93LS1RX7

iTrader: (8)

Again it has nothing to do with the fuel lines being equal length or any of that. It is the rail losing pressure trying to pressurize the rail once the fuel solenoid opens. It isnt bad for the motor because there is no nitrous in the engine at that point so it isnt going to cause major problems.

Again the fuel still makes it into the engine before the nitrous.

Slowhawk

iTrader: (12)

How about running a progressive controller?I was under the impression that the controller pulses the nitrous solinoid?

On another note I would not worry about the spike.I ran a TNT kit on my car for 16 bottles and it had the spike.I used to spray a bottle in under an hour on the road

JF WS6

Personally, I'm not worried about the spike doing damage to the engine, I'm worried about getting off the line with my M6 without bogging horribly on the line and running a crappy 60'. I just don't want to have the same problem as JS12 is experiencing. I hoping this is a unique problem to his setup because it sounds to me as if his spike/hesitation is longer than just a 1/4 of a second or so like Charlie was describing.

I want this accumulator to come out ASAP!! LOL....

93LS1RX7

iTrader: (8)

Talk to NX they have it completed they just need to get it in production.

A progressive controller wont help either. You need something to supplement the rail so that it does lose pressure. The acumulator isnt a real complicated thing to do you just need a small tank that can hold pressure and a solenoid valve that opens when the nitrous system hits. that is all. or just run a seperate fuel supply and tap off that instead.

JF WS6

Well, I do have a twin Walbro intank setup.... do you think the high pressure of both pumps running (I've heard with both going and the stock FPR it can be around 60 PSI) would lessen the effect when the pressure drops in the fuel rails?

Mike, have you had a chance to run your RX7 yet with this kit? If so, what kind of experience did you have with this hesitation/lean spike thing?

bad2000ss

iTrader: (6)

That isn't a bad idea, a dedicated fuel system that is activated when the nitrous is activated could work. You would just need to know how much pressure would need to be added to the rails to compensate for the initial loss.

CAT3

iTrader: (9)

Mike, please explain how you say the fuel still gets there before the nitrous? I cannot agree with that at this time. I am looking at logs, I see a normal AFR, hit the dummy switch and bam theres the 22.9:1 afr, sounds like a definately lack of fuel and then all of a sudden the 10.x:1 afr running the juice. Imagine the dmage that would happen if the car had nitrous going into it, but the fuel lien busted and very little fuel was getting to the cylinders???? It looks the same on the logs from when my fuel line burst on the Walbro pump, and yes I ran a 150shot on the same time, it was a slower run, with a stench of leanness, little gas and damn near burnt the plugs and engine up....but it was ok in the end. Now, again, the fuel is not getting there first or else it would be rich as hell then mellow out to the juiced afr. To prove this, hook up a wideband, go run the kit and if you have the same hesitation you will see it. My wideband took 18sample in one second, and in that portion, like .22 to .31 seconds, you see the afr go LEAN then rich and level. There is no way the fuel is getting there first!
The fuel accumulator should actually be opened the split second before the solenoids open if you want to ensure the rails stay full, at the same time and there may stillend up being a minute delay!

Brains

iTrader: (7)

The accumulator is automatic -- it's nothing more than a reservoir of fuel held under pressure by a big spring. Any time the fuel pump is running and there's excess supply (ie. not maxing out your fuel system), it's going to pressurize the fuel rail, and fill up the accumulator. When you spray, the sudden initial demand your regular fuel system cannot keep up with will be met by the accumulator.

JS12

lets hope the accumulator works like it is supposed to. i am depending on it to work like it should so i dont have to put a completly different fuel system in there.

JF WS6

Why have I not heard about the NOSzle system having this problem? It doesn't use a seperate fuel supply correct? And it also doesn't use high flow fuel rails to feed fuel to the system either just the regular stock rails.

Just wondering what the difference between the 2 is.

BMN

CAT3 is rite. It's just taking to long to get the fuel rail to presurize before the N20 hits. I bet this problem could be solved with a small circuit that delays the N20 noid from opening for a 1/4 or 1/3 second delay. I could make this thing no problem. Anyone want to use it?

Gold Z

iTrader: (3)

If you can make it I'd like to try it.

93LS1RX7

iTrader: (8)

That wont solve the problem. The nitrous IS NOT getting there before the fuel. I will explain later but I am at work. The probelm is the fuel is gone for a second. Not just the fuel going into the NXL but also the fuel going directly into the fuel injector. YOU HAVE NO FUEL for a millisecond (thats not 100% true you have fuel it just has 0 fuel pressure so it aint going any where it is just sitting still). You can do whatever you want to the nitrous lines they have nothing to do with it.

You have to either A: Have a seperate secondary fuel source or B: Use an accumulator that will allow the fuel pressure to stay up constantly because it is always "back feeding" the rails ANYtime the pressure drops below whatever level you set for the accumulator.

JF WS6

LS1RX7 is right..... there isn't any fuel left in the rail for the engine OR the N20 system.

I'm still curious why I haven't heard of the NOSzle system having this problem when fed off the stock fuel rails.

You don't think a high pressure single fuel source would do the job? I hope I get my parts soon so I can do some tests on my car. I'm going to have my 2nd Walbro intank fire up when the system is armed. I think with a system like that and especially if a larger feed line from the tank was used it would keep the pressure up enough. The accumulator is an easier way to fix the problem though however.

93LS1RX7

iTrader: (8)

Isnt the NOS system a seperate fuel source? Not tapped of the stock rails. If so then that is why there is still fuel going to the injectors so you dont have the problem.

If it is off the stock rail I would be curious too. Any NOSsle guys want to chime in?

JF WS6

You CAN use a seperate fuel source, but from what I've seen most guys have their fuel feed lined tapped directly of the drivers side fuel rail on the Schrader valve. I'd think that system would have even more problems with keeping fuel pressure but I've never heard of anyone having a problem.

93LS1RX7

iTrader: (8)

I will have to take a look at some of the NOS setups and see what I can figure out.

JF WS6

Here ya go.... you can plainly see the fuel feed tapped off the schrader valve on Chicago Z06's setup.....

https://ls1tech.com/psjpics/images/Z0610.7.02%20004.jpg

93LS1RX7

iTrader: (8)

It looks like it may be because there is MUCH less volume after the fuel solenoid. We have to fill up the rail then the lines where that is just the distrabution block and the lines. I think that may be why they dont notice it and then the just attribute the "spike" to being caused by the nitrous. I would be curious to see one of their atuotap readings when they hit it. I bet it does the same thing just less severe cause of the volume.

As far as the nitrous getting there first it just doesnt happen. The nitrous is a liquid that turns into a gas travels from the bottle to the nitrous solenoid. When the nitrous is activated the solenoid opens pushing the gaseous nitrous forward at the same time the liquid fuel is moving forward too. Even though the fuel is moving slightly slower at this point it is in the state it is going to be burned. It gets "sprayed" into the combustion camber but it remains a liquid.

Mean while the nitrous is moving past the solenoid as a gas and bam it hits the nitrous jet. At this point the nitrous turns back into a liquid because of the back pressure caused by the restriction in the line also know as the jet. Nitrous turns again into a liquid and it also gets "sprayed" into the combustion chamber. The problem is the traveling and then changing state then getting sprayed into the combustion chamber takes time. During this time is when the fuel gets there first.

The old tortose and hair. Even though the nitrous is technically moving faster it is not moving fast enough when you factor in the changing of state from gas to liquid.

Now all this happens very very fast Im talking milliseconds. But that is the way it is.

CAT3

iTrader: (9)

Mike, got it. takes some time to digest and put into nitrous flow for idiot terms, but the thought sunk in finally. I am curious as to this accumulator and its design. Better be able to hook it up neatly this NXL is just too damn pretty to be messing with.