Is n2o bad for the car at low rpm?

[red2001caaaamaro]

I drive an all wheel drive eclipse automatic. Car has, or will have, a pretty large turbo with alot of lag. I was thinkin I'd squeeze off a 50 or 100 shot to get me off the line. Problem is a guy ( who i thought sounded like he was talking out his ass ) from the dsm sight told me nitrous is bad for the motor at low rpm's. I figured it would be the other way around, but is there any truth to this?

[317indy]

Yes, its true. Nitrous needs a certain amount of fuel for the nitrous to properly work. Your car does not make enough fuel pressure in the lower RPMs as it does the middle/upper.

The best thing you can do is spray the intercooler not the engine.

[red2001caaaamaro]

So with supporting fuel mods, it would be okay?

(ps, spraying intercooler does not help turbo lag );)

[317indy]

If your lower end could handle all that compression, then I would ventrure to say sure, but I wouldnt spray a turbocharged 4 cylinder.

Get a bigger fuel pump, and adjustable fuel pressure regulator and prolly some bigger injectors and a custom tunned ecu.

[red2001caaaamaro]

Originally posted by 317indy
but I wouldnt spray a turbocharged 4 cylinder.
Why not? I will have all of the formentioned mods, pump inj and piggy back computers, and I will not be spraying and boosting at the same time. Plan is to hook the nitrous up to a boost guage. Once it hits 10 lbs the nitrous will stop spraying. So basically from a stop, to half way through first until boost hits.

[red2001caaaamaro]

The internals can support 400+ hp. Given the appropriate fuel and timing were supplied, are there any other reasons why nitrous could be bad at low rpm's?

[317indy]

nitrous + no fuel = running lean = big bang theory.

[Bad30th]

Try it and let us know how it goes. :)

The "physics" of it would be that it's harder to turn the crank at a lower RPM, and with more violent combustion vs. harder resistance you're more likely to break something.

That's the only valid reason I've heard so far.

Bad30th

[GOT SPD]

It is not a fuel issue, it is a physics issue. At lower rpms the motor can't burn all the extra fuel and nitrous and it can puddle and cause a back fire. That is why you see cars blow the intakes off at the starting line. I have seen a car bog off the line and have such a violent back fire that 30 seconds later the front of the car was engulfed in flames.

If you are running a 75 to 100 shot I would try not to spray below 3000 rpms and if it is a 125 or bigger I would stay above 3500.

[red2001caaaamaro]

50 shot?

[red2001caaaamaro]

Is there any thing to get me off the line?

[317indy]

Originally posted by 14.5 drift
Is there any thing to get me off the line? Umm its AWD, Youre gonna launch trust...

Launch that badboy at like 5k-5.5k. :yup:

[red2001caaaamaro]

Originally posted by 14.5 drift
automatic large turbo with alot of lag.

[jaywoo]

Well, something else to think about. You didn't say if you were planning on a wet shot or dry. The bad part on a wet shot is the fuel puddling in the intake at low RPMs. That's what causes the backfires. Nitrous itself cannot cause a back fire, because it is not flamable by itself. It needs fuel. So, at lower RPMs, you have less airflow, and on a wet shot a greater chance of a backfire in the intake from puddling. A dry shot doesn't do this on a direct port fuel injected car like your DSM or the LS-1, since the fuel doesn't run through the intake.

With all of this said, I'd run a window switch to keep the kit from spraying below 3000rpms. Also to turn it off shortly before your rev limiter hits. With your auto AWD, I'm sure you will be power braking to build boost off of the line. As soon as the RPMs pass 3000 and you are at WOT, the spray hits, builds boost quicker, and zoom zoom. :)

[red2001caaaamaro]

I really dont like to power brake.

You were going in one direction with the dry shot that was soundin good, then jerked the chain thee other way, lol. You had me thinkin a dry shot would be safe at lower rpm's because there was no back firing issues. But then you said the 3000 limiter thing. confused?!?!@?!?!?

Why not a dry shot from idle?

I will also be running an afc

[jaywoo]

I said about the window switch because it's a realy good safety device. I wouldn't spray below 3000 rpms, but if you have to, I'd go with a dry shot for that reason (no puddling of fuel). You could always go with a progressive controller or a dual stage. :)

[GOT SPD]

I think a progressive controller would be the best option. The dry shot off the line is the best idea and that is why you see a lot of two stage systems where the first stage(off the line) is dry and the second stage(usually wet) comes on after the 60'.

[317indy]

Originally posted by GOT SPD
I think a progressive controller would be the best option. The dry shot off the line is the best idea and that is why you see a lot of two stage systems where the first stage(off the line) is dry and the second stage(usually wet) comes on after the 60'. I doubt he wants to spend 600$ on a damn NX "maximizer". :rolleyes: I cant believe people buy those things for that much...They should only cost about 200 if that.:2guns:

[red2001caaaamaro]

I would not use the nitrous for any thing other than the 60. After that it is the turbo's work. :D Thanks guys.

[GOT SPD]

Originally posted by 317indy
I doubt he wants to spend 600$ on a damn NX "maximizer". :rolleyes: I cant believe people buy those things for that much...They should only cost about 200 if that.:2guns:

When you are running large shots they come in handy and are just another bit of protection against a possible nitrous mishap. Nobody said going fast was cheap. When you build a car to go fast like I have, $600 for a controller is nothing.

[Z284U2TRY]

I would suggest a stall and a 50 dry shot out of the hole. I kid I use to hang with sprayed a 75 wet with an auto supra to spoool the turbo and didnt have any problems. I have sprayed my car below 3000 but not reccomended.

[Eastern Bowtie]

I have a 1995 Caddy Eldorado. Northstar powered. One weekend I thought it would be cool to throw the ol' 150 wet shot on it and get some numbers from it.

Everything was working great. I ran low 14's @ 108 all night long. There was no traction every pass. I let my friend take the last pass and forgot to tell him not to spray it till around 2500-3k+. He went into the burnout box and began spraying right off idle. The whole side of the intake blew off and the engine engulphed into flames. I don't know how a dry should would differ but stay away from the Wet shots under 3k Rpm's.;)

PS. Sign on to TurboFord.org. Post this question in the BS forum and they will tell you what you need to do to run Juice off the line. That site is devoted to 4cyl Turbo's and there are people using 50-100 shots to spool big turbo's.

[CT Morgan]

Originally posted by Z284U2TRY
I would suggest a stall and a 50 dry shot out of the hole.

Bingo. Get a moderately stalled torque converter to get the rpm's up and you really don't need to spray more than a 50 shot. Nitrous reacts a little differently in a turbo car (added oxygen plus chemically cooling the intake charge) and tends to make bigger gains from smaller shots. It will also help the turbo spool up a LOT quicker.

The reasons you don't spray much at low rpms and the reasons you don't want the engine under a lot of boost at low rpms are the same and they center around cylinder pressures. It's a lot of unneeded stress on the components and excess pressure on the bearings even if it's a built engine. The excess pressure will also increase blow-by as well.

[Collin]

here is what an n20 backfire looks like

http://www.drugg.net/bird_roast.htm

this is my friends car.....:(

[red2001caaaamaro]

dry shot or wet?

[Collin]

wet

[GOT SPD]

ouch....i have seen that happen to a couple cars only the fires was extenguished before it engulfed the whole car.

[Z284U2TRY]

Cool someone is reading my posts.:cool:

[red2001caaaamaro]

so today I did a torque brake and found my car stalls at about 2100-2200 rpm. Would it be safe to say I could run a 50 shot (dry) from that rpm til spool up of the turbo?

[GOT SPD]

:yup:

[Eugenio_SS]

+50 hp @ 2000RPM = +131 tq
the reason people do not spray at low rpms, is due to added tq.
You will be fine spraying it from that point on.

[red2001caaaamaro]

Originally posted by Eugenio_SS
+50 hp @ 2000RPM = +131 tq
the reason people do not spray at low rpms, is due to added tq.
You will be fine spraying it from that point on. hehe, perfect for a gsx