Hey All,

I have the opportunity to spray my car (unsure if its wet or dry kit) on my supercharged Maxima.

Some Info on the car.

Currently WOT A/F is 10.8-11.1 (Tap on MAF sensor)
DW 600cc Injectors
Walbro 255
Aeromotive AFPR @ stock pressure
Stock ECU

Now I don't want to spray in 1st,2nd or 3rd. I'd like to spray right as I shift into 4th gear. The reason is because 4th gear is slow with a supercharger and boost really goes low (4-6psi). Id like to do a 50 shot. Just to help the car pick up some speed in 4th gear. I'll get some info on the kit tomorrow.

Is it worth doing this? Best trap speed is 109mph, would I notice an improvement if I spray just 4th gear?

Thanks!

 

There would be an improvement, but not much.

If you're gonna put nitrous on the car, spray in every gear. Kind of common sense, but, the sooner you start spraying, the more your times will drop.

 

I would spray all gears, if you going to use it and have it available, why not?
Do you still have the meth hooked up? nitrous in combination with meth/water is nuts, a 50shot would probably be the equivalent of a 75shot.

Just be sure your fully aware of how nitrous works, the risk's, etc...

 

I still have the meth (not hooked up but can). Would it not be a little dangerous to spray with my current boost level in all gears? stock timing? I have to do a bucket load of reading on this.

Explain the risks Streets

 

Personaly, I would not spray a 50shot at 13psi on stock timing.

Maybe in 1st gear to get out the hole but that's it

 

Yah, I'm creeping away from this idea as well. I'll re-adjust my tape to hit 11.5 A/F and call it a day. I could setup the J&S and retard timing after 10psi. Say 2 degrees per psi. But I feel nitrous is like a cheat lol, and might get expensive if I get hooked on it. I'll do some thinking and see where I want to go with this.

Thanks

 

I concur with the above. Boost plus stock timing + nitrous = engine damage.

 

nitrous isn't cheating it's another form of forced O2 like turbo and s/c, personal I would stick to using the JnS as a safety device and not a tuning device but to each there own.

I would suggest getting headers, 3inch y-pipe and exhaust or headers, y-pipe and cutout if you don't already have this setup. As the most important thing with nitrous is getting the exhaust gases OUT, nitrous really, really likes this and with you already being boost it's extra important

 

I have a 2.5" exhaust, budjet y-pipe, OBX headers. I'd like to put a cut out right after the y-pipe. Would that help out as much as a 3" catback?

 

it would hope more but only when open an 3inch exhaust would be better all the time. it depends on what your looking for

 

The cutout would be good, but what size pipes are you using to join the front and rear header sections, and what size is the collector? If the collector is 2.5" then a 3" catback won't add much. When I installed my OBX headers, I cut off the front and rear plumbing just as the pipes curved back, then had a local racer's muffler shop extend the two stubs with 2.5" tubing into a 3" collector, which then merged into a 3" hi-flow cat and 3" catback by Warpspeed. The exhaust work back to the 3" cat only cost me about $160, I think. I have a whole thread on the project somewhere in here. I then had a 3" cutout merged into the 3" collector, which was worth +7HP NA on a dyno. The cat is now gone and replaced with a 3" pipe and a Flowmaster D-50 SUV muffler at the end, which sounds great.


"It's gotta breathe"

 

You Def need a free flowing exhaust, not sure if 2.5 is enough.

As for spraying, you HAVE to retard timing, if ur not going to retard then dont spray. Also remember that the JS has a feature that you can hook up the solenoid's power to it, once your solenoid gets power, the JS will retard X amount.

As for the risks, there are many, dont spray at very low rpm's (below 3k), do not hit rev limiter while spraying!!! Timing and fuel have to be on point.

 

Wait, I'm out of my element here but how in the heck is 4th gear slow?

4th is short like 2nd gear, (in comparison to 1st and 3rd).

 

4th gear is horrible...1st to 3rd are great, 4th = me rocking in the car going crazy

To tell you the truth 2nd kinda falls on its face aswell, its very picky on when you shift from 1st gear. Sometimes its good though!

Also talking about a 5-speed

 

Thanks Streets, glad I got the good info I came her for. I'm pretty sure I'd benefit from a 3" exhaust system. I guess I'll just workout on nailing those 60 foots and everything else should fall into place.

 

Seems like your quickest gears are the problem, could be the tune, cause the AFR changes via gear/engine load, right?

 

From what I've seen, if you tune based on the MAF sensor, the voltage readings are consistent in all gears...

 

I'm just quoting from what I hear from other boosted guys, again still out of my element on this one, but I know the Z32 guys have different maps based on gear because of the engine load in each gear.

 

Hmm...

I wanna see some logs on this.

 

Foh sho, need to get ahold of em.

 

You are correct. With my magical tuner tape on the z32 I'm getting consistent A/F reading at WOT/ Shifting. When I was tuning via EMU I would have a nice 2nd gear A/F then a rich A/F after shifting into 3rd.

 

Hmmm, I dont have any of those issues.

 

this

Spraying on a boosted car = no first gear spray ... no care

i plan on turbo'ing aswell and will spray off the line ... once i find the right traction combo lol ...

 

Whats the fastest you've done on the quarter mile?

 

I have yet to take it to the track.

 

The crap thing about being SC is the boost drops off, thats why 4th gear really sucks. Though I'm planning to have my limiter raised to 7k for next weekend. Should definitely change when 4th is engaged.

 

Yeah it does once you shift, but when I do it drops to about 5-6psi and climbs back up rather quickly.
SCers arent too great for the track.....................but fun on the street