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Discussion Starter #1
hey people,

i just put a NOS adjustable dry nitrous kit on and i am having a little problem. with the dry kit you hook a vacuum line up to the fuel regulator to increase fuel pressure from 30-35 psi stock to 60-70 when the nitrous is activated. the problem is, is that the fuel reg. on the speed6 is built with the fuel pump in the tank so i cannot increase fuel that way. is there a map sensor on our car? or do you know of another way i can increase fuel pressure by vacuum? the kit works o.k. right now but there is moderate detonation so i know the kit is not working to full potential. please let me know what you can find.

p.s. i know this is only my first or 2nd post but i have been reading this forum for a few months now and know it is a great place to be. thanks for any help.

mr.lupkes
 

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this is a MAF vehicle. it does have a sensor for intake manifold pressure, but the ECU does not adjust fuel trims by its values. i dont think you'll be able to adjust fuel by vacuum. i dont even know if you'll be able to use a fuel controller to adjust the values for shots of NOS since fuel tuning isnt sporadic like injecting NOS. the fuel system is also direct injection, so it will be different than most other cars. i suggest you take a look at another car with a direct injection spark ignition and MAF and see if someone installed NOS. vw perhaps.
 

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Since the NOS goes by the MAF in a dry setup, shouldn't it add the extra fuel automatically?

Or is it difficult for the MAF to detect NOS?
 

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There are two fuel pumps.

One in the tank and one in the engine bay just before the injectors.
 

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What kind of line pressure is there between the tank pump and the injector pump? Is it even reasonable to use a off the shlf NOS kit with our fuel pressure?
 

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What kind of line pressure is there between the tank pump and the injector pump? Is it even reasonable to use a off the shlf NOS kit with our fuel pressure?
[/b]
Pressure is 62.4 psi coming from the tank, it's bumped to 435~1667psi by the high pressure pump under the hood.
 

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So if we can bump it to about 1800psi at WOT, we should be good for a 50 shot.
 

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At 1885psi the relief valve opens up!
 

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Discussion Starter #9
when installing the kit, the destructions said it needs to be at 65-75 psi and thats what the vacuum hose from the nitrous regulator to the f. pressure reg. does. i started with a 70 shot and it detonated so i thought the 50 would make it better but no luck. the improvements are obvious and nice but would be better with a little more fuel and no detonation
 

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That kit is designed to work with a regular fuel pressure regulator, it will not work on our cars. Also the turbo is undersized and when you hit nitrous it will increase the boost as well. I am all for nitrous but right now it's not the way to go for the Speed6. Even a direct port nitrous injection setup in the manifold would be a bad idea IMHO due to the design of the injection/cylinder heads. Your best bet is to fill the tank with CO2 and plumb it as an intercooler cooler.
Sorry man,
Mike
 

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I smell catastrophic rod through the hood engine destruction in the near future....

A DRY nitrous kit CANNOT be used on a DI engine. It was designed for port injection only.

A dry kit adds more fuel to the engine by pinching off the fuel return line to bump fuel pressure on PORT injection vehicles thus making the injectors work past thier rated range and deliver more fuel with the dry nitrous spay.

It will no way in hell work on a DI vehicle. Never, unless you want to see piston salad.

Theoretically a WET kit will work but it has not been tested. There are few concerns in the DI cycle that would make me weary about running it as well as the heads and intake manifold are not made to accept a fuel air mixture. You could get pooling and blow your manifold and part of the head straight off.

Personally I would shy away from the nitrous until sombody confirms safe fitment or you have enough money put aside for a new engine and possibly a new hood. As doing shit wrong could end up looking like this...





I say if you sprayed already you are extremely lucky not to have done any long term damage. Im not sure how you hooked it up but you cant just add nitrous without fuel!!! Good thing the car runs pig ass rich as is or you might have cooked your pistons already.


CLIFFS: STOP what you are doing right now and step AWAY from the bottle... You are VERY lucky you have not already broken anything.
 

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Since the NOS goes by the MAF in a dry setup, shouldn't it add the extra fuel automatically?

Or is it difficult for the MAF to detect NOS?
[/b]
ON the kits for the GM cars LS1 LS2 and LS6 engine. It sprays before the MAF and the Computer adds the extra fuel. Not sure if our cars will be able to do that.
 

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I don't think it would be wise to run nitrous through your turbo and ic. Not sure that would be very good for either of them. Let me know if I'm wrong or if someone has tried this on another car.
 

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I don't think it would be wise to run nitrous through your turbo and ic. Not sure that would be very good for either of them. Let me know if I'm wrong or if someone has tried this on another car.
[/b]

Yes it is very bad to run nitrous pre turbo... It leads to the compression of the nitrous charge.


If you absolutely HAD to run nitrous on the car I would start with a wet kit plumbed post IC and turbo. No way you are gonna run a dry kit without long term engine damage.

The best way to do it is to do a port injection nitrous where your manifold is drilled and tapped for seprate nitrous and fuel injectors which injects nitrous close to the head and runs its own standalone fuel delivery solnoid and pressure regulator.

 

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Spraying a turbo car is no problem if done CORRECTLY... but when Mr. Effer posts I read carefully, and fully trust him that N20 on DI is a bad idea...
 

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He just said a dry kit was a bad idea. I'm down for a 50 shot if it can be done safely.
 

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I too am down for a 50 or even a 75, but I want Zex, NX or NOS to design a kit specifically for this car before I attempt to put a universal kit on.
 

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He just said a dry kit was a bad idea. I'm down for a 50 shot if it can be done safely.
[/b]

It can be done thats for sure... How safely I cant comment because I have no experience with nitrous and DI.

Theoretically a wet system will work without problems if plumbed correctly.

I never liked dry systems anyway, back when I was souping up hondas a dry system was only safe for about 50hp before you really started pushing it. Increasing the load and operating range on a fuel injection unit to make it deliver more fuel is not very precise or reliable. Its a band aid solution for those too lazy to install a proper system.

Single Point "Wet" kits are ok if done right. They are downright dangerous if done wrong as I have seen manifolds blown off from fuel/nitrous pooling.

Direct Port Nitrous injection is the best becuase it minimizes if not eliminates pooling. Is VERY precise and reliable. The only problem is its a bitch to install and its the most espensive.

I know dry kits have made recent improvements with some kits electronically controlled but its still not ideal. Call me old school, I have been in the import scene for 10 years starting with hondas then moving to subarus with a small bit of experience with the toyota 3sgte. I also have a purely recreational intrest in the Mazda Rotary Engine just because its intrigues me. Dry spray still smells like fish to me.
 

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Discussion Starter #20
thanks for the help to all. i talked to my local mazda dealer and the tech today after i started this. of course he said from a dealer point of view that "warranty void and bad idea" but after that he said it wont hurt the motor like most would think. wed. night were going to increase fuel pressure when nos is sprayed and see how it goes. i am also going to get the turboXS fuel cut eliminator b/c he said when sprayed its trying to go over 18 psi boost and that its cutting the fuel thats why there is mild detonation. 'littleeffer' i do appreciate your help though. and everyone for that matter. i plan on continuing this and we will see what happens. tomorrow i will put up pics of the installation and i will see if he will let me upload the info his laptop records while driving. not sure if he will but i can definately try. thanks again
 
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