haw001

Have a few for me

Must be from all that driving, you bastard! At least you get a bit of a break for the next 2 months.

Thanks for all the Birthday wishes! Have had internet troubles for a couple of days, so haven't been online. Did spend the afternoon of the 21st rolling around under the car getting the new rear cradle in drilled and bolted up. I took my time with this one as Rob had put the fear of god in me over my ability to drill the holes in the right place so I made up a little plastic template to make sure that I got it centered. So I drilled pilot holes, measured against the standard cradle, then drilled the holes to 11mm which is the size of the first taper on the cradle pegs. Next came the hard part, which is to try and raise the damn thing in place single handed. With it sitting on 2 jacks I had to run to either side of the car, raising each side a little at a time, at least 5 times to lift it into place. In the end it proved to be ok, with one hole about 1mm out and easy to correct. Repeat the process another 3 times, once to find the holes were slightly too small for the second taper, another to find that the modifications fouled on the chassis rail requiring some butchering with a angle grinder, and a final time to bolt it up, and the whole thing ended taking up the entire afternoon, but I'm really happy with the results. The cradle may as well be welded to chassis. I'll post some pictures soon.

I bought the steel last week. Where did you manage to find the cheap stuff, and how cheap was it. The Chromoly that I bought was marginally cheaper than the equivalent mild steel, but it still was not cheap.

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Where do you want to leave it, Sydney or Melbourne? Sydney I can't help out for long, the front yard has to be cleared for when we move out in Jan. In Melb you could leave it at my warehouse for a while if you needed. It's lock up, but no guarantees on security. If pieces go missing, I may be responsible, but I won't be held responsible

Thanks. Let me know if it works out. I won't be in Melb on the weekend, but I can get someone to organise it if you are heading back to Sydney with room.

Anyone heading from Melbourne to Sydney in the near future who wouldn't mind strapping a bonnet to their roof? It doesn't weigh much, but somehow I think Auspost is going to charge on size not weight. Also have a fibreglass bumper which needs to go if anyone is feeling extra generous. I'd be mighty thankful and would be happy to pony up some tools as way of thanks.

Does anything fit in a supra?

I'm really looking forward to the Hicas removal solution. Even with a lock bar, I experienced the rear end 'float' at different speeds. Just feels unstable. There's just no way that you can lock something that has a universal joint as a mounting point.

Here are the pics from the weekend: These are the bastard counter weights welded on to the cradle And this is what happens when you pick one up to see how heavy they are even half an hour later. Anybody have any crimes they need comitted? I've got no fingerprints til they grow back. Mount point for the anti-hicas toe arm. Still a work in progress These are the mounts welded up. The brackets still need to be cut to the correct length and tidied up, but we won't do that until it's all mounted up and the ideal mounting point is determined. We'll drill new holes when we know what level it will be at. Cadle mounts capped over and welded. Next I'll drill out holes in the correct location and the cradle will be solid mounted.

No problems bringing them down, just may have trouble calling them carry-on. The real struggle is going to be getting a bonnet and bumper back to Sydney!

I'm not coming to Melbourne til the 23rd of November. Happy to bring them with me then, but if you need them before then they'll have to be shipped. It's possible that I may have a pallet coming down next week, but no guarantees.

Do have both front and rear. I can't get them this week, but Duncan probably can, he's sealing the motor on Wednesday I think.

I'm having internet problems at the moment which seems to be stopping uploading of attachments, so I'll have to add those later. After a pretty shi__y start to the day, we were lucky to have Rob help us out with the cradle mods, which was fortunate as about half an hour into the work, I managed to burn the ends off the index finger and thumb picking up the cradle counter weights which had been removed a full half an hour prior. They are so think and solid that the steel just soaked up the heat and wouldn't let go of it for at least an hour. It still has work to do on it, but the groundwork is done. I'll post the pics shortly.

I think to be effective you will need to use a brake input at the very minimum or a longitudinal G-Sensor would be better. Most of the stress on the front diff would have to be under loaded cornering, ie when hammering out of a corner after a braking maneuver. Most mechanical failures fall into 2 categories, the first is a result of long term wear and tear which weakens a part until it lets go. It's mostly a series of compound failures or small failures which grow until the part can't hold anymore. The second is a caused by a rapid shift in the force applied which causes catastrophic failure. In this case the part may have been able to withstand the forces applied if brought on gradually. This is likely to be the problem with the front diff. I know this is over simplified and not based on any testing, but it does make sense when you think about it. Come off the straight at full noise and you should be breaking until you are at least 30-40% into the turn, from there you immediately will hit the throttle to pull yourself out of the corner. Your revs should still be up so the power comes on strong and hard. At this point you a mid way through a hard arc, which means the front and rear diffs will be directing maximum power to one wheel each. Add to that a 50/50 split in power and you have the reason for the diff failing. I'm pretty sure that Nissan were aware of the problem and have limited how fast the power is transferred for this reason. They bring it on gradually (relatively speaking) to avoid the shock.

Brad, I'm interested in pursuing it further. At first glance I would have to think that getting access to the code for the standard Atessa would be the best possible option, if it can be had. I did have a lend of a modified one, so someone has it. A bit of investigation is in order.

Which Motec are you using to manage the 4wd? The 4wd system has always been what really attracted me to the GTR over other cars. Let's face it, it's rather heavy, rather complicated, and despite the common punter belief, far from bulletproof past a certain point, but no other car has the in built beauty (at least not at them time) of an electronically controlled 4wd system. The RB is a great engine, but there are lot of great engines out there and it's getting a bit long in the tooth. The main problem is that the car was not sold specifically for the track or the tarmac, it's a road based system and thus the 4wd system is rather dumbed down to accomodate regular road use. I've used 4wd controllers which modify the lateral inputs and a modified Atessa computer, but have often thought that the best bet would be to use the 4wd system in a way similar to the way F1 used to 'cheat' (before it was banned) and program for a specific track. I don't mean that you would GPS every corner, but certainly have a different program for a track with a long straight, or hairpin, or a different setup for track and tarmac. At the very least, you could modify for different spring rates and tyres, which greatly affect 4wd use.

Makes a lot of mechanical sense Dave, and I assume it saves a bit of weight without all the clutch packs in the transfer case, but could you not fix the problem electronically using the standard setup and either altering the computer or changing the inputs? You can mess with the g-sensor inputs to give you more or less 4wd based on lateral movement, and I assume you could do the same with the abs inputs as well, or even more radically, do away with the 4wd computer altogether and setup your own basic 4wd activator. It's sounds as though what you are trying to achieve is to dumb down the 4wd controller so that it operates at full lock, thus 50/50 split all the time except for when under braking. That could be achieved pretty simply without any circuit at all by simply using a brake switch or the forward output of the g-sensor and a relay tied into you atessa pump power feed. Under normal operation, full power to the pump causing lock, brake on, no power, free wheeling. With a little more complexity by building a pretty simple circuit, you could modify this to be something more complex with a partial load on the pump so that you have a lower 4wd split rather than nothing. From memory, there are also some Jap tuners who have craked the Atessa computer. If you can find them, then you can accomplish all of the above with a bit of simple reprogramming.

No, you should be able to use a single maf.

If you've got all the rest of the gear to go with it already like the manifold, exhaust, not to mention the computer that will work with a MAF then you may as well give it a try, but if you don't, then these things will add a lot to the cost and not be reusable if you switch back to twins.

Accusump was about $250 second hand, plus whatever fittings and hoses will be needed, say another $30 should cover it. It will be located where the Hicas pump/solenoid thingy used to live, that is under the plenum on the chassis rail. About as short a line to the oil feed as possible without screwing it straight into the block (which could be a bit difficult). I'll mount the manifolds and turbos tomorrow, which will cover one side at least. Still waiting on the plenum for the other side.

Definitively keep the twins. On the track torque is as, if not more, important that pure kws. The big single sounds great, and yes you will spend most of the time above 5000 rpm, but you just won't be able to keep it there all the time. You can get bogged down in traffic, miss a gear, or simply shift up too soon and find that your too far in to shift down and yet still stuck before the boost kicks in. Even when it comes to the twins, you need to decide which way you want to go. Top end or bottom torque. Duncan and I have (or had) very similar cars except for the turbos and there was a subtle difference. His bigger N1 turbos should have made more power, but tended to take longer to spool up. i prefer smaller faster spooling turbos to pull you off the line and out of the corner, and still I can tell you that there have been tons of times when I have been in the wrong gear waiting for them to spool up. It's a painful wait. The other big advantage is a more linear, predictable, power curve. With the big single, you get nothing, nothing, nothing, then wham, whiplash. It just doesn't lend itself to dealing with traffic on the track or the short windy tracks like Wakefield. Ask around with all the other people who actually have caged and raced a car with others in a race scenario, not just those who have GTRs they take for track days. I raced against plenty of big muscle cars with big hp way over what I run, and they can't come anywhere near a well set up rb26 when there is any sort of cornering.

Don't worry Kel, I'm sure I can help Duncan build up your shoe fund! I've got a pile of catalogues a mile high to sort that one out.