Hi guys,

My friend just bought a 1996 3.9 and we just wanted to know if there are any known weak spots as far as parts are concerned? Like crank, rods or pistons?

We have a turbo, large air to air intercooler, fmu so we are only going to run 8 psi just for a quick hp gain for a weekends work.

Thanx in advance for any help.

Chad

 

You can't run a tubro on a 3.9, engine won't take it, it will run too lean and burn the pistons and there is no way to manage the tubro on our ECU's.

 

Hi Mike, I appreciate your input but to be honest I wouldnt worry about me being able to get fuel delivery, with a walbro 255lp pump and 100 psi in the fuel rail im sure there will be no problem with fueling for a measly 8 psi. And even if thats not enough (which it will be) il run a resister mod inline with the water temprature sensor to make the engine think its doing a cold start under boost and it will prolly inject enough fuel for 20 psi of boost, most engines under cold starts will crank as much as 4:1 air fuel ratio and this is at @ 45 psi rail pressure, @ 90 - 100 psi it will poor in. And if this all fails which it wont, il run some extra injectors in the intake manifold and use a aftermarket map sensor to start them pulsing under boost.

Fueling is the last of my worries tbh, I just didnt know what these engines are built like inside .....

So has anyone crammed a bunch of nitrous into a stock engine and seen what the stock crank and rods can handle?

Have a good one guys.

 

First, the tranny won't take that sort of torque, the spider gears won't hold up, you'll over heat it and drop your liners and what good is that sort of power in an old top heavy wheeler that just needs a little more torque.
As a retired Rover service manager, I have seen a number of people try what you are talking about and that is as far as it has gone.

 

"Hey bubba! Watch this!"
Be sure to put the video on Youtube.