Cadillac Owners Forum banner

1 - 20 of 26 Posts

·
Registered
Cadillac
Joined
·
3 Posts
Discussion Starter #1
Hey, I'm new here. Hi, what ever...

Any who.

I've had my '92 Seville for about half a year now (100k miles at purchase, for $2,700), so far it's an AWESOME CAR! I was looking for Cadillac's for sometime, almost gave up until I found this car. It's red, in GREAT shape for it's miles and age.

So far, no problems except a cracked EGR vacuum tube (fixed), and that's it. Everything is working great.

Now, what I'm wanting to do after a while, is upgrade the performance.

But I was wondering, is there anything I should do first? Considering it's age and miles? To prevent anything from breaking under pressure?

After that, what are the best mods to increase performance (that are cheap, and won't require much tear down)? Are there any supers or turbo's that will fit and work on the 4.9? I know there's been computer issues on the newer 96+ Cadi's, would there be any on mine?

Thanks. :)
 

·
Registered
1993 Eldorado, 4.9L, 200k miles
Joined
·
273 Posts
Stick w/ the fundamentals...you mentioned in your post that you've had your car for about 1.5 years and it had 100k miles at the time of purchase. I'd suspect that it now has 115-125k miles. At this mileage, there is good probability that some of the major mechanicals will need replacement....alternator, water pump, ISC, Catalytic Converter, AC, Vcc,...some report transmission replacements in the 125-150k (Mine, as well as others, have gone 200k, however). If you're lucky, you will not incure the expense of replacing struts, radiator, heater core or ignition coil. Plan funding for these items before thinking about any "Mods".

Regarding turbo/super additions...forget it. Page back and go to the topmost sticky which chronicals a turbo install.....2 years and it doesn't appear even close yet. I didn't read the entire thread, but one of the last things done was replace 1 of the major mechanicals mentioned above in this post.

1 quick and easy performance improvement is had by advancing the timing by 3 degrees (Do a search on this forum for further information). It is as simple as rotating the distributor. Make sure you run hi octane fuel as the engine will be more suseptible to pinging which could destroy your engine.

The #1 fundamental, however, is to know your engine. The title of your post is "4.9ltr Northstar performance"....a 4.9L Northstar does not exist...your car either has a 4.9L traditional pushrod engine or a 4.6L Northstar. The 4.9 is rock solid and can easily go 200+ miles w/ proper maintenance. The 4.6 has mixed reviews and has its pecularities. I could be wrong, but I believe all '92 Seville's had the 4.9L.
 

·
Registered
Cadillac
Joined
·
3 Posts
Discussion Starter #6
Stick w/ the fundamentals...you mentioned in your post that you've had your car for about 1.5 years and it had 100k miles at the time of purchase. I'd suspect that it now has 115-125k miles. At this mileage, there is good probability that some of the major mechanicals will need replacement....alternator, water pump, ISC, Catalytic Converter, AC, Vcc,...some report transmission replacements in the 125-150k (Mine, as well as others, have gone 200k, however). If you're lucky, you will not incure the expense of replacing struts, radiator, heater core or ignition coil. Plan funding for these items before thinking about any "Mods".

Regarding turbo/super additions...forget it. Page back and go to the topmost sticky which chronicals a turbo install.....2 years and it doesn't appear even close yet. I didn't read the entire thread, but one of the last things done was replace 1 of the major mechanicals mentioned above in this post.

1 quick and easy performance improvement is had by advancing the timing by 3 degrees (Do a search on this forum for further information). It is as simple as rotating the distributor. Make sure you run hi octane fuel as the engine will be more suseptible to pinging which could destroy your engine.

The #1 fundamental, however, is to know your engine. The title of your post is "4.9ltr Northstar performance"....a 4.9L Northstar does not exist...your car either has a 4.9L traditional pushrod engine or a 4.6L Northstar. The 4.9 is rock solid and can easily go 200+ miles w/ proper maintenance. The 4.6 has mixed reviews and has its pecularities. I could be wrong, but I believe all '92 Seville's had the 4.9L.
Actually I said I've only had my car for half a year. Any who, I've only put like 1,000 miles on it so far (did an oil change about at about 800miles). I only take it to work, and a few other places, normally short drives. I try to get it on the high way when I can, to help clean the engine out.

Before winter, I am going to get it inspected, and replace whatever is needed.

Any who.

As for the super and turbo, I wasn't sure if there was a good one for the 4.9 yet. I googled it, and didn't find much. I didn't think I'd be able to find one. lol, worth a try though. =P

Yes, I do run premium fuel, 91-92 octane. I like to get the better power and MPG.

As for the 4.9ltr Northstar, I'm not sure why, but I vividly remember seeing "Northstar by Cadillac", or something like that on the air filter cover art. Though, the actual engine was the 4.9ltr Fuel Injected engine. I'm not sure, I' have to check it again before i head out today.

BTW, I'm more of a computer guy, than a car guy, so I'm not that familiar with cars.

Thanks for the help.
 

·
Registered
Sedan de Ville, CTS
Joined
·
4,764 Posts
Hey, I'm new here. Hi, what ever...

Any who.

I've had my '92 Seville for about half a year now (100k miles at purchase, for $2,700), so far it's an AWESOME CAR! I was looking for Cadillac's for sometime, almost gave up until I found this car. It's red, in GREAT shape for it's miles and age.

So far, no problems except a cracked EGR vacuum tube (fixed), and that's it. Everything is working great.

Now, what I'm wanting to do after a while, is upgrade the performance.

But I was wondering, is there anything I should do first? Considering it's age and miles? To prevent anything from breaking under pressure?

After that, what are the best mods to increase performance (that are cheap, and won't require much tear down)? Are there any supers or turbo's that will fit and work on the 4.9? I know there's been computer issues on the newer 96+ Cadi's, would there be any on mine?

Thanks. :)
I just checked several oil filter listings. Most companies (NAPA, ACDelco, Pennzoil) indicate that all 92 Sevilles had 4.9. (Fram says that all 92 Sevilles had the Northstar, and that 93 Seville had either the Northstar or the 4.9. Apparent error??)

At any rate, as others have said, check your engine. You should be real happy that you likely have a 4.9. Much less complicated engine than Northstar. Just that will save you $$.)

Good luck.
 

·
Registered
'98 Buick Regal LS - '91 Caddy Seville - '87 Caddy Seville!
Joined
·
4,425 Posts
There was no 4.9 liter Northstar, and there never will be. If there is badging that says otherwise on a 1992 Seville, someone placed it there to make people think it was the Northstar; the Northstar didn't come out until the 1993 model year on the Allante and Seville STS.
 

·
Registered
76 Eldo (54k), 76 Eldo (52k), 78 Eldo (9k), 85 Deville (43k)
Joined
·
668 Posts
The above posts are correct. ALL 1992 Sevilles had the 4.9L engine. NONE had Northstars. If you have an engine compartment with a "swoopy" air cleaner, then you have a 4.9. You might be confusing the verbage with the sticker that reads, "Made Exclusively for Cadillac by General Motors," encircling a 4.9 insignia.

In any case, aftermarket mods for this engine are not really available. And even if they were, the 4T-60E transmission just couldn't take it. Remember, when this transmission first came out in 1985 (as the 440-T4), it was sitting behind engines that only produced 190 lb-ft of torque (both the Cadillac-sourced 4.1L V8 and Buick-sourced 3.8L engine). GM delayed production of the 1985 C-body cars (Cadillac Deville, Buick Electra, Olds 98) because they had durability issues with the transmission when it was first launched.

Only 6 years--and, granted, many improvements--later, the engine was sitting behind the 4.9, producing more than 50% additional torque than the original 85 C-body engines. Stressing the transmission with more power just isn't a good thing. This is why GM created the 4T-80E for the Northstar: despite the similar torque ratings for the Northstar and the 4.9 (upon which many transmission are rated), GM felt the current transmission just couldn't provide the necessary durability, given that many drivers of the Northstar would probably like to drive aggressively.

Recall that prior to the 92 Seville/Eldorado introduction, Cadillac pretty much built grandpa/grandma mobiles for people that GM thought would rarely accelerate hard. I think it's a pretty true statement that if you drove most any 80s GM car (not truck) very hard, you were asking for trouble (4.1L V-8--blows gaskets, 3.8L V-6--rod knocks, disintegrating camshaft gear, 2.5L I-4--camshaft gear disintegrates, 2.2L I-4--leaky headgasket).

On the other hand, if you drive them normally, nearly all of these engines/transmissions (save the 4.1) will last forever.

With respect to your car, if you rarely force full throttle upshifts, your transmission will last forever. Those that last only 120-140k generally fail because their drivers likely drove them a bit aggressively. Freeway driving also helps.

The only thing that you CAN do cheaply with a 4.9 is advance the timing a few degrees, which might get you close to 10hp. I wouldn't go any further than that. Don't advance the timing too far, or you'll really hear the No. 1 main bearing start thumping. You can also get a more free-flowing exhaust, but you'll need to increase the pipe diameter directly after the manifold, buy a free-flowing catalyst, and a performance muffler. Just putting a performance muffler on will only net you about 5hp tops.
 

·
Registered
1992 Town Car Cartier & 2014 Accord LX MTX
Joined
·
34,087 Posts
Yeah, according to our 4.9 mod gods on here (Illumina and GhostC) the only things you can do to the 4.9 to increase performance, aside from advancing the timing, is to install a performance muffler, and to install a CAI. Ghost C is the only person to ever make a CAI for the 4.9, and the muffler most commonly used is a Flowmaster Series 80, which is intended for the Camaro/Firebird, but fits the deVille too because like the F-Bodies, the deVille's muffler is mounted sideways.
 

·
Registered
1992 Town Car Cartier & 2014 Accord LX MTX
Joined
·
34,087 Posts
Cold Air Induction.
 

·
Registered
76 Eldo (54k), 76 Eldo (52k), 78 Eldo (9k), 85 Deville (43k)
Joined
·
668 Posts
NAPA also sells a performance muffler, and it's considerably cheaper than the Flowmaster.
 

·
Registered
90 Eldo -SOLD-, 98 ETC -SOLD-, 86 XR4Ti Track Car, 07 Ranger
Joined
·
963 Posts
Ok, everything everyone is telling you about not being able to mod this engine is not true. I agree that you should pay attention to base mechanicals first, suspension, brakes, tranny rebuild, engine rebuild, etc before you go to town on making power or you'll just break a lot of parts. That being said here's some info on REAL performance upgrades, not just CAI, bolt on Cat back exhausts, and performance chips:

I would point you Pennock's Fiero Forum where a 4.9L swap is common in Fieros and the writeups farily detailed. There are 2 I would look at and potentially contact the members for more specific information in your quest for parts:

1) A 4.9 Turbo setup, it used the stock 4T60 Caddy tranny with a reburned/tuned factory PCM and wiring harnesshttp://www.fiero.nl/forum/Archives/Archive-000001/HTML/20060811-2-064940.html, he's not the origional owner and I couldn't find the origional thread by PBJ (who as I recall is a member here as well) but if you contacted him you should get some info on "Pete" who burns the PROMs for the 4.9L turbo...

2) Naturally asparated 4.9L performance thread: http://www.fiero.nl/forum/Forum2/HTML/061613.html, includes ported, polished, big valve heads, delta cams/springs using N* pistons in the 4.9L. If you got "Pete" to help you out in the ECU department you'd be able to do this, I think the end result was power output on this 4.9L that was slightly ahead of a N* and the power was made in the lower RPMs when compared to a N*, I want to say "Pete" is in Canada somewhere.

All of this is great but if you read the threads and do some digging you'll see how much custom work a forced induction build is as there just aren't any off the shelf 'kits' that bolt on. To install a turbo you're going to need to spend a considerable amount of time custom fitting/welding up custom headers to get all that exhaust feeding a single turbo or even 2 turbos. For a roots/screw supercharger you'll need to fab up a custom intake, for a centrifugal supercharger, that'd be the easiest route in terms of customization cause all you'd need is enough space to locate the CSC, fab up a custom bracket, get a longer serpentine belt and plumb up an front mount intercooler into the stock intake, never touching the exhaust unless you wanted to open em up to help flow. Really the only thing you'd have to worry about on a CSC is the harmonic balancer and front crank seal longevity since you'd be 'overloading' it, but regular replacement of the balancer should minimize problems...
 

·
Banned
2005 STS4 1SG: GM Acc Lights, Corsa, Platnium Grille, Volant
Joined
·
15,987 Posts
There was no 4.9 liter Northstar, and there never will be. If there is badging that says otherwise on a 1992 Seville, someone placed it there to make people think it was the Northstar; the Northstar didn't come out until the 1993 model year on the Allante and Seville STS.
And the Eldorado ETC
 

·
Registered
Cadillac
Joined
·
2 Posts
The reason you can push this engine harder in a Fiero is the the same reason a motorcycle transmission wont work in your car "MASS" the Fiero weighs in at nearly half the weight of theses big Caddies the loads the 4.9l would see in a fiero are no where near what you see just driving to the grocery store and back.

None of us would expect a transmission designed for a 300lb motorcycle to propel a 3000lb car reliably. V8 FWD and 4000lb are a precarious combination and any performance gains should be approached with that in mind.
 

·
Registered
1992 Cadillac STS Seville
Joined
·
6 Posts
There was no 4.9 liter Northstar, and there never will be. If there is badging that says otherwise on a 1992 Seville, someone placed it there to make people think it was the Northstar; the Northstar didn't come out until the 1993 model year on the Allante and Seville STS.
I own a 1992 sts 4.9L Northstar and Ive owned a 1994 sts 4.6L Northstar. It its a northstar motor its factory made and called the northstar 4.9L even tho it is much better than the 4.6L as I owned a 4.6L in 07 and now in 2010 I own the 92 4.9L as its a way BETTER NOTHSTAR...

I can take a picture of the engine if you want to see....
 
1 - 20 of 26 Posts
Top