I'm going to be buying either the hrs dual dry kit with the purge, or the wet kit with the purge... So i've been doing a lot of reading and i've found so much and info in some areas and then so little in others.... I read somewhere and needing to change injectors for a 125 shot of dry, is this true? Whichever kit i buy i will be getting a tune shortly after install, so i probably won't spray it without the tune... But really should i have any problems with all the correct safety switchs? also what is the max so a stock fuel system can take I've seen just change the plugs then in other threads i've seen change the plugs and get a tune for a 125 shot so someone help clear some of these things up?

 

The reason you are seeing so much different information is every car responds to mods differently. It is not a standard if you are going to spray "X" hp in a dry shot you must run "Y" injector. You have to look at it is a factor of total HP. Will my injectors supply enough fuel to support the HP I am going to make. ( NA power plus Nitrous )

You would be surprised how many people would never dream of adding a H/C package to their car without considering the fuel system, but will throw a 150 shot at a stock car.

A wet kit is easier to tune the fuel side with a jet change instead of changing injectors. But wet is more dependant on bottle pressure. Both wet and dry will put the same demands on the fuel pump.

Look at your HP goals now and in the near future. A Racetronix kit is only $249 and will support 600+rwhp...not much to send and know it will handle it.

 

I'm going to be puttin a ls6 intake, pacesetter long tubes, tsp true duals, ported throttle body, and the nitrious all at 1 time... So i hope to be in the 450 range with the nos.... will stock injectors handle that? and the racetronix kit what all does that do i tried to look on your site but didn't find to much info on it? and for a first time user would you suggest the wet over the dry?

 

The racetronix kit upgrades the stock pump to a Walbro 255 and boosts the voltage to the pump. all in all not to hard of an install. The hardest part is replacing the intank pump.

I would not reccomend using stock injectors at the 4-450 hp range if you go with a dry kit. With a wet kit the injectors would be fine. Wet or Dry is a question that does not have a clear cut answer. I am running a wet kit as I fell more comfortable with the kit supplying the extra fuel. Some people do not like the idea of fuel in their intake manifold so they go with a dry shot. Either style will work fine if properly set up.

Wet shots are just easier to "tune" by changing jets. To "tune" a dry shot will require making PCM changes or changing nozzle placement.

 

ok last question would i need the racetronix kit if i went with the wet kit? you've given me the info of the month, which is going to cause me to order a wet kit... THANK YOU!!!!

 

The racetronix is not mandatory, but I would consider it one of the safety components, wet or dry.

Better to have it and not need it...than need it and not have it

 

Here's some reading for insight. Myself, the safety factor of the dry hit gets my vote.
http://home.ican.net/~jsetter/nitrous.html
Robert

 

not enough fuel will toast a motor...thats that, you decide if you want a new pump or not...(not trying to be rude, but thats a fact!)

 

I did both the same day to end up with a two stage.

What I learned was dry, although said to be safer and easier to install, has a bit more to it than just throwing the nozzles in and going with it. Nozzle position is critical, as well as logging or testing the setup before jumping to a 100 or greater shot. Dry is dependant on your fuel injectors, your pump and the nozzle position relative to the MAF. You, like me have a 99 which the stock injectors are 26 pound/, where the other years 97,98, 2001-2004 have 28 pound/.

I was only able to spray a 50 dry safely w/ a 11.5 AFR. A dry 75 got me too lean with a 13.+ and an injector duty cycle well over 100%. Todd, with pretty much the same dry setup on his Vette (nozzle position different and an aftermarket MAF) can spray a 125 no problem with those 26 pound injectors (he is spraying right at the MAF). Putting 42's in for injectors I can spray over 100 easily now. Now this was in my case, I am sure there are many who have bolted a dry kit on and sprayed a 125 with no issues...

The same day we tested the wet and that worked right out of the box up to a 150 shot for me (tested 50/100/150). This being said maybe some have had trouble setting up a wet shot, but I did not.

What I learned in my case is wet is easier to setup and tune than dry. Tuning for the wet is put in the recommended jetting, hit it, check the AFR with a WB and jet up or down on the fuel as needed (wet kit you might want some jets either side of the recommended fuel jetting).

Dry, I needed to add the bigger injectors, and now I am using EFI Live to fine tune what the PCM commands when I spray. Robert will chime in and tell you to tune the dry with rotating the nozzle(s) away or toward the MAF as needed and that is fine too, but that is not the way I am choosing to do mine. Now that my dry shot is up to par, I am liking the dry more and more

hrs I am guessing is HSW? Matt was helpful with troubleshooting my dry setup and getting me the 42 pound injectors (I am running some custom hoses from him also). Talk to him on the phone and and bring up these points, he will point ya in the right direction, as will the other nitrous vendors (Dynotune, Nitrous Outlet, Nitrous Direct).

Bottle heater
TR-6 plugs
and window switch are what you should be considering to add

With my dual stage with stock injectors I was able to hit 466 HP, but my injectors were pretty well maxed out (seemed to have plenty of pump but I think the stock Vette Pump and the F-body pump are different)...

 

Thanks everybody for the great info on the subject.... I'm still a little confused on which 1 i want, its like the more info i read the more i change my mind....

 

the decision to be made is:

Do I feel more comfortable with (1)fuel spraying through the intake, (2)or relying on the factory PCM picking up the nitrous and supplying the fuel w/the injectors.

To tune A/F do I want to (1)change fuel jets, or (2)adjust nozzle placement or PCM tuning.

If you answer 1 go wet, 2 dry is the choice

 

oh Ray.. there ya go.. stirring up the wet/dry thing again. You know Robert will be here any second.

The question for me (just me, mine, only me) was:

1. Do I trust my $5000 motor to a $40 solenoid or a $600+ computer, a field of engineers, and years of experience/testing?

I do agree that AF tuning would be simpler by changing jets. Your point.

...but PCM tuning a dry system also allows you the option of pulling timing in wot N2o runs and back to NA on the same program.

 

not meaning to say one is better than the other just trting to point out the big differences.

I will never say wet is better than dry or vice versa...they both have good points and bad points.....it is up to each end user to make the decision for themselves.

 

You can always do what I did, BOTH

 

Well, here's what I have been finding, really the only time you get into trouble with a dry is when going to big for your injectors, and leaning way out.

We are getting a good mapping of nozzle location for most CAI, so this really should promote no relocating of nozzles. Generally, if nozzles are located correctly, you'll end up with a mid 11 a/f ratio, and no need to PCM tune. Now some slight tweaking in the PCM can help some for those that wish. If nozzles are in the correct spot, then if a rich condition occurs (you won't go lean if they are placed correctly, unless you run out of injector) just rotating nozzle will work, once again no PCM tuning needed, however, you can adjust for rich in PCM if you like.

Some would like everyone to think that there is some great problem with dialing in a dry hit, there is not.

Yes, on the 26 pound injector cars, you'll run out of injectors sooner. Why GM put these in there is behond me.

You can also have two complete tunes in one concerning timing and fuel if you like with dry hits, try that with your wet hits.

Would you rather have,
1. A blown motor running a wet hit
or,
2. A motor that does not blow-dry

I have been asking this question for years, "Try to find someone who has hurt their motor running a properly set-up dry hit", still no takers. Sometimes one will say I know a guy who knows a guy who's brother, blah, blah, blah... Now this can not be said about wet hits, as the mechanical aspect will cause issues every now and then.

Wet hits are certainly safer than ever before, but the inherant design of the dry makes it safer, and just as powerful.

A dry with the additional purchase of injectors is about the same $$ as a wet kit, but with the additional safety record. That is why I have switched to dry, and I also have mucho more experiance with the wet kits. I do run a wet 3rd stage on my car, but don't tell anyone.

Now with all that said, it may be easier for you to just put a cheap wet kit on your car. Only you can make the ultimate choice, and with the knowledge you can find on this site from guys like Beer and Ray this will actually become easy. Good luck on which ever route you take.

By the way, dyno tuning or logging for DC (if dry), KR and a/f should be done starting smaller then work up and you'll have less issues.
Robert

 

That is the only thing that saved me with my dry kit when I went tried the 75 Dry. Had I bolted that on and Sprayed away 100-125 dry with no testing, I would have been Lean and it would have just been a matter of time for the motor (and EVEN worse, the dreaded I told you so from the Mrs. ). It identified the injector problem despite using an proven "mapped out nozzle location".

I think the key to which ever system type you choose is logging the AFR/KR and starting small and working your way up to see what you can safely do...

 

I do have some 36 lbs accel injectors sitting in the garage so it probably wouldn't hurt to throw those on with the dry kit? Someone said something about the corvette having a better fuel pump is this true? or would i be ok with stock fuel pump and the 36lbs injectors?

 

If you already own the injectors, I would do the dry with the 36's injectors installed. You will need to change the IFR table using Tuning software though to get it to work correctly.

 

yeah i just have to swipe them out of my dads garage we bought them to put on a built L98 but they were to big for it, so now they are sitting.... Would it be a bad idea to drive it with them installed before i get it tuned since the place i will be installing it all is almost 2 hrs away from the dyno place....

 

But the proven nozzle location is correct right? You had 11.5:1 a/f with the 50 shot, then ran out of injector on the 75 shot . Once the injectors were upsized, the location was still correct for proper a/f right?
Once we have the injectors then we can safely increase the nitrous jet size (after a/f is checked). So, I guess I am trying to say the mapped locations work until injector limit is reached, and it's not a limit of known injector locating. Having the Valet mode in your EFI Tuner should provide some nice tuning options?

One thing I might point out, I went 480rwhp on stock fuel system with the 28lb'ers and ran a 11.04 at 135shot.

There is easy math for sizing injectors.

Emoney, are those Ford SVO injectors?
Robert