nitrous

[S2 Ant]

Sounds like my method of just chucking the wet kit on and driving wasnt the best of ideas then LOL altho it ran very well and no problems that i noticed

[Jeffer]

Same for me, I'm looking into the same nitrous story. Are there any BTDT with running nitrous on serious boosting engines? I def want to install a system on my car for the 1/4 miles

[QuattroFever]

anyone built any nitrous engines. have you guys allowed any PTW clearance for the added heat the nitrous adds?

[JP]

Running turbo with nitrous there is no requirement for big nitrous figures, as the cooling effect of the n2o due to the latent heat transfer as it enters the air intake charge results in a denser intake charge for the turbo increasing it's efficiency. So it is quite common to see 50-60hp gains on a 30-35hp shot of nitrous on a turbo car already producing 450hp (if the nitrous system has been fueled correctly).

Because of this no real extra PTW clearance is required if being sensible, as for ring gaps the same as any high boost engine so again no major issues there if staying sensible.

The biggest mistake most people make is when fitting a wet system designed for NA cars to a FI car is that they t off the original fuel system, which is based on a rising rate pressure regulator. Keeping in mind that on a 45psi wet system 1psi fuel pressure change is equivalent to a 1thou jet size change as you start to come on boost the nitrous system will seriously overfuel resulting in lower than expected power figures for the jet sizes fitted as you bog the engine down.

The other problem I've seen repeatedly is people fitting progressive controllers that use a duty cycle to control nitrous and fuel flow increasing until peak power of the jet sizes is achieved. The problem here is both fuel and nitrous are cycled at the same duty so no way on earth will the 900-950psi bottle pressure of the nitrous flow proportional to the 45psi of fuel pressure. Simple physics any manufacturer that claims they've solved this issue is lying. So on the initial onset of use of a progressive controller the result is a running lean condition which starts detonation, unfortunately this will not stop until you back of throttle.

So as a rule of thumb if someone really wants to add 100hp of nitrous to a 450hp turbo car the best route is as a 2 stage setup of 50hp and 50hp shots independently fueled from a separate pressurised system from the main and you should be able to get a 120-150hp gain. Depending how well the jetsizes have been matched, also at this point I would advise 1-2 heatranges colder on the spark plug which will counteract your detonation.

For a smaller power gain you drive a turbo turn the boost up.

[driftin jo]

Running turbo with nitrous there is no requirement for big nitrous figures, as the cooling effect of the n2o due to the latent heat transfer as it enters the air intake charge results in a denser intake charge for the turbo increasing it's efficiency. So it is quite common to see 50-60hp gains on a 30-35hp shot of nitrous on a turbo car already producing 450hp (if the nitrous system has been fueled correctly).

Because of this no real extra PTW clearance is required if being sensible, as for ring gaps the same as any high boost engine so again no major issues there if staying sensible.

The biggest mistake most people make is when fitting a wet system designed for NA cars to a FI car is that they t off the original fuel system, which is based on a rising rate pressure regulator. Keeping in mind that on a 45psi wet system 1psi fuel pressure change is equivalent to a 1thou jet size change as you start to come on boost the nitrous system will seriously overfuel resulting in lower than expected power figures for the jet sizes fitted as you bog the engine down.

The other problem I've seen repeatedly is people fitting progressive controllers that use a duty cycle to control nitrous and fuel flow increasing until peak power of the jet sizes is achieved. The problem here is both fuel and nitrous are cycled at the same duty so no way on earth will the 900-950psi bottle pressure of the nitrous flow proportional to the 45psi of fuel pressure. Simple physics any manufacturer that claims they've solved this issue is lying. So on the initial onset of use of a progressive controller the result is a running lean condition which starts detonation, unfortunately this will not stop until you back of throttle.

So as a rule of thumb if someone really wants to add 100hp of nitrous to a 450hp turbo car the best route is as a 2 stage setup of 50hp and 50hp shots independently fueled from a separate pressurised system from the main and you should be able to get a 120-150hp gain. Depending how well the jetsizes have been matched, also at this point I would advise 1-2 heatranges colder on the spark plug which will counteract your detonation.

For a smaller power gain you drive a turbo turn the boost up.

What you said does not make sense ! The S2 does not use a rising rate fuel pressure regulator.
It is relative to manifold pressure at all times !
Therefore the fuel delivery from an injector taken from the fuel rail will be the same at any boost pressure.
The nitrous delivery will be reduced by the increase in manifold pressure thus the mix will get slightly richer but not by very much, you start off boost with 58 psi / 4 bar then say add 1.5bar boost this is only 21.75 psi this is not going to resist the 900 psi nitrous very much as this works out at only a 2.5 % reduction in flow !

[QuattroFever]

as i understand, intake charge is cooled but peak cylinder pressure is higher so piston gets hotter and engine makes more heat.