Northstar Changes

[cadillacjeff7777]

This post may be more abstract.

Years ago I had a 93 Seville and a 95 SLS. The 95 SLS had the N* while the 93 had the 4.9L. I always loved that 4.9L. It was an all around power house. I was always disappointed with the power out of the N* as it felt like it was quite lacking in the lower end but was able to pass in the higher end.

Now fast forward to 2008 when I test drove and even kept for a weekend, a 2004 baseline Deville. I was "Wowed" by the horses under that hood. That car felt like it moved like nothing else that I was familiar with. Long story short, we ended up settling with a supercharged Buick Regal GS.

Now in 2011, We purchased this 2008 DTS. I don't feel the "Wow" that I did with that 2004 a couple of years ago. I may have acclimated with the supercharged 3.8L in that Buick. Don't get me wrong, the car does have plenty of power but I just am not sure if it's all that it once was. It does feel like though that it is fairly strong up until apx. mid pedal and there after is the same.

On a side note, I have not been overly impressed with the suspension. That 2004 Deville rode much nicer then this DTS. I am sure that it is the T part of the car's name. A touring suspension...But it does not even have the electronic dampeners in the struts/shocks...And yes, I feel a difference in cornering between this and my 95 SLS with the electronic suspension.

Anyone with any thoughts, ideas, remarks? I am just kinda throwing this out there to chew on a bit.

[cadillacjeff7777]

I will mention that the 95 SLS did have an error if I recall but I am not sure of it's relevance. I may be off base here but I think that it had a code for the lockup not working properly. I do remember that it had something to do with the transmission. I even remember buying the part 6 or 7 years ago and it was only twenty something...But I never got it installed.

[KHE]

I have an '05 Deville (base) and it rides as well as my RWD Fleetwood Brougham. I bought it almost a year and a half ago. Plenty of power and 28 mpg on the highway to boot.

[Texas Jim]

I will throw out a couple of thoughts...

First, I figure you got acclimated to power with the Supercharged Regal..

Speaking for just "MY" car, mine feels stronger the more it winds up... all the way to when it shifts to the next gear.

It is about the same from dead stop to about 3500 RPM... then it comes alive and wants to run.

Don't misunderstand me... it isn't a dog taking off.

It will spin the wheels and the front end slides sideways if you STAND ON IT from a dead stop on anything other than GOOD CONCRETE.

It will chirp the tires on a WOT 1st to 2nd shift.

I have driven several of the newer DTS's when my car has been in for service.

Some of them just till the next day... a couple of them for several days at a time.

A couple of them I liked really well.

They drove well and ran good.

I have noticed some slight differences in some of them as far as how well they ran... not much, but a little noticeable.

The last DTS I drove... a 2010 was absolutely AWFUL on a road trip.

We took it on a 1200 miles trip while we had it. (I wished later I hadn't)

There was so much body movement in it that you would almost get seasick going down the road.

The body was never "STILL" on it if it was moving.

It was constantly pitching front to rear and side to side.

I do admit... I think there was something basically WRONG with the car.

Maybe it had been in a bad wreck and not repaired properly... I don't know... but I do know, I am sure glad I didn't own it. :)

It was a very TIRING car to drive.

If I had to drive a car that beat me up like that one did... I might as well drive a GEO Metro... at least I could 50MPG out of it.

I was so glad to get back home and back into my 2006.

When all is said and done...I far prefer mine with the MIRC suspension.

It is really smooth on a good road and very tight and controlled on a bad road.

The MIRC suspension is all computer controlled.

On a nice smooth road.. it just floats along... get it on a rough road or a crooked road and the computer adjusts each individual wheel damping force up to 1000 times a second to keep the tires in contact with the road surface.

It even stiffens the outside shocks when you turn a corner or take a curve at high speed, to help keep the body more level.

As far as performance.. I took it to a 1/4 mile strip back last summer.

it ran 15.4 thru the 1.4, but that was at almost 100 degrees outside temp, 3/4 full of fuel and all of our luggage for a weekend trip in the trunk.

One reason it didn't do a little better was too much wheelspin when first taking off.

That killed my elapsed time, because it would not come off the line HARD like it needed to.

I have 96,000 on this car and put 40,000 on one just like it that burned in my garage fire in Nov of 2006.

I STILL enjoy driving it and it is probably the best car I have ever had for a long road trip.

You can drive it all day, at any speed you want to run, and still feel good at the end of the day.

[BodybyFisher]

Jim, I recall that you were disappointed in the performance of this 06 vs the performance of your prior 06, am I mistaken? Isn't that what caused you to look into getting the PCM tweaked? What did you do again and what gains did you get?

Did the prior 06 have MIRC?

[Texas Jim]

Jim, I recall that you were disappointed in the performance of this 06 vs the performance of your prior 06, am I mistaken? Isn't that what caused you to look into getting the PCM tweaked? What did you do again and what gains did you get?

Did the prior 06 have MIRC?

You are correct about the two cars.

They are virtually identical,, except this one has NAV (the other one didn't) and the other one had a power sunshade for the rear window and this one don't have that.

Both have MIRC.

This one seems to have a little more of a LAID BACK attitude and the first one had a WHAT ARE YOU WAITING ON...LETS GO.. kind of attitude.

Maybe the names will give you a hint... the first one was named SHARK... this one is named GHOST.

Even after tweaking the ECM and the TCM... it still isn't QUITE the car the first one was (but it's close) ... but I still REALLY ENJOY driving it.

It is actually a FUN car to drive... and it is a wonderful road car.

The main gain I have is it is a LOT more drivable now.

The trans works like I want it to.

It will downshift easier, back to a lower gear.

It shifts firmer than it used to.

I eliminated most of the torque management that is built into the newer ones.

I changed the fuel tables and fuel slopes.

I changed the total amount of available timing the engine can use,

and a bunch of other things I can't remember right now with out looking at the computer file for the ECM.

I need to hook the laptop up to it again and see if I can UP the fuel mileage without taking too much of a hit on Performance.

I am planning a few long trips this year and every little bit of mileage I can get will help.

I am retired now and on a fixed income... and SS don't pay very much.

[CoupeDTS]

I owned a 99 STS, and a 00 DTS, and test drove a 01 DHS. The one that rode the nicest suspension wise was the DHS. I didnt like the DTS and STS ride quality. It was way nicer than most cars but my fleetwood rides way smoother/cusionier. Which is expected, the DTS and STS were performance luxury cars.

The STS felt faster than my DTS. Maybe just because its slightly a smaller car? Not sure on that one, but it felt faster. I wont even compare power to my fleetwood, its like apples and oranges with way different powerplants. Northstar had way more upper end power and the LT1 has way more low end power. And the DHS having the weaker engine definately felt a little weaker.

I always was curious if a base 00-05 deville rode smoother than a same year DTS. Sounds like from what KHE says its yes.

[cadillacjeff7777]

...I need to hook the laptop up to it again and see if I can UP the fuel mileage without taking too much of a hit on Performance.

I am planning a few long trips this year and every little bit of mileage I can get will help.

I am retired now and on a fixed income... and SS don't pay very much.

Whooa! Wait a minute...You are reprogramming the modules using a laptop computer??? You've got my attention.

Any details on doing this?

[BodybyFisher]

Jim, it is interesting how much impact the MIRC suspension has given your experience with the floaty one you drive.

[Texas Jim]

Jim, it is interesting how much impact the MIRC suspension has given your experience with the floaty one you drive.

As you know... I don't usually dilly dally around when I go somewhere..

If I drove like a lot of the Cadillac and Lincoln drivers I see.. I would probably prefer the softest suspension I could get..

But I hate the floaty ride and since I actually DRIVE mine... and not just go along for the ride...I want it to be as stable and stuck to the road as possible.

The MIRC suspension, in conjunction with good tires, gives me the handling I need and want.

Yeah, yeah, I know... a 'vette handles better...... but we are talking Cadillac... where you can cruise in luxurious comfort, as fast as you want to go... all day long.. and still feel like going out to a nice dinner at the end of the day.

I can guarantee, when I buy my next one.. it will have MIRC.

[Texas Jim]

...I need to hook the laptop up to it again and see if I can UP the fuel mileage without taking too much of a hit on Performance.

I am planning a few long trips this year and every little bit of mileage I can get will help.

I am retired now and on a fixed income... and SS don't pay very much.

Whooa! Wait a minute...You are reprogramming the modules using a laptop computer??? You've got my attention.

Any details on doing this?

The guy that did my first tune on the modules is going to be in Kansas City April 29 thru May1

My DTS was the first Cadillac he had ever tuned.

He specializes in Chevy and GMC pickups and SUV's.

He is in high demand and travels all over the country tuning vehicles.

After he tuned mine, I bought the complete software package that he uses.

http://www.efilive.com/index.php?page=shop.product_details&flypage=flypage_EFILive.tpl&product_id=63&category_id=11&option=com_virtuemart&Itemid=54

Here is a link to a truck forum I am on and to the Kansas City tune.

http://www.truckmodcentral.com/forums/showthread.php?t=15468

[cadillacjeff7777]

...I need to hook the laptop up to it again and see if I can UP the fuel mileage without taking too much of a hit on Performance.

I am planning a few long trips this year and every little bit of mileage I can get will help.

I am retired now and on a fixed income... and SS don't pay very much.

Whooa! Wait a minute...You are reprogramming the modules using a laptop computer??? You've got my attention.

Any details on doing this?

The guy that did my first tune on the modules is going to be in Kansas City April 29 thru May1

My DTS was the first Cadillac he had ever tuned.

He specializes in Chevy and GMC pickups and SUV's.

He is in high demand and travels all over the country tuning vehicles.

After he tuned mine, I bought the complete software package that he uses.

http://www.efilive.com/index.php?page=shop.product_details&flypage=flypage_EFILive.tpl&product_id=63&category_id=11&option=com_virtuemart&Itemid=54

Here is a link to a truck forum I am on and to the Kansas City tune.

http://www.truckmodcentral.com/forums/showthread.php?t=15468

I like it but it says that it is for 2006 and older obdII systems.

[Texas Jim]

The guy that did my first tune on the modules is going to be in Kansas City April 29 thru May1

My DTS was the first Cadillac he had ever tuned.

He specializes in Chevy and GMC pickups and SUV's.

He is in high demand and travels all over the country tuning vehicles.

After he tuned mine, I bought the complete software package that he uses.

http://www.efilive.c...emart&Itemid=54

Here is a link to a truck forum I am on and to the Kansas City tune.

http://www.truckmodc...ead.php?t=15468

I like it but it says that it is for 2006 and older obdII systems.

FlashScan V2 supports the three major OBD protocols used by GM vehicles:

1. OBDII CAN for scanning, data logging, reading and re-programming most 2006 and later model years.
2. OBDII VPW J1850 for scanning, data logging, reading and re-programming most 1996 to 2005 model years.
3. OBDI ALDL for scanning and data logging most 1995 and earlier model years.

From another page...

06-09 Cadillac DTS 4.6L

[pcg]

Jeff, one thing to consider is the differential. Having owned 7 NS's, the fastest was my 99 Concorse with the HO 300HP engine coupled with the lowest ratio gear set available from GM. I believe that was the heavest and fastest one I've owned or driven. The gear ratio is listed on the RPO label and it makes a hugh difference.

[rockfangd]

Ok this may sound weird but

my 96 Deville has about 200000 miles and it flys, both from a stop and passing. You can easily roast the tires although I do not.

my 97 Seville has 108000 miles and lacks power taking off but has plenty of passing power. Likes to redline.

Both have same drivetrain but my Deville blows away my Seville.

I drove a 99 Deville and couldnt stand it. no giddyup on takeoff but passed good, 90000 miles.

my 85 Deville was snappy with the 4.9L and would roast the tires right off but was harder passing on the highway.

lol. I love my 96 Deville.

[Texas Jim]

Ok this may sound weird but

my 96 Deville has about 200000 miles and it flys, both from a stop and passing. You can easily roast the tires although I do not.

my 97 Seville has 108000 miles and lacks power taking off but has plenty of passing power. Likes to redline.

Both have same drivetrain but my Deville blows away my Seville.

I drove a 99 Deville and couldnt stand it. no giddyup on takeoff but passed good, 90000 miles.

my 85 Deville was snappy with the 4.9L and would roast the tires right off but was harder passing on the highway.

lol. I love my 96 Deville.

That is kinda odd...

You would think that the 96 and 97, having the same drivetrain, would be pretty similar in performance.

There almost HAS TO BE some difference in the ECM programming...but I don't have a clue what it would be.

Mine is pretty good at taking off, but it really likes to run after you pass 3500 RPM all the way to the 7000 RPM redline.

My Mom had an Eldo with the 4.9.

It ran good but no GUTS at higher RPM.

[cadillacjeff7777]

My 95 would not break tires loose at take off unless on gravel or wet pavement.

[Texas Jim]

My 95 would not break tires loose at take off unless on gravel or wet pavement.

With traction control OFF...Will the '08 spin the tires if you want it to?

[cadillacjeff7777]

My 95 would not break tires loose at take off unless on gravel or wet pavement.

With traction control OFF...Will the '08 spin the tires if you want it to?

Yes, with the T/C off. I'm tellin' ya...She was not all that exciting in the lower end. She did have over 300k on her when I bought her. 304K I think. In fact, I found it via this forum. A guy listed it on eBay many years ago and someone posted about it on here. I figured what the hell and bought it. Drove it back to Michigan from Birmingham Alabama. Drove it for another two years and totalled it on a telephone pole drunk one night.

I assume that my 08 would spin the wheels. It feels like it has the power to do so. I have not attempted.

[pcg]

With TC off the car starts out in second gear to help protect itself. That's why it seems like a dog.

[Texas Jim]

With TC off the car starts out in second gear to help protect itself. That's why it seems like a dog.

Not on 2006 and newer...

It still starts out in 1st gear.

[pcg]

I did not know that. Thanks for the info Jim.

[cadillacjeff7777]

Well, T/C on or off, that 95 was a little doggish at low end. I always figured that it was tuned that way in the computer's programming due to the EPA and the "Greenies".

[hot rod]

My 96 deville has been awesome to drive. I accidentally squealed the tires at the kids school this am. on the expressway it passes with ease. It gets decent gas mileage and looks darn good for 15 yrs old. The torque steer is unbelievable and takes a bit to get used to. I really love this car .Its all original untouched.

[cadillacjeff7777]

Well, y'all make me wonder what was wrong with my 95. Who knows. I bought it with 304,000 miles on it and totaled it two years later with 336,000. She served her time well.