My knowledge of this is questionable. More questions to come.

I began last week making the custom TBI bracket to mount the switch to actuate the shot.

Looking over the necessary parts on Summit site. I see Edelbrock offers two
fogger nozzles. One low pressure(carb) and another high pressure(EFI). My set up can be said is neither. Comments on that ?

I have a TBI system running 19.5 lbs FP using VAFPR. So 19.5 is the number. I see NOS offers nozzles but not fuel pressure referenced. I believe I will use two of their standard nozzles. I have no clearance due to Vette hood and cannot use a spray bar. I will tap my Holley high rise "dual plane" at front and back for the 2 nozzles. They will shoot downward at angle facing each other. I would like to start with a 75 HP HP shot. Maybe my choice is 50 or 100?

Now the dumb question. How is the A/F ratio "tuned"? Since my fuel pressue is not carb nor high pressure what to do? I understand jets vary in size. Is that how the resulting A/F is determined? I believe the solenoid is only an on/off switch so to speak. I do have an Innovate WB currently in use.

Is the desired A/F commanded richer? I am at 12.5/1 currently. I understand the cooler plugs and pull 2 deg timing at WOT.

 

ttt

 

Ronney,
Have you thought about running with a top shot system. NOS makes one that sounds right up your alley for your situation.

If you are going to be running a NO2 system I highly recommend getting a dedicated fuel supply. If your only shooting a smaller shot then you could Tee off of your existing lines. If you tee off of your lines you could mount a regulator dead head style and use that to supply your fuel solenoid. This will allow you to bring the Flowing PSI down to the levels that NO2 kits will specify in their directions.

Usually on a wet kit you will want somewhere around 5.5 PSI flowing pressure. The sizing of the Nitrous and Fuel jets as well as bottle pressure and Flowing fuel pressure are what is going to give you your air/fuel ratio.

Hope this helps a bit.

 

Top shot? I will look at their site to define. I have a carb bonnet on TBI unit. No room for a plate as my bonnet rubs a bit on bottom of hood. My options I can see are to place the nozzle in the bonnet(cast aluminum) or tap the manifold in top of plenum area. Not much room there(dual plane). I think it best to run 2 nozzles for better distribution.

so far I am thinkin I will cut the Aeroquip hose feeding TBI and splice in an Aero T fitting and neck down to -4 AN for fuel. I already have a "custom bracket" for switch and solenoids along with purge.

As far as fuel supply I run a TPI pump that I believe can feed adequately. I run a WB as well to monitor. On my n02.bin I can enrichen WOT PE to 12.0/1 to start as well but I understand the n02 shot is another issue.

I need to run 19.5 lbs to fuel motor as it is. I can up FP considerably with my injectors. I use VAFPR so I can pull down FP at idle. so I would have same FP at fuel side of n02nozzle. I understand I need to swap in an appropriate jet? Is their a calculator I can use to decrease jet size based upon 19.5 vs 5.5 FP? Maybe I check with n02 manufacture on that.

 

Here is what he is reffering to as a top shot kit

http://www.summitracing.com/parts/NOS-05090NOS/

You can call pretty much any of the nitrous companies and they should be able to get you a starting point on the jet with the fuel pressure you are running.

Here are the instructions for the NOS TBI nitrous kit. The jet chart is on page 9, I also typed it below the link

http://www.holley.com/data/Products/...NOS%20scan.pdf

HP Increase - Nitrous/Fuel Jet
60 - 36 / 26
100 - 47 / 36
120 - 52 / 39
135 - 65 / 42

 

Thanks. I dont have the required room. My TBI injector pod barely clears the carb bonnet. So only option is to drill tap either pleanum of manifold or the bonnet. I think I will do the bonnet as distribution in the manifold runners may be better. I hesitate to use one nozzle due to unequal distribution. My TBI unit(7.4L) just happens to be tapped for a bracket to allow a WOT micro switch. Apparently GM did so to allow some sort of vacuum adjustment at WOT in the 7.4L truck line? I modified the bracket to support switch and solenoids.

 

I wouldn't trust a single inlet on nitrous and fuel side going direct into the manifold if you dont get the right atomization..... BOOM I have seen this before. Unless you are talking about mounting it in the intake tract instead of actually inside the manifold.

It's more expensive but if you have no room you could always go to a fogger style setup with an individual fuel and nitrous injector for each runner.

 

you can do a dry set up good to 50 to 75Hp hit.
and plum that into you air cleaner bonnet.

all you spray is NOS.. it safe and fun...

you can install a 2 jet set up that will install into you air cleaner also
sitting just above the TB. NOS sells all the parts to do this.

this same Kit is used to install a kit into the Base of carbs..

if you use a wet Kit, Gas and NOS getting sprayed into you eng.
then you can tap into you fuel line. running to your TB.

it would be good to about 150Hp hit.. reg it down to 6 1/2 PSI.
no less with the 150Hp hit.

the Kits will Give you all the info on this..it's not Voodoo.. but it can Bite you. IF you dont play right with it..

there is a Video on you tube you see the car blow the hood off
with NOS.. (300+HP hit)they dont say anything.. but from watching the Video.. hes purgs..stages..His car Dies..at this point he needs to STOP!
and clear out any NOS in his intake.. But all he DOSE is just crank it.to start it up..and ...KKKAABBBOOOOOMM!!!..
AKA..nos Granade!
and yet another one this guy just keeps cranking it..lol
http://www.youtube.com/watch?v=1hzMsqo04jk

more then half of the backfires are on kits with more then 100hp hits
out of them. most or more them most are from leaking parts.
/goofs. iv install setups on chain saws..and the last one was a NOS wippet (wip cream) CO2 looking bottle on a nitro burnning remote controle race car 1/10 scale...lol that one was Fun.. you would Hit it.. and the car would spin out...lol

I love NOS been running it from way back 1982 till today..fun stuff!!

 

To clarify I will use two nozzles and tap into the aluminum bonnet aiming each over top of TB unit. Each nozzle is fed by both fuel and N02. I will tap the fuel line and add an "AN Aeroquip T".

My TBI is at 19.5 lbs fuel pressure at WOT. I wiill ask manufacturer for help on appropriate fuel jet as I believe they are calibrated at carb FP.

 

ronny,
I just installed a dry 50 shot on my tbi. actually i upped it to about 70 today. I am still in testing/tunning phase but ive got some nice gains!!without ANY MISSES OR BACKFIRES. i went through 2 N20 tanks few AFR problems but i just about got it at 13.1 @ WOT with about 70 shot of spray a little more tuning and i think it will be perfect!

When you say the word nitrous everyone cringes! if the FBI monited this forum they would be paying everyone a visit since bomb explosion is used in about every sentence! fact of the matter is NOS is non-flammable (by itsself) as you prob know this.

i know you said you have little room under the hood nos makes the kit with a very thin TB spacer that is a wet system. Its pretty slick! here is the part #05153NOS click on instructions there is alot of info there even tuning information. this plate goes under TBI im sure this kit will work for you, maybe you can take .25" or so off that bonnet, or if your using TBI spacer eliminate it and your home free!

if your only looking for 50-75 i say shoot a dry system and tune. i set up a nitrous only tune so with a flip of a switch im in Spray mode!! bigger than that id say wet is only option. here is the jetting for a tbi N20/Fuel

Suggested Baseline Tuning Combinations for NOS TBI Wet Manifold Kits
Configuration N

2O Jetting
(Nitrous – Fuel)
Fuel Quality Ignition Timing Plugs

05153-V6NOS 36/26 92+ octane pump gas Standard Standard
05153-V8NOS 47/36 92+ octane pump gas Standard Standard

05153-454NOS 65/42 92+ octane pump gas Standard Standard


Even though your running 19xx fuel pressure your nos jet would be the same. now the fuel jet well that one they may have a formula for or trial and error. there $8 bucks a piece. so if your fuel pressure is 20% higher then stock.use a 20% smaller jet on the fuel side. that should get you in the ballpark. the jets are in thousands of an inch .020,.031,.069

those fogger jets your talking about accept 2 different jets. 1 for n20 and 1 for fuel.

I thought about spraying wet over my tb as well, i dont think its a good idea.

As for the intake directely porting them ehhh i think it would work! ive seen that done before (not on TBI) but it would work!

My final .02
If your just looking for 50-75 shoot it dry

75+ that holley tbi kit is the way 2 go!

the direct port ! well i like it ! but i wouldnt want to be one of the first to try it keep me posted!! and finially just watch that Wide band closely oh and per 50 shot -2deg timing! good luck!!

 

Thanks for responding. I have negative room above bonnet. It rubs as it is on bottom of hood. I could shave the bott of bonnett(alum) but that is best done by a machinest so $$$ there. actually I doubt I have .25 inch in bonnet casting to take off. I think it best to use a drill/tap of the alum casting and direct fogger nozzles one on each side over the TB venturi. BUT while I was surfing the NOS catalogs I see a kit for LT1-LT4 which I think is same dia of my intake tube or 4 inches at bonnet. At air filter I have 3.00 inch so I bet a "ring" would work in intake tract. I will call N0S tech line.

I was told by RBob to go wet so that is what I will do.

Any reason I cannot drill the jets on my drillpress with vise to larger increments? I believe they are brass. If I find I am too rich or lean by 5% I can always compensate in my PE tables for that as well as micro switch set to 95-100% TPS.

 

that would be a terrible idea

 

I don't think it's a terrible idea. But you won't find a bit that small! Remember these holes are tiny .030 of an inch. So my smallest drill bit was .055 when I thought of that. Good luck!!

 

I did not realize how small they are! I am sure the manufacture can get me close. Car in barn till 4.1.10 so plenty time to plan.

 

Just buy the parts.. what you have to buy 2 jets? $15.00

if i go smaller i have to Buy 16 jets now thats some cash.

but Just Buy them..

 

Whichever way you decide to shoot it!! dry, wet, enema, maybe even a syringe.. your going to like it!! i have a supercharged jet ski that im trying to order a kit for now, along with every other toy i own!! thats how much i like it!!