BlackRx7

I know you can crack or melt the apex seals if you use a big enough shot, I was only planing on using a 50-75 shot, my car has 156,000 miles on it but I did the atf treatment and she idles like new at about 1100 rpm. So should I? I can get a used wet kit for $300 what do you thinK??

cezonetheillest

where can you get that wet kit for 300? i was really thinking about running N02 in my car somewhere between a 50 shot to 75 shot.

thanks

J-Rat

iTrader: (2)

there is a BIG writeup on using Nitrous in the rotary, by our very own gas huffer, Scathcart.

Oh, and by the way:

Kenteth

lol ahh classic

Atticus

Did anyone else catch the idle at 1100 rpm? You shouldn't be idling that high, IIRC.

91_fc

... unless he adjusted the idle.

FrostRacing

or has a monster street port (and he dosent)

Tofuball

Fix your car before you even consider runing NO2.

Parastie

Hehehehe, he said NOS....hehehehe

rotaryracer1

iTrader: (1)

u should be fine to run a 50 to 75 shot. i currently am running a ZEX dry kit witha 65 hp shot i have had this system on my rx7 for almost 3 years now and have not had any probs. the pro's: your cars alot faster while shooting and its hella fun. the cons:it cost $40 to $50 to fill the bottle each time. i only get about 10 full out 1/4 mile runs with a full bottle. if you use it on the street u will get more life out of a bottle cause you dont use it for a full 1/4 mile street racing. i have no good luck with posting serious questions like yours on this forum, people are just ******** that have shitty answers. i hope i could help u.

J-Rat

iTrader: (2)

And your response was a WEALTH of information..


Here is the complete writeup by scathcart:

https://www.rx7club.com/showthread.p...hlight=Nitrous

FrostRacing

rotaryracer1 your car looks very nice, is that a gst or gsx back there?

Rxmfn7

iTrader: (4)

May I ask what front bumper that is? Its very nice.

casio

that and the write-ups that have been done and other threads that have helped.
https://www.rx7club.com/showthread.p...hreadid=278515 for example.
http://www.fc3s.org/how_tos/engine/nos_wet.html
http://www.fc3s.org/how_tos/engine/nos_dry.html

totallimmortal

Umm yeah I'd look into why its idleing that high most engines would idle smooth that high if your engine is running great and a stock port it should hold a much lower idle. If your havving problem holding a lower idle i'd fix that before any nitrous and my only advice is go with a wet kit if you can afford it that way you don't risk goin lean

scathcart

I think the miles are a bit high, and that idle makes me worry. What are the compression numbers?

Too big of a shot does not crack apex seals. I have easily run 250 shots without destroying the apex seals. Incorrect fuel and timing is what will destroy the apex seals.

I personally would save for a rebuild, and then go for nitrous.

casio

one thing i dont understand is tuning for an engine with a stock ecu running nitrous, but not always. i dont see a way to quickly change fuel 'maps' without a standalone. does the s-afc have a way to save settings? i searched for links on nitrous earlier and never came up with anything remotely touching this question, though i wasnt exactly looking or searching for this either.

poor_red_neck

I'm not sure if I understand your question fully... but I'll give it a shot.

Say you want to upgrade your injectors.. you have stock primaries, and 750 secondaries. You need some way to control how much fuel is being spit out because the ECU thinks you have stock injectors. The pulse width is still the same, but the injecors are larger... so you're running richer than you should be. You can use the afc to modify the AFM's readings. Why its called a "piggy back" I guess. You modify it in 600 rpm intervals (alteast for my s-afcII) by removing or adding (maxxing out though) upto 50percent, or taking out upto 50 percent fuel per 600 rpm. You can do this all the way to 8500. So when you goto the dyno and they hook up the wideband, they know how rich or lean you are in certain RPMs. You tune the afc to this, and it modifies the ECU's input of the AFM... yaddya yaddya yaddya.

The problem comes when you have nitrous. The cheapest way to do it would be tune the AFC with a wideband WHILE spraying, that way you get "percect" (or near perfect) fuel/air ratios while spraying. Maximum HP. Now during normal driving, you'll be running slightly rich. Don't know any other way around that. (cheaply)

totallimmortal

go with a wet kit it injects the extra amount of fuel with the nitrous, that way you tune the car to run perfect without nitrous so you get the max HP you can without hitting nitrous, then when you push that little button you get a shot of nitrous and fuel so you still stay between rich and lean instead of having to run your car rich so it won't lean out with nitrous, wet kits are much safer to IMO

casio

well thats what i'm saying. i know how to tune it, but if youre making 130 horse at 5K and spray 100, thats a lot of extra fuel to just 'run rich.' i've never dealt with an s-afc (though will in a month or less hopefully), so i dont know if they have saved settings so you can switch. ..or if there's another (better) way.

poor_red_neck

My safcII can't save more than one saving I wish it could though... and just easily toggle to your 2nd (nitrous) setting.

casio

i'll have to look into wet kits as this seems to be said too easily. not so much "too good to be true," but too simplified. i'll look into wet kits and their functions and how they acheive their functions. you can't just "add fuel" magically. adding another couple of injectors isn't a minor deal. like i said, i dont know how these systems work, thats just what i'm getting from the summary.

totallimmortal

A wet system comes with 2 jest one nitrous and one fuel, you put in a jet for what shot you want, ie. a 50 shot nitrous jet with it's corosponding 50 shot fuel jet. It is that simple maybe why it seems so simple, note that you aren't adding injectors although I've seen some fogger systems on piston motors that have a nitrous fogger and fuel injector in each intake runner, check out a summit racing catolog many of the kits have jets with 2 intlets one for the nitrous line and one for the fuel line, They sell 500 shots there is no way you could tune to run a 500 shot, the engine would be way to rich to run without nitrous.

scathcart

For both wet and dry, tuning is generally done outside the fuel mappings.

For wet systems, fuel is metered in separately via its own fuel injector, called the fogger, which also adds the nitrous. The amount of fuel is jetted in via restriction jets in the fogger. The restriction size determines fuel flow for a given fuel pressure, and corresponds to the relative size of the nitrous jet.

Dry systems reatin the stock injectors and run an FMU (fuel management system). The stock fuel maps are untouched; when nitrous is engaged, the FMU merely ups the fuel pressure so that the stock injectors add more fuel (or alter the vacuum signal to the fuel pressure regulator to alter the fuel rail pressures.)

Only aftermarket EMS control fuel addition via injectors when spraying.

If this doesn;t make sense, let me know, and I will try to clarify.

scathcart

To clarify: almost all nitrous systems add fuel completely separate from the stock fuel injection system.

Wet really is as simple as you make it, and much more tunable. It is all I run.