260DET

Yep, my conclusion is that to build a reasonably reliable 4L60E transmission for my purposes would involve a virtual replacement of every significant OE component. And that would not give reliable engine braking. So a 4L80E it is.

All this sort of air flow manipulation has been done before, it seems here as is usual that it's all up to what the rules allow. Wow. I would have thought that drag reduction would be the first priority to the extent that component cooling and induction air were allowed to the bare minimum that would not degrade overall performance. Without knowing the rules it's impossible to comment more than generally like this.

That's going to increase drag though isn't it.

Have reached an impasse with the 4L60E, down shifting through the gears with engine braking appears to be a crucial weak point. Sonnax kindly offered some advice which would help but the basic mechanicals remain the same, they have no plans to bring out any mechanical improvements as they have done with some other components. So it's back to the drawing board to look at the 4L80E, might open a new thread for that.

Trying to find out the details of this car's auto.

Yep, 6500RPM is plenty given the torque spread of the LS3. Besides, the 4L60E is not the strongest auto around so there's that to consider too.

Cool, could be a hookers name too Ignore that

King Z ain't so bad, at least he is not in business putting himself out there as The Z Guru. Knew a bloke like that, took a while for those sucked in to realise he was not, either that or else they didn't want to agree that they'd been sucked in.

Boat places sell fans like that, actually ships chandlers or whatever they are called are good for all sorts of thing like fans, ducting, vents, switch panels and so on.

Yep, it's going to be a full manual sequential shift auto using a stick in the usual place, I don't like paddle shifts but that is an option. At present, subject to further advice, the torque converter will be a 10" diameter job with a lockup, stall around 2,500RPM. Have started the parts collection by ordering a aftermarket six element planetary gear set which raises the 2/3 gear ratios to give a more competition orientated 2.84/1.55/1.00/0.70 ratio set. Which with a 3.9 diff and the usual tyres will at 6,000RPM give gear speeds of 64/118/183/262KPH. Not ideal but close enough.

It's still all to be decided Cary, I have two shops working on a proposal and hope to get them to cooperate to get the best possible outcome. Apparently the 4L60E is considered fragile but doable for my 500hp application, it will weigh around 70kg all up compared with 110kg for the recommended 4L80E which is just too heavy. As a comparison the Z32 manual box I have weighs around 55kg. It will have a fully operational converter which I guess is needed for speed variations from loading the car onto a trailer to flat chat down a long straight. Heat management is going to be critical in that situation.

Now that the Z has a LS3 in it the 4L60E option is on, have spoken with someone who builds racing transmissions and he is going to sit down and think the requirements through to come up with a suitable package. Aftermarket circuit autos are almost non existent here so it's different for him but he's keen to do it. Without finalising anything we talked about having a clutchless 9" converter and a manual bump shift setup. Once it's all been worked out and decided on I'll fill in the details here. Comments welcome in the mean time.

If you want to use off the shelf front struts, the Arizona stuff is pretty good. At least as a starting point. MCA suspension here are happy to use the Arizona gear as a base for their various racing options. If you want advice on what poundage springs etc telling us your car's corner weights would be useful.

If you are prepared to get an L series engine done overseas then there are a couple of builders in Australia who routinely do proven L performance and race engines. One provides a drive in drive out service including a race track test and tune. Over the last few years there has been enough local demand to pay for the development involved so to them the L series is much more than a gunna engine. Gunna get round to it some day.

Forgot to mention re an accumulator with an electric valve, the switch can be mounted at the blanked off point at the front left of the block where it will be more responsive to an oil pressure drop than say where the standard oil pressure switch is located. In effect if the accumulator oil input is at the point near the oil filter the accumulator electric valve will open before a potentially damaging oil pressure drop occurs at the engine itself so maintaining oil pressure. To the extent that the accumulator has the capacity to do so of course.

Now this thread is starting to deliver As to the effectiveness of an accumulator, it is absolutely pointless using one without a one way valve, no discussion will be entered in to. As to oil pickup filters, have a look at one off a VG engine, certainly much better than a lot of the aftermarket ones which don't have sufficient surface area. On a personal note, my plan is to use two electric head scavenge pumps switched by the Haltech. Can't see how oil drain down cannot be a potential problem for a V8 performance engine so it will be covered, one less thing to consider.

Five speed Tremec is what you need, lighter and a much nicer shift.

Don't quite understand your question because whatever fits works and the choice between a R200 and a R180 usually depends on how much power is involved. It's basically a plug and play setup.

Excellent build

You know your market but I would have thought that the five speed Z32 box, which is still available new and in improved form, would be a better choice. One thing I've wondered about is if the lower fifth gear from a Patrol gearbox would fit, for racing the standard Z32 fifth gear is too high. Current Z32 box is a good one, improved syncros for starters.

Oil vapour would primarily be the result of windage is my un/educated guess. But let's stop for a moment and consider the LS engine. What we have is a relatively compact crankcase supporting say six litres displacement, that's eight large cylinders pumping away with the inevitable blowby all of which is contained by the crankcase until it can be vented somewhere. On the stock LS that pressure is vented up the available passages into the heads, at the same time oil in the heads under the influence of gravity is draining down through whatever of those passages which are available and so going in the opposite direction to crankcase pressure movement. Which inevitably hinders both. The solution to which is............. Unless someone has a relevant comment on the above I'm calling it a day, cheers.

What specifically are these solutions alainburon, that would be a start. Because the conclusion I came to after doing hours of research was that there were products out there as usual but no proven solution other than to go dry sump. I like others in this topic are not writing stuff for fun, saying that there are solutions without specifying them is pointless.

As a general observation, oil mist with combustion gasses that have blown into the crankcase is not a good mixture to have coming back into the intake, from a performance point of view. heavy85's setup partially minimumises that problem by removing part of the oil mist and condensing it in containers. The amount of condensed oil mist he collects shows just how much is involved, it seems pretty significant to me. But as far as I can tell the setup does not change the amount of combustion gasses removed from the crankcase so it has no influence on lubrication matters compared with stock. Which still leaves me thinking that, other than using a vacuum pump, the only way to improve head oil drain down is to vent the crankcase directly to the atmosphere, and, remove oil from the heads either by external drains or scavenge pumps. Ideally, a vacuum pump if used should draw from the crankcase. Does all that make sense?

What SUNNY Z said/did.

On adding head oil drain down's, relying on gravity would be better than nothing but still subject to the usual forces that cause the problem in the first place. They would have to be a fair size too which makes effective installation more difficult and expensive. If, if, I do anything it will involve two electric scavenge pumps switched by the Haltech ECU. Smaller lines, just drill and tap the heads at the back. Unfortunately my Z is in storage while I work on the house, not happy, Z is more important than any house