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does anyone know where i can find a chip or programmer for my 97 etc i have exhaust, intake, plugs, wires, ceramic brakes and new rotors i want so more power what other mods are out there. what would happen if i removed the resonator i dont know what it does and also should i get a new cat. I also read something that you can override some functions on the ECM like spark timing and such does any one know how to do this. :gun2: :gun: :cop:
 

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1995 ETC, 75 Deville, Cad500 powered 73 Apollo, 94 Mark VIII
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You can't do a single thing with your PCM. I believe you can view some parameters, but I know you can't change any of the things you mentioned.

As far as the resonator, it's kind of like a 3rd muffler. You ever been in a loud car crusing on the freeway where the noise kind of reverberates in your head? Well that's what a resonator is there to prevent. I left mine on and I don't know if there is a performance gain in removing it or not.

The stock cat isn't too restrictive. Some people have opted for aftermarket high flow cats, a few have just removed the cat. Since your car is a 97 you don't have the option of removing it since there's a post-cat O2 sensor to measure catalyst performance: remove the cat and you get codes. An aftermarket cat might be worth it, I don't know how well they flow vs the stock cat.
 

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How about opening up the scrawny little hole on the side of the pcm box so more air can come through. I'm working on this myself right now. Only problem - can't seem to get the pcm box out of the way. Any ideas?
 

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Mccalist said:
How about opening up the scrawny little hole on the side of the pcm box so more air can come through. I'm working on this myself right now. Only problem - can't seem to get the pcm box out of the way. Any ideas?
Don't. The N* breathes IN just fine. Start cutting holes in your airbox and who knows what might get sucked in there. The airbox is placed, configured, and secured where it is, for a reason.

Don't you think the Northstar engineers considered opening up that scrawny little hole themselves?

Exhaust and juice are the only real ways to goose your (street legal) Northstar...
 

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'93 STS (sold), now looking for a CTS Wagon soon!!
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All the modifications to make horsepower & torque will make you go faster, but the one component I hear little about is, transferring that power to the wheels.

The transmission.

I put a lot of time & money into my GMC truck, but the most single difference was building the tranny. A much more solid transfer of power to the wheels!

But don't attempt it, unless you get a GOOD tranny builder!

I can suggest where my tranny was built, which is, Art Carr, of Calif. Perf. Trasnsmissions in Huntington Beach, Ca. ask for Andy or Art.

They know what they are doing.:stirpot:
 

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Engineered Performance makes an LSD conversion for the stock diff, and Yank will build you a Torque converter to whatever specs you want. These trannies are NOT cheap to to a performance rebuild on. I don't really see the need as long as the engine is un-modified. It would be nice to find someone who could make a beefier set of CVD's, so that you could run sticky drag radial, or even slicks without worrying whether or not your CVD's are gonna break in half on the next run. A set of M/T DOT drag radials, an LSD, some beefy CVD shafts, and a 3200rpm stall converter would make for a real nice, stop light to stop-light machine. Probably would do to bad at the track either, although I would recommend a trans-cooler as well.
 

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CORRECTION:

I AM NOT CUTTING HOLES IN the AIR box. It's the port that leads into the PCM box. No risk of sucking anything in anywhere there wasn't a risk before.

Why do you think the northstar intake is fine? Did you design it? Did you talk to someone that did? I happen to be a mechanical engineer, and know that design is driven by many factors other than what may be important to some shmucks on the internet ten years from now.

Do you know what happens when an air intake is taken off in its entirety (and thereby eliminating the flow restrictions therein)? The air pulled in to the cylinders on their intake strokes encounters fewer obstacles, and has to overcome less friction on its way. This means that, compared to when the intake sytem is intact, MORE AIR (and combustible oxygen) enters the combustion chamber. More oxygen means greater combustion and the release of more energy.

It follows that eliminating any one of those restrictions in the intake path will allow the engine to produce a commensurately greater amount of power.

You were plainly wrong. So, if you are going to continue to comment, please make an effort to reason, rather than just state your poorly-drawn conclusions.
 

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The thing about that is, that many have tried and seen little or no results from their efforts. Sure you remove one obstacle that is in the air's path, but it's not a very restrictive path. You also have to look at how it will affect the powerband of the engine. Chance the path of air flow into the engine, will affect you hp and torque curves. It's just like when you port the intake side of a head. If everything else is left stock, you end up with a larger volume of air flow, but at the expense of velocity. You now have the ability to flow more air, but the force pulling that volume of air through has now decrease. IN the case of the N*, this results in an increase in high RPM hp, at the expense of low RPM torque, which is the last place this engine needs to loose power. Hell, just throw a K&N filter in there, and you'll see a difference.

Unless your particular engine is making over 400hp, I doubt it's anywhere near the point, where it's not drawing the maximum amount of air it can. The intake design is more than capable of flowing the maximum amount of air that the engine can handle at WOT. Of course, if you were to increase that amount of air, say by increasing the stroke of the piston, or the intake cam lift, than you may find that less intake restriction is neccesary. Neither of the afore mentioned modifications are usefull in a street driven vehicle though, so in the end it's a moot point.

You know, alot of people don't seem to understand the relationship between the volume of air, and the velocity of the air flow itself. It's not just how much air you can flow through a particular opening, but also how fast you can get it through. A great big hole does nothing, if there's no "OOMPH" behind the air flowing through it. This isn't some SBC where you can port the intake side of the heads, and just throw a higher lift cam and some different jets in the carb to compensate. It's a finely tuned piece of machinery. Every part is designed to work in harmony with every other part. The second you go messing with something on the instake side, it will affect the rest of the system.


It's a simple fact that these engines suffer the most at the low end, due to their lack of torque at low engine speeds. As I'm sur you know, being the mechanical engineer that you are, Torque is the engine's ability to turn the wheels, it's what carries your HP up through the RPM range, and is what provides that head snapping acceleration one feels when they mash the pedal. This is where intake velocity really comes into play. At low RPM's, you want the highest speed possible for the air flowing into the engine. The less restriction, the less speed, and therefor less torque. At high RPM's velocity is not so inportant since the pistons are traveling at a great enough speed top draw in all the air they can, providing there is little or no restriction. It's the balance between high air velocity at low RPM, and large air volume wiht little restriction at high RPM that's critical. There's a reason why the low RPM runner stage in dual plane manifolds is a lot longer than the high RPM runner. The longer path results in a slight restriction which helps accelerate the air into the cylinder.

All this can be affected by simply changing the air filter. Some people may say that's bull. They're the ones who choose to use the K&N, and cut holes in ther intake box.

In short, even if you could somehow magically get the air box to flow an extra 200cfm of air, it simply won't help unless you can change the rest of the engine accordingly. It has to be able to use this extra air, or else it'll either do nothing, or hurt performance.

I think I speak for most here, when I say, dyno your car first. Then cut your bigger hole in the airbox, and then dyno it again. If you see an increase in low end torque below 4400rpm, then I will commend you as being one of the few who have succeeded. If by some chance you manage to shift the torque curve further up the power band (even if you make like 10 more lb/ft and HP) I'll laugh, because you will still have done nothing for low end performace.

Everyone is always saying how they wish the car accelerated faster, or how they wish it jumped off the line like that other car they had with the big pushrod V8 in it. It's LOW END TORQUE that gives you that. Where we need a power boost is below 4k rpm. That's where you'll get that quick off the line acceleration from. That's where you'll get that head snapping feeling when you mach the throttle at a light.

Now if someone could find some magical way to get the new VVT system to work on an L37 N*, I would be impressed. That's what these engine could benefit from. It's part of the reason why the new N* in the STS produces 20 more ft/lb's fo torque at the same RPM (using L37 for comparison). Having the ability to vary your intake (and exhaust) valve timing means that there is less of a compromise between air low rpm velocity, and high rpm volume, which benefits both low end torque and high rpm hp. On an engine like that, small changes to the intake side are not as critical.



Anyway, my rant is over. Do as you will. It's obvious that mere peons such as ourselves could not possibly hope to comprehend the fine inner workings and details of such an extraordinary piece of machinery. I guess you'll just have to be our resident expert on the Northstar from now on. All heed the master in all his infinite wisdom...:worship:
 

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Take care choosing the aftermarket air cleaner. I have been told by an experienced Dealer mechanic, etc., that air cleaners that require oil, may contaminate the air intake sensor. Amsoil makes a "nano-filter" using no oil.

To me, K&N suck. Just look through the filter....... Which is the problem....If you can see through it, it doesn't block all the little crap. ( Technally speaking)
 

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Mccalist said:
CORRECTION:

I AM NOT CUTTING HOLES IN the AIR box. It's the port that leads into the PCM box. No risk of sucking anything in anywhere there wasn't a risk before.

Why do you think the northstar intake is fine? Did you design it? Did you talk to someone that did? I happen to be a mechanical engineer, and know that design is driven by many factors other than what may be important to some shmucks on the internet ten years from now.

Do you know what happens when an air intake is taken off in its entirety (and thereby eliminating the flow restrictions therein)? The air pulled in to the cylinders on their intake strokes encounters fewer obstacles, and has to overcome less friction on its way. This means that, compared to when the intake sytem is intact, MORE AIR (and combustible oxygen) enters the combustion chamber. More oxygen means greater combustion and the release of more energy.

It follows that eliminating any one of those restrictions in the intake path will allow the engine to produce a commensurately greater amount of power.

You were plainly wrong. So, if you are going to continue to comment, please make an effort to reason, rather than just state your poorly-drawn conclusions.
Yes we have. A former member who is a GM powertrain engineer. He has told us many many times that they "left nothing on the table" when it comes to power output. As he put it "All the low hanging fruit has been picked". Do you think that they would design a restrictive air intake when builing a world class engine that has won awards? Why restrict the output with something so cheap and easy to fix? The TB is infact the "bottleneck" or restrictive factor in the intake system. Like danbuc said, dyno it before and after. That will tell the tale. Seat of the pants dyno means nothing. Post your dyno results, inquiring minds want to know.
 

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Mccalist said:
<snip>

Why do you think the northstar intake is fine? Did you design it? Did you talk to someone that did? I happen to be a mechanical engineer, and know that design is driven by many factors other than what may be important to some shmucks on the internet ten years from now.
Yeah, your'e right. The $10+ million that GM spent on designing the Northstar should have been spent on garden shears instead.

You were plainly wrong. So, if you are going to continue to comment, please make an effort to reason, rather than just state your poorly-drawn conclusions.
Had you been on this forum for more than a few weeks, you would have read, as Ranger mentioned, the numerous posts, technical articles, and exhaustive responses were were lucky to have, from a member of the Northstar Engine Development team. It was HIS reasoning, rather than any poorly drawn conclusions on my part, that I attempted to pass on. Forgive me if it offended your superior knowledge...

As has been suggested. dyno readings before and after, with all extenuating variables removed or allowed for, is the only way to measure performance gains or losses after home-grown modifications. Believe me, if your pruning shear alterations nets more than 3 HP, you'll have every Northstar owner on this forum prowling the KMart garden department.
 

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Ranger said:
The TB is infact the "bottleneck" or restrictive factor in the intake system. Like danbuc said, dyno it before and after. That will tell the tale. Seat of the pants dyno means nothing. Post your dyno results, inquiring minds want to know.
This is all very true and just to add my $0.02... Before you'all go out and buy a bigger TB... That won't help either, the first real "bottleneck" that you want to fix on the this car is the exhaust cross over pipe that goes "under and over" (or is it "over and under") the transmission. This pipe is swashed a fair bit to make it fit the tight space and provide for normal ground clearance... This is the first thing that you want to replace...

Good Luck doing it BTW... If GM engineers could have removed this bottleneck they would have done it too...
 

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Go get your new filter, the previous owner of my car did so. He only got a SES light and couldn't figure out what it was, until I bought it. The filter kept ****ing up MAF sensor....so put in your new filter and keep replacing your MAF sensor.
 

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ELDORACER said:
i have exhaust... i want so more power ... what would happen if i removed the resonator i dont know what it does ...

If you remove the resonator you will change the exhaust note of the Northstar. The resonator is designed to work best in the frequency range where the engine makes the most noise; but even if the frequency is not exactly what the resonator was tuned for, it will still produce some destructive interference -- the dimensions are calculated so that the waves reflected by the resonator help cancel out certain frequencies of sound in the exhaust. Engineers spend hours to get the desired exhaust tuning.

This may sound trivial, but compare these two exhaust tones--one has the resonator intact (only mufflers) the other one has a cat-back with no resonator, only what appears to be straight through mufflers.

Same engine...


Example 1) Mufflers replaced (chamber style muffler--Flowmaster)

http://s74.photobucket.com/albums/i269/the727kid/?action=view&current=MVI_4438.flv



Example 2) removal of resonator, as well as mufflers replaced (straight through muffler?--Boar)

http://vids.myspace.com/index.cfm?fuseaction=vids.individual&videoID=770660775&n=2&Mytoken=C19315D1-7D41-152A-2104D42533ED4CBA33658622
 

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I understand that for a given volume of air to flow through a three-dimensional space in a specified period of time, the smaller the cross-sectional area is, the faster the the air must flow. But so what? If the velocity was the key factor there would be a drinking straw coming out of the engine. The key is volume, and under a given pressure differential, during a fixed time period, more volume will enter through a large opening than a small one.

As for the northstar expert, people tend to be very defensive about their work, whether it was good or bad. I'm not saying the n* is bad, only that inlet port is.

The bottom line remains: when a gas moves through a system (the intake and cylinders), under a pressure differential (vacuum created in cylinders), into a fixed space (max volume in cylinder), over a fixed period of time (proportional to rpm), friction through the inlet will effect the volume of air entering the cylinders, because the air is compressible. Again, if you have more air, you have more oxygen, you have more combustion, and more energy released. Whether this energy is capable of making it to the wheels is obviously affected by the other systems on the car, but these can be modified as well, and it doesn't change the fact that the engine is now producing more power. This is all pretty straight forward, and it would be ludicrous for someone to blindly accept a statement that stands in stark contradiction thereto. I would appreciate comments that are directed to this line of reasoning, and not just conclusions drawn by someone whom we cannot question (ie.- no hearsay).

And again, it's not the airbox, it's the plastic intake port that sits up against the PCM box. The cross-sectional area of this thing is much smaller than that of any other component in the system. So if you think it's not a bottleneck - think again. And, just because I used a cheap tool to fix an oversight (or conscious decision made for reasons about which we can only speculate) does not discredit the physics underlying the modification.

Alas, while all the baby ducks are busy following mama-disregard-all-common-sense-duck around in the land of close-mindedness, my cadillac will be just a little bit faster than theirs.
 

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mtflight said:
hey man thats my video and its copy written and therefore i am filing suit for your illegal posting of it rofl just kidding

mtflight is right mine and the kids exhaust are completely different. he swapped in a set of flowmaster mufflers and called it a day result more refined throaty sound kinda like a vette which is what the kid wanted. mine i completely made my own exhaust from the cat back at my job at a muffler shop using 3 inch pipe back into a 2.5 inch y pipe that goes to two full boar mufflers and a set of z/28 camaro tips. result more 60's muscle rumble at idle and roar at reving kinda like (i know bad to compaire Caddy to a Ford) but a Mustang GT.
 

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Mccalist said:
I understand that for a given volume of air to flow through a three-dimensional space in a specified period of time, the smaller the cross-sectional area is, the faster the the air must flow. But so what? If the velocity was the key factor there would be a drinking straw coming out of the engine. The key is volume, and under a given pressure differential, during a fixed time period, more volume will enter through a large opening than a small one.

As for the northstar expert, people tend to be very defensive about their work, whether it was good or bad. I'm not saying the n* is bad, only that inlet port is.

The bottom line remains: when a gas moves through a system (the intake and cylinders), under a pressure differential (vacuum created in cylinders), into a fixed space (max volume in cylinder), over a fixed period of time (proportional to rpm), friction through the inlet will effect the volume of air entering the cylinders, because the air is compressible. Again, if you have more air, you have more oxygen, you have more combustion, and more energy released. Whether this energy is capable of making it to the wheels is obviously affected by the other systems on the car, but these can be modified as well, and it doesn't change the fact that the engine is now producing more power. This is all pretty straight forward, and it would be ludicrous for someone to blindly accept a statement that stands in stark contradiction thereto. I would appreciate comments that are directed to this line of reasoning, and not just conclusions drawn by someone whom we cannot question (ie.- no hearsay).

And again, it's not the airbox, it's the plastic intake port that sits up against the PCM box. The cross-sectional area of this thing is much smaller than that of any other component in the system. So if you think it's not a bottleneck - think again. And, just because I used a cheap tool to fix an oversight (or conscious decision made for reasons about which we can only speculate) does not discredit the physics underlying the modification.

Alas, while all the baby ducks are busy following mama-disregard-all-common-sense-duck around in the land of close-mindedness, my cadillac will be just a little bit faster than theirs.
Dude, you need to read this post: http://www.cadillacforums.com/forums/northstar-performance-technical-discussion/68040-k-n-intake-i-want-one.html
 

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CadillacETC1997 said:
hey man thats my video and its copy written and therefore i am filing suit for your illegal posting of it rofl just kidding

mtflight is right mine and the kids exhaust are completely different. he swapped in a set of flowmaster mufflers and called it a day result more refined throaty sound kinda like a vette which is what the kid wanted. mine i completely made my own exhaust from the cat back at my job at a muffler shop using 3 inch pipe back into a 2.5 inch y pipe that goes to two full boar mufflers and a set of z/28 camaro tips. result more 60's muscle rumble at idle and roar at reving kinda like (i know bad to compaire Caddy to a Ford) but a Mustang GT.

You did a good job. Definitely improved the exhaust flow with the bigger pipe. I was illustrating the sound difference--sounds like you said--more throaty and powerful... and very different due to the resonator.

Because I didn't copy your video and relabel it as mine or put it up on my server, but rather linked to it--you can't sue me! j/k :thumbsup:
 
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