260DET

You could try closing off right across where the prototype bits you have added are. Then duct the front of the radiator in. It's pretty hard to explain without pics or drawings but done properly you should get more front downforce. Aero for us amateurs is about knowing the basics and then trying to apply them to every bit of add on bodywork we do.

When mixing and matching like that there are different bore size slave cylinders available, if you are not getting enough clutch travel then go one bore size smaller. I've done this using the measurements provided by some sellers on Ebay. I'm assuming that your slave cylinder type is the same.

Yes, the only dyno sheets I really take notice of are those that show detail like the DynoDynamics ones do. A video of the actual car on the dyno with a real time view of the screen is even better. Not everyone is out to bend figures but in my opinion if figures are going to be claimed then respect the target viewer and do it properly.

Z32 ECU, for everything. Specialise.

Exiting engine bay air, tricky one. Side exits do involve less drag compared with bonnet top vents which however do contribute to downforce by adding to the amount of air at the high pressure point at the bottom of the windscreen. One extra reason why more power is good, less concern about drag so in effect power can be converted to more grip.

OK thanks, must do something good then.

This is an interesting project, some good work being done. On the splitter design, why are the trailing edges that face the wheel wells turned up rather than being left flat? The strakes there would be to guide air to the wheel wells but I don't follow the reason for the turn ups. Any explanation?

Why go to all the trouble to fit a Nissan multilink rear suspension unit when the original semi trailing arm unit can be made to work very well. Did someone shorten the arms of a S13 unit to make it fit? That is ridiculous, it will ruin the geometry. Keep in mind also that the S13 unit has a lot of built in anti squat which is not great for a sports car. Back to the stock suspension, anyone heard of the E30 BMW M3 and how well they handle? Well they had a semi trailing arm rear suspension and strut front, there is plenty of info around on how they did theirs, see my post here for example http://forums.hybridz.org/topic/85166-s130-suspension-tech/page-9?do=findComment&comment=1080407. Mods are great but only when they do what they are supposed to do and at the right price.

This posted before? Anyway if anyone wants to get serious with the rear suspension then have a look at what BMW did with the E30 which has semi trailing arm rear suspension. This is the way I would go http://www.e30m3project.com/e30m3performance/tech_articles/susp-tech/rear_curves/

Funny that you should mention the Z31, there is no significant demand for what you are offering in AU (Nistune?) but any tuning ability that can be added internally to the stock ECU could have the occasional taker. Just thinking out loud.

Pity that there are not more books written by the old school experts, the real experts, the blokes who got their hands dirty. The bare history by itself can be fascinating, the information in effect perpetuates their working life.

More to do with the make and type of dyno I've heard Tony although I guess some operators from anywhere give in to temptation and customer expectations. I once sort of asked my operator to push a few buttons to give me an inflated power sheet but he refused.

It helps if you can visualise what is going on when the engine is running, keeping in mind that air (like water) under pressure naturally wants to go straight ahead. If air is required to turn the widest arc possible is best at the start, tapering down towards the last cylinder. Just takes a bit of thought because even air flow to each cylinder is the most important factor of all.

Yeh I guess that I'd better leave the perennial dyno accuracy thing alone. But, can't help myself here, some people do disrespect some US dyno figures as pony power, not horse power

We used to have the 'free' thing in AU too, it's only an old Datsun after all, not worth anything. There is still some of that of course but S30's are more popular than ever, it's amazing what scarcity courtesy of rust and smashes does to prices. Plus there has been an explosion in the numbers being used for competition, once there is a bunch competing together then money starts to circulate in increasing amounts

Dynopac is a hub dyno? Dynojet is an inertia type and a Dyno Dynamics is a retarder type. All will show different figues I believe, obviously a hub dyno will read more than a wheel on rollers dyno for a start.

There are castings and there are castings, from what I've read the VG castings were special whatever that means. Electramotive certainly did not used standard sized valves for a start so it follows that other flow restrictions would have been attended too and perhaps the valve actuation system as well. On the L series, given that these engines are still being widely used in competition I cannot understand why, instead of the secret squirrel business, all the old time expertise is not available for sale today. I'm not particularly interested in what it is but, for example, if it involves modifying standard parts then an exchange service may be appropriate. What is the problem?

MAP sensor only G. I guess that it will have to remain a mystery as to why the VG33ET apparently delivered a lot less power than other engines, I hate mysteries but sometimes enough is enough. It's just not worth the $10K I'd guess would be needed to be spent on the heads, valve train and so on plus a decent exhaust manifold system to give it a real go. Which is a pity because the engine was all set up to with a VG30DE crank and oil pump with custom adjustable cam wheels etc, oh well, thanks for your tenacity G and good luck with your build. Edit: The local view is that the cams are causing excessive exhaust back pressure into the cylinders. Anyway, someone may find something helpful out of all of this.

Interesting discussion but it does not explain why my VG33ET does not deliver anywhere near the power plenty of others claim. I'm not going to spend more time and money on it because the VG30DET does what is required and because the only advice I have that makes sense is that to get 400whp bigger inlet valves and higher lift cams are required. Plus the attendant head work of course. I do suspect that the single cam's inlet runners are restrictive, they certainly are significantly smaller in diameter than the VG30DET ones but who knows? Pity that all the race knowhow on these engines has been lost, I should have coughed up $15K years ago for a complete, genuine Electramotive donk EDIT The local opinion suggests if there is a problem then it is likely to be the cams. S2 JWT cams no good?

Of course there was a fan used, see at 0.07 the big square grille thing at the right edge of the picture. Powerful thing, put it too close to the front and the bonnet would have to be lowered due to the wind force, walk in front of it and it would just about blow you over. Same IC used with both engines, it is ducted unlike most and works very well. A data check made when the car was on the track confirmed this. This is what pisses me off, the whole setup was built to a high standard without using any potential power robbing shortcuts. .

NZ made TTI box bolted to a RB26, he is rapt. First run, more to come. Colour me green http://www.youtube.com/watch?v=caJ-80A2Zng&feature=youtu.be

Pretty much like my effort except mine was a rear entry because in a 280ZX there was more height to be had there. Height is needed so that air can turn 90 degrees into the inlets instead of skipping over their tops. Good on you for having a go, just make sure that there is a significant improvement to be had at the end of the day. See my thread on the viability of the good old single cam VG

So what may cause inlet temps to rise to the point where in practical terms there is no point in using more boost? Vid of dyno tune of first VG30DET version, the 33 was next

Not going to get into a pissing match about it, the reasons for this sort of 'difference' in power figures have been going on forever elsewhere, it's quite common. Who is 'right' and who is 'wrong' is of no interest to me. The reason for not pushing the subject VG33ET's boost past 15 psi has been explained several times, intake temps in a hot climate are of relevant interest but there was no indication that there was much more past 15 psi anyway. I was there and saw from the dyno screen what was going on, from memory I said something to the effect of 'stick it up it and see what happens', if it could not do the numbers the VG30DET option was there with only an oil leak to fix. With a circuit car you soon find out what is real and so don't mess around with a loser engine. I'm no dyno expert but the bloke who did the tuning is so, with the appropriate corrections, the two runs with the ET and the DET were as close as is practical. There has to be some measure of comparable performance, in the circumstances this is as good as it gets.

Going back over all this, the only conclusion that I can come to is that no VG30ET using original type heads and valves would produce anywhere near 400 whp on the dyno mine used. And there is no reason to think that there is anything wrong with that dyno or the way it was used. It's a pity that horsepower figures can't be properly compared internationally.