Tie me up! Tie Me Down!
We’ve decided the turbo definitely has a hate-hate relationship with our car.
Shortly after the track day testing we also discovered a turbo completely loose from the manifold. This was the same exact problem that kept this car out of commission at 2008 Thunderhill LeMons! Then, it was nuts backing off the the studs. Knowing this was a problem we replaced the split-washer and nut combination with mechanically crimped lock nuts. So what gives, right? Well, the nuts did their job, admirably well: they were locked to the stud. It’s just that the stud back out, instead! Augh!
So out comes the turbo/manifold combination. In a flash of frustration, I thought of tack welding the nuts to the turbo, after tightening. This would definitely prevent both the nut and the stud from backing out. Then thought of a less drastic option of tack welding the nut to specially shaped washers which would lock against the side of the turbo. But Scott came up with our ultimate solution, which was to wire-tie the studs, aircraft-style, to prevent them from backing out.
So will this be enough?? If you find us with our heads under the hood instead of driving- this will likely be the issue. 🙂
Boost Leak!
We had a chance to look more closely at the turbo, wastegate and related system. Seems like the wastegate works correctly- good. What we did notice was the wastegate was cracked open by default. Whaaat? A quick check with the previous owner confirmed my suspicion- a boost leak was engineered into the system, to limit boost pressure and work within the capabilities of the primitive “engine management” (such as it is) consisting of only a rising rate fuel pressure regulator and nothing else. No wonder we could only feel the turbo way up top!
Heat!
Yeah. On top of all of that, we can get the temps to creep up under extended, long periods of heavy engine load. This can be modulated with power- back off the power, the temps come down. Still, we are looking to block off the top and bottom of the area in front of the radiator, to force more air into the radiator, and prevent spilling. We’ll see what we can do here. We have no track-day opportunities left, so we will be flying blind with these fixes. Yay!
So that makes a few big problems revealed by the Track Day.
1. Fix your fluid leaks!
2. Secure loose bolts.
3. Check for overheating
4. Design your aerodynamics correctly- if you know how.
It’s a truism of racing: the bigger the race, the bigger the untested change (fix?) you’ve made to the car just before it.