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Whats the most nitrous you can spray in a stock motor?

20K views 21 replies 11 participants last post by  The Caretaker 
#1 ·
Its a low mileage motor with a nos wet kit?
 
#2 ·
first i would make sure you've done all the supporting upgrades. fuel pump, injectors, ignition, exhaust, etc. that being said several of us have sprayed a 150-200 shot. i think Kenny Caniff was using 175, Chris Mallory went for 200 a couple of times if i recall correctly. i made probably a 100 passes at 150 with my heads/cam set-up. all of us were well into the 11.s
 
#3 ·
If your stock engine is already tweaked to the max, then (in my experience) you won't see any significant gain past a 150 shot. And that's also assuming you have the mixture and timing optimized on the 150 shot.
With my bolt-on setup, I tried the 175 many times and never bettered my 60', ET, or mph that the 150 shot gave me.
The limiting factor is the stock cam's short exhaust event. You get more cylinder pressure/work on the power stroke, but the pumping losses on the exhaust stroke eat into the torque output, and the residual exhaust in the cylinder further limits how much it can inhale on the next intake stroke.
 
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#5 ·
For a car where the NA ET is already wrung to the max (not just mods, but tuned and tweaked), you can pick up anywhere from 1.0 to 1.3 sec ET with a 150 shot. For a car that is not optimized NA, who knows............maybe even up to 2 sec ???
 
#10 ·
Nitrous won't tax your springs any more than running it NA. In fact, you want to rev it slightly less before the shifts, since the nitrous will move your powerband to the left.
If your stock engine is solid and you get the nitrous fuel and timing right, it won't hurt it at all. If you're missing any one of those three things, all bets are off.
 
#12 ·
Yep, same for wet.
Either way, make sure your fuel supply is up to the task. A genuine Walbro 255 (not the knockoffs that claim to be "Walbros") + a Racetronix harness or equivalent is your best best. You may be OK with a new/good stock pump with good voltage supply (ie Racetronix or equiv), but I'd put a pressure gauge on it and watch it as you increment up to the 150 shot.
 
#15 ·
On a forged 355 or forged 383 stroker what's the most shots of nitrous you can run and still be good for a daily driver ?
 
#14 ·
damn I just learned a lot. I been trying to figure what upgrades to make first and what i want out of my SS in the long run. Yall just helped a lot. I just learded a **** load just lurkin. Thanks.


Vic
 
#20 ·
I think what he means is that when adding nitrous,it excentuates the existing power bands tendencies.in this case filling out the power and in the low and midrange areas.power gains will taper off as you run out of camshaft in the upper rpm range.i think I'm having this happen on my car.im spraying up to 5600 and shifting at 58.stock cam,springs,and rockers.
 
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