Adam W

Can anyone explain to me why an aftermarket BOV will go off when you rev the car at idle, but with a stock BOV, although the same boost pressure is being generated, there's not even a hint of a tickle of a whisper of a sound of a pressure release? EDIT: And would this still happen if you had the stock BOV in place? Does that then mean that whatever pressure is present in the system would "prefer" to go through the aftermarket BOV because there is less resistance there?

Yeah, it was probably a four cylinder undertray for a three wheeled two-stroke car that runs on washing up liquid . . .

That wasn't the black Scooby, parked in front of the car park on the grass at Bolney was it? That H&S (he had the stickers) system was quite fruity

For quality custom exhaust work, you can't go wrong with Hayward and Scott. My mate has just had one made up for his GT40 and the quality is sensational - it makes the Blitz and HKS stuff look agricultural! Expensve though, and I'm not sure where they're based. Apexi N1 are popular in the states but I know nothing else about them.

Option 2 will be much easier than option 3 I reckon. It'll only take em an hour to bend up a bit of pipe to join the backbox to the cat, they could spend ages messing about with an existing bit to try and make it fit. A word of caution though - I had some exhaust work done by Top Gear in St Albans, and I was so excited about starting the car up and hearing it, I didn't think to check their workmanship. I found some nasty bubblegum weld and a badly re-bent bit of pipe when I got home If it was me, I'd go for the Hiper. They sound excellent.

The thermostat should be just on the engine side of the radiator top hose. If the rad is blocked you can often feel hot and cold spots on it with your hand when the engine is warm - it should be a uniform temperature all over. The best way to try and clear it is by removing it, and running a hose through it from the top inlet and then from the bottom outlet. If it 's badly clogged I would be tempted to buy a new one though.

Whatever makes you think that this gentleman isn't from England Rich? The main engine differences between UK/US spec and Jap spec are the turbos and the fuel system, so if you're changing both of those then it doesn't matter which car you start out with. Are those honest-to-goodness English horses, or those weedy little American ponies?

The pump will be rated at gallons per hour (gph) at a certain pressure. Increasing the fuel line pressure will mean more fuel is squirted through the injectors as they open, but if the pump can't supply that volume of fuel at that pressure you'll still lean out. Work out how many gph you need to attain your horsepower goal, work out what line pressure you will need to squirt that much through your chosen injector setup at 75-85% duty cycle, and then choose a pump that will flow that much fuel at that much pressure. Calcs are available on the RC engineering website, but remember they will be talking about american horses so leave yourself some headroom.

Arrrrggghhhhhh! Alex! Do it properly! I'm picking my new fuel pump up from Chris next week - guaranteed 600bhp, very reasonable price.

Not wanting to knock Petes product *at all*, but there are dedicated nitrous controllers, including window switches (ie operating in a rev "window" as you describe Ian), progressive NO2 introduction to the engine, auto shut off at high/low boost, safety interlocks . . . everything in fact, currently available. For this particular application, it might be beneficial to use a unit designed specifically for the job in hand. Perhaps you could use Petes unit, in conjunction with the daylight sensor on the dash, to automatically lower the windows at 4000rpm+ in tunnels?

I think if you have it set too "soft" then the spring will release under high boost, and you will notice your boost (when accelerating) will go up and up and up, and then level off at alower level then previous, as air starts to leak out of your BOV. If you set it too hard, then (I think) you may have problems with compressed air flowing back against the turbos before the valve opens. Or it will not release at all at low-medium boost pressures. I guess also if you set it too hard, then it will not "fire" when you rev it at idle, which is the main reason most of us buy BOV's!!! I haven't got any experience of this yet, but I also have a vent-to-atmos BOV which I will be fitting soon, so I will be interested to hear other peoples thoughts.

I have the Blitz SUS (with a homemade cold air intake) and it looks and sounds lovely. Filtration is only average though - the best cone filter out there is currently the Apexi one, available from Paul Whiffin, this seem to have the best flow AND the best filtration. It doesn't look as good though . . . .

Wouldn't it be a LOT easier to buy a temp sensor which provides the "correct" scal of output voltage? ie one that is proportional to temperature, rather than inversely proportional?

I wonder if you could do something similar, but use your air con to cool the IC rather than the inside of the car? Or maybe adapt the internals of a freezer to get the intake air REALLY cold!

Is a chargecooler an air/water version of an intercooler? I'm sure I read that they were less efficient than an air/air IC. Do they use the engine coolant for cooling? That's at about 100 degrees isn't it?

I think it may refer to the block being O-ringed? I've never heard of this with an engine that has a metal head gasket as standard, but basically a groove is cut into the block surface around the cylinders, and a wire (usually copper) is pressed into the groove. Then when the head goes back on the wire presses into the head giving extremely high clamping forces and warding off a blown head gasket.

Everyone always recommends Micheldelver tyres, not used them myself but they're meant to be well cheap, even including delivery.

I know, I know, I just didn't want to confuse the issue! My new turbo arrived last week, it was balanced at 180,000 rpm apparently! Mmmmm . . . boost

It's normal to show a vacuum when idling - the turbo is not spinning as there is not much exhaust flow, so the engine is relying on the suction of the pistons to vacuum the air into the cylinders. Your boost pressure does sound a little low if you have lost both cats. Also, you should hit max boost at about 5k rpm after the 2nd turbo has come online, and then possibly a slight creep upwards as you head towards the redline

Does the MkIV have forged pistons as standard? I looked into some for my Mk3 . . . £££££££

It's funny isn't it. The NA has got about 230bhp or so as standard, and as Flip said, that's enough to get some decent starts off the line, frighten unsuspecting passengers, and make the car a lot faster than a lot of other "performance cars" out there. Surely any sane person would be happy with that, wouldn't they? And yet, the vast majority of people of this BBS have TT supras, which put out around 300bhp as standard. A vast output, which ten years ago would have been right up there with the best that ferrari or lamborghini could do. A stock TT is right on the brink of being a supercar in terms of straight line performance, I bet everyone remembers their first drive, thinking that the second turbo was gonna punch them right through the drivers seat and into the miniscule boot. And to top it all, 99% of TT owners, within a month of getting their car, get bored! They want more power, more noise, more everything, and they keep wanting it no matter how much they have of it! And all this in a country where the maximum speed it is legal to attain is 70mph, a figure which a stock NA get's to in seven or eight seconds, with two or three gears to go. Mad, ain't we?

Reminds me of a joke: Brad and Flip are driving along in a Volkswagen Beetle while there Supras are being serviced. The car stops suddenly, and Flip jumps out and opens the bonnet. "Here, Bradsta, your engines fallen out!" "It's alright Flip, there's a spare one in the boot"

Hang on a sec . . .you said it was too loud at Pod! Weren't you gonna swap for JB's mongoose? Anyway . . . even if Blitz don't make one, I'm sure a custom place wil be able to knock one up. I'm getting a pipe made next week for the centre of my Mk3, 3" stainless four foot long with a couple of bends. Should be about £50 I reckon. Powerflow exhausts, they have places all over, do a search on the web for them.

What, you're fitting the nozzles in the rear wheel arches? You could have a switch that activated them above half steering lock and half throttle, just to keep you on your toes

1) 60k miles if using platinum plugs, 12k miles if using normal ones (which is probably a better bet) I THINK! Somebody will correct me if I'm wrong 2) NGK are good, steer clear of brand names like Blitz or HKS, you pay way over the odds for nothing special. 3) There are six, one for each cylinder 4) Check the service history to see when they were last done. A good indicator of a high tension problem is missing on high boost (when the ignition system is working hardest to create a spark). This could be either plugs or HT leads.