Adam W

Stronger valvesprings are normally needed to stop the valves bouncing off their seats at high revs. As you're pushing the valve further into the head you need to be sure that the valve springs won't reach full compression (coil bind) before the peak lift is reached, you'll have a pretty chewed up cam lobe if that happens. Disclaimer: I've been reading up on pushrod engines lately but I think the above is still true!

From what a couple of happy Mk3 owners have said, £5-600 sounds reasonable for an install like this. You'll start off with 25bhp jets and go from there. Make sure you get a progressive controller with it, the installer will do a better job of explaining how this works than I could but highly recommended for engine safety reasons.

You know, I don't think even Brads mega-Supra is going to get much attention at this meet

Heh heh, if only that were true!

OK Phil, I just need a diameter or a range of diameters to give you a table of numbers.

Right; I'm assuming this is for gas flow not liquid. I've found the equations you need and they're bloody complicated, I understand them but not well enough to explain them to someone with no experience of fluid dynamics (not wishing to be patronising or Mycroftian here, but I'm guessing that's you!). To get really accurate figures, I'd need lots of information about the pressure difference across the valve, the flow rate through it in metres cubed, and the absolute temperature of the gas going through it. ie things which are pretty difficult to measure without a fair bit of gear. However, if you give me the diameter of the butterfly in mm I can do you a table of opening angle vs percentage of max flow rate, based on lots of assumptions etc which should be accurate to within 15% or so. If you want accurate figures, you're going to have to invest in manometers, temp probes, a hotwire flow meter, all sorts of crap!

I know that I have this info, and I'm pretty sure I can remember how to use it! Give me a couple of days and I should be able to give you an answer. Do you know the pipe diameter?

BHG can cause oil and coolant to mix, but more common on the supras (mk3's and 4's noth do this when they go) is that the coolant passage blows into the combustion chamber. Your oil isn't contaminated with white gunk, but you'll lose lots of coolant, overheat, and blow white smoke out the exhaust. Sounds more like a problem with the coolant system to me. A rad cap is about £3, change that even though the garage said they'd changed it. It's the most likely culprit and the cheapest thing to eliminate.

How did you do in the race? At least you survived it!

You don't wanna excuse it, be proud of it! Enjoying fast cars is nothing to be ashamed of!

The point people are making is that the stock TC is so slow to react that you can easily have spun into a lamp post before the computer realises anything is wrong (ask me how I know!). I just keep the revs below 3k when I'm cornering in the wet, well out of the turbocharged fun zone

"It operates by simultaneously applying the forward and reverse clutch packs of an automatic transmission while its both in gear, and the torque converter is at or near it's stall speed" :eek: Good info in that link, thanks.

I thought they were analogous (cool word huh?) to revving up to 3200rpm (or whatever) in a manual at every standing start before engaging the clutch. Hence a bit embarassing cos it sounds like you're at Santa Pod as you're pulling out of your driveway in the morning ... Might be wrong though. While we're on the subject, can anyone tell me what a transbrake is, and how it allows you to build boost on the line (it's another thingy you can do to auto cars apparently).

Lots of good info there! Just one point - Top Methanol drag cars run about 2-2500bhp and run in the mid sixes I think. Top Fuel cars run on nitro-methane (although they have to start the engines up on methanol), put out around 6000bhp (difficult to measure exactly!) and run mid to high 4's @ 320mph . . .

Yeah, but it's impossible to read the display while you're on the move. I've got both, but on reflection I could have gone for the normal Greddy gauge and used the p/h/w features on the Blitz DSBC.

Yeah, you need an electronic boost gauge with a peak/hold/warning function. Greddy do a good one for ~£250, there may well be much cheaper alternatives though.

I'm 99% sure you're right Ian but I can't remember enough fluid dynamics to fiure out why I think what would happen is, turbo number one would produce 50 units of air, turbo 2 would then come online and produce 80 units of air. You'd get about 110 units of air heading towards the intercooler, but 20 units of air blustering around getting confused because of the pressure difference between #1 and #2 turbo exits. Not sure if thats an accurate explanation, but I'm positive you'd get lots of inefficiency, heat build up, etc.

It adjusts the spring tension in the BOV. If you find it leaking boost at WOT then tighten it up, it if doesn't blow-off properly at medium boost levels (ie a chittering noise) then loosen it.

Hi all, Not strictly a car related a question but here goes anyway. I've got a viscosity meter down in the lab at the moment which I need to calibrate before I can use. You can buy viscosity standards from laboratory suppliers but they're hugely expensive, so I was thinking . . . Is there a way I can convert from engine oils grade (ie 15W/40 etc) to poise or centipoise (the metric standard unit for viscosity), which is what the machine reads in. Alternatively, if someone has a bottle of multigrade sitting next to them at this moment, could you search around on the label and see if it has any viscosity readings on it in poise, kilodynes, anything really. I'd check myself but I don't have any oil with me and I'll have to order the standards today if I can't get any oil info . . . Cheers!

Not required . . . except by sauteed onions.

The rubber water hoses seem to perish (probably due to the heat), I just ordered a new one for mine this morning. There's also a flanged joint between the metal pipes and the turbo itself, perhaps these nuts are loose or the gasket is leaking. Try HERE for more Mk3 info.

Size matters, but the efficiency and design of the cores is even more important. What cores would you be using?

As Terry says, the pinouts are different so you'd probably need a full UK engine loom as well to hook everything up with . . . I believe for big bhp purposes the Jap MAP sensor is better anyway (assuming it's hooked up to an aftermarket ECU).

I got straight out of my 80's-tech Mk3 Supra with standard brakes and then drove a J-spec supra with standard brakes (this was at JIC), and was shocked at how totally awful they were. Then I drove a J-spec supra with UK brakes, and they were an absolute pleasure to use. AFAIK the two MkIV's were using standard pads . . .

Absolutely no point in replacing the stock BOV except that it makes a "PSSCHEW" noise when you lift off or change gear, as long as you're on stock turbos or (probably) hybrid turbos. If you're running mega boost from a big single or GT Twins than there is so much air whooshing about that you need a bigger/stronger valve to release it all quickly.