting in a pause while things got engaged. This pause is now entirely gone, and the gears slip in very, very fast. I have easily cut the time for each gear shift in half.

                        I will run with this solution until my cluth hose starts squirting brake fluid. At that time I will upgrade to brake pipes with an even larger inner diameter.

                        The aeroscreen has now been tested at speed. The headwind hits my approximately on the forehead, resulting in a nice hairdo redo. I can also switch the aeroscreen for the old windscreen inside 10 minutes.

                        Tomorrow is mapping day, at which I will try the whole thing with a helmet.

                        On a side note. Yesterday when I took the car for a test drive around the block to check out that the engine didn't lean out, I managed to stumble upon two motorcycle CHPs monitoring a speed trap at an intersection stop sign.
                        I smiled nervously at them as they surveyed my car, aeroscreen, goggles and a laptop that was spewing out log data. A silent moment extended until I blurted out "It is legal, you know." and carefully took off.

                        Strangely enough they did not stop me.

                        /Magnus F.


                        • #13
                          Aha, there is almost always a good reason for physical phenomena :wink:

                          Anyway, I would fix it sooner than later. Not worth breaking down during a track weekend. Or, like my clutch cylinder last year that gave up on the freeway ramp 5 miles from home. Then call wife to be towed home and call Michael M. while on the tow line that I am not coming for the blat :roll:



                          • #14
                            Thanks Gert, I'll fiddle about w/ it tomorrow. If I don't get too itchy to just go out for a short blat that is. The weather is perfect.

                            Uh, what's up next weekend?
                            A day you don't go a hundred is a day wasted


                            • #15
                              Gert - would you be interested and willing to do a corner balancing session next weekend with your scales? I'd like to see what mine is like before the Streets of Willow.

                              edit: Oops, I forgot I work on Saturday till noon, but I'm available Sunday.