luv'n my 7

whats the biggest shot of nos you can put on a streetported motor with straight pipe exhaust and a stock fuel delivery system? What should i put on my car if i wanted to do a 100 shot?

Rxmfn7

iTrader: (4)

There have been multiple writeups on nitrous sytems for our cars. Doing a search would lead you to multitudes of information. Basically, installing a N20 system will require the same precautions as any other type of forced induction. For a 100HP application, you should be looking at upgrading the fuel pump as well as at least the 2ndary injectors. If you do a search, look under the member "Scathcart" He did a few writeups.

Bebesito21

i wouldnt go over a 50 shot with the stock fuel system...but if you have a street port you should be upgrading the fuel system anyways

Rxmfn7

iTrader: (4)

Streetporting wont require changing anything to the fuel delivery system unless you have something really radical. The stock N/A fuel system is fine for about 250HP,which just a normal streetport and bolt-ons will not give you.

luv'n my 7

tyhanks guys thats all i really need to know!I've read his write up's before. But that was a while ago, i thought i have to upgrade my fuel system if i were to go to a 100shot! But a 50 shot for know, until i get my fuel system upgraded should be ok correct?

Rxmfn7

iTrader: (4)

As long as it is a wet system I would think just a 50 would be ok. Might wanna get a A/F gauge just to be on the safe side to see where you are at.

Bebesito21

ok...Rxmfn7 you may know more than me and have lots of experience but my car has a 100 shot setup and ive gone through what he wants to do. if you want to do a wet setup at a 50 shot at least upgrade your fuel pump. The stock one might not be able to keep up the pressure to feed the 4 injectors and the fuel selenoid. at least itll be insurance....rich is better and lean especially with nitrous. and that 250hp stock fuel system crap is b.s. it changes for each car. it depends on the condition of your components and what your mods are. i hate how people read something from someone who has alot of posts and then assume its written in stone. the only reason i disagree is because ive upgraded my fuel system (yes on an NA oh no) and got good results on the track, and the nitrous works flawlessly.

Rxmfn7

iTrader: (4)

I agree with you, I am street porting my engine and will be upgrading the 2ndary injectors as well as the pump. I just said that the stock fuel system ( assuming everything is working as it should be ) should have no problem running a 50shot with some light bolt ons. Ive seen it done, and everything works great. I agree with you that if you have a 100shot that at least the pump should be upgraded. Is it completely necessary for a 50 wet shot, I dont think so, no. I did recommend a A/F gauge just to he can monitor whats going on.

Bebesito21

A/F gauge might not be as accurate as he needs it. It has a delay before the lights tell you where you are at. Might be enough to blow his motor....maybe not with a 50 shot, but i say better safe than sorry. And a walbro is only like $95 + shipping. Maybe an A/F gauge and an EGT gauge. But id rather spend on stuff that i can use no matter what i mod than spend on a rebuild.

c-squared

FYI, I've got a system set up and tuned by Sean (scathcart).

The "250 hp on a stock system" is a general calculation based upon the duty cycles of the injectors at their maximum safe duty cycle and stock fuel pressures. Condition of components does not really matter (even a worn pump can support this kind of flow). The stock injectors can only flow enough to support this level of horsepower and still keep a safe duty cycle so that your injectors don't burn out.
It is not crap. It is a correct calculation. Unless you have a form of forced induction, bridgeport or larger porting, there is never any need to upgrade your fuel system on an N/A.

With a wet set-up, injector duty cycles do not matter. The only concern is maintaining your correct fuel pressure. This is accomplished by having enough fuel being fed through the rails. To maintain pressure, the rails receive flow from the pump, and bleed off whatever exists in excess and sends it back to the tank. Adding a larger pump will just have more fuel flowing back to the tank the majority of the time, and guarantee that the fuel rails will not lose an amount sufficient enough (to the ntirous solenoid and injectors) for rail pressures to drop.

A 50 shot will be fine on the stock fuel system. Above that, switch to a walboro fuel pump.

As for nitrous tuning, there are several gauges better suited than an A/f gauge. Bottle pressure and fuel pressure are a given for tuning, and an EGT will be a better indicator of rich/lean while on the bottle.

RXmfn7? Why are you upgrading your secondaries?

Kanaida

crap, if you're going to do just a 50 shot, you can safely run a dry setup. No need to push wet unless you're doing 75+. Even Sean said that...

-Kanaida

Rxmfn7

iTrader: (4)

Im going with a very, very large streetport, as well as about every bolt on you can get. Im aiming for 200RWHP N/A. Will the 2ndaries be 100% necessary, I dont know. But I will have a SAFC to tune them, and dont want to run lean to find out I need to upgrade the secondaries.

Bebesito21

all that may or may not be true on a new stock fuel system. im giving the man advice to avoid blowing an engine. id rather pay 100 for a fuel pump than 1000 for rebuild. i upgraded my fuel system before the nitrous and saw performance gains. but like i said every car is different. these are old cars with varying wear and tear. but whatever...i could argue till im blue in the face. luvin my 7, i gave you advice that worked for me. do whatever you feel is best but be careful. none of these guys are gonna drive to your house and help you repair damages to your car. N2O, turbos or any other performance mod is dangerous to an engine if the proper preventative steps arent taken and the careful maintenance isnt applied before starting.

c-squared

How would it not be true? The pump, even when worn, will flow enough to support the max-85% injector duty cycle flow at the stock pressure. The fuel pressure regulator does not wear, so the pressure will not change. The injector duty cycles are calculated by the ECU, and do not change.
What is the difference in injector delivery between a new and old fuel system? Slim to none. Check it out with a wideband.

What performance gains could you see from upgrading your fuel sysetm, as well? The only possible gain would be from lowering the pressure on your FPR so that your car ran leaner. This is especially dangerous when you go to run nitrous.

For giving suggestions on proper preventative steps, I think you are going in the wrong order. You should upgrade your fuel system when necessary, not "in case I might need it". The proper steps would be to tell the user to get the proper array of gauges to support the driver, so that he may watch during tuning to see if he does need to upgrade. Fuel pressure, nitrous pressure, EGT, and a/f should all come way on the list before fuel mods, especially with something as low as just a 50 shot.
Without this information being fed to the user, it doesn't matter WHAT you have done to your fuel system, you still would have no clue as to your car's a/f ratios and combustion pressures. You NEED this information to run safely.

Rxmfn7

iTrader: (4)

He's just saying that it would be a good idea, just in case. Is it 100% necessary, not at all.