Out with the old | In with the new

[TurboWood]

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

[11Budlite]

Enjoyed reading your build Daniel, it's going to be a beast!

 

As far as the speedometer issue, it might be worth trying a new sensor. I removed the "sensor wheel" on my old Birkin and just aimed the sensor at the bolt heads on the driveshaft with the correct gap and it always worked perfectly for me. If you're not able to get it to work there are always GPS speedometers that I've heard work well but have no personal experience. Speedhut even has gauges that you can change the looks of (font, needle color, etc) to try to match your original gauges.

[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

[jbanker]

Daniel,

 

I have enjoyed reading your post on the turbo Ecotec build. I think you and I may be the only ones with on this forum with FE5 boosted Ecotecs Se7ens. I have a SuperStalker that was converted from a supercharged 3800 GM V6. It has been a fantastic upgrade from the heavier power plant to the stage 3 Hahn after market turbocharged little 4 banger. I have found that dialing back from 13psi boost to about 6psi makes it very street able yet break traction in every gear even without flat footing it.

Keep the development post coming.

 

Jack in Indy

[TurboWood]

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

[TurboWood]

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

[TurboWood]

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

[xcarguy]

Dyno complete and successful! . . . 301hp to the hubs . . . there is a traction problem . . . I did lose traction in 3rd . . . put my foot in it!

 

Sounds like it’s doing exactly what it was designed to do. :party:

[drewbrese]

Awesome!

[Bonjo2]

outstanding

[TurboWood]

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

Edited July 13, 2019 by TurboWood

[TurboWood]

I finally installed the air inlet duct I bought too long ago. Apparently a baby boy was the motivation I needed.

 

Also, since my last update I did some more tuning on the engine and was able to resolve a few things that were bothering me. The idle never seemed to follow the tables, but was good enough to not be a big problem. However, the one really annoying thing that came with it was a crazy high (3-4k) cold start idle. It turns out I was using an AT calibration that caused both issues. 

 

Daniel