metro turbo engined mini

[blister]

i recently bought a ny trex system off ebay and the bottle is full but my question is how do i fit it as it has no instructions

the engine i have is a 1275 metro turbo engine with a cosworth intercooler

[Robert56]

what is the model number of the kit? can you give some info on what motor your talking about, a 4 banger, a straight 6 or... mr223 is our Ny-Trex info guy.
Robert

[blister]

i have got a straight 4 cylinder single carb turbo engine 1275cc 8v carb

the model i have got is 110010 - efi 4&6 wet nitrous system i think, as i purchased it off ebay it looks the same on here though,

[Heretic]

Hmm this could get interesting.

That's a blow through style, single carb motor. So you want to put the nozzle in the charge pipe right before the carb. Point it so it sprays the carb opening. You might a have tight bend right before the carb, but try to get that nozzle so it doesn't have to spray around corners. Put it right in the corner if need be. Most nozzles spray slighty down off the tip (not at a true 45, more like a 60 degree) It's better to ge a straight shot spraying right at the carb. Less chance of fuel falling out.

Do use the Wide Open Throttle switch!

If it was my engine, I wouldn't spray much more then the 35 on it. Maybe the 50 if it has forged internals and a good metal headgasket. It's sounds like a cool car. I have a 68 Midget with a 1275, and my dad has a Triumph GT6 and MGB GT. Brits cars are alive an well in my family. Nitrous isn't very popular in the UK is it? But it is legal to use on the road there, unlike here. I thought most overseas guys go with WON by default.

[blister]

the minis plenum is a seal unit that is pressureized and cant be drilled what about inlet manifold after the carb

[Heretic]

Hmm. Are you talking about that little collector box on the carb? I kinda just assumed you eliminated that with the addition of the intercooler and new piping.

But you have this style?


Your kit came with a Nozzle Adapter, like so.



Drill a hole here in about the locations shown below. Insert and silicone that adapter in there. This might seem like common sense, but the piece on the right goes inside the box, and the nut on the left goes on the outside. That way you can visually see inspect and see that nothing gets sucked into the motor.




It's made out of steel right? Your other option would be to drill a hole and carefully weld a 1/8" NPT bung to that box.


That plenum under the carb is much too small to insert a single nozzle into and hope for even distribution. You surely melt something down. Unless you want to buy 4 Nozzles and go direct port. But You'll have a hard time, jetting it down to a small shot like that. Nitrous Express does make a small 1/16" NPT fogger for applications like that.

If you have something different please post a picture.

[blister]

will get photos up of my engine as soon as possible, that is the same engine as i have got just mine has a intercooler fitted,

what sort of bhp shall i jet it all up to? fuel,
one more questions do i need another fuel pump?

[Heretic]

What kind of fuel pump do you have now? (I'm guessing an external electric of soem kind? Return line?)

Most importantly, what is the base fuel pressure?

Really need to know those 2 things to get close to a base jetting. I have no idea at all what kind fuel pressure a Metro Turbo engine runs? But there is a good chance since it's carbed the fuel jets you have in your Universall kit are wrong.

[blister]

at the moment i have got a multipoint inject fuel pump and a fuel regulator

the fuel pressure is at about 3-4psi at idle and gets to a max of about 12psi

[Heretic]

Hmmm

How much boost does that motor run? Most carbs run about 7psi base pressure, so it sounds like you are only running 5psi of boost? You need to unplug the vaccume line on the regulator and see what the fuel pressure is. Or check the fuel pressure with the fuel pump running, but the motor off. (You can't check with the regulator vaccum line on, and idling, it lowers the pressure by a few psi)

When you know that base pressure (I'm guessing about 7psi) Use this jet calculator enter the the Nitrous Jet you plan to run (I'm not sure what all comes with that kit for jets) and it will give you a fuel jet to start at. Use Base Fuel pressure, not max fuel pressure under boost. If anything guess the fuel pressure low. If it It looks sort of like 6.5psi on the gauge? Enter 6psi into the calculator.

http://www.ny-trex.com/calculator.php

If you're using an EFI pump off something, that should be enough for a small shot.

[blister]

7psi of boost and the fuel pressure increases to a max of 12psi

the fuel pump is built into the tank and it is from a multipoint injection mini 1275,

i think i want about 25bhp shot so i put into the calculator

fuel pressure 7psi
nitrous pressure 950
nitrous jet size .026
no. of jets 1

and thats said i need a 0.023 fuel size jet

increase of 26.36hp is this noticeable power i know that my engine will take it but is it worth it?

[Heretic]

That's 26hp at your peak output.

But assuming you start spraying at say 3000rpm, your peak torque will be up by a good amount more when it first hits. Torque will also stay up by a good chunk when your are under your peak RPM. More power is always worth it, especially in lightweight cars.

Do the math, in a 1800lbs car with 100whp, adding a 25hp shot takes over a whole second off your 1/4mile (400m) sprint. Worth it indeed!