TurboWood

Thanks for the feedback! I’ve wondered if anyone was reading my short stories. I drove the car a few more times and it is sarting consistently and I’m not getting any CEL. The car is really starting to show its legs. It’s a bit cool in southern Cal, but it still lost traction in 3rd when I started pushing. The ECM can do gear based TQ targets, but the ECM doesn’t know vehicle speed right now. I may have to change that so I can go WOT in all gears. It was somewhere around 2003 that I last drove my Supra with somewhere around 600hp. I had always built that with the vision of having 700rwhp eventually, but never really got there. Even so, at 600-ish it was a rush. When I started this Caterham project I targeted a similar lb/hp figure which is how I came to 300rwhp. Right now I’m probably close to where I was with a 600hp Supra. In 5th cruising at 45 I can just give it some gas and quickly get to 70. Shifting down is optional. I find that remarkable considering I have a 0.82 5th with 3.38:1 diff. The other thing I forgot to mention was I added an overflow tank for the intercooler system. I was losing water each time a drive the car as I have a radiator cap in the circuit. I must have puked a little water each time. That should now be solved. Before going to the track I think I’ll need to add an oil temp gage. I can tell from oil pressure when my oil is up to temp, but I don’t think that passive approach is going to be good enough for me to protect the engine. Time will tell if I have enough cooling capacity for track time. I’m basically stock CSR except for adding a 2nd radiator in front (for the intercooler). I have to assume that will cause me some risk of overheating the engine. Daniel

I have a few updates. The large amount of exhaust fumes was primarily caused by a failing wastegate tube. I did almost all the wrong things for a structural weld. The one thing I did right was have a flex section between the exhaust manifold and the WG, but this meant the return tube was carrying all the load. This tube was thicker than the downpipe, it was welded to the outer radius of the downpipe (so, thinner wall due to stretching), the WG was largely cantilevered, and the downpipe hadn't been filled during welding (contaminated weld). Combining all this meant that weld failed 100% after 300miles. I've re-welded it now and added some support structure to help strengthen the joint. I'm now at 550miles with no new evidence of an issue. I gave the engine it's first oil change a few weeks back. In the process I discovered that one of the intercooler mounts had also cracked. It turns out bent aluminum plate doesn't have a good fatigue life...go figure. The intercooler is hard mounted to the front of the engine (air to water) so it sees all the engine vibration. This has also been welded back together and strengthened. Interestingly there were no ill effects of that failure. I almost decided to leave it off, but decided I would give it another go. If it fails again then it will probably be time for a soft mount. The more interesting piece of news is I discovered today that my cam sensor connectors were reversed. Both the intake and exhaust cam use the same connector so you can just swap them. I hadn't given this much thought as the way I had it seemed to work better with the harness so I assumed it was right. I was wrong. I had been fighting a check engine light for cam timing on both cams, but the engine seemed to run fine. After swapping them I can feel a noticeable power difference. I got sideways in second at part throttle which caught me a bit off guard . It seems "running ok" in a such a light car is actually not ok. If everything is right it should be mental. I can only wonder what full boost will be like. Happily it seems this may have also solved a hard starting problem I was having. The car wouldn't start consistently and if I cranked a long time it would backfire. I thought it was due to a low voltage spike during cranking (possibly confusing the ECM), but (crossing fingers) so far the engine fires up consistently and more quickly now. Knowing where the cams are on a dual variable timing engine appears to be important. The speedometer issue is the last real problem. I'm not real sure what to do. I'm tempted to just buy another sensor and give it a shot. Are there any other tricks besides the axial spacing of the sensor? Daniel

They really should throw the IRS into a std. chassis. The front shock arrangement is cool, but doesn't bring a lot of function. It also make shock/spring changes more difficult. Daniel

Where do you stand on the white letters on the tires? I sort of liked it a few years ago, but now it's just too common. I suppose these isn't much need to make a 7 look more unique anyway. Daniel

Thanks for sharing!

I now have the title so it's fully legit. I don't have a mounting bracket for the license plate, but I've passed plenty of cops with no ill effect. I think I'll just carry the plates with me and see how long it takes to get harassed. SoCal cops don't tend to mess with expensive looking cars. I've been trying to convince myself I have the 3.38:1 diff. I thought I had nailed the rpm to speed ratio well enough to say it was actually 3.62, but after spinning the tires and counting driveshaft rotations I think it is indeed 3.38. This was relatively important to me because my engine doesn't rev to 9k so I need some taller gearing. Even with the 0.82 5th gear I feel like the engine is screaming on the highway. I can drive around everyone in 5th gear w/o issue. It's hard to control myself! I'm fighting a few small oil leaks and I've found a few loose bolts, but overall it seems to run great. I need to take it to a dyno to get the WOT AFR calibrated, but that will have to wait for after break in. The other thing I've found is that I get a lot of exhaust fumes into the cabin. I'm definitely going to need to add some type of extension to the exhaust to prevent this. Knowing that direct injection exhaust is relatively bad for you (much smaller particulate sizes than diesel) I would like to avoid breathing them all. I'm also still fighting the speedometer. It just doesn't want to read over 60mph. I've moved the sensor all over the place and it either doesn't read or drops out at speed. I did make the well known modification to the wiring by grounding the sensor to the chassis near the sensor. Before this I was having issues with the speedo jumping with the turn signal and cutting each time I pushed the brakes. Those issues are solved. I went to my first C&C in Palos Verdes last weekend. That was the most Porsches I've seen in one place outside a Porsche meet. I arrived late and parked away from the crowd, but it was fun. Daniel

Good luck recovering your car! I'm surprised they wanted to take the risk after seeing what they had. A 7 like this is so unique that about all they could do is use it for personal entertainment. Any respectable buyer would likely join one of the few 7 groups and quickly figure out what was going on. Daniel

Plates in hand! I’ve done about 200miles now. I haven’t been able to open it up fully yet, but it is fast. I’ve only seen 5k rpm (briefly) and 5psi (of the 20 or so it will see). Looking forward to being broke in and tuned for WOT! Daniel

I passed ! All I have to do now is go to the DMV and get plates. Daniel

Wish me luck!

We are cooking now! I got the O2 closed loop issue solved. Apparently GM (or ECM supplier) elected to have a dedicated “ground” for the O2 sensor that had a 1v positive voltage. My aftermarket harness had this at the common chassis ground. i drove the car for about 50miles yesterday and I have the referee inspection tomorrow. The next step will be some tubing so I can really romp on it, but according to my log I hit 5psi boost at 5000rpm and it was already fast. 20psi and 7000rpm on the way . Daniel

The upside down method worked at a different gas station. It seems the nozzle design is something I’ll have to pay attention to. The car is now about 99% ready. I had the alignment inspected and weighed. Nothing is far off, but I’ll probably make a few tweaks. The car weighed 1630 with me in it and a full tank of gas. That puts the car around 1430 which from what I can tell is about 100lb more than a normal CSR. My cast exhaust manifold, turbo, intercoooler, and girthy engine explain that. Hopefully it’s well compensated for with an extra 100hp too . Daniel

Ok, after driving the car some more here are my additional questions: - How do you put gas in these cars? I spent probably 10min to get about 2gal in at the gas pump. I tried every angle I could, but just couldn't get the nozzle down far enough to push open the check valve. This meant I was only able to fill it at the rate that this valve leaked. Is this just due to the CA nozzle design or am I missing something? - After multiple attempts I can't get the speedo to work consistently. I tried moving the sensor, but only got a few blips of speed. Is this know to be finicky or should I start looking for issues? I'll try adjusting it again. Can the sensor be too close? Daniel

A friend of mine takes on much bigger projects than me and I made a similar comment to him as you did here. His reply was that all it takes is the stupidity to start and the percistence to finish. This project definitely turned out to be bigger than I had anticipated and had I really tried to plan in greater detail I probably would have talked myself out of it. Daniel

Oh, I forgot to mention, I stopped by the DMV yesterday and they gave me a new 3mo temp tag so I can drive it legally! Daniel

Thanks guys! It was definitely everything I hoped for and I haven’t even been able to mash the go pedal yet. The turbo spools quickly and sounds awesome. I’m glad I went with a vent to atmosphere BOV (I guess there is a little ricer in me). I passed the brake and light inspection today. The guys was super easy going and seemed to skip a few steps since I drove it there. Let’s hope the BAR is as smooth. Daniel

I drove it!!! There is still the issue with the o2 sensor, but the fans did turn on and it drove great! The clutch was easy despite the light flywheel and 3.38 rear end. Tomorrow I should finish the break and light inspection. The BAR exam is planned in mid August. Daniel

Here is a pick of the pedal box. You can see how much extra wiring the gave me for the DBW pedal. One of these days I’ll shorten it. I’m still waiting for the new ECM from Alfa. I talked to him Tuesday and they promised to ship immediately, but haven’t heard since. I built the tach frequency circuit I mentioned it a previous post. A friend from work is going to test it. Hopefully he doesn’t let the smoke out. The rest is basically done. If the ECM solves the problem my next picture will be from me driving around the block! Daniel

email sent

Short update: 1) The engine idles! I added the two missing sensors mentioned above and made a few small calibration changes. 2) Unfortunately the O2 sensor still isn't reading. I confirmed the sensor details, bought the right one, confirmed (with a blow torch) that it works, but the ECM still doesn't see it. Alfa Fab is sending another ECM for me to try 3) Since the engine idled somewhat properly I was able to find and fix (hopefully) the main leak. It was it a tough spot, but should be taken care of now 4) I didn't mention it before, but I thought I had a leak in my radiator piping that is welded to my radiator for the water to air intercooler. It turned out to be a lose plug...DOH! 5) I cleaned up some of the wiring near the intake manifold. If you look close at the last pick you can see the starter solenoid bolted to the intake manifold and a bunch of wires zip-tied to a chassis tube on the car front side of the intake manifold. I also discovered that my engine does have a mounting point for a central knock sensor so I moved one to that position and removed the other (remember from the post above that my more modern ECM uses 1, but my engine came with 2) 6) The Dakota Digital box works, but it only has options for 4, 6, or 8 pulses per rev. which does not work with my 1ppr Caterham gauge. Fortunately my Dad designed a simple flip-flop circtuit that should divide the signal by 4. Hopefully I can find enough parts at Fry's to make it . 7) I changed some connectors on the harness work I had done. For some stupid reason (likely in a rush to get the car running) I used unsealed connectors in a few spots. This is now fixed 8) I added a throttle opening (yes, opening) spring. The drive by wire throttle has an internal spring that is quite stiff. It's hidden under the pedal box and to make it fit I had to significantly reduce the length of the arm. I attempted to compensate for this through a series of lever arms before attaching to the factory Caterham pedal, but the pedal remained a little more stiff than I liked. I discovered that I could loop that factory Caterham throttle return spring between the shortened DBW throttle and the edge of the pedal box. So, I just added a catch point to the edge of the pedal box which significantly reduced the pedal effort. Once I get the ECM updated (and hopefully have a functioning O2) it should be go enough to drive around the block! Daniel

I suppose this means I could put the check valve on the oil filter/cooler line then. This should keep my tank full and only create a 1-2psi drop in oil pressure feeding the engine. Daniel

Bringing this back from the dead as I had an interesting thing happen. My oil filter/cooler attaches to the block at the left rear corner, near the top of the block. It is fed by the factory oil pump which draws from my dry sump tank. Effectively this means there is a hose from the bottom of my oil tank to the factory in-engine oil pump. Last weekend I needed to disconnect the filter/cooler to diagnose/fix a leak. In the process I pressurized (with a bicycle pump) the fitting on the block which is the output of the oil pump. This forced the oil back into the oil tank. After doing that my oil tank has remained full. This was a surprise to me since the gravity/head-pressure of the oil in the tank is obviously still there. Why didn't my tank drain like normal? Is it a siphoning effect that has been avoided by having the filter/cooler disconnected? Daniel

John, You make a good point. My annoyance is more with standard sedans having these flashing brake lights. It's probably a good bet on these oversized gokarts. Daniel

I HATE blinking brake lights. It does get attention, but it's a distraction. Most of them turn on every time you depress the brake. If you could have it only turn on with a significant braking event then it would make sense. Maybe a pressure switch on the brake line? Daniel

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