Dale FZ1

Before giving the front bar a tidy up, perhaps figure out what cooler mounting and ducting is needed, and whether you'll even retain the stock bar? Richo's build thread has a lot of good info/pics. What sort of power will you chase out of this thing? I've wondered how a Hypergear TDO6SL2-20.5G would perform for a track application like this. Mightn't go much past the 300kW mark but it should be responsive and reliable unit.

Nice work. Keep the pictures and build story flowing.

Powercruise format with a few successive squirts along straights but nothing really sustained isn't likely to result in extreme oil temps that requires a cooler. Suggest you concentrate on the issue which appears to be the lifters. Removing cams and lifters for cleaning/reinstall will take time but not lots of $$. Also suggest you speak with the cam manufacturer and determine whether the profile you are running is compatible with hydraulic lifters.

You've got a new engine screwed together, but no indication if the lifters were freshened up and scrubbed clean before installation?

Probably the best bet would be to get in touch with Hypergear and see what is available. Stao seems to be a whizz with making units that bolt up to stock manifolding and taking OEM dump flange pattern.

A crack will only ever get bigger. I would avoid using that housing because it will give problems and downtime for the car at some stage. There's enough gear on the market where you really don't need to reuse an old OEM housing.

^^ Very nice looking result but the boost control does look suspect. Makes me wonder how things would go with a larger capacity RB engine?

What is a HRC turbo?

^^ Stout result that. Well done. What fuel, and other than the HX35 family, what are the exact turbo specs? Would like to see a dyno sheet just for interest sake. The OP was asking about something suitable for a 30DET engine

^^ This then poses the question of why not have Stao supply a complete turbocharger spec that has been trialled and proven? I have no preference/suggestion one way or the other, but reckon for a Garrett devotee an external gate setup on Mark's unit would have been a half decent option even if it no longer resembles a stocker.

Don't kid yourselves. The fastest ones used rocket fuel. No category of racing has an absolutely level playing field.

Good news, hopefully it's putting out enough to make this spec turbo worthwhile as an upgrade option. Does it feel good to drive in terms of transient response and delivery? Be good to see the torque curve but probably fair to say it's a mid-rangey thing doing its best between 3000 and 5500?

PM sent.

Don't be shy, keep us updated and informed.

Probably comes down to the issues of budget and tuner preference which way you go with ECU. What do you think of the steering wheel and boss setup? Did it change the length of reach to the wheel? Presuming slightly smaller diameter is there any noticeable difference in steering effort? And any obvious flex in the wheel if you apply in/out pressure to the rim?

^^ post #12 he confirmed it is a TDO6H-25G 10cm. Bigger turbine impeller than a TDO6SL2-25G Off topic, the main difference between the T67-25G and the TDO6SL2-25G appears to be the diameter of the centre shaft, and the centre bearing housing (non water cooled vs water cooled) configuration. Compressor housings seem to vary between 0.7A/R with 4" inlet snout, and 0.6A/R with 3" inlet snout. But the impellers are the same on both of those units. +2 for wastegate spec and setup as per previous.

I'll have a stab since the experts are still in bed. I like the guides in that pan, seem to be pushing oil towards the scavenge pickup points. Mounts dropping the whole engine an inch or two for improved CoG?

^^ +1 for fan shroud, regardless of whether you're using a mechanical or electric. The aim is to achieve airflow through the whole core to promote heat transfer. You will find the OEM "splash tray": running back from the lower radiator support is an important cooling element so make sure it is retained. Off topic, but is that black 32 the one you are putting on the track? Ride height looks like it might give some suspension travel and geometry issues unless you've done a LOT of work in that area.

Do you know what spec wastegate actuator this turbo has? If the plan is to run it up to/over 20psi then by rights you'd do best with an actuator rated up in that range. With preload correctly set, you'll stand a chance of keeping the wastegate valve properly seated for longer and get a more reasonable rate of boost rise. Probably worth checking what is available from various suppliers. Try the likes of Kando, Hypergear, and GCG.

It's very lazy coming up onto boost as per earlier comments. Maybe throw up a pic or two of your setup? 100% agree with Stao you need to be confident that the cam timing is set correctly. Not just lining up timing marks, but by using a degree wheel to know with certainty the valves are opening/closing when they should be. With that resolved first, then move to the turbo. You appear to have gone with a 10cm IW turbine housing? General consensus is that those ones aren't good at permitting proper boost control, and boost response is also average. But it's one of those talked-about points on a forum and I have no direct first hand experiences with that turbine setup. Thinking you will have to play with it a bit to get a reasonable understanding of the truth. Three things I would look at are the wastegate actuator spec, correct/best setting of its preload, and setup of your boost controller. It's looking so lazy to come on that it makes me wonder if the wastegate valve is just blowing open. The impeller OD sizes on the turbo you have are roughly 78mm (comp), 67mm (turbine) which gives a very rough correlation to a GT3576. 10cm housing roughly equivalent to a 0.63 A/R. On an RB25 with cam upgrade and everything setup properly it's probably fair to think you would see it making best torque across 4500-8000rpm. Under 3500 it's not going to be responding super-quick.

The factory MLS gasket is the best. Suggest using a straight edge across the flange faces to make sure no warps are promoting leaks.

How hard are you going to rev this thing? It's been a little while since we've seen you in a Skyline, keep at it.

^^ both valid points, although the OP already has built his bottom end as RB25 (pistons use different gudgeon pin height), and the Garrett branded casting does not look to be any less bulky in the critical areas. I'd maintain the view that if he wants to go to the trouble/expense of split pulse then look further afield than Garrett and reap the benefits.

If there is one issue about the centre bearing housing I really dislike, it's that Garrett make it so compact (short) that getting spanners onto oil/water lines is very difficult. This is more evident once you start using bulkier split pulse housings that push over into that area. Recent experience with fitting up a GT3076 / 1.06 split pulse combination was memorable in that respect.

If the application is not road-only, or an occasional weekend toy, you will generally be running at elevated engine rpm (yes?). There's a few unknowns regarding flow capacity of the split pulse housing vs a comparable single scroll design of same/similar nominal A/R. Possibly the 1.01 TS will be only moderately higher flowing than a 0.82 single scroll, so I'd suspect that a little more efficient scavenging at higher PR and rpm will give a bigger power number with little difference in response and power down low. That is without changing cams. The cam change is really only going to effectively shift your torque curve to the right, maybe counteract the benefits of the TS. Using anti knock/detonation strategies ie. E85 fuel or water injection should naturally lead to higher output, so shift the curve upwards. I'd give it a go, you might be surprised how driveable the combination is. Your power output is going to be capped by the capacity of that little compressor, but good setup/tune should yield 325-340rwkW across a broad range. I'd also recommend broadening your tastes and think about Borg Warner split pulse units rather than just change housings on your existing spec Garrett.