I am picking up a Compucar wet system tomorrow for $350 including all jets (75-200), purge system, 10# bottle and warmer, bottle gauge, blow down, plus all the wiring switches, solenoids and hoses. This is a complete kit but I have heard Copucar uses sub-standard solenoids. I plan on getting a new set of solenoids and sending the Compucar set off for a rebuild and using the NO2 syl. for a safety measure on the Nitrous side. I have been looking at the NX solenoids and was wondering if they would be a good choice. I have no experience with Nitrous and any tips would be great but I plan on pulling about 4 deg of timing and going with a colder plug for a 125 shot, is this a good estimate? Once I have the system installed I had planed on sticking it on the dyno and ensuring I have no spark knock then spraying and seeing where I am at. I have a second ECM I plan on having a NO2 only tune on because the Delteq offers no real way to pull timing that I can find. I am also a little scared of nuking the rear end and plan on installing a first gear lock out and a window switch. Any advice on what you guys are running would be great and any install tips.

 

Sounds like your doing everything right. I run a NX system with all the options, been running it for over 3-years now and the solenoids are still strong. I'll also add that NX was designed by the same guy who developed NOS, the late John Stewart.

I recommend running NX nozzles and jets with the solenoids as well, the jets and nozzles also make a big difference. Also do not recommend pulling any timing, NX will say the same thing. Instead, tune the car as best as possible without the nitrous, make sure you have an adjustable fuel pressure regulator for the fuel half of the nitrous system, and have the nitrous tuned on the dyno. While on the dyno dial in the right fuel pressure so that your AFRs are just a tad rich. Once done, you'll be pretty much set to go, and shouldn't have to mess with the timing.

With that forged motor, you shouldn't have any problems running a 125-shot, hell most stock motors can handle 150-shot. I'd try to go direct port injection and go 200-shot

 

[QUOTE=jaymitchell01]
Also do not recommend pulling any timing, NX will say the same thing. Instead, tune the car as best as possible without the nitrous, make sure you have an adjustable fuel pressure regulator for the fuel half of the nitrous system, and have the nitrous tuned on the dyno. While on the dyno dial in the right fuel pressure so that your AFRs are just a tad rich. Once done, you'll be pretty much set to go, and shouldn't have to mess with the timing.
QUOTE]

Thanks for the responce. I don't like using an AFPR, actualy have one that I am not using, but would rather add fuel through tuning. I am going with a wet system so I would thing as long as the A/F is correct the FPR would have little effect. I am currently at 13:1 A/F ratio what A/F should i be looking at 12.7:1?

 

You can buy a MSD digital 6 plus ignition box & when you activate the nitrous it retards the timing to what you have it set at.I have this on my 96 & it works great....I would double check with the not pulling timing out theory , I've never heard that......Pulling timing out is not to keep it from running rich or lean its to keep it from detanating!!!!

 

I don't think the MSD box will work with the Delteq. I agree with the timing and called today to verify and they told me to pull about 4 deg's with my combo. I was told that with a bone stock LT1 you can run a small shot without pulling timing but my car is far from stock and has been tuned for max HP (i.e. timing added).

 

Is that what NX told you? If so, then I guess you should run with that advise. Not sure how your going to tune the nitrous system though without an AFPR, how are you going to adjust the system if you find out your running lean or rich? You can't do it via the tune because then your engine will only be on target when nitrous is engaged, the rest of the time your engine will be off. If you want, you could run a second fuel pump just for the nitrous system with an AFPR, which will keep the system separate from the fuel system for the motor. That is actually the more ideal and safer way to go.

I could be wrong, but I always thought detonation results from a combination of running too lean and too much timing, resulting in combustion before the piston reaches top dead center. If not, then what causes detonation?

I recommend shooting a message to Nitrous Junkie, he's a foum member, and probably knows more than any of us. He can also probably tell you the best AFR for your motor.

 

I don't understand what an AFPR would do for tuning????? I am going with a wet system and the FPR is not hooked to the nitrous like it is with a dry system. The tuning on a wet system is done via the jets for both fuel and NO2 but even if I wanted to add a little fuel I can use the PE tables and make the A/F what ever I want at WOT and I can tune to any or all RPMs. again I don't like AFPR's and see no need for them as long as I have the ability to tune the ECM.

I am new to this and have a ton to learn but here is a link I found with some great information and I find your post prety confusing. Do you have a wet system, and if so why can't I just change the fuel jet to add or subtract fuel?

http://www.go-fast.org/z28/new_to_nitrous.html

 

Run 2 nitrous solenoids as a safety feature ,all the other junk is just that.
If you lose oil presure you will lose the motor anyway,lose fuel presure then it may be a good idea to run a fuel presure cutoff switch but at the speed you are going I doubt it would not save the motor anyway.
NX solenoids do fail and I have had it happen with the nitrous solenoid.
With your motor 106 race gas is needed.
Retarding timing is usually 1 1/2 degrees for every 50 shot .
Most Nitrous kits require a FPR because all kits use different base presure and jets ,Barry Grant uses 45 psi as their base ,where NX uses 40 psi as their base starting presure.
I run both and prefer the barry grant system to the NX and not just because NX cost me a corvette.

Sometimes those PKE 's open up more than just doors.

http://www.mrp.org/mayphoto05/dsc_0837.htm

 

Again, I am confused as to why I would change my fuel presure? Why would I not just change the fuel jets in the nossel to adjust the A/F for the nitrous or add fuel through the PE tables in the tune? The reason I am being kind of stubbrn about this is if I change to an AFPR then it changes my tunes fuel maping for the base tune on both my nitrous tuned ECM and my ECM I have for everyday driving. as I have yet to find an AFPR that is as liniar as a stock unit. This is one of the biggest reasons I didn't go with a Dry kit. Also isn't a nitrous filter a good idea?

 

Nitrous filters are always good .
I pump Nitrous and I can tell you horror stories .
That is why I do everything myself.
The fuel presure issue is not something you have to change it is what the manufacture recomends for their system to operate .Every system uses diff jets and every system is rated with diff orfices in the fuel and nitrous solonids.
I switched my LT1 to a carb and just installed the ZEX plate system just to see what it will do.
ON that one I have to run an Aeromotive regulator that takes the fuel presure from 43.5 psi to 8 psi and I use another regulator and a barry grant external pump for the nitrous fuel.
I use 3 regulators in all.
And just so you know I am lazzy so I would use the regulator to change the fuel presure to run faster or slower.Changing jets is to much work sometimes.
You just need to watch the o2 sensors or use a pyromoter and keep it around 1275 degrees out the exaust.
If the solonoid Nitrous screws up this will be the result.
I had all the back up 's in the world except a back up solenoid on the nitrous.
This is what happends when they leak .
That on is the 86 .
My 94 I run the barry grant unit.
I have since switched to cold fussion.
This is a pic of the 86 at the main race of the year .
No one was hurt put only in america do people run to an explosion.
http://www.mrp.org/mayphoto05/dsc_0837.htm

 

REDC4,
Thanks and I plan on having two NO2 solonoids just to be on the safe side. I am sending the Compucar one off to get it rebuilt for $20 and ordering two new solonoid, one for fuel one for nitrous. So I will have one for Fuel and two for nitrous.

 

I would make sure the orfice is the same diameter, on my nitrous it is .093 and both need to be the same size solenoids .

 

Thanks and will do, but I thought the saftey solonoid could be a larger diameter, Am I off base here?

 

Nope you are right you can go with the same size or bigger.
I have had guy's come back with the smaller solonoids in front when the larger should have been their,and nothing of which I told them what to do.
Now I just throw out some info and see if they ask questions.
I think you will do fine.

 

They make some nifty, ignition retard boxes. These boxes will retard the ignition when your nos activates so you don't have to manually back off the timing. Neat stuff. I have one, but haven't used the NOS yet. a friend of mine has one and is pleased.

FWIW i have the NOS big shot kit on a carbed vette. My research drew me to the conclusion that WET is the way to go, so you are off on the right foot.

 

I have the Delteq system so there are no boxes, well there is one but it is around $800 with all the parts needed.

 

800.00 Yikes!