Retard motor for NOS- HELP PLEASE

[Ls80]

Hi all, I have a L76 with NOS installed. I put in a Nitrous 2 Outlet Winmax to control it which has an output wire for retarding the motor.

I was told 2 degrees per 50hp. My tuner said to buy MPVI2 and then he can give me two tunes to switch between but surely there is a way to use that output wire to trigger the retardation?

I am hanging to use it but don't want to ruin a new motor either.

Hops someone can suggest a solution.

Thanks.

 

[Immortality]

I don't think the factory PCM comes with a nitrous timing retard function Listen to your tuner.

 

[1978vcar]

LISTEN TO YOUR BUILDER.. and immortality ( be nice..lol)they both know their stuff
If in doubt find someone who knows and checks installed correctly
if need go drags or burn out boys and ask, trust me n2o great stuff instant power boost, etc ( as want I to run myself as well)
BUT GOES BANG IF NOT CORRECTLY SET UP!.. As I am trying to get my kit installed myself on an old VB stroker
I live in the middle of nowhere and 6hr a return trip to Townsville and I will wait till get mine done.
as 1 F#@! up and motor Gonski
TOTAL rebuild.
BIG $$$$ time.

 

[Deuce]

How much shot will you feed it?
Just tune it 2° back so it's always ready for nitrous.
2° n/a in the upper rpm ain't gonna be noticed on the street.

 

[Skylarking]

Thinking outside the box for a moment, can’t E85 capable tables be added to L76 ECU where those E85 tables are modded to cater for the NOS timing needs when shooting NOS into a 98RON mixture? Then it should just be a matter of triggering the appropriate E85 table using whatever mechanism the Flexfuel sensor uses to indicate E85… Obviously using such would mean you’re no longer able to run alcohol based fuels as those modded tables won’t suit…

 

[Immortality]

Thinking outside the box for a moment, can’t E85 capable tables be added to L76 ECU where those E85 tables are modded to cater for the NOS timing needs when shooting NOS into a 98RON mixture? Then it should just be a matter of triggering the appropriate E85 table using whatever mechanism the Flexfuel sensor uses to indicate E85… Obviously using such would mean you’re no longer able to run alcohol based fuels as those modded tables won’t suit…

Problem is E85 normally has more timing in it. It also uses the flex sensor to monitor E %age and adjusts the timing appropriately, it's not just a simple on/off type switch/sensor.

Apparently there is a trick that can be done using the air temp sensor (search HP tuners nitrous timing retard) but again you are fooling the system.

If you wanted to do it properly than some sort of aftermarket ECU system would be the go but for a bit of fun is it worth the cost/effort?

 

[Skylarking]

Problem is E85 normally has more timing in it. It also uses the flex sensor to monitor E %age and adjusts the timing appropriately, it's not just a simple on/off type switch/sensor.

I was suggesting setting up the E85 tables with appropriate timing as required for NOS. Then one can select E85 table via some circuitry.

I’m assuming the flexfuel sensor measures alcohol % and sends an appropriate PWM signal to ECU to represent the amount of alcohol in the fuel. The amount of alcohol will influence the amount of timing change… A clever circuit can take a 12v signal from the NOS system (for a given shot) and send a static PWM signal that represents 85% alcohol level to the ECU which selects the E85 table. Since the ECU will only ever see that one E85 PWM signal, in essence it will act like an on/of switch to jump from petrol to E85 tables which would have been adjusted to retard the timing the required amount.… Or have I misunderstood what the E85 tables are and what a tuner can actually do to them to adjust timing and injector pulse for a given flex fuel sensor % signal?

 

[Immortality]

My understanding of flex fuel is that there are 2 sets of tables, 1 for straight petrol and 1 for E85. Now if the tank is full of straight petrol it runs on that map and visa-versa for the E85 but when there is lets say 50% E in the tank the PCM will adjust to suit by moving between the 2 tables the appropriate amount.

 

[1978vcar]

Glad I own an old Bcast 308/355 stroker just going over install instructions basically says
set up activation circuits - safety, etc
run n2o ( line)
connect fuel (line)
connect solenoids to carb kit base plate
bingo basically from look at drawings and instructions ..
modern technology hey..
BUT on a serious note is there a difference in square and spread bore for a wet shot on an old stroker?
And if I can downsize my set up ( 125 hp wet 10lb PowerShot box set single shot)
want to down to 50/80hp.( car retarded 3 degrees now do I need to advance or anything?)
also,
do I have to re-jet both fuel and n2o inputs after solenoids and into carby or just n2o jet?
As reading about olm8s instal above I reckon I can give mine a crack with a bit of help.
modern technology hey....
holley 650 vac secondaries

 

[Immortality]

Yes, re jet both the fuel and N20 as per the instructions recommendations.

Not sure if Holley makes a nitrous plate to suit spreadbore carbs?