Rb20 And Lag

[iz32]

could small shots of NOS be used in the lower RPM range to bring the turbo on earlier or perform a little better between 2500-5000rpm?

just a general though and not knowing or experiencing nos setups at all

Im thinking using standalone ECU spare outputs to control it but with the rpm range and how its to be used, im not too sure about.

is it simply nos on/off via electro/mechanical switch or can you implement incremental spray increases/decrease to tie it in with rpm/vac pressure/afr..?

im also thinking the tuning side would be a nightmare between the nos off - turbo on boost rpm range.

anyways, its just some food for thought......

[R31Nismoid]

Anything can be done, not street legal though

[bubba]

Direct port nitrous injection

[gfunkk]

haha NOS

how many cars on this site do you see with NOS....

big cams are the best place to start for power off-boost

[clip14]

yes a small shot of nitrous can bring on boost a lot quicker.

nitrous is used in drag cars to spool the large turbo's off the line (the ones which do not use antilag) much healthier for the turbo and cost effective as well given that these type of cars only spend a few seconds on the bottle - throttle plate is left open for the remainder of the run so the turbo does not come off boost.

it is not a stupid idea like some people have dismissed.

the tuning side of things is not as complicated as you might think.

nitrous has is an expanding compressed gas and simple thermodynamics will show that this drastically decreases the intake charge and cylinder temperatures reducing the likelihood of detonation.

a wet nitrous system injects fuel as well as nitrous into the intake charge (on top of the fuel injectors). since the oxygen content in combusting nitrous oxide is a set ratio, the amount of fuel injected in a wet system will match the amount of nitrous injected, resulting in no change to the fueling maps of the engine ecu. timing here could be an issue, as the timing maps can be load/boost dependant, but again due to the decreased cylinder temperatures, less likelihood of detonation due to advanced off boost timing. boost will come on and timing will be pulled anyway.

in terms of nitrous control, a separate map can be used if your ecu is advanced enough/has the capability. many top of the line ecu's such as the very expensive autronic and motec do have a lot of tuneablility. simple method is to use a simple position sensor on your throttle/accelerator pedal i.e. at 100% throttle (push switch on the foot well floor) or any percentage of throttle opening (wired into your TPS or other position sensor) to activate the nitrous. a rpm based nitrous activator will result in an empty bottle quickly i assume.

you theoretically could wire into a vac/pressure source, and trigger when your intake plenum see's atmospheric pressure (which theoretically is when you have the throttle wide open or full engine load) but there are situations where this will activate when you dont want it.

target afr is just way too complicated - engines under cruise conditions run lean, on boost, a lot richer. not sure how you'd work this one.

here's a real world example for all you haters (albeit an extreme but you get the point)

"To put it into perspective, the Boostlogic drag car ran a 13.9 @149mph without nitrous, and a 7.86@187mph with nitrous, but we only sprayed for two seconds out of the hole. Granted, that's taking everything to an extreme (GT5591+225 shot) but nitrous makes any lazy turbo into a totally streetable one."

[clip14]

  gfunkk said:

haha NOS

how many cars on this site do you see with NOS....

big cams are the best place to start for power off-boost

are you being serious?

big cams to me means long duration, more overlap

both qualities which decrease low rpm performance

[R31Nismoid]

lol @ big cams the best place for off power boost, total opposite

[funky monkey]

big cams are only good for top end power would make the lag even worse if anything

[joeyjoejoejuniorshabadoo]

wow... big cams, sexy sounding lumpy idle and quicker spooling...

can you tune my car pls

[battery]

setup anti lag! flames and shit!!!

[clip14]

  battery said:

setup anti lag! flames and shit!!!

turbo death

[TTT]

big cams.. lol..

he must have meant to get 3mm apex seals..

they decrease lag on an RB20det

[Phobic]

hahaha what are you talking about of course 3mm apex seal increase your off boost power in a rb20 i thought that was obvious haha

[Sqd32]

since we are on the topic....... do what the n/a pp rotor guys do and just shorten the diff gears

[Butters]

My Rb20 on NOS vs some other engines around these parts.

Had 75 shot of gas and made of peak of 250rwhp with stock turbo.

http://spreadsheets.google.com/pub?key=pHf...mp;output=image

As you can see not much touches it in the 3000 - 3500 rpm range.