: What did Cadillac do to get more power?



darien99
02-26-07, 08:55 PM
Out of the later 4.6's like the XLR. The intake manifold appears to be different from our's..would this be a nice bolt on modification for us? Didn't they also go to a roller lifter setup? Any info/tips?
Edit:I guess this should have been posted in northstar performance..:tisk:

ewill3rd
02-26-07, 08:56 PM
The big kicker is Variable Valve Timing on all 4 cams.
Not a "bolt on" of any sort.
Some other things are different too, but I think the VVT is the primary difference.

CadillacSTS42005
02-26-07, 09:01 PM
also the fact the motor is straight rather than inverse...
it allows for better headers

fwd N*s bottleneck is the xover pipe...

Ranger
02-26-07, 10:06 PM
Roller followers were added in 2000. Not for performance but for oil life and milage increase.

I'll move this to the Northstar section for you.

darien99
02-26-07, 10:39 PM
Thanks for moving it Ranger.

Didn't know about the VVT, and I didn't think about the exhaust manifold design either. You'd think with those improvements they would have seen a bigger gain. :confused:

BodybyFisher
02-27-07, 12:24 AM
coil on plug also....?

fpmesiIII
02-27-07, 03:19 AM
yeah i heard lack of spark plug wires helped with increase gas mileage.

ewill3rd
02-27-07, 07:02 AM
FWD N* has coil on plug ignition since ... I think 2000... right Ranger?
They just use a bigger coil assembly. There are two big coils as opposed to 8.

fpmesiIII
02-27-07, 08:05 AM
FWD N* has coil on plug ignition since ... I think 2000... right Ranger?
They just use a bigger coil assembly. There are two big coils as opposed to 8.


yes 2000 was first year for coil on plug ignition. I forgot to read the original posters post. thought we were discussuing the 2000 N* changes. my bad.

codewize
02-27-07, 07:11 PM
Right, cam followers, no lifters.

Ranger
02-27-07, 10:29 PM
FWD N* has coil on plug ignition since ... I think 2000... right Ranger?
They just use a bigger coil assembly. There are two big coils as opposed to 8.
Yup 2000 was the introduction of roller followers & COP ignition, but don't you mean 4 coils?

BodybyFisher
02-27-07, 10:33 PM
Did they institute direct injection yet?, I think I recall the guru mentioning that it was coming. Audi is using direct injection, here is the description

FSI is an ingeniously efficient fuel-injection technology that squeezes more power out of every drop of gasoline. By injecting fuel directly into the combustion chamber milliseconds before ignition, FSI creates instantaneous combustion.

BodybyFisher
02-27-07, 10:49 PM
FWD N* has coil on plug ignition since ... I think 2000... right Ranger?
They just use a bigger coil assembly. There are two big coils as opposed to 8.

This is what I meant. EIGHT COILS, one for EACH cylinder.....

The ignition utilizes a coil-on-plug arrangement, which maximizes spark energy, eliminates spark plug wires and improves electromagnetic compatibility performance. The ECM precisely commands ignition spark event and timing. Four pencil coils are assembled to a bracket for modular assembly, one module for each bank. During engine assembly, the coil modules are assembled to the top of the cam covers so that the coils fit into tunnels in the cam covers and cylinder heads, and connect directly to the spark plugs.

See this article, it gives me a boner, Anatomy of an Engine - the New Northstar V8, specifically IGNITION SYSTEM

http://autospeed.drive.com.au/cms/A_1569/article.html

ewill3rd
02-28-07, 08:25 AM
I haven't seen it yet but I know Direct Injection is coming to the V6.
The only DI engine I know of out there right now is the turbo engine in that little Saturn thing.

The FWD N* ignition system is similar in design and operation to the RWD VVT models. It is just a different arrangement, but I know what you mean.
They are doing a lot of things with some pretty high tech stuff here lately.
It is actually quite amazing.

darien99
02-28-07, 10:41 PM
I noticed there's a different style intake plenum on the 2000+ motor. Was this design for more power or to be quieter?