Hey everyone!! I've done tons of research and read old threads and this is what I have come up with. My two favorite engines are the LS1 and the N*. What does everyone think? The LS1 and the N* are both really light, and thats why I'm looking at them. The LS1 has alot of torque, but won't rev like the N* will. The reason I like the LS1 is because of the avaliable power just driving down the interstate. I have never driven a car with a manual transmission LS1 or any car with a N*. I definitley want to keep my 5spd tranny becuase I'm going to be autocrossing some. Right now I'm leaning toward the LS1. Here's what I plan to do with my car (in order of importance):
1.Daily driver (occasional heavy foot coming away from a stoplight or something, but not dropping the clutch or anything)
2.Autocrossing

Any input from people who actually drive these cars would be helpful. Thanks!
--Bryson

Hi Bryson

The only two people that are going to be able to tell you about the LS1 are Orville and I. Well CrazyD almost he drove it but didn't get a chance to really drive it before it spun a rod. They are both nice swaps. The thing the nothstar has going for it is that it doesn't require an adapter plate. But the LS1 has more potential in the long run, and there are allot more after market parts for it. I believe Ben is working on a manual set up for the north star. I won't comment that much on it because I really don't know that much about it( you should contact him I bet he would help you with the info he has). Drive an LS1 z28 or TA. They drive remarkably similar. I drove my friends 99 M6 WS6 soon after she bought it and fell in love. They are extremely smooth, but so is the northstar.

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LS1 in and running :)

http://ls1swap.tripod.com/

quote Originally posted by LS1swap: Hi Bryson The only two people that are going to be able to tell you about the LS1 are Orville and I. Well CrazyD almost he drove it but didn't get a chance to really drive it before it spun a rod. They are both nice swaps. The thing the nothstar has going for it is that it doesn't require an adapter plate. But the LS1 has more potential in the long run, and there are allot more after market parts for it. I believe Ben is working on a manual set up for the north star. I won't comment that much on it because I really don't know that much about it( you should contact him I bet he would help you with the info he has). Drive an LS1 z28 or TA. They drive remarkably similar. I drove my friends 99 M6 WS6 soon after she bought it and fell in love. They are extremely smooth, but so is the northstar.

I'm doing a N* as well. Will and Ben (Artherd) are a fountain of knowledge; they both are doing N* 5 speeds and will is done. Another guy did one as well, can't think of his username. These guys have been invaluable to me. Another adavntage with the N* is that you can lave the tranny mounts where they are, whereas the LS1 you need to move them over to the left I believe. Correct me if I'm wrong on this. The LS1 is a torque monster out of the box compared to the N*, but as far as potential goes, I would beg to differ on the LS1 being the best. CHRFAB gets hundreds of HP out of them. Not only that, but since we are limited in our choice of transmissions, the ratios better serve an engine that likes to rev out as opposed to making its power at the bottom. I love the LT-1 and assume the LS-1 is a lot like it, but better. I wouldn't hesitate to do either, but the N* is more to my liking.

As for the mating of the tranny to the N*, easy as pie. Give yourself about 2 hours with a high speed and a rotary file and you'll be done. All bolts and dowels line up except 1 bolt, which misses by about an inch. You can leave it or make a block to pick it up. the drawback to the N* is that you either need to screw with an OBDI computer, or buy a 1300 CHRFAB or another system. Whereas the LS-1 computer hooks right up to my knowledge. So take you pick, just go in with about6k minimum.

I forgot about will doing the northstar... I certainly didn't know he is done. That is great! Is his the first manual northstar swap Fiero???. They are both great swaps and you couldn't go wrong with either. The trans does not need to be moved over like the LT1( no optispark ). That has been posted a few times but neither orville or I did that. the computer is simple to hook up once you get around VATs. There is also software called LS1 edit which allows you to do custom programming. Not trying to talk you into one or the other. They are both great modern swaps. He is right about the cost they are a little pricey, but if you are doing most of the work yourself you should be able to save a little on that.

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LS1 in and running :)

http://ls1swap.tripod.com/

quote Originally posted by LS1swap: I forgot about will doing the northstar... I certainly didn't know he is done. That is great! Is his the first manual northstar swap Fiero???. They are both great swaps and you couldn't go wrong with either. The trans does not need to be moved over like the LT1( no optispark ). That has been posted a few times but neither orville or I did that. the computer is simple to hook up once you get around VATs. There is also software called LS1 edit which allows you to do custom programming. Not trying to talk you into one or the other. They are both great modern swaps. He is right about the cost they are a little pricey, but if you are doing most of the work yourself you should be able to save a little on that.

I'm not sure if he's first. Another guy did one too, but I can't think of who it is. One guy went with a 2 disc clutch, the other the Centerforce.

So you don't have to move it, a major plus. The weight is negligible. The LS-1 a pushrod, N* a twin overhead cammer. They're both high reliability engines. The LS-1 is based more upon low end torque than the N*. It would be cool if someone could find or modify a tranny that has a final drive of .50 or so, so that you could utilize the LS-1's effective power band. The Pontiac Vibe has a 6 speed, but I wonder what the final drive in 6th is? I think GM will soon come out with a heavyduty 6 speed that will handle gobs of torque and have a nice final drive ratio.

The difference between driving feel between the LS1 and L37 (300 HP N*) is mostly displacement. The two engines are cammed approximately the same, the LS1 just has more displacement. The stock N* stretches its power band out a little more on the top end, however.

The LS1 is harder to put in a Fiero as it requires an adapter plate and an electric water pump (or a 2" move and custom axles).

Both engines require engine mount fabrication. I used the stock Cadillac forward mount bracket in the middle of the left bank and a custom fabbed bracket similar to the stock Caddy bracket on the right rear of the engine. I used GM polyurethane transmission mounts in these locations.

I used the stock Fiero rubber transmission mounts. I will shortly be replacing the front one with the same kind of poly mount I used for the engine and the rear one with a mount from WCF.

Both engines require a custom flywheel. For my conversion I plugged and redrilled a neutral-balance V6 flywheel. KFGroup will shortly have an aluminum flywheel available for the Northstar. For his car, LS1swap took a Fidanza flywheel and had a billet aluminum spacer machined to put the friction surface at the right location.

The LS1 waterpump is awkward in the Fiero engine compartment. It requires either a move to the left or a remotely mounted electric waterpump. The Northstar waterpump is on the rear of the engine and is driven off the back of the left bank intake cam. It fits the Fiero engine compartment just fine.

AFAIK, the LS1 doesn't require mods to the trans itself. The Northstar starter, located in the valley where the cam is in the LS1, requires some removal of the webbing in the bellhousing of whatever manual transmission you use with it. Also, the later cast throwout arm for the Getrag requires grinding the outer 1/3 or so off the cup that holds the end of the slave cylinder push rod to clear the crossover manifold that the water pump uses.

The Northstar electronics are a mess. The OBDI controls are largely unhacked, but there are a few people working on them. The '96+ OBDII controls are untouched and not practicably workable. There is a 275 HP program which has been modified to run with a manual trans. I am working on doing the same conversion with a 300 HP program. The LS1 controls are much easier with the availability of LS1 Edit.

You asked about driving it, didn't you? I have a 275 HP chip running a 300 HP engine. From chassis dyno results, I estimate about 280 at the flywheel. I'm working on a 300 HP chip, which will give more power at the top end and raise the rev limiter from 6200 to ~6700.
When I roll into the throttle in first from about 1000 RPM, the rear tires spin unless I'm on new, clean, grippy pavement and the tires are warm. I'm running (cheap) 255/50-16's on 16x8 Grand Prix wheels. Launch with more than 2500 RPM on the clock and the tires just light up. With the 275 program, the engine hits the rev limiter just when it feels like it's really stretching its legs. The extra 500 RPM the 300 HP program allows will be very welcome. I don't have track times for it yet as I'm having clutch trouble and need a transmission overhaul (third gear synchro was toast when I bought the trans ).
As I'm using a lightly modified factory program, it retains stock driveability, which will be nearly perfect when I replace the rubber trans mounts with poly. It acclerates easily from 1000 RPM in 4th gear.

Anything else?

Yea Will's here! Hey, I'm going solid with solid mounts on the engine and trans, and poly bushings on the cradle; will this vibrate like a SOB? Also, what is 1st gear at redline doing (MPH)? What clutch are you running, the CF right? What clutch problems are you having? Thanks Will....

I did it the other way around: poly engine mounts and aluminum cradle bushings. When I first start it it's smooth as glass. Once it warms up I start having idle quality problems, I think because of a vacuum leak I haven't found yet. It's amusing that the open loop system maintains a better idle quality than the closed loop system. How hard is it to maintain a 750 RPM idle, anyway? If I were THAT concerned with vibration, I would have gone with the Cadillac engine mounts.

I'm using the Archie/Centerforce clutch. It's great. It has the same streetability as the stock clutch but hangs onto the Northstar just fine. I gooned up the installation. I don't remember exactly, but I think I put flat washers under the heads of the flywheel bolts without checking for clearance to the hub springs. As a result there's some drag even when the clutch is fully disengaged. This prevents proper shifting. On the upside I'm the king of clutchless shifting.

1st gear at 6200 is around 33 mph.

quote Originally posted by Will: I did it the other way around: poly engine mounts and aluminum cradle bushings. When I first start it it's smooth as glass. Once it warms up I start having idle quality problems, I think because of a vacuum leak I haven't found yet. It's amusing that the open loop system maintains a better idle quality than the closed loop system. How hard is it to maintain a 750 RPM idle, anyway? If I were THAT concerned with vibration, I would have gone with the Cadillac engine mounts. I'm using the Archie/Centerforce clutch. It's great. It has the same streetability as the stock clutch but hangs onto the Northstar just fine. I gooned up the installation. I don't remember exactly, but I think I put flat washers under the heads of the flywheel bolts without checking for clearance to the hub springs. As a result there's some drag even when the clutch is fully disengaged. This prevents proper shifting. On the upside I'm the king of clutchless shifting. 1st gear at 6200 is around 33 mph.

You're using the OBDI computer, correct? So your idling problems are related to that do you think? Ya, it's better to go solid with the cradle, that way it stays more rigid for the rear suspension. I haven't fabbed the mounts yet, so I can go rubber, but I was thinking it would be better for clearance and easier to go solid. I'm using the 201502 clutch as well. Glad to hear it works well. So you placed washers under the flywheel bolts? Probably to distribute the stress from the plugs and new holes, right? So what is dragging, the clutch disc on the bolt heads? Or maybe the clutch springs? Is it noisy as well? Do you know of anyone else that has a running N* with solids? I know Ben is running solids and says there is little clearance, so it might be detrimental to use rubber due to the shift. Apparently you have no problem. What is your aft clearance? Thanks for all the help Will.

Why should idle problems be related to an OBDI computer?

It has the symptoms of a vacuum leak. wcapman on this forum got this chip originally and it's been running fine for him for a long time. I'm running a copy of his chip.

wcapman's also running solid mounts.

I haven't taken the clutch apart yet, so I'm not sure what the problem is, but I think it's drag between the springs and the bolt heads. No noise.

I made a new forward cradle Xmember moved forward a couple of inches. With the Northstar in the 2.8 location the oil level sensor plug interferes with the stock forward Xmember. Maybe using an Aurora oil pan could fix that, since the Aurora doesn't use an oil level sensor. I'm not sure since I've never seen an Aurora pan. The N* oil filter adapter also interferes with the stock forward cradle Xmember. A remote oil filter adapter like CHRFab sells could be used to get around this and use the stock Xmember.
Things are tight, but the engine doesn't move in such a way as to hit anything.

quote Originally posted by Will: Why should idle problems be related to an OBDI computer? It has the symptoms of a vacuum leak. wcapman on this forum got this chip originally and it's been running fine for him for a long time. I'm running a copy of his chip. wcapman's also running solid mounts. I haven't taken the clutch apart yet, so I'm not sure what the problem is, but I think it's drag between the springs and the bolt heads. No noise. I made a new forward cradle Xmember moved forward a couple of inches. With the Northstar in the 2.8 location the oil level sensor plug interferes with the stock forward Xmember. Maybe using an Aurora oil pan could fix that, since the Aurora doesn't use an oil level sensor. I'm not sure since I've never seen an Aurora pan. The N* oil filter adapter also interferes with the stock forward cradle Xmember. A remote oil filter adapter like CHRFab sells could be used to get around this and use the stock Xmember. Things are tight, but the engine doesn't move in such a way as to hit anything.

I heard that it can be a pain to eliminate all the gremlins with the OBDI, so I just figured it might be the problem.

How's the vibes for wcapman, has he told you about any problems?

Ya, I have already done that with the fwd crossmember too, at your advice and Ben's. Then I boxed in the stub that remained where the fwd tranny mount goes. I then ran a section of rectangular box in-between the stub and the new crossmemeber for added support. What I was referring to was the aft row of cylinders hitting the truck firewall. Ben said his comes about 1/4" away, and I thought that if you had solid mounts the engine might contact it upon torque reaction. Just asking a bunch of dumb questions so as I get further into this I won't make errors and will go the way I need to. Thanks again, Ed.

I am going with the CF DF too, so I will be sure to check all that when I finally get together with it.

I have an inch or better between my aft cylinder head and the trunk wall. Just measure carefully where the end of the 2.8 crankshaft is (fore/aft and up/down anyway) and put the end of the N* crankshaft in the same spot. I have an '87 and he has an '88 so there may be some slight differences there. I know on an '88 that a 2" move to the left is required, unless you want to go to coil overs and do surgery on the right strut tower.

quote Originally posted by Will: I have an inch or better between my aft cylinder head and the trunk wall. Just measure carefully where the end of the 2.8 crankshaft is (fore/aft and up/down anyway) and put the end of the N* crankshaft in the same spot. I have an '87 and he has an '88 so there may be some slight differences there. I know on an '88 that a 2" move to the left is required, unless you want to go to coil overs and do surgery on the right strut tower.

"Just measure carefully where the end of the 2.8 crankshaft is (fore/aft and up/down anyway) and put the end of the N* crankshaft in the same spot."

Ya, that's what I had in mind, thanks for the confirmation. Maybe Ben has his 3/4" aft of that. Or maybe, like you said, the 88's are diff. I have an 87, so your news is welcome.

"I know on an '88 that a 2" move to the left is required, unless you want to go to coil overs and do surgery on the right strut tower."

Oh really, I did not know that. Why is that, is the 88's 2.8 located 2" to the right in stock form? Or are the struts different? Great to get all this info from someone with experience, hope all the other kids are taking note .

quote Originally posted by I'm Back: Oh really, I did not know that. Why is that, is the 88's 2.8 located 2" to the right in stock form? Or are the struts different? Great to get all this info from someone with experience, hope all the other kids are taking note .

The '88 strut towers are 1 1/2" closer together than the '87 strut towers. That means that each tower is 3/4" closer to the center of the car. I have something less than 1/2" between the right strut tower and the aft cam cover. Since the engine only moves fore/aft in reaction to torque, this particular clearance isn't an issue, as long as it clears.

I guess you wouldn't have to move it 2". A 1" move would do fine.

The 2.8 doesn't care because it's a much smaller enginer externally. You don't have an appreciation for the way this engine fills the engine bay until you see it sitting there. I call it a perfect fit. It certainly should have been done by the factory, had the Fiero been around in '93.

quote Originally posted by Will: The '88 strut towers are 1 1/2" closer together than the '87 strut towers. That means that each tower is 3/4" closer to the center of the car. I have something less than 1/2" between the right strut tower and the aft cam cover. Since the engine only moves fore/aft in reaction to torque, this particular clearance isn't an issue, as long as it clears. I guess you wouldn't have to move it 2". A 1" move would do fine. The 2.8 doesn't care because it's a much smaller enginer externally. You don't have an appreciation for the way this engine fills the engine bay until you see it sitting there. I call it a perfect fit. It certainly should have been done by the factory, had the Fiero been around in '93.

OH, I didn't realize the left/right was almost an issue and is and issue w/the 88's. You know how the tranny mounts are slotted? Should I move the engine/trans assy to either extreme in that slot, or should I install both axles in the trans, and install the rear spindles in the ball joints to let that establish the placement within the slots? I'm thinking the latter, but I'll bet you know. Thanks Will.

Ya, that would be hot to have a stock N* Fiero. As someone has alluded to, it wouldn't happen because it would embarrass the F bodies and challenge Corvettes.

has anyone ever done a 4.3 N* with a paxton supercharger? I want to eventually do a swap, and my uncle (a car god) keeps telling me thats what i should use if i were to ever swap. where can i find lots of info about swaps and everything? Are there any links that would be useful? or should i just seach the forum.

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Red 86 SE 2.8

Rate me if I've helped or just if you liked my responce.

Who's doing the Northstar swap with an automatic transmission if I want to have it done?

4.3? What's a 4.3?

I think belt driven centrifugal superchargers are useless.

quote Originally posted by Will: 4.3? What's a 4.3? I think belt driven centrifugal superchargers are useless.

Ya, WTF is a 4.3 N*. The N* is 4.6

GM makes a 4.3 V-6, but I don't know that it comes with a SC. The 3.8 comes with a SC on select vehicles. Please elaborate on your engine info and gurus like Will and Ben will help ya out.

quote Originally posted by bryson: The LS1 has alot of torque, but won't rev like the N* will.

I understand that you haven't driven an LS1 ever before, so it's understandable you might think this, but it simply is not true. I've owned an LS1 car from almost the moment they were available five years ago, and I can assure you that it is indeed a revver; it is not a low-torque-monster like its LT1 and L98 predecessors by any means. Its torque increases progressively with RPMs and was designed that way to make more power. It just revs to 6000 instead of 7000 because of its pushrod valvetrain.

Now listen carefully to what I'm about to say, because everything after this paragraph builds upon it: Torque times RPM equals power. When an engine makes torque above 5252rpm, it makes more power than torque even if the torque stays the same as the RPM increases. Now read it again.

What the LS1 does is make 45 more horsepower than the N* with 1000 less rpms. It does this with greater displacement and more torque across the entire RPM band.

Put in practical terms, if the LS1 made the same torque at 7000rpm that it does at 6000rpm (about 300 ft-lbs), it would make 400hp. Yet the Northstar makes 300hp at 7000rpm, so it does this with about 225 ft-lbs.

What does this mean in everyday terms? The LS1 is more fun, more powerful, and has more usable torque than a Northstar in everyday driving. It doesn't have to be wound to 7k to get its max power, because it also makes more torque than a Northstar at lower RPMs. It does all this in spite of having one cam instead of four, sixteen valves instead of thirty-two, one timing chain instead of....

Both engines are tough installs in a Fiero for sure, especially with a manual trans. I ultimately did not go with an LS1 in my car for lots of reasons, but I am still one of the biggest LS1 fanatics you'll ever meet. It is a marvelous engine any way you look at it, but especially when you look at it with a trained eye.

Dave

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In a desperate attempt to find out all I can about the northstar, and possible modifications, I found this. It's talking about a N* that is 4.2L not 4.3L but it is supercharged, but it says Evoq, nothing about Paxton. Not to mention it's not in production yet if ever.

"Future Northstar? Here is the write-up for the Evoq Supercharged Northstar:
The 4.2-liter, 32-valve V8 features a supercharger with an intercooler, and variable valve timing (VVT) with a new low-friction valvetrain that combine to provide considerable power output, producing 405 bhp (302 kW) at 6400 rpm and 385 lb.-ft. (522 Nm) of torque at 4000 rpm. This impressive performance is accomplished in a relatively small displacement and in an environmentally conscious package. The supercharger assembly is a compact, totally integrated unit with the intake manifold, intercooler and rotor housing," said Roxann Bittner, GM Powertrain senior designer and member of the Evoq engine project team. "This configuration provides the increased airflow that produces 'power-on-demand' while allowing the engine to deliver impressive fuel economy during normal driving."

quote [B]Originally posted by crazyd:[/B I understand that you haven't driven an LS1 ever before, so it's understandable you might think this, but it simply is not true. I've owned an LS1 car from almost the moment they were available five years ago, and I can assure you that it is indeed a revver; it is not a low-torque-monster like its LT1 and L98 predecessors by any means. Its torque increases progressively with RPMs and was designed that way to make more power. It just revs to 6000 instead of 7000 because of its pushrod valvetrain. What the LS1 does is make 45 more horsepower than the N* with 1000 less rpms. It does this with greater displacement and more torque across the entire RPM band. Put in practical terms, if the LS1 made the same torque at 7000rpm that it does at 6000rpm (about 300 ft-lbs), it would make 400hp. Yet the Northstar makes 300hp at 7000rpm, so it does this with about 225 ft-lbs. What does this mean in everyday terms? The LS1 is more fun, more powerful, and has more usable torque than a Northstar in everyday driving. It doesn't have to be wound to 7k to get its max power, because it also makes more torque than a Northstar at lower RPMs. It does all this in spite of having one cam instead of four, sixteen valves instead of thirty-two, one timing chain instead of.... Both engines are tough installs in a Fiero for sure, especially with a manual trans. I ultimately did not go with an LS1 in my car for lots of reasons, but I am still one of the biggest LS1 fanatics you'll ever meet. It is a marvelous engine any way you look at it, but especially when you look at it with a trained eye. Dave

"Now listen carefully to what I'm about to say, because everything after this paragraph builds upon it: Torque times RPM equals power. When an engine makes torque above 5252rpm, it makes more power than torque even if the torque stays the same as the RPM increases. Now read it again. "

So with the N*, you can cam it up with springs for $800 and go to about 8,000 rpm, Ben should know for sure. I realize you can put $800 into the LS-1 and get performance out of it as well, but not like that.

"The LS1 is more fun, more powerful, and has more usable torque than a Northstar in everyday driving."

Well, since we're both going off speculation, since neither of us have our V-8 Fieros together, the "more fun" contention is speculative and subjective. The, "more powerful" assertion is too general. The, "more usable torque" contention is dependent upon available gearing, which most favors the N*. And the, "everyday driving" statement assumes you're not racing on weekends and that you're driving it everyday, not to mention that driveability is yet to be determned by you or I.

"Both engines are tough installs in a Fiero for sure, especially with a manual trans. I ultimately did not go with an LS1 in my car for lots of reasons, but I am still one of the biggest LS1 fanatics you'll ever meet. It is a marvelous engine any way you look at it, but especially when you look at it with a trained eye."

More tough than a 3.4 pushrod, but the N* is not that tough. I believe that the N* is much easier than the LS-1, but that is just what I read. Actually, the N* is easier with the manual than with the N* automatic (4T80E). You use the original tranny points and fab your own engine mount points. The tranny takes about 4 hours to mate. You can use the original shafts as well, but it would be nice to upgrade. We can agree that the LS-1 is a fantastic motor. I think the N* is better for the Fiero based upon the available gearing. Per Will, the N* does 33mph in 1st gear @ 6200rpm. With that, the LS-1 would do about 25mph, which makes the short gearing a detriment to the LS-1 toruqe. With the N*, put cams and springs in and run 1st out to maybe 45mph @ 8,000rpm. That's what I mean by the available trannies favoring the N*. If GM makes a 6 speed FWD tranny with a .60 or better final drive, the LS-1 will definately move up the list.

Truth be told, we can banter about all the pros and cons of each engine till we're blue in the face. I would love for guys with each engine intheir car to run a drag strip and a road course. They could run head-to-head, or run the same track and get time slips, but I would love to read about it.

quote Originally posted by crazyd: I understand that you haven't driven an LS1 ever before, so it's understandable you might think this, but it simply is not true. I've owned an LS1 car from almost the moment they were available five years ago, and I can assure you that it is indeed a revver; it is not a low-torque-monster like its LT1 and L98 predecessors by any means. Its torque increases progressively with RPMs and was designed that way to make more power. It just revs to 6000 instead of 7000 because of its pushrod valvetrain. Now listen carefully to what I'm about to say, because everything after this paragraph builds upon it: Torque times RPM equals power. When an engine makes torque above 5252rpm, it makes more power than torque even if the torque stays the same as the RPM increases. Now read it again. What the LS1 does is make 45 more horsepower than the N* with 1000 less rpms. It does this with greater displacement and more torque across the entire RPM band. Put in practical terms, if the LS1 made the same torque at 7000rpm that it does at 6000rpm (about 300 ft-lbs), it would make 400hp. Yet the Northstar makes 300hp at 7000rpm, so it does this with about 225 ft-lbs. What does this mean in everyday terms? The LS1 is more fun, more powerful, and has more usable torque than a Northstar in everyday driving. It doesn't have to be wound to 7k to get its max power, because it also makes more torque than a Northstar at lower RPMs. It does all this in spite of having one cam instead of four, sixteen valves instead of thirty-two, one timing chain instead of.... Both engines are tough installs in a Fiero for sure, especially with a manual trans. I ultimately did not go with an LS1 in my car for lots of reasons, but I am still one of the biggest LS1 fanatics you'll ever meet. It is a marvelous engine any way you look at it, but especially when you look at it with a trained eye. Dave

I agree that the LS1 is an awesome revvy engine that makes 45 more horsepower than the stock N*. But I just want to clarify some things. I would have to agree with Will about the biggest difference being the displacement. Let's compare the engines!

Horsepower:
300 @ 6000 rpm (N*L37)
275 @ 5600 rpm (N*LD8)
345 @ 5600 rpm (LS1)

Torque:
295 @ 4400 rpm (N*L37)
300 @ 4000 rpm (N*LD8)
350 @ 4400 rpm (LS1)

Redline:
6700 rpm? (N*L37)
6200 rpm? (N*LD8)
6000 rpm (LS1)

Displacement:
4565cc~4.6L (N*L37)
4565cc~4.6L (N*LD8)
5666cc~5.7L (LS1)

I'm not sure about the N* redlines, I just used some numbers Will posted. Let me know if I misinterpreted something when reading those, Will.

Okay, here's basically what I am having a problem with:

quote Originally posted by crazyd: Put in practical terms, if the LS1 made the same torque at 7000rpm that it does at 6000rpm (about 300 ft-lbs), it would make 400hp. Yet the Northstar makes 300hp at 7000rpm, so it does this with about 225 ft-lbs.

First of all, the L37 northstar makes it's peak power at 6000rpm, not 7. The N*'s redline isn't even 7000rpm either. In fact, if the N* did rev to 7000rpm it wouldn't even be making 225ft/lbs of torque, because it doesn't make 300hp at it's redline; it makes 300hp at 6000rpm, and slightly less than that at redline. The LS1 doesn't make 345hp at 6000 rpm either; it makes 345hp at 5600rpm. You have to take into account how each engine is cammed and where it makes its power. I don't believe comparing redlines is fair, since they don't really determine anything but how far you can rev the engine before it breaks. Sometimes redlines don't even represent THAT!

It makes some sense to compare the LD8 too, because the LS1 and LD8 both make their PEAK hp at the same rpm, 5600.

There are different ways to look at or calculate this, but all mean basically the same thing.

So, lets take the peak hp and divide by the displacement to get horsepower per liter:

L37- 300hp/4.565L = 65.72hp/L
LD8- 275hp/4.565L = 60.24hp/L
LS1- 345hp/5.666L = 60.89hp/L

Now since the LD8 and LS1 make their peak hp at the engine speed, the they would also make an equal ratio of torque per liter at 5600 rpm. I've never actually heard anyone use torque per liter, but it seems relevant. Now actually at their peak torque, the N* makes MORE Tq/L. The LS1 makes it's peak torque at 4400rpm, the LD8 makes it's peak torque at 4000rpm, which may mean that it's cammed lower, but stretches out it's power band because of it's 32valve OHC design. And the L37 and LS1 both make their peak torque at 4400rpm, hence Will saying they were actually cammed similarly, that the LS1 had more displacement, and the N*(L37) stretches out it's power band a little more.

So you see why I agree with Will saying the biggest difference is displacement.

I think the LS1 and N* are both GREAT engines and either would be awesome in a fiero.

Man, I didn’t know what I was getting into when I started this post. BUT Will(obviously my hero, nay... the wind beneath my wings <wiping away a tear of happiness> ) couldn’t have said it better himself(actually he probably could have) . But I wasted my time instead of his valuable time.

Please correct me if I’m wrong on anything, people. Sorry it was such a long post. I hope it makes sense, I tend to ramble and repeat myself often.

[This message has been edited by Borgio (edited 11-15-2002).]

Nice reply Borgio . Ya, I agree with all that except one thing:

"I don't believe comparing redlines is fair, since they don't really determine anything but how far you can rev the engine before it breaks. Sometimes redlines don't even represent THAT!"

They (redlines) determine shift points though. And with the limited standard trannies that can be used with the Fiero, gearing is preestablished so the only thing we have to work with is the engine. I bet the LS-1 Fiero runs out quickly, but I would love to ride in one . They're both great engines in every way though......gotta give GM props for doing them both.

quote Originally posted by I'm Back: Nice reply Borgio . Ya, I agree with all that except one thing: "I don't believe comparing redlines is fair, since they don't really determine anything but how far you can rev the engine before it breaks. Sometimes redlines don't even represent THAT!" They (redlines) determine shift points though. And with the limited standard trannies that can be used with the Fiero, gearing is preestablished so the only thing we have to work with is the engine. I bet the LS-1 Fiero runs out quickly, but I would love to ride in one . They're both great engines in every way though......gotta give GM props for doing them both.

Agreed My point in saying that was that true redlines(engine speed limits)have nothing to do with where you get your power. But you are absolutely correct. Not only do the getrag gear ratios fit the N* well, but also, an LS1's redline is so close to it's peak power that it may actually drop further down in it's power band than would be best, not fully benefiting from where it's powerband would otherwise end. I'm in NO WAY dissing the LS1 fiero. Just comparing engine factors and limits and such.

quote Originally posted by I'm Back: Nice reply Borgio .

Thanks, did you like the part where I was crying because I was so happy?

[This message has been edited by Borgio (edited 11-15-2002).]

Hey everyone,
Thanks for all the information. It's helped me a lot in my decision. I think I will go with the LS1 simply becuase fo the resources open to me. As far as the N* goes, does anyone around Charleston SC have one I could possibly get a ride in? I understand torque/hp/rpm a little better now. Thanks again,
--Bryson

[This message has been edited by bryson (edited 11-15-2002).]

Thanks for clarifying the specifics on the RPMs for peak torque & HP numbers on the two engines, you're right I was way off. I'll take a look at it again later tonight when I have more time.

Dave

"Thanks, did you like the part where I was crying because I was so happy?"

Ya, I know the feeling everytime I look in my garage .

quote Originally posted by Borgio: Please correct me if I’m wrong on anything, people. Sorry it was such a long post. I hope it makes sense, I tend to ramble and repeat myself often.

Thanks. I was beginning to think I was the only one who could look up specs on www.gmpowertrain.com

Here's one I like, that illustrates popular misinformation:

LS1:
Peak power: 5600
Peak torque: 4400
Power band: 1200 RPM

L37:
Peak power: 6000
Peak torque: 4400
Power band: 1600 RPM

The popular conception is that the LS1 is a torquey engine, while the Northstar is a revvy, peaky engine, while the truth is exactly the opposite.

I like thinking about ftlbs/litre (specific torque) because it much better illustrates the quality of cylinder head design and camshaft matching than specific power, which is easily distorted by RPM.

I typed up a bunch of junk about why I like the N*, but I decided that I didn't want to send this thread further into bench racing than it currently is.

Okay, I went back and re-read all the specs, and I realize now why I made that mistake. I was mixing up the LT5 (ZR-1) engine with the Northstar L37 (from which it was derived) in thinking that it revved to 7000rpm. I don't like making goofs like that, but I'm also mature enough to admit when I'm wrong.

So let me restate what I misstated previously based on the correct figures. It means that from max torque to max power (4400-6000rpm), the L37 Northstar goes from 295 down to 262 ft-lbs. The LS1, from max torque to max power (4400-5600rpm), goes from 350 down to 324 ft-lbs. It can also be shown that it makes more torque than a Northstar at every other point in the rev range. Assuming they both weigh about the same except that the Northstar is top-heavy and the LS1 is bottom-heavy, which would you really rather have?

Will, you are mistaken in saying that the LS1 is peaky. Its torque curve is smooth and progressive, with little deviation from its median. And specific output, whether torque or horsepower, is the most meaningless value ever conceived in the context of engine power. It's only important to guys who have mini-displacement engines that have nothing else to brag about when they get their butts kicked by a larger-displacement engine. Far more important is how much power an engine makes for its overall physical mass and volume.

Somewhere I have the dyno of my Corvette which shows it puts more torque to the wheels than the Northstar ever does at the flywheel.

I have driven a Northstar in a '93 Eldo, and it's a nice engine. But it's no LS1.

Dave

quote Originally posted by crazyd: Okay, I went back and re-read all the specs, and I realize now why I made that mistake. I was mixing up the LT5 (ZR-1) engine with the Northstar L37 (from which it was derived) in thinking that it revved to 7000rpm. I don't like making goofs like that, but I'm also mature enough to admit when I'm wrong. So let me restate what I misstated previously based on the correct figures. It means that from max torque to max power (4400-6000rpm), the L37 Northstar goes from 295 down to 262 ft-lbs. The LS1, from max torque to max power (4400-5600rpm), goes from 350 down to 324 ft-lbs. It can also be shown that it makes more torque than a Northstar at every other point in the rev range. Assuming they both weigh about the same except that the Northstar is top-heavy and the LS1 is bottom-heavy, which would you really rather have? Will, you are mistaken in saying that the LS1 is peaky. Its torque curve is smooth and progressive, with little deviation from its median. And specific output, whether torque or horsepower, is the most meaningless value ever conceived in the context of engine power. It's only important to guys who have mini-displacement engines that have nothing else to brag about when they get their butts kicked by a larger-displacement engine. Far more important is how much power an engine makes for its overall physical mass and volume. Somewhere I have the dyno of my Corvette which shows it puts more torque to the wheels than the Northstar ever does at the flywheel. I have driven a Northstar in a '93 Eldo, and it's a nice engine. But it's no LS1. Dave

"Assuming they both weigh about the same except that the Northstar is top-heavy and the LS1 is bottom-heavy, which would you really rather have?"

I'm installing mine upside down to reverse the weight distribution, so there . Isn't that kind of negligible? I imagine the N* is a bit lighter. What weights are you contending at what points in the engines, from top to bottom? Besides, how much does the adapter plate weigh?

"And specific output, whether torque or horsepower, is the most meaningless value ever conceived in the context of engine power. It's only important to guys who have mini-displacement engines that have nothing else to brag about when they get their butts kicked by a larger-displacement engine."

And what rationale do guys with bigger displacement engines use when they get beat by guys with smaller displacement engines? I agree that the totality of the engine's output, from idle to redline is far more important than one obscure point, although I don't see where Will was alluding to that. The old, 'There's no replacement for displacement' rhetoric is antique. Ever see an RGV250 beat a bored GSXR1100 on a nationals road course? I have. There's no question that the LS-1 is agreat motor, but it has it's limitations and undesireable attributes. With a front engine, non-transverse, rear wheel drive car I would prefer the LS-1. But with the Fiero and available trannies, I think the N* is the best choice. HP and torque is one issue, and driveability is quite another. What are your rpm based shifting speeds with both engines? I would guess:

LS-1 -
1. 25
2. 45
3. 65
4. 90
5. xx

N* -
1. 33
2. 55
3. 80
4. 105
5. xx

N* with better springs (8k redline)
1. 45
2. 70
3. 95
4. 120
5. xx

These are just educated guesses, it would be cool if someone that is math competent would mathematically figure these out.

If I had an old El Camino and was going to throw an engine in it, I would go with the LS-1. But with the Fiero and available trannies, I like the N*. There is no such thing as the best overall engine or vehicle for all occasions.

"Somewhere I have the dyno of my Corvette which shows it puts more torque to the wheels than the Northstar ever does at the flywheel."

Note to self: Scratch plans of installing N* into Fiero. I agree, the N* isn't the best engine for a heavy, rear wheel drive car in many circumstances.

"I have driven a Northstar in a '93 Eldo, and it's a nice engine. But it's no LS1."

The Eldo is no Vette either; apples and oranges. Scientifically the best way to distinguish one element over another is to remove all variables except one, and this is called the independent variable. The I.V.'s in this case are the LS-1 and the N*. The best way to establish superiority would be to install each engine in like cars with like transmissions and test them. Test them in all kinds of conditions to establish a variety of strengths and weaknesses. I'm all for that.

Oh boy....

crazyd,

Common misperception is that the LS1 is a low RPM engine like its predecessors. It's not. You said so. I said so. I'm just amusing myself playing with numbers. Don't get your panties in a bunch about LS1 dominance.

Of course the LS1 puts more torque to the wheels than the Northstar makes at the flywheel. It's 24% bigger than the N* and doesn't have 24% driveline loss.

Yeah, more power wins the race. More specfic torque makes any engine more driveable and produces more power from the same displacement without increasing RPM or adding forced induction. It's important from a design standpoint. BMW's 3.2L M3 engine could easily be made to produce 315 HP at ~8500 RPM instead of ~7500, but it's a lot more driveable with ~82 ftlbs/litre than it would be with an LS1 like 65. That's a testament to quality cylinder head design. You've probably read my opinion of GM's developmental V12 which everyone hails as a much better engine than it actually is.

I'm through with this "debate". I'm only going to reply to technical or driving experience questions about the N* conversion.

[This message has been edited by Will (edited 11-15-2002).]

Wowwy! Is 9k rpm with the upgraded springs? That's shweeeet, 135 in 3rd. You would never leave 3rd gear in the 1/4, which means fewer shifts, which means less time lost between shifts. So the 6200 times are obviously experienced through actually driving the car, not just bench racing, which is what we need more of. Can't wait to get mine together, may be a while longer.

[This message has been edited by I'm Back (edited 11-16-2002).]

I honestly think you could not go wrong with either choice. I think it might take more than springs to get a northstar to 9K. I would think you would at least need lighter pistons. (I have no knowledge to back this up just my thinking) the difference between 7K and 9K is a bigger leap than it sounds Besides that I would hate to see my clutch disk go that fast. What is the stroke on the N*??? Maybe it can.... I could be wrong, but it would have to be pretty short.

But like will said the point is kind of mute. I don't plan to ever hit the rev limmiter in fifth

------------------
LS1 in and running :)

http://ls1swap.tripod.com/

Alan Johnson of www.CHRFab.com supposedly winds stock short blocks with worked cylinder heads beyond 9000 RPM. Obviously a specialized clutch and flywheel are required for that sort of RPM. The Northstar has a stronger bottom end than any production small block, including the LS1.

[This message has been edited by Will (edited 11-16-2002).]

I am not that familiar with the north star... What makes its bottom end so strong. Not starting a debate, but I doubt it would be stronger than an LS1. They have six bolt mains, and powder metal rods. It would have to have a steel crank, and a set of H-beam rods to be stronger. Maybe equal (I don't know) but stronger I doubt it.

The Northstar doesn't have main caps. It has a one piece lower crank case held on by 20 bolts. It's up on a stud girdle straight from the factory. <'99 they used powdered metal rods and a cast crank. For >'00 they went to forged crank and rods.