: 4.0L Northstar, more related to vin Y or vin 9?

11-04-08, 12:21 PM
I was wondering....does the 4.0L Northstar share the intake cam with the vin Y or vin 9 engine? Or is it something completely different?

11-05-08, 10:27 AM
The 4.0 has the same intake cams as the LD8 275hp. The exhaust cams are the same as well. You can bump up the HP a bit by installing L37 intake cams, but I'd have to check to see if there's enough clearance for the added valve lift. I meant to do that already, just haven't had time. If worse came to worse, the pistons may need a bit larger valve reliefs- some die-grinding might do it, if need be.

11-05-08, 10:29 AM
What's amazing is that the 4.0 puts out over 1 HP/cubic inch in stock form, with LD8 cams. I'm planning to see if I can get L37 performance from a 4.0 with some intake and exhaust mods...

11-05-08, 11:10 PM
Oh, so it is the LD8...cool!

11-07-08, 07:00 AM
i have read over on the aurora forums that putting the 300hp cams in there doesnt really do much for performance when it comes to real world driving. they say the lack of low end takes away from the car and the top end charge isnt worth the trade off. i dont know if the ECMs were reprogramed or not, most likely not.

11-07-08, 09:12 AM
True, but the Aurora's (Autobahn optioned Auroras) had the 3.71:1 final drive- so you barely even need torque with those gears....lol.... I know my '96 Aurora (now sold) could take on 5.0 Mustangs and beat them, and I didn't modify the car at all. It moved.

Auroras had another final drive for the non-Autobahn cars, for the 4T80-E, 3:48:1. I guess that's a compromise for performance and fuel economy.

11-07-08, 09:20 AM
A 3.48:1 gearset in a 2000-2004 STS would create a peppy sport sedan with great highway gas mileage. The 200-300 rpm drop at 65 mph would give another 2-2.5 mpg at steady highway cruising.