mitymikec

iTrader: (2)

Hi guys, just had a few questions about the WET SHOT EXPLOSIONS I have seen..What is causing these backfires or explosions? Is it a sticky solenoid?
Is it the fuel solenoid? Shooting to low? I have always run dry shots on my car and never a problem but recently bought a TNT wet kit..Is there one brand name that is having more of this issue then others?
Would spraying a dry shot down low and hitting the wet kit once rolling by a way to avoid the explosions? What size injectors ppl going with for a 250wet shot? Thanks..MIke

Robert56

iTrader: (2)

Hey Mike, nice seeing ya over here. I will let some others give input before I butt in too much. The intake backfires are caused by a few differnt reasons, however they become such explosions because of the fuel in a dry designed intake. Dry shots can on occasion have a back fire, yes some vapor in intake from reversion, but they are just little hic-ups and do no real damage. Have you read the wet vs dry thread down below somewhere, we talk about this issue.
Robert

mitymikec

iTrader: (2)

I had to chase u down into here to get some advice from the pro..lol
Let me hear ur take on this..

mitymikec

iTrader: (2)

I would rather not have to read through the WET VS DRY thread..I have heard all the so called pros..I am a dry guy myself. Just wanna know if i can lessen my chances of explosion if i do something different then the others.
If i can out of the hole with the dry shot then arm the wet kit would i be lessenning my chances of booming???? 150dry out of the hole and 150 wet about 60 ft out..

Danger731

iTrader: (3)

From what I've read ? to be safe get your RPM's up before spraying, a lot of knowledgeable guys are burning up motors by spraying out of the hole.

Robert56

iTrader: (2)

Some reasons and things to consider.
Well one of the most common reasons for the intake backfire is the lean spike upon activation, coupled with spraying big and at a lower rpm.
A stuck closed fuel noid, leading to lean out and/or detonation.
A sticky or partialy opening fuel noid.
Detonation leaving a hot spot ie: carbon build up, plug electrode, casting flash; this can leave an ignition source at the wrong time and boom.
A bog launch can also invoke the dreaded back fire.
High over lap cams.

Now the dry is much much less suseptable to these bad intake explosions, so yes doing your dry outa the hole would go a long way in making the added wet hit safer and less prone to problems. Also, if this is a used kit, throwing a rebuild into the noids might be a good idea, good strong noids are paramont.

Just make sure your tune is spot on. timing low (can pull with dry hit, write up in personal web site in links), octane high, plugs cold and a good fuel supply is the best means to a safe big hit. Now with all said, having all that fuel in the intake even on the upper end, or through out the pass, anything going wrong...well there are plenty that have the intake back fire running down the track? Myself, I would up the dry shot, bigger injectors and a fuel pump, dual stage it and an easy safe 300 hit is at hand, but I do have a 3rd stage wet on my car...

Yea, i am also going for the 300hit this year, going after blumachine's 10.5 run (I got bumped down a spot). Looks as though you still have the fastest ls6/auto stock longblock in all the land.
Robert

NXRICKY

iTrader: (1)

Many things can cause a backfire and a very large % of the cause is the person behind the wheel. Not all just a large %. Most off the line backfires are cause by spraying too low of an rpm, vs the amount of juice. See a 25hp shot might be able to spray off idle. a 50hp shot 1500 rpm+ and so on. The reason is the nitrous displaces the natural air in the intake. IF you off set too much and too low, the air will stall (or bog) cuasing the flame in cylinder to ignite the fuel cahrge in the intake.
Wet system back fires can range from slight, too HOLY **** what just happen.
Runing a window switch is the one of if not the most important saftey items you can run.
You can run a wet /dry package just spray the dry first then the wet.

have fun stay safe. and congrads on being to dog with your set up.

Ricky

mitymikec

iTrader: (2)

thanks guys i appreciate the help..What injectors r u running and what size pump? I am looking at changing the pump. Do i have to change the whole canister or can i open it up and change the pump myself? ThX..MIke

mitymikec

iTrader: (2)

anymore feedback on this? I will not be running the stock motor this year, i sold it and have built a 347 forged motor by Canadian Peformance Engines.
This thing will be getting alot of spray through it..What injectors and pump r u guys using?

Robert56

iTrader: (2)

Your overall hp is the deciding factor on your fuel system. What i did was the racetronics pump and hot wire, good to 600plus hp with the return and reg at the rails which I added (you allready have them). Go to the racetronics site and they tell you what you can do to get over 700hp with their pump.
Now sizing injectors will be based on your n/a hp and dry hit included. Here is the math.
(projected bhp x .5) / 6.4 = min inj to meet 80% duty cycle rule.

So lets say your target rwhp is 600, then add 15% to get bhp.
690 x .5 = 345
345 / 6.4 = 53.9 min inj to meet 80% rule

Now the 80% rul eis more of a longevity rule, so running past 80% on a few 1/4 runs is not really an issue. I am running 42 Ford Svo's, which are 47/48's at our pressure and will be going to 600rwhp.

The pump change is a breeze on our cars, cajundude from the vette forum has a write up with pics, and everything comes in the Racetronics kit.
Robert

mitymikec

iTrader: (2)

Can i just open the canister up and put any pump i want in there? I was hoping not to have to buy the whole kit and just replace the pump. What HP is the stock pump good to?

Robert56

iTrader: (2)

The pump and/or the replacement pump come out as one piece. The kit really is just the pump and some gaskets, along with the hot wire kit going to the alt which can add an additional 20/30% to the pump. Some run the stock pump to 600rwhp, watch for going lean and/or pressure drop then you'll know you are running out of pump. Now if your concerned on having a problem, then pushing the stock pump to your level of hit would not be rec in my opinion. Got to have a spot on tune and fuel system to safely run a 300rwhp shot, even with a forged motor.
Robert

mitymikec

iTrader: (2)

So the injectors are a must for dry shot and NA applications? The pump is definately a good piece of insurance for Dry, Wet and NA right? I figure i will be making about 650-700rwhp so i best invest in some injectors and a pump..
Thanks for all ur help Robert..

Specialized

iTrader: (15)

Now, I was looking into the stock L67/GTP/SC 3.8 injectors to install into my car. I have some left over from an old gtp I had, and I believe theyre rated to ~38lb/hr. I would think that I could go with these (all tuning included) and spray safely a 150hp (75 x2 stage) dry with 243 castings and a small (relative) 224cam. I plan to push no more than 550 total rwhp, but I would guess that down the road, numbers will increase.


What Im wondering is: should I try to save myself a buck, and get a few more gtp injectors to complete an 8 piece set, or should I just buy green tops?

Robert56

iTrader: (2)

Yep, yep and your welcome bro.
Robert

hoezee

here is my car with a nitrous explosion
http://www.youtube.com/watch?v=spVa69uHryY

Robert56

iTrader: (2)

The green tops will fit your hp goals much better, with a little room to grow. I only paid 80 bucks for mine from a Lighting buddy.
Robert

mitymikec

iTrader: (2)

Did the lightning come with 42lbs? I need to find a few Lightning buddies.

mitymikec

iTrader: (2)

Guess i can't cheap out and will buy the injectors and pump..

Robert56

iTrader: (2)

Yes stock, and these guys are allways cranking up their blowers so they go bigger injectors, lots of used sets out there. Actually, I had a site that was selling new green tops for 160, but they disappeared, maybe check around.
Robert