TurboWood

Thanks Mike, good feedback as always. My auto cross buddy suggests bfg rival S1.5 which I had down selected before looking at sizes. The issue is the front where only a 205/50 is available. Do you think it would fit? What size Hoosiers are you running? You know CA gets a bad wrap, in my experience cops don’t give nice cars much trouble. The number of bmw/merc/etc. driving around with no plates is crazy. Maybe having tires that throw stones at all the cars behind me would be different though ;). Daniel

My CR500's are starting to get to the wear bars which means I need to have a new set ready. I have a 2013 CSR which according to what I've read have 7" and 9" wheels with 195/45 and 245/40 tires. I understand fronts have moved to 195/50 with the ZZS and according to tirerack there are no 195/45 options so it looks like 50 series is in my future on the front. From what I can find only the Hankook RS-4 is available in both sizes, but I'm wondering how stupid it would be to run Hoosier's on the rear? I have stupid power (300rwhp) and tq (320ft*lbs) which can be managed in 2nd gear today (with passenger), but more go-grip would be welcome. So, what's the right path? Am I silly to walk away from Avons? I just have a hard time believing Avon has some special sauce that mainstream tire manufactures have. BFG even mentions the Rival S1.5 is an upgrade to the Rival S for lighter cars. There are plenty of race miata's out there and if Avon made a magic tire I imagine they would use them. Daniel

Mike, Tracsport is great, they built my transmission. I’m glad to hear the Sierra diff has some strength, and I guess it’s time for me to check some bolts! Good luck on the new build. Daniel

Mike, Thanks for the reply and fuel pump info! Would you mind sharing some more information about the upgrade you made? While I've lived with the stock pump at similar power levels, the time at those flow rates has been limited so an upgrade is likely in my future. Similarly, I'm curious about the differential support. Does your new CSR still use the Sierra diff? This is my biggest concern for going with stickier rubber since my peak TQ is well over 300ft*lbs. If the tires stick in a low gear I should be able to rip it apart (thankfully (?) my tires can't even handle 3rd gear WOT). Daniel

Very impressive! You are making a beast for sure. I would love to see the dyno plot. I’m surprised you needed to upgrade the fuel system. Was this a precaution or a know limit? Daniel

For what it’s worth, my 2013 kit has no connection between the engine and the sensor used for the gauge. I put in a different engine than what Caterham sells, but I used the Caterham water temp gauge/sensor. My fans are controlled by the ecu. Daniel

It’s good to see one of these. Please note that while 40 were made, only 3 were imported to the US. At least that is what I was told by Caterham USA when I ordered mine. I had asked Caterham for some documentation of this, but they declined. Daniel

fun thread :)…. I have about 3k miles on my ‘13 CSR after being on the road in 2018. I need to put more miles on it! Daniel

I may not be the best reference here as I have a turbo 2L and no track time yet, but I find my SPC 5-spd (1:1 4th) to be more than enough. I would even consider a taller rear end (3.38 now). It seems to me that a top gear 1-1 only makes sense if the car is mostly dedicated to the track. I wouldn’t want to lose my overdrive. Daniel

Mike, You are probably right, but my turbo engine is putting about double the torque of the 485 through it. I have a Quaife ATB in it, but the case and the gears have to survive. 80's diffs and modern turbo engines don't give me warm fuzziest. My buddy had a turbo NA (1st Gen) Miata that he kept blowing diffs in despite being a mile high. All I can say is hopefully the safety factor in Ford was bigger than Mazda back then. Daniel

Great, I wonder if they managed to squeeze the BMW diff in it or if they still use the older Ford unit. Blowing that thing up is my biggest concern since upgrades are limited. I may never try slicks just for that reason. Anyway, it's good to see some life coming back. They must have done some development if that article's claim is correct that it is available in the standard/S3 chassis which I don't think was ever true before. I did recently grab a CSR Ford non-limited slip diff from Caterham on heavy discount which suggests they were purging inventory. That gives me a backup, but it would be great if there was a better option. It's probably a big wish to have it fit in the same chassis though. Daniel

Vote from me for CSR. I’m not experienced with the various chassis, but the CSR is very comfortable on the street. I can keep up with any other vehicle on rough road so long as I don’t fear hitting the sump. With the doors on my wife almost fell asleep on a short blat. I’m only 1k miles in, but it hasn’t bitten me yet. Daniel

I had my first factory part failure. The hose clamp on the fuel pump gave up, resulting in a steady drip of fuel from the fuel tank. Fortunately I discovered it as I arrived at my friends house. This friend is a fellow car guy and had everything needed to fix it, including a proper fuel hose clamp. We had it together in 20min and continued on with our short blat. The car can put down most of its power with a passenger. I still get surprised how much the traction changes depending on the passenger. The photo is upside down for some reason. As oriented the culprit was the lower right hose. You can see how much wetness there is which is all fuel. Daniel

Nice looking car! The 620r nose is interesting. Does it require you to install the zues fasteners or make any chassis modifications? Daniel

That is indeed a lot of carbon. Do these engines run closed loop? Daniel

Dyno complete and successful! It runs 16-17pis boost and just touched 301hp to the hubs. I was only able to drive it for a little while afterwards so all I can say is there is a traction problem. It was a cool day in SoCal so maybe a poor benchmark, but I did lose traction in 3rd. The ECM also runs by torque targets which will need some fine tuning to make the car more predictable, but it's nice knowing I can put my foot in it! I also redid the foam the the hood sits on. I was seeing some wear between the hood and chassis. I occasionally also heard some rattle there as well. To solve this I bought a big foam sheet from McMaster that I cut strips out of. The hood is much more secure and no more rattle. Daniel

I had a temporary setback. Thankfully I asked the guy (Sean from Church Automotive) to slowly work up to full throttle because I had no boost control! The plugs on my TiAl WG had come out preventing the WG from opening. We weren't able to figure that out on the dyno, but clearly we had to stop when boost was shooting >25psi. I've addressed that now and took it for a test drive. Everything seems to be working properly (boost relatively stable around 14psi). What we did figure out on the dyno is I should be close to 300ft*lb at 3500 with 18psi. He reconned we could keep that 300 to 5500-6000 before tapering down. 300ft*lb = 300hp @ 5250 so I should be good! This dyno is a hub dyno though so there is some loss between tire and road that isn't captured, but I think I'll live with that . More to come... Daniel

Please cross your fingers, I'm taking the car for Dyno + tuning this Saturday. I have about 750 miles now and it's running great. I drove it last weekend for C&C and some curvy roads nearby. Hopefully I hit my 300rwhp target! I still have the speedo issue, but haven't had the motivation to try anything else. Daniel

What does the gauge read if the sensor wire is grounded or open circuit? Sudden changes like that strike me as electrical. It's hard for me to buy a thermostat issue unless somehow it's letting surges of cold water out (not sure how that would work). Maybe the higher pump speed is driving something? Does it happen if you free rev the engine? One wild thought would be a plugged radiator. Maybe the higher pump speed is able to momentarily force flow through? Daniel

Definitely interesting. Where in the world would these two vehicles ever both be at? Daniel

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!