So, I did a track day in the GT-Four again to do some testing. Didn't go so well.
Long story short, was struggling to get the car running ok all day, it was running like a bag of wet farts, going in to limp mode. Found an issue with the fuel pressure, was able to bump it back up, but I suspect a problem with the fuel pump so I called it a day. The engine didn't feel strong, the intake temps were high (it was a hot day) and the track was damp (also patchy rain).
Got it home, left it for the night, then looked at it the next day.
Found oil on the front of the engine, below the head gasket. Cleaned it up, started the engine, there is oil seeping out of the head gasket. No oil in the coolant, no coolant in the oil. Brand new Cometic HG. So I check the head studs and they were loose. Re-torqued. Leak gone. I suspect this was a big contributor to the car feeling like crap. I had torqued these in the right sequence, in equal steps, with the right lubricant, to the correct torque value (ARP head stud value) but hadn't retorqued after a heat cycle (ARP says this isn't necessary). Hopefully that sorts it.
Anyway, also decided I would sort my intake temps and lose the water to air charge cooler and instead run a FMIC. So, I got to work removing the old setup, and began to clock my turbo.
I'm going to get an angle welded on to the outlet of the compressor, pointing out where the arrow is. This will allow for easier pipework.
So then I had to come up with a bracket for the wastegate actuator.
That's what I came up with. The water pipes bolt to it as well so everything is nice and secure. I've tested the actuation with some compressed air and there is no flex in the design and it operates smoothly and freely.
Anyway, while I was working on that I discovered that the manifold had a crack in it, but thanks to a mate with a spare I've now got a replacement.
I'm on a bit of a spending hiatus at the moment, I have some higher priorities at the moment, but my time is free so I decided to get stuck in to prepare the car for it's next phase.
I've stripped out the sound deadening in the cabin, in preparation for the half cage installation. I still need to clean the remaining residue off but it's getting there.
That's all that came out of it, around 8kgs.
My plan at the moment:
- Drop the fuel tank, replace the Walbro 255 with a Walbro 460. Replace the lines back there to E85 compliant items at the same time. Run all new fuel pump circuit, relay and fuse for this to rule out any wiring issue that would have caused the pressure drop. It's an important circuit so I'd rather just make a new circuit than rely on the 27 year old loom.
- Design a new battery bracket and weld to floor.
- Get half cage welded in.
- Paint entire floor, rear strut towers etc and roll cage gun metal grey. Was going to retain the side plastics at the back, but obviously no rear seats. If the paint looks nice I won't put the carpet in, either.
- Fit turbo back up with new outlet.
- Front mount intercooler, plumb + ducting in the front.
- Source a spare ST184 bonnet and make a radiator exhaust vent and possibly ducting. (I'd love a group A bonnet, even Carbon, but it's not in the budget yet)
That's my current list. I didn't have any air in the coolant system at all, even after letting it get quite hot, so I'm confident of my swirl design. The question is now whether or not the radiator is up to the task or if it needs a larger one. I have good hopes with the proper ducting, I think my problems at the last track day were mainly due to stupid hot weather, high intake temps from the water to air cooler and loose head studs.
That's all for now.