I have searched and searched for a thread about someone putting nitrous in the 4.9. Found only one mention, and all it said was BOOM!.

Is it safe to do a wet shot of nitrous on a 150K mile 4.9L? From what range? 25-100? If it isn't possible, why?

its been talked about in the performance 4.9 threads....conclusion was that the limiting factor is the transmission

Hmm...did they take into account a rev-range of nitrous? not through shifts? And I thought the 4T60E was used in the 300+ hp/tq trucks GM makes?

The trucks use a 4L60E. This is a completely different transmission made for rear wheel drive vehicles.

So is the transmission too weak to handle a 25 shot in mid-rpms?

Transmission will hold a 25 just fine....but do you really think its worth it...for just a 25 shot?...i would do no less then 75....the tranny should hold out on that too...but I would be sure to drop the pan and change filter first...get it runnin with clean fluid first.

I would be concerned on the pistons being able to hold up and not shatter (scatter?). They are cast, not forged, and not meant for high power. Anyone know how beefy or weak the rods are? By the time you are getting to 300 hp this needs to be addressed.

I would recommend sticking to a 50 hp shot, and be cautions on the harsh application of it, keep it in one, gear and never ever allow a gear shift with the bottle on! That is sure destruction.

So would a 75 shot be safe then? It would be wet, so the fuel thing wouldn't matter...and cars are supposed to be able to handle half of their HP in nitrous stock. What is the redline of the 4.9?

If I was to ever put N20 on my '93 DeVille....

it would be a NOS Sneaky Pete system, it is a 35shot, and the stuff is so small, you don't see it under the hood and the bottle can even go under the seat etc.....

I woudln't do 75shot on a stock 4.9/4T60E.....

I think redline is 5000 rpm, at least that is all I would even consider. And considering power is already dropping after 4400 rpm, I would suspect you won't make any differences in going past 5000 anyway, unless you are some sicko with a turbo 4.9..... (you know who you are...)

But something to consider for you sicko's, Nitrous is also a poor man's intercooler. It superchills the incoming air, so it works AWESOME with a turbo...

the 4.9 redlines at 5250RPM, mine has never gone ab outg 5,100RPM under WOT, and usually shifts right around 4,900RPM....

I was looking at Zex systems, with an on-switch and TPS, so it only activates at WOT. Also, it has an rpm range during which it activates, so it won't go through shifts.

You can likely work out something in the logic where it is disabled in all but say 1st, 2nd and 3rd gear and disabled in 4th, and disabled during VCC Apply.

A few simple transistors would work nicely on the side of a relay to the N2O solenoid.

So when it shifts, it disables the bottle flow.

What's VCC apply, and why would I disable it in fourth? (Not rude, just wondering) If i wanted to use it on the highway, would using it in fourth gear be bad?

Also, the local tuner said he'd install it for $350....would it be possible for me, having very little car knowledge, to install it safely? Is 350$ worth it?

Anyone.....anyone....??? Bueller.....Bueller

What's VCC apply, and why would I disable it in fourth? (Not rude, just wondering) If i wanted to use it on the highway, would using it in fourth gear be bad?

4th is over drive... using nitrous in 4th gear would be pointless for a few reasons:

at highway speeds, if you floor it, it downshifts into 3rd, not 4th... 3rd gear will run to ~130mph

nitrous in 4th at slower speeds may cause alot of internal stress on the trans

not to mention the car would accelerate slow.... but if you floor it, it will automatically downshift to the lowest gear, so unless you plan on doing more then 130mph with your 4.9 (good luck) then you don't need to worry about it.

Also, the local tuner said he'd install it for $350....would it be possible for me, having very little car knowledge, to install it safely? Is 350$ worth it?

From what you have said, no, I wouldn't install it yourself, you can easily blow up the engine if not done right, $350 is a very good price IMO, but make sure it is a good shop that is doing it, or you'll blow up or engine, and they will say its your fault.

You can install it yourself. It's not hard, just a bit time consuming running the wires and lines. I wouldn't pay $350 to have it installed. You're not going to hurt anything as long as you follow the instructions.