View Full Version : Performance Survey - New Owner - Seeking Ideas

02-11-06, 01:24 PM
I am the proud 3rd owner of a nice red 1997 Deville. garage kept, all current maintenence, mostly highway miles (and only 69,825 at that)...pretty nice car. my dad hs had 2 devilles that i loved so this was a natural progresion for me (even coming from a mustang GT).

However, i know the potential of a powerplant such as this. What are the most common mods for a 4.6L northstar equipped vehicle? are there any PCM tuning options? TB's, exhaust work, etc?

Also, for those who run forced induction, how well would a typical northstar take to an extra 75-100hp from a wet nitrous kit? i only ask because my mustang kit was universal and complete. all i need is to do the wiring which is not hard at all...

I'm thinking first off should be a cold air intake of sorts and a full length exhaust. i don't get a sniffer but it has to pass visual meaning resemblance of cats must still be there.

Also thought of a TB/MAF combo but that seems harder to find (the MAF part) and also not sure how well a different MAF would fly with no ability to tune.

and of course there's the NX kit.

What do you think and what all have you done to your N* cars? if you have dyno pulls too that would be helpful as well...

thanks in advance!

02-11-06, 04:09 PM
The most common, although not much, would be intake, and exhaust. Let your car breath a little. I personally think the intake is pointless, because your stock filter keeps the most amount of dirt, dust and grime out of your engine, more then any K&N cone. Although, cold-air intakes still seem to be very common.
People also seem to do a lot of exhaust upgrades. 2.5-3.0 inch pipes, cat-back, ect. I'm going to get two Dynomax Super Turbo muffles and run 2.5 inch all the way back. And maybe even get the MagnaFlow highflow cat. That mod alone will get you a few numbers, and sounds very VERY cool! :cool:
The PCM is just about out of the picture... Basically: Good luck with it.
Eldorado1 sells bored out 80mm Throtle Bodies, I would like to get one, but he may stop production! Buy one now! He sells the spacers too.
Mark99STS made a turbo too! It's quite the dent in the pocket, but by FAR the best performance mod for a Caddy that I know of. Upgraded fuel lines and a torque converter is all good stuff too, you can find those thanks to Marks topics also!
As for the NorthStar handling a 75-100 HP wet shot, it should be fine. Of course, like any engine, you don't want to over-do it. But then again, the NorthStar is BUILT to handle power! :thumbsup: 100 HP is the max I'd go.
And there is nothing wrong with the stock MAF! It straightens out the air, and believe it or not, is one of the "best" MAFs you can have in your Cadillac. I wouldn't bother with a new one.

02-11-06, 05:23 PM
exhaust was something i promised myself. i plan on duals w/X section and flowmasters. wanna be unique.

intake was also a given. i have no clue how i'm gonna accomplish it but i have a source for stainless and could have one fabbed up if i come with blueprints

75-100hp is all i'd jet for and throw away the rest...don't need to grenade it anytime soon...

02-11-06, 05:44 PM
One of the things I keep hearing about the wet nitrous kits, are the intake backfires that literally blow up the intake.

I would be a little nervous with a wet kit, best/safest results would be using a direct port kit... but then again you pay for your safety in monetary costs.

02-11-06, 05:53 PM
the intake backfires typically are the result of an improper setup. yes it can happen, but then again a major backfire can still occur with a direct port kit, or you could melt your motor, or any number of other things...i've seen backfires on several LS1's/Stangs/etc but for every backfire there's a thousand that are flawless even when spraying ludacris amounts of juice...

02-14-06, 04:51 PM
Hey guys,

I'm a new caddy owner and am interested in this post as well. I've done some searching but can't quite find the definitive answers about what really has numerical value and what does'nt.

Now.. when it comes to nitrous I'm a bit informed on that front. :cool2:

With a stock motor (stock tune) and a fixed hit kit like your NX system. I'd suggest three things. These three will insure problem free shots assuming everything else is up to par.

1) Run excessive octane fuel. Try to run 2-3 octane higher than the motor is called for.
2) Run a one range colder plug and decrease the gap by 0.005"
3) Make the *nitrous* line going from the **solinoid to injector** pipe twice as long as the fuel line. (Nitrous at 900 psi and fuel at 50psi travel at differing speeds. If the pipes were equall length? Guess which one gets to the nozzle first... Initial lean out is why soooo many people have had problems ;))


02-14-06, 06:02 PM
all my lines are already setup, with nitrous 2ft and fuel 1ft long from solenoid to nozzle. have bottle warmer and remote opener as well. very nice setup. i haven't changed the plugs yet but planned on that with the new wires.

did not know about the gap...thanks for the tip!

02-16-06, 05:07 PM
It's just a little insurance.. closing the gap down a bit.

At times spark plugs will have a "creep" to the gap when spraying. Setting them tight will help to insure it gets lit time and time again.


02-16-06, 07:17 PM
More insurance would be to use a window switch and only spray from about 3000rpm up.