The Northstar is no more special than any other engine to swap into a Fiero. In and effort to remove some of the cloud of ignorance and fear around this engine and get some more Northstar Fieros on the road, here are pics of what I've done so far:
Transmission bellhousing mod (Getrag):
Minor sculpting of the engine bellhousing flange to accept the clamp block so that the last bellhousing bolt can be used:
Original Idler pulley location:
New Idler location:
Mods necessary to change idler location:
Will have more pics tomorrow of changes to the fuel rail to turn it around and put the fuel connections in the same place they are on a stock Fiero.
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01:40 AM
PFF
System Bot
artherd Member
Posts: 4159 From: Petaluma, CA. USA Registered: Apr 2001
Hey Will, looking good! (looking very good, you're furthur along than I am :)
I ended up going about the tranny bolthole 'problem' the exact same way you did, heh.
PS: got a couple of questions on your tranny, will the Torsen LSD be useable in a stock '88 getrag? Also, what are you doing for clutches. I've yet to make my decision there.
The swap is going so well, it's hard to imagine why this isn't done all the time!
Best! Ben.
------------------ Ben Cannon 88 Formula, T-top Metalic Red 88 Formula, Silver 87 Coupe, Metalic Red "Every Man Dies, not every man really Lives" -Mel Gibson, "Braveheart"
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03:46 AM
Jay Member
Posts: 1107 From: Toronto Ontario Canada Registered: May 2000
Will I'm envious that you are going with the manual without an adapter plate. I was told it wouldn't line up and hence went with the auto. Mind you the auto still kicks butt!! Have you resolved the problem with the eprom yet? Will the Aurora work? I may have someone to custom make me a chip to remove whatever I want from the program but it won't be cheap.
------------------ Jay 1986 Northstar GT www.members.home.net/jaygrande
Outstanding Will. Thank you for taking the time to post those detailed photos. The possiblities for N* 5spd swaps are looking better all the time. Once question, do we want to consider how cutting back that webbing will affect the strenght of the bellhousing?
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09:34 AM
BigTurbo87GT Member
Posts: 90 From: Leesburg, VA, USA Registered: Oct 2000
Hey Will, what exactly did you do to make the last bolt hole on the engine line up with the bellhousing on the transmission? Did you have to tap the middle engine/bellhousing bolt on the left side? Mine is capped/plugged. Looking from back of engine: x marks hole that is plugged.
o o / \ X o / \ o o
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03:41 PM
BigTurbo87GT Member
Posts: 90 From: Leesburg, VA, USA Registered: Oct 2000
Ok, disregard first question, I now understand what you did for last bolt on right side. You didn't happen to make a couple of those "clamp blocks" did you? It looks like a nice piece of machined aluminum.
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03:48 PM
Jay Member
Posts: 1107 From: Toronto Ontario Canada Registered: May 2000
Will, just a suggestion. Change the starter now while everything is apart or at least check it out, reason is mine went a few weeks ago and although it wasn't too bad changing it (intake, fuel rail, throttle body comes off) it is easier when everything is out of the car. Also if you are putting a new O ring on the throttle body you'll need to get a new one when you remove it to get to the starter. It seems that there is alot of heat trapped under the intake. I also found alot of road debris hidden under there, it's a good time to clean it all out. Next week I'll be installing a hood scoop I got on e-bay to relieve some of the heat build up. Looking good Will!
------------------ Jay 1986 Northstar GT www.members.home.net/jaygrande
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04:05 PM
lowCG Member
Posts: 1510 From: seattle,WA U.S.A. Registered: Jun 99
Hi Jay, one of the first things I did was to buy a new starter just for that reason :)
The engine does indeed bolt right up to the getrag, and an 88 V6 flywheel will even work (re-drilled to the northstar's 8bolt pattern, as opposed to the 2.8's 6bolt pattern. I personally am getting a new flywheel that is drilled this way from the start.)
Computer wise, I am going with a fully aftermarket ECU (that uses all stock sensors, and coil pakcs) wheras Will is using the stock computer with an Aurora PROM. Will be intresting to see both results!
The ECU is going to cost me $1,300 from chrfab.com (one day I'll have ot do their northstar hotrodding mods, GRIN! :)
PS: the tranny modifications are minimal, we don't even cut any external metal (where most of the stregenth is needed; the metal we do cut is I belive mostly for dust containment :) In comparison, look what the Caddy 4.9 guys do, and their swaps have been established as reliable. in *raceing*.
Best! Ben.
------------------ Ben Cannon 88 Formula, T-top Metalic Red 88 Formula, Silver 87 Coupe, Metalic Red "Every Man Dies, not every man really Lives" -Mel Gibson, "Braveheart"
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09:38 PM
Aug 3rd, 2001
Will Member
Posts: 14249 From: Where you least expect me Registered: Jun 2000
Plugged and re-drilled flywheel will be used with a CenterForce Dual Friction clutch. I thought about using the FieroShop's aluminum flywheel, but $550 for a flywheel seemed a little steep, especially considering the setup is already a V8 with a V6 flywheel.
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01:40 AM
PFF
System Bot
Will Member
Posts: 14249 From: Where you least expect me Registered: Jun 2000
Originally posted by BigTurbo87GT: Did you have to tap the middle engine/bellhousing bolt on the left side? Mine is capped/plugged. Looking from back of engine: x marks hole that is plugged.
o o / \ X o / \ o o
That hole isn't in the Northstar block because it would be too close to the cooling jacket. Don't worry about it. Since it comes from the factory that way, the setup must be strong enough.
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01:42 AM
Will Member
Posts: 14249 From: Where you least expect me Registered: Jun 2000
Originally posted by artherd: PS: got a couple of questions on your tranny, will the Torsen LSD be useable in a stock '88 getrag?
Yeah, if you can get one. I got mine from www.mantapart.com It was $1500 and one of two they had. They only have one now
The Torsen also has the reluctor wheel style VSS integral with the case. Unless you machine the case, you're stuck with the reluctor wheel, instead of gears like the Fiero has. I'll be working on some electronics to convert between the two signals.
Damn... I dropped that roll pin. Did you see where it went?
The Northstar definitely belongs in the Fiero. I accidentally dropped one of the shackles I had used to lift the engine. It promptly fell down into the most inaccessible place it could possibly fall into--under the starter. This is definitely Fiero behaviour.
I'm not worried about the starter. I can always push start it if the starter goes. And I don't feel like spending that much for preventive maintenance of such a relatively unimportant system.
[This message has been edited by Will (edited 08-03-2001).]
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01:53 AM
HarryG Member
Posts: 587 From: Central Ohio, USA Registered: Sep 99
An 88 v6 flywheel can be used (it is neuturally balanced) I am having one made as normal, but drilled for the northstar.
Later I plan to try a double-disc clutch setup, but for the first car I will use a single kevlar disc.
Man, this is fun! WIll, do you sit next to the engine in the garage late at night and make 4-cam revvy-noises and pretend to shift at 6,000? I know I do!!! ;))
PS: race ya, let's see who brakes something first ;)
Best! Ben.
------------------ Ben Cannon 88 Formula, T-top Metalic Red 88 Formula, Silver 87 Coupe, Metalic Red "Every Man Dies, not every man really Lives" -Mel Gibson, "Braveheart"
Originally posted by Will: The Torsen also has the reluctor wheel style VSS integral with the case. Unless you machine the case, you're stuck with the reluctor wheel, instead of gears like the Fiero has. I'll be working on some electronics to convert between the two signals.
I believe this is the circuit you need. Used this in my Quad 4 install with the Quad 4's Getrag and VSS.
Paul
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03:13 PM
rockcrawl Member
Posts: 2528 From: Lehigh Valley, PA Registered: Jul 2000
The torque from the 4.9 was enough to totally destroy a Gleason/Torsen differential in only two years of autocrossing. And this was not "bang" shifting the transmission either
[This message has been edited by rockcrawl (edited 08-03-2001).]
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04:39 PM
Raydar Member
Posts: 40906 From: Carrollton GA. Out in the... country. Registered: Oct 1999
Just out of curiosity, what are you guys using for motor mounts? Fabricating them? Purchased from a vendor? Not like I can afford to do a N* anytime soon.
------------------ Raydar - aka Steve
Black 88 Formula. Red 88 Duke coupe. "The Project" 88 Formula parts car. "The Donor"
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04:50 PM
Jay Member
Posts: 1107 From: Toronto Ontario Canada Registered: May 2000
Will, Keep em coming!! Raydar, my engine is solid mounted to the cradle with no bushings. The caddy is so smooth you don't even feel it vibrate. Mines been in almost 2 years and nothing has broken yet.
------------------ Jay 1986 Northstar GT www.members.home.net/jaygrande
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06:00 PM
PFF
System Bot
Aug 5th, 2001
Will Member
Posts: 14249 From: Where you least expect me Registered: Jun 2000
Originally posted by artherd: An 88 v6 flywheel can be used (it is neuturally balanced) I am having one made as normal, but drilled for the northstar.
Later I plan to try a double-disc clutch setup, but for the first car I will use a single kevlar disc.
Man, this is fun! WIll, do you sit next to the engine in the garage late at night and make 4-cam revvy-noises and pretend to shift at 6,000? I know I do!!! )
PS: race ya, let's see who brakes something first
Best! Ben.
My flywheel was free. I know a good machinist who likes to go to Outback.
I'm not sure about double disk clutches. I'll have to do a little math and see if they have a higher moment of inertia than single disks. A higher moment of inertia on the clutch disk means more load on the synchros when shifting.
Hells yeah I make 4 cammer revvy noises!
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11:03 AM
Will Member
Posts: 14249 From: Where you least expect me Registered: Jun 2000
Originally posted by Raydar: Just out of curiosity, what are you guys using for motor mounts? Fabricating them? Purchased from a vendor? Not like I can afford to do a N* anytime soon.
I'm using the Fiero forward and aft transmission mounts. Rubber for now until 300 ftlbs destroys them, then I'll record how long it took and install West Coast Fiero poly trans mounts.
For the engine, I'll be using the stock Northstar left bank mount and bracket. Since this mount is close to the forward cradle rail, making a bracket to weld onto the cradle rail and accept the bottom of the mount shouldn't be hard. I want to do a fourth mount at the right rear corner of the engine trans assembly, but I haven't hashed out the details yet. I'm also going to use a dogbone brace. I think I will hook one end to the stock Northstar dogbone bracket on the pulley end of the engine, and tie the other end to the strut tower.
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11:08 AM
Will Member
Posts: 14249 From: Where you least expect me Registered: Jun 2000
I don't know if I can do that. I wasn't able to get the conversion done before I have to go to flight school later this week. The rest of it will have to wait a couple of months. I have a few pics of what I did to the fuel rail. I basically turned it around so that the Caddy fuel supply and return are in almost exactly the same place as the stock Fiero supply and return.
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11:12 AM
Will Member
Posts: 14249 From: Where you least expect me Registered: Jun 2000
I emailed Greg of Team Python. He had this to say:
What actually broke was the Gleason Torsen itself, which took out the Getrag trans case. All the trans and final drive gears appear to be OK. The diff was originally designed for the Getrag used in the early 90's for FWD road race cars with the Quad 3 and 2.8~3.1L V6's, it just happens to be the same model trans that the Fiero used with the V6. Gleason was the manufacturer of this "Torsen" (Torque Sensing) differential. They designed it with a very high torque bias ratio (6to1) which when used in a rear drive application, i.e. Fiero, it generates a lot of understeer when on the throttle up to the point that traction is lost and it suddenly becomes oversteer, much like you would expect from a locked diff or a spool, with the exception of being able to turn in with throttle off. With the high torque output of the V8 and the high torque bias ratio and very big sticky race tires, the internal wear in the Gleason Torsen is highly accelerated. Ours wore to the point that the gears rode up on top of each other and exploded the diff which then broke the transaxle housing. We have since found some other very experienced racers that had also found out that this type of failure is common. A company named Zexal now makes basically the same unit for late model GM's like the Camaros and such. I have found out that they have to be replaced at least a couple times a year if raced on a fairly regular basis. They now have a race version that lasts longer than the production version but still has limited life. Though we didn't use it as long, we had used a Quaife in the Isuzu design 5 spd behind a 3.1L V6 for Autocross and have since decided that for autocross and street that it was probably the better way to go, especially since you will not find any new Gleason Torsen diff's anymore. The one we had that broke was one of only two new ones known to exist when we bought it 3 years ago. Bill's Isuzuperformance has the Quaife's for the Isuzu design 5 spd used in the Fiero. He lists the Quaife for the Muncie/Getrag that is used in the Fiero, but if you ordered it now, it would not be deliverable until 2003, he calls this "available". Otherwise Bill is decent to work with.
L8R,
Greg Duncan Other Half of Team Python 84 A/Prepared Fiero Q4 88 E/Modified Fiero 4.9L V8 Tucson, AZ
I guess I'll pull the Torsen out and save it for a lower torque application. Good thing I haven't buttoned up the trans yet.
I also removed the 1-2 and 5-R bias springs from the trans. It ought to shift more like a proper RWD shifter instead of pushing the shifter out of the 1-2/5-R gates and into the 3-4 gate.
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09:30 PM
Aug 6th, 2001
artherd Member
Posts: 4159 From: Petaluma, CA. USA Registered: Apr 2001
Hrmm. Will, that site you sent listed some "plain spring clutch" limited-slip diffs as well, I wonder if they would hold up better in a street-driven application?
Personally, at least with the 2.8 v6, I find I spin both tyres roughly equally even when cornering. thank transverse engine and mid-engine layout.
An LSD would be good fun to try.
The dual disc clutches generally have a great deal less rotational innertia, I don't know if the Quartermaster setup uses a flywheel, or just a flex plate, but the latter design radically lowers rotational innertia. think of it, NO flywheel! McLaren uses this design, as does the Pagnani Zonda (both with V12 engines, that thusly arrive at redline in a few hundred milliseconds.)
I need to have one in my hands before I will know for sure what will be done to rotational innertia, but the two chief reasons for a multi-disc clutch are drastically reduced innertial moment; and the allowed reduction of engine mounting height. F1 cars use 7-disc setups using only 4.5" dia discs to put the engine's crank nearly on the ground.
As of yet, I don't know if I can afford a quartermaster clutch, the point might be moot :)
------------------ Ben Cannon 88 Formula, T-top Metalic Red 88 Formula, Silver 87 Coupe, Metalic Red "Every Man Dies, not every man really Lives" -Mel Gibson, "Braveheart"
