Important: Improvements on Saturn Alternator Swap

[kicker91laser]

Great info Glenn. There is a thread over on the dsmlink forums about the Saturn alt swap, some of those guys were going with the self-exciting armature and not having good luck with it, looks like the self-exciting armature may be the problem.

 

[turboglenn]

Yea, the reason the wiring is not vital is because there's several ways to excite the alt externally and then it's also internally exciting, so it will always produce a charge, just how good of one depends on how you do the wiring on the install and if you really do any.. I have been told that you can attach just one wire to the battery and it will charge on it's own, but again, just not to the level required by factory engineers, but good enough for the average backyard mechanic who wants a good alt that can be run on many different apps. and even as a one-wire unit.

 

[talondsp1]

This is great info Glenn!! I am the one who started putting these Saturn Alts on our cars. I had great results with them wired up like they are in the Saturn, so I never looked into what the other pins did.

This will really help stabilize the voltage under load, by running the S wire to a spot that sees a drop. (like you stated)

I am glad you looked up this info, now we can get the full potential out of these great alternators.

 

[turboglenn]

Cool, I'm glad you didn't take my thread as an "i'm right, he's wrong" type of thing because it was totally and only meant ot add on to a great idea!

I'm glad some one put in the leg work on the physical side of things to find one that worked on our cars and would have correct enough mounts and the pully of the right type and in-line enough to use right out of the box! I had just come to terms with the fact that i will replace the Alternator, and both the clutch master and slave cylinders once every 2.5 - 3 years

The main thing that prompted me into googling this was the fact that after the GM alternator install i was pleased as could be until i went out that night with the headlights, A/C on high, radio turned up and holding the brake with the turn signal on, and then i saw the tach start jumping with the turn signal and was almost en-raged at my car swearing i was going to have to re-wire the entire thing or remove my CDI box at night in order to be able to run my car with my creature comforts on again

Then, thankfully after hours of reading online and calling many alternator shops and picking their brains did i get a better understanding of the alt and what i needed to try and do with it. I found a lot of write-ups on jeep forums where they were using the "L" and "S" only with great results but couldn't figuyre out why they DIDN"T use the "F" wire, so again i went to calling places and talking with people and then i hit the jackpot with this old boy cooter john jack (or one of his kin) and got schooled on the chevy alts dating from 1929 until now. I started telling him what i was bothered with and he would argue about somethign i didn't even say (clearly a communication break down from a generation gap in general sentence structure and modern wording of thought) . I told him how i had the car wired and then i was asked "well, why you got the field and dummy light wires hooked up?" *Strong southern accent* to which i only exclaimed "cause that's how i read to do it!"and so after about 30-40 minutes of this guy's jibberish ramblin's bout the south and her beauty, old glory, and CS alternators i had enough info to start playing with wires and a voltmeter until i learned i could almost "re-set" my voltage levels with a variance in the resistance to the alt's best source of self monitoring.

Well, that got long, there were cops here for a bit asking who owned the car with out of state plates and why he was here (I have an employee that drives up here from st. joseph to work for a few weeks at a time), my best damn employee too! and i have neighbors that have to call in every parking violation they can find (nothing better to do)

Glenn

anyway, good night fellas.... lets talk more alts tomorrow

This is great info Glenn!! I am the one who started putting these Saturn Alts on our cars. I had great results with them wired up like they are in the Saturn, so I never looked into what the other pins did.

This will really help stabilize the voltage under load, by running the S wire to a spot that sees a drop. (like you stated)

I am glad you looked up this info, now we can get the full potential out of these great alternators.

 

[ApexVIII]

I rewired mine; I ran a 4ga from the alternator to the fuse box, leaving the 2 stock 8 gauge wires, also ran an 8 gauge ground to the battery ground

I am getting 14.3v charging at idle, acc running.

With the lights on I am getting about 14.1-14.3v at idle

If I turn the AC on low with the headlights on then I get about 13.8v at idle

If I run the AC on max and the headlights on I am at about 12.5-12.6 where before any rewire I was seeing 11.8-11.9 with them both on high.

 

[turboglenn]

Those are some pretty good numbers at idle.. The more i test on mine i think that our pulleys and drive system might be geared to have the alt spinning a little too slow at idle. I've noticed a drop still at an 800 - 900 RPM idle, but if i raise the idle to 1100/1200 range then i get a full charge at idle with a minumum voltage of 13.8 - 13.9 with everything on, where if i go with the lower idle under your same scenario of lights, AC etc.. I can only get between 12.7 and 13volts, but that's still good enough for me.

This alt swap still has to be one of the best mods i've ever done to this car. Everything performs so much better with the proper voltage levels :yeah: Fuel pumps pump bettter, injectors open faster, and the spark seems to be more consistant. My big-time happiness is the injector/fuel pump gains I was able to drop a LOT of injector pulse off of almost my entire fuel map. The cruising areas were still close but idle and high RPM areas gained a respectable chunk of extra fuel that was very pleasing to have after going with 1000cc injectors and dual wally 255's in search of enough E85 flow to support my turbo, now i no longer am in the 100% IDC range at any boost level or RPM, the highest i spike right now is 91% at 31psi and 5000RPM, then after that, due to VE the fuel needs diminish slowly after 5500 on up to 8500 leaving me some room to work with on airflow improvements again . I totally blame voltage shortages on a lot of past tuning issues that i was constantly battling.

I always wondered why my car just didn't seem to pull wel above 7500 RPM compared to other DSM'si have worked on with similar mods. But, with no other changes than the alternator and it's wiring and then pulling all the extra fuel out of the tune my car revs to the moon without even flinching.

Usually when i loose all traction in 2nd or 3rd the engine would rev to about 7500 and float there until the car caught up (I had always assumed valve train issues even with the BC springs) but now she flies up to 8500 - 9k like it's nothing and the other night as i posted somewhere on here, I hit my 9500RPM rev limiter = WOW My eyes about popped out of my head and i had an awefull fear that something was hurt based on it never wanting to go past 8k previously

 

[My1GLaser]

Should I find a slightly smaller 4 rib pulley and run it?

My car felt like it pulled better above 7000 after I just ran the S wire the other day. The car def has more spunk now. I haven't even driven it yet since running the 4ga power wire. It too damn hot!

 

[turboglenn]

Should I find a slightly smaller 4 rib pulley and run it?

My car felt like it pulled better above 7000 after I just ran the S wire the other day. The car def has more spunk now. I haven't even driven it yet since running the 4ga power wire. It to damn hot!

If you found one that would bolt up, stay aligned correctly and is a tad smaller that would probably be the most ideal way to go. Although the mod is just fine as it stands, everything can be impoved upon. Talondsp1 came up with the idea and mounted the first saturn alt to a DSM then wrote tutorial on how to do it for us all....Then I came up with this little additional wiring info that improves the function. Now, maybe, it's your turn to come up with the ultiamte pulley to completely finish the converion

 

[ApexVIII]

just if we can find a underdrive puley for the alternator for these Saturns!

 

[turboglenn]

Underdrive's would slow it down.. We would have to find over-drive pulleys where the alt pulley is smaller than what it is from the factory. I'm pretty sure most under-drive kits use a larger pulley to take some of the load off of turning it and turning it less times per engine revolution

but you're on the right track... IF i could get my lazy arse around to building my keyway cutting tool for the lathe then i could do pulleys for this, it's easy to just turn one out of aluminum but cutting the slot for the shaft requires a specific tool that i can either build cheaply in about 6 hours or buy for a tad under 200 bucks... Maybe this will be my motivation

 

[ApexVIII]

Underdrive's would slow it down.. We would have to find over-drive pulleys where the alt pulley is smaller than what it is from the factory. I'm pretty sure most under-drive kits use a larger pulley to take some of the load off of turning it and turning it less times per engine revolution

but you're on the right track... IF i could get my lazy arse around to building my keyway cutting tool for the lathe then i could do pulleys for this, it's easy to just turn one out of aluminum but cutting the slot for the shaft requires a specific tool that i can either build cheaply in about 6 hours or buy for a tad under 200 bucks... Maybe this will be my motivation

hrm, on my old car, (96 mustang GT)
the under drive kit came with a larger crank pully, but a smaller alternator pulley, so the alt would still spin the same speed, but the others could be slowed down

so i was thinking it woudl be the same for a saturn underdrive kit, if it is then that one pulley would be great

 

[turboglenn]

it should have been a smaller crank pulley or they were over-drive pulleys. When you make the crank pulley larger it's going to move more feet of belt per revolution and the smaller the alternator pulley will spin it more times for the same amount of belt length in feet because theres less surface or "roll-out" on the alt pulley

 

[talondsp1]

I didn't take it in a bad way at all. I was actually glad to see someone had been messing with it to improve it.

That is funny that he asked you why you had the L and F wires hooked up, because that is how GM had them in the Saturn.

I am glad you put in the time and found out about the S terminal. I am going to hook it up to my dist block in the back, and see if my voltage improves even more.

David

Cool, I'm glad you didn't take my thread as an "i'm right, he's wrong" type of thing because it was totally and only meant ot add on to a great idea!

I'm glad some one put in the leg work on the physical side of things to find one that worked on our cars and would have correct enough mounts and the pully of the right type and in-line enough to use right out of the box! I had just come to terms with the fact that i will replace the Alternator, and both the clutch master and slave cylinders once every 2.5 - 3 years

The main thing that prompted me into googling this was the fact that after the GM alternator install i was pleased as could be until i went out that night with the headlights, A/C on high, radio turned up and holding the brake with the turn signal on, and then i saw the tach start jumping with the turn signal and was almost en-raged at my car swearing i was going to have to re-wire the entire thing or remove my CDI box at night in order to be able to run my car with my creature comforts on again

Then, thankfully after hours of reading online and calling many alternator shops and picking their brains did i get a better understanding of the alt and what i needed to try and do with it. I found a lot of write-ups on jeep forums where they were using the "L" and "S" only with great results but couldn't figuyre out why they DIDN"T use the "F" wire, so again i went to calling places and talking with people and then i hit the jackpot with this old boy cooter john jack (or one of his kin) and got schooled on the chevy alts dating from 1929 until now. I started telling him what i was bothered with and he would argue about somethign i didn't even say (clearly a communication break down from a generation gap in general sentence structure and modern wording of thought) . I told him how i had the car wired and then i was asked "well, why you got the field and dummy light wires hooked up?" *Strong southern accent* to which i only exclaimed "cause that's how i read to do it!"and so after about 30-40 minutes of this guy's jibberish ramblin's bout the south and her beauty, old glory, and CS alternators i had enough info to start playing with wires and a voltmeter until i learned i could almost "re-set" my voltage levels with a variance in the resistance to the alt's best source of self monitoring.

Well, that got long, there were cops here for a bit asking who owned the car with out of state plates and why he was here (I have an employee that drives up here from st. joseph to work for a few weeks at a time), my best damn employee too! and i have neighbors that have to call in every parking violation they can find (nothing better to do)

Glenn

anyway, good night fellas.... lets talk more alts tomorrow

That would be great to get a pulley to speed it up a tad. That would make it awesome at idle! Are you using the Saturn pulley on yours?

If you found one that would bolt up, stay aligned correctly and is a tad smaller that would probably be the most ideal way to go. Although the mod is just fine as it stands, everything can be impoved upon. Talondsp1 came up with the idea and mounted the first saturn alt to a DSM then wrote tutorial on how to do it for us all....Then I came up with this little additional wiring info that improves the function. Now, maybe, it's your turn to come up with the ultiamte pulley to completely finish the converion

 

[turboglenn]

I didn't take it in a bad way at all. I was actually glad to see someone had been messing with it to improve it.

That is funny that he asked you why you had the L and F wires hooked up, because that is how GM had them in the Saturn.

I am glad you put in the time and found out about the S terminal. I am going to hook it up to my dist block in the back, and see if my voltage improves even more.

David

WOW! all the way in the back to the distribution block will be the ULTIMATE test of the alternators output capabilities... Please do this soon and post back, i'm already anxiouse to hear the results!!

And about the L and F, i was looking at the saturn schematic wondering the same thing, and if everythign i found says there's no reason to hook up both then why did GM do it? I may have to study to figure that one out some more

That would be great to get a pulley to speed it up a tad. That would make it awesome at idle! Are you using the Saturn pulley on yours?

I'm using the saturn pulley at the time and if i can find an extra to use to compare to the mitsu one and so i can start machining the first overdrive pulley for our application. I'll make the first one out of aluminum and see how long it lastsand find a level of overdrive that will maintane at least 13.5 volts at idle NOw there is one other way to "dial in your voltage" but it would be far more towards the "advanced user" and in case that isn't warning enough i'll just say you take the risk of burning your car to the ground by doing it (there it's off my shoulders now ) and that would be to source the signal from a wire deep in the harness either interior or engine bay, but any really small 12v source, and then using a 10k pot in line to modify what the alternator sees fed back while you monitor it in real life and set it to a place you consider safe.. Then just secure the pot so it can't get "adjusted" by accident or meddling friend who likes to push buttons...What i do on customer cars when i put pots anywhere that the signal thye modify could be dangerously distorted is to put them in a small project case with a whole for adjustment, then i'll squirt a gob of hot glue in after i set it so it takes some effort of cleaning to even get to it again

 

[knochgoon24]

Why don't you source it off the 12 volt ecu power wire? That way, at least your ecu will be seeing a pretty constant voltage.

I not sure when I'll be installing my alternator. I'm out of town trying to find an apartment before school starts next week.
I'm sick and tired of my headlights dimming and my fuel pump whining because I only have 10v when stop at a stoplight. A 700 rpm idle isn't helping that at all.

You could probably do some pretty quick math to figure out what size of pulley you'd need.

If you have a 700 rpm idle and don't get full voltage until 1000 rpm, you'd need (1000-700)/700 = 43% smaller in CIRCUMFERENCE
So just do the 2*pi*r thing to get the correct numbers.

One size pulley might not be perfect for everyone because of differences in wiring, but it will be better than nothing.

How much extra metal is on the Saturn pulley? I don't have it with me, but could it be turned down small enough?
We send it to you, you mill it, send it back. It would save on the costs, which is what this is all about, right?

 

[turboglenn]

Why don't you source it off the 12 volt ecu power wire? That way, at least your ecu will be seeing a pretty constant voltage.

well, sourcing the signal FROM the ECU's power feed would not help add to its voltage any nore than sourcing it from any other spot as it would be reading only, and not out-putting anything through that wire directly. But sourcing it correctly from the start with will keep the voltage to the ECU more consistant either way. And ultimately the whole purpose of this addition is to keep the voltage more consistant everywhere.

I would want some kind of link between my alt and ECU either way though because I can't seem to find very many old haltechs in the junkyard

Also, i've been reading up on the other wires that go to the ECU in many cars, and in a lot of cases now days the ECU actually controls the alternator to some extent.

 

[knochgoon24]

I was suggesting the ECU because the logger obviously shows there's a pretty good power drop there. Not sure if it's the best spot. I think the key to getting a constant (safe) voltage from the alternator will be fine tunning with a pot on a signal wire. I'd hate to fry the battery.

Obviously, these cars have sub-par wiring. I can't even power my 75watt power inverter through the cigarette lighter. I ended up hard wiring a 200 watt one to the battery.

 

[turboglenn]

Sorry i was thinking too simnply and thought you meant that the ECU would see some voltage back from the "S" wire and getting the ECU powred from it. But knowing what you meant now i definitely agree that if the alt signal wire could see what a logger or the ECU sees then adjust based on that, it would definitely improve the situation.

If there's any factory fault on these cars that i would say is just too annoying to be ignored or replaced with aftermarket; it would be the wiring harness for sure. If there's one issue that bothers me it's electrical issues in OEM wiring when they've got the money and the engineers to buildtraction control, electronic suspension and so forth but half the dash gauges won't work due to "a factory flaw", it's like they do wiring on drunken tuesday or something.. Thats also the only true complaint i have about BMW's, I love their cars but hate the eletrical system in them as well. ( seems common on german cars, and if i were a conspiracy theorist I would write some long rant about the link between mitsubishi and mercedes benz based on their common link in diamler-chrysler)

EDIT: good thing i'm not a conspiracy guy because i've already linked ford's wiring to their part in JAguar, and am now thinking that's the great revenge of germany, to get stake in all our car companies and have their engineers come in and ruin the wiring making our cars seem inferior while they continually improve al german cars to the point wher in 2054 there's 90% mercedes taxi cabs, small off looking domestic cars that rival only the smart car in shear brawn and handling abilities and are primarily available in Wal-Mart and lower class communities where they are praised for the free huffy bicycles that are included with the purchade of a new vehicle...okay i'm going to stop before this snowball gets rolling

 

[knochgoon24]

I have other wiring gremlins too. The alternator swap will be a band-aid fix for a few.

For some reason, I'm drawing a power through a few circuits even with everything off. (ex. 71mA through the sunroof fuse, 27mA through the power seats)

I have about 125mA of random current going somewhere. I hoping that the new alternator will at least fully charge the battery. My power inverter is useless without the car running because the battery is always dead/dying. I can't just start the car for short bursts either because the alternator isn't putting out enough to charge the battery during idle.

 

[turboglenn]

I have other wiring gremlins too. The alternator swap will be a band-aid fix for a few.

For some reason, I'm drawing a power through a few circuits even with everything off. (ex. 71mA through the sunroof fuse, 27mA through the power seats)

I have about 125mA of random current going somewhere. I hoping that the new alternator will at least fully charge the battery. My power inverter is useless without the car running because the battery is always dead/dying. I can't just start the car for short bursts either because the alternator isn't putting out enough to charge the battery during idle.

although i don't have the sunroof and power seats to loose current to, but the rest of it sounds very similar to what i've had to deal with as far as poor charging, running inverters with the car off and not charging enough at idle to do what 90% of cars can right off the showroom

The saturn alt was something i was honestly unsure of but I was really ready for anything i could do to improve the old girls charging system (my next step was to completely re-wire the OEM system with an OEM alternator, but the saturn install was so nice and the performance improvement is so great it's something i wish i had done years ago ( but i didn't know about it until joining tuners...so thank you tuners for that one big time!!!

 

[ApexVIII]

hm ysaturn alternator died today... or atleast i think it has

i installed 2 1F Capacitors for my sub yesterday, charged the Cap's lastnight connected everything

started the car this morninig and it was at 11.5v so i backed out of the driveway and took off and it went to 14v for 2sec then back down to 11.5 for about a min then back to 14 while i was driving, then right back down to 11.5

i had to get to work so i just kept going and it slowly went down to 10.8v over the 40min drive :/

ill check it out when i get home.... if i can make it home

 

[97gstnick]

Do you think running the "S" wire to fuel pump's power wire would be a good source?

 

[BoostedTalonTS]

Should I find a slightly smaller 4 rib pulley and run it?

My car felt like it pulled better above 7000 after I just ran the S wire the other day. The car def has more spunk now. I haven't even driven it yet since running the 4ga power wire. It too damn hot!

As far as 1G's go, I have had good results swapping out the Saturn alternator pulley for an Unorthodox 2G Mitsu pulley... IIRC, the Saturn pulley measured 2 1/4" and the Unorthodox pulley was closer to 2". It is 4-rib vs the Saturn that was a 5-rib pulley. It has the same shaft diameter as the Saturn alternator, but I needed to use a few washers to space the 2G pulley so it would line up with the belt again.

In my case, I was sitting at 13.8v (not using the "S" terminal) at idle (750 RPMs) after the pulley swap. Although the side benefit of the 2G pulley was more voltage at idle, my original concern was that I wanted more clearance between the subframe and the Saturn alternator pulley (I'm using the Jay Racing Saturn Alternator Relocation Kit).

Many thanks TurboGlenn for your research The "S" terminal was the only thing that I have not attempted yet... I would love to see 14.3v in the higher RPMs. I will go wire it in now & let you know my results.

Great thread

 

[talondsp1]

WOW! all the way in the back to the distribution block will be the ULTIMATE test of the alternators output capabilities... Please do this soon and post back, i'm already anxiouse to hear the results!!

I am in the middle of an auto swap, so I can not do this just yet. I bet it would make the voltage pretty good and stable. I can't wait to try it.

And about the L and F, i was looking at the saturn schematic wondering the same thing, and if everythign i found says there's no reason to hook up both then why did GM do it? I may have to study to figure that one out some more

That is just GM for ya.

I'm using the saturn pulley at the time and if i can find an extra to use to compare to the mitsu one and so i can start machining the first overdrive pulley for our application. I'll make the first one out of aluminum and see how long it lastsand find a level of overdrive that will maintane at least 13.5 volts at idle NOw there is one other way to "dial in your voltage" but it would be far more towards the "advanced user" and in case that isn't warning enough i'll just say you take the risk of burning your car to the ground by doing it (there it's off my shoulders now ) and that would be to source the signal from a wire deep in the harness either interior or engine bay, but any really small 12v source, and then using a 10k pot in line to modify what the alternator sees fed back while you monitor it in real life and set it to a place you consider safe.. Then just secure the pot so it can't get "adjusted" by accident or meddling friend who likes to push buttons...What i do on customer cars when i put pots anywhere that the signal thye modify could be dangerously distorted is to put them in a small project case with a whole for adjustment, then i'll squirt a gob of hot glue in after i set it so it takes some effort of cleaning to even get to it again

That would be pretty cool to do. You sure wouldn't want everyone running around with one cranking it up all the time.
Let me know how it goes with the pulley. If you make one, I would buy it for sure. I bet it would really be awesome for a 160 amp alt. Because they seem to need even more rpms at idle.


Sorry about my delayed responses, this site does not notify me of new posts, or pm's.

 

[turboglenn]

No worries on responce time...sometimes i'm gone for days at a time and don't get to even see the 'net.

The pulleys are a definite thing... I cut the blanks already, and turning them won't be an issue at all. THe only thing i don't have is a broch/keyway cutter for making the notch if the alt has a woodruff key on the shaft (not sure if it does but i would imagine so)

I plan on building a few extras when i do mine so that the few people that I know from this thread wanting them can get one. AFter that i may do a secondary run of them if they go off well. I will let you know when the first ones come off the lathe