quote Originally posted by dratts: ... My N* was installed by a caddy mechanic in NC and uses the th125, It has a recepticle to plug in the caddy instrument panel on the passenger side.

How were they mated together ?

I only put about 300 miles on it driving from NC to GA where it got a 355 body installed. I've only dragged it once and my technique was to hold the brake and floor the accelerator until rpms maxed, then let off the brake and go. It uses the caddy ecm and I don't know how successsful the caddy mechanic was in dealing with the transplant issues, but it was a lot of fun on the curvy roads between Charleston and Georgia. For years the fastest sbc fiero had a th125 in it. I have one of Ryans computers and a wiring harness set up for a stickshift that I might be willing to part with. There are a lot more options now for the N* fiero transplant than there used to be. Ryans was the first as far as I know. I may still have the caddy mechanics # if we want to find out how he dealt with the torque converter and flexplate issues. I see Ryan is posting on his N* itb project. Maybe he can chime in.

I totally believe that a th125 would be just fine. 300HP doesn't need many gears and the car doesn't weigh enough for the torque to really max out.

I would stay away from the th125 for durrability reasons. As complicated as it sounds, the getrag conversions are not that hard to do. The only special tool you need is a grinder, everything else can be done by a machine shop.
I know that some people on here are running the 4t80 trans, i am not sure what they are using for a computer though.

quote Originally posted by FieroBrad87: Ok well NorthStar 4.6L and a 7730 ECM. I just can get the power to the wheels so far. Maybe fabbing a manual into it ISN'T the worst possible idea.

Its really not that hard to do. All you need is a 88 Fiero v6 flywheel, take it to a machine shop and have the crank holes plugged and redrilled for the N* crank bolt pattern.
do some trimming on the bellhousing inner web to clear the starter snout ..half hour or less of work. The Muncie will work with mods to the water log or shift linkage If you use a Getrag trans the linkage will clear the N* waterlog. That way you can use your stock Fiero manual axles, use the stock trans mounts. There is one bolt hole that doesnt line up, its really no big deal to remedy or just leave it unless you plan on really hammering the car then its easy to make a flange. Consider this as compared to an auto swap which means if your car is a manual you will have to run auto trans cooler lines to a auto radiator or a good trans cooler, possible modded axles, fabbed trans mounts, etc. By running a manual you can use ryans tune on a 7730 ecm which eliminates the trouble of getting a trans controller or putting in a different auto than what the Northstar came with ..just some food for thought.

quote Originally posted by 1986 Fiero GT: A forum member whom I don't care to mention has talked with me several times about this setup, but his answers to my questions are like watching the TV show Lost. I've since given up trying to get any information out of him.

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Easiest/cheapest swap would be the 4t80e and northstar with stock PCM (you would need an OBDI 93-95 N*... but not good for performance or aftermarket parts). Slightly harder would be 4t80e and 7730 ECM with something like the PCS module to control the tranny. Harder yet would be using the 65e, but looking back on it, is probably how I would have done it. You shave about 100lbs off the rear end, and have more go-fast parts for the transmission.

For the 7730 option, I posted everything you need here:

http://northstar.7p.com

[This message has been edited by ryan.hess (edited 03-02-2010).]

As Ryan suggests, the cheapest is probably going with the stock Cadillac automatic tranny and an early PCM from a 93-95 N*.

You could use any plastic intake engine up to 1999 as long as you transferred a throttle body and spacer from a 1995 (or a 4.0 Aurora using the same throttle body and spacer as the 95 N*) engine. That would allow you to use the early wiring harness/PCM with a later 1995-99 engine. That's what Howell Engine Developments recommends for their N* set-up/wiring harness:
http://howellefi.com/customer/home.php?cat=293

That would leave you with just the axles to do along with getting it on your cradle.

quote Originally posted by mcaanda:

Hah, you just know what I'm talking about. Dude is infuriating. Meh, oh well, I'll figure it out..I don't even have the car put together to test things yet either.

quote Originally posted by IXSLR8: As Ryan suggests, the cheapest is probably going with the stock Cadillac automatic tranny and an early PCM from a 93-95 N*. You could use any plastic intake engine up to 1999 as long as you transferred a throttle body and spacer from a 1995 (or a 4.0 Aurora using the same throttle body and spacer as the 95 N*) engine. That would allow you to use the early wiring harness/PCM with a later 1995-99 engine. That's what Howell Engine Developments recommends for their N* set-up/wiring harness: http://howellefi.com/customer/home.php?cat=293 That would leave you with just the axles to do along with getting it on your cradle.

Brad I have an early intake and throttle body so your covered if you want to go that route

quote Originally posted by IXSLR8: As Ryan suggests, the cheapest is probably going with the stock Cadillac automatic tranny and an early PCM from a 93-95 N*. You could use any plastic intake engine up to 1999 as long as you transferred a throttle body and spacer from a 1995 (or a 4.0 Aurora using the same throttle body and spacer as the 95 N*) engine. That would allow you to use the early wiring harness/PCM with a later 1995-99 engine. That's what Howell Engine Developments recommends for their N* set-up/wiring harness: http://howellefi.com/customer/home.php?cat=293 That would leave you with just the axles to do along with getting it on your cradle.

How is that an advantage? My friend with the engine works at a machine shop too and already offered to do up the flywheel. It's looking more and more like this is going to be a manual.

[This message has been edited by FieroBrad87 (edited 03-03-2010).]

quote Originally posted by FieroBrad87: How is that an advantage?

If you decide to use the Caddy PCM, it can only be done with the 93-95 PCMs/engines. If you swap a 96-99 engine to the earlier style intake/TB, then you can theoretically run a 93-99 on the Caddy PCM. Just gives you a bit more leeway on engine choices.

quote Originally posted by 1986 Fiero GT: If you decide to use the Caddy PCM, it can only be done with the 93-95 PCMs/engines. If you swap a 96-99 engine to the earlier style intake/TB, then you can theoretically run a 93-99 on the Caddy PCM. Just gives you a bit more leeway on engine choices.

I have the engine...

Well then I suppose it doesn't much matter then, haha.

quote Originally posted by 1986 Fiero GT: Well then I suppose it doesn't much matter then, haha.

Yeah, having the engine so readily available is how this whole thing got started...

quote Originally posted by Erik: I believe Ryan has a controller on his with the tapshift. You must be running a built up 125 otherwise it wont last long with the torque and rpm the N* puts out

I think you're right about Ryans tap shift controller. What would rpm have to do with the reliability of the th125?

quote Originally posted by dratts: I think you're right about Ryans tap shift controller. What would rpm have to do with the reliability of the th125?

Higher RPM's means the clutch packs get to slip more during upshifts. They are a wear item, but they'll be wearing faster.

So have we figured out if a th125 will bolt to a N* somehow? My mechanic seems to think it could handle it.

The 125 will bolt up. I used one to store a N* (so it would not fall over) the 4t60 would not bolt up with the water log on the n*. USE a trans with OVERDRIVE or you can't pass a gas station!

quote Originally posted by ryan.hess: Higher RPM's means the clutch packs get to slip more during upshifts. They are a wear item, but they'll be wearing faster.

On a 3.4 DOHC with the 4t60-e in the w body the engine is limited to 5500rpm IIRC rpm wise, because of trans reliablity issues which now that I think about it doesn't bode well for a stock 4t60 for use in the N*. I would think the 125 being an earlier design probably wouldn't like high rpm with a good amount of torque either in stock form

The 4t65ehd that I was going to replace it with is now going to replace the isuzu in my lambo, so I'll just baby the th125 for now. The sbc with the 125 which I referred to probably was built up. I just tried to look it up on the forum and can't find a mention of a sbc 2with th125. The list hse been replaced by un updated version and I can't find the old one.

[This message has been edited by dratts (edited 03-03-2010).]

quote Originally posted by dratts: I finally found the car. It's at v8 archies under pat ciarcia. Also in the archives under pats ultimate nhra drag fiero. Although I dcan't find more info yet, pat had a performance shop and it was referred to as a racing automatic. GMs built 4t65ehd was also converted to a 3 speed. Maybe the car doesn't get to shift into fourth during the quarter.

A fellow Iowan and fiero enthusiast think his screen name is LAMBO has a Fiero with the 125 built up with a SBC I haven't rode in it but from what I've been told it was very quick. He was planning on selling it last time I was there at his storage facility.

The last I heard of it was in 2007. Archie thought that a guy in Mishawaka In. had it then. It's been changing hands a lot. The original builder had a shop called C&C performance, but the phone number is no longer any good there

I just called JPT Transmissions, The place who built the 10.3 second 1/4 th125. They're closed til Spring but here's their number 1 {517} 663 0578.

[This message has been edited by dratts (edited 03-03-2010).]

quote Originally posted by 1986 Fiero GT: Hah, you just know what I'm talking about. Dude is infuriating. Meh, oh well, I'll figure it out..I don't even have the car put together to test things yet either.

Im in the same boat - I've gone back and forth wondering if I should do this, or if I should do that. Currently I have a fully unlocked MEFI 4B with the stock N* tune as well as the program and cables to modify it, but the thought of SD tunes is a little weight on the mind. I'm right there that the point where I'm ready to cut and solder wires - Once you start there's really no turning back.

I was hoping that there would be a solution to it soon, but like you for me it really matters not other than to see what is going on. I've actually been looking to scope out another set of jack stands so that there's no flat spots in the tires. Its going to be a bit before I head back out into the garage to do more than shoo away the crickets...

--Allen

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quote Originally posted by mcaanda: Im in the same boat - I've gone back and forth wondering if I should do this, or if I should do that. Currently I have a fully unlocked MEFI 4B with the stock N* tune as well as the program and cables to modify it, but the thought of SD tunes is a little weight on the mind. I'm right there that the point where I'm ready to cut and solder wires - Once you start there's really no turning back. I was hoping that there would be a solution to it soon, but like you for me it really matters not other than to see what is going on. I've actually been looking to scope out another set of jack stands so that there's no flat spots in the tires. Its going to be a bit before I head back out into the garage to do more than shoo away the crickets... --Allen

You and me both...I've been waffling for about 6 months now, and I'm finally getting sick of seeing my car fully disassembled for the third summer in a row. It won't be like that this summer. Ideally, I'd love to run a Moates Roadrunner (just a '0411 with emulation hardware built in, for those that don't know), so I can have a GM J1850 databus. That's what I really, really want. I've just been asking so many people for so long if anybody has an OS for it, and where I can find it that I'm starting to get frustrated. I refuse to spend $600 on a computer and Monodax or HPTuners license, then spend a week wiring it up only to find out that I've wasted my time as there is no .bin file that will let the engine start. I need a definitive answer before I make any decisive movements...it's just my nature. I've got a '7730 laying right next to me on my nightstand if worse comes to worst, but as I said...I would greatly, greatly prefer OBDII. Anybody, Bueller?

[This message has been edited by 1986 Fiero GT (edited 03-04-2010).]

I'm 80% sure I'm going with a TH125. I've been feeling around for someone to make a custom flexplate.

A little bit of news for us N* owners regarding the 96-99 PCM's. Apparently the 96-99 are now programmable by Westers in Alberta:

http://www.cadillacforums.c...orking-together.html

quote Originally posted by IXSLR8: A little bit of news for us N* owners regarding the 96-99 PCM's. Apparently the 96-99 are now programmable by Westers in Alberta: http://www.cadillacforums.c...orking-together.html

I guess if you want to keep the 4t80e tranny it's good news.

So Bob at transmissionadapters.com says he can make me a one-off flexplate for my N*/TH125 plan. Then he starts running his mouth about how he did one with a 4T80E and blah blah blah. Basically I'm an idiot and his way is the greatest thing that ever happened. I think he was telling me that I was going to have to run the engine off the Caddy ECM anyway. I bet this dude has the fastest car in his trailer court.

Here's some free advice:

WHEN SOMEONE OFFERS YOU MONEY FOR YOUR SERVICES, TAKE IT!

Good luck Bob. You're gonna need it.

I am also starting a N* with the 4T80-E swap. I have a PCS controller and wiring harness for the tranny. How I am going to control the engine is the question of the day. I like the 7730 option, reliably and reparability are a must, but there may be more out there.

As you can see Wester's list FULL Tuning for 96 to 2003 and I know he will do full tune on 93 to 95 Northstar's



I have Wester's DDT for the Shelby Northstar setup. I gave him the information to get the VDF built



I will not do anymore harnesses

Spoke w/ Lyndon this afternoon and it sounds as if they are pretty close to finally getting complete access to the N* ECM. I guess there was some mis-info that they were working off of which was leading them down the wrong path. I guess while working with the code recently there was a break though which really allowed for some serious progress to be made.

He's working with a guy who has a 2oo1 N* that I guess they are putting into a bike ( which is flat out insane IMO ) and working out the bugs. I spoke to him about the need for eliminating the auto trans stuff which it sounds as if they have handled and should not be an issue.

Time will tell, and if so this could be pretty cool.

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quote Originally posted by mcaanda: Spoke w/ Lyndon this afternoon and it sounds as if they are pretty close to finally getting complete access to the N* ECM. I guess there was some mis-info that they were working off of which was leading them down the wrong path. I guess while working with the code recently there was a break though which really allowed for some serious progress to be made. He's working with a guy who has a 2oo1 N* that I guess they are putting into a bike ( which is flat out insane IMO ) and working out the bugs. I spoke to him about the need for eliminating the auto trans stuff which it sounds as if they have handled and should not be an issue. Time will tell, and if so this could be pretty cool.

FInally, a legit OBDII ECM option for Northstar swaps! Hmm...perhaps I should give Lyndon a call, haha.

quote Originally posted by mcaanda: Spoke w/ Lyndon this afternoon and it sounds as if they are pretty close to finally getting complete access to the N* ECM. I guess there was some mis-info that they were working off of which was leading them down the wrong path. I guess while working with the code recently there was a break though which really allowed for some serious progress to be made. He's working with a guy who has a 2oo1 N* that I guess they are putting into a bike ( which is flat out insane IMO ) and working out the bugs. I spoke to him about the need for eliminating the auto trans stuff which it sounds as if they have handled and should not be an issue. Time will tell, and if so this could be pretty cool.

I talked to Lyndon yesterday. He's completely reverse-engineered the code for the '96-'00 Northstar and '96-'03 Aurora for the factory PCM. He said he's working on the '01+ stuff for the Northstar now, but he didn't give me an ETA. I wonder if he can still retain the cam phasers and such? Hmm...maybe I'll experiment with that when he's done.

I just wonder exactly what I'm getting for my $500. I feel like there should be some sort of tuning suite included, because $500 seems like a lot to pay for just a tune. I guess I'll throw a few more questions at him tomorrow when I call him back to actually order a tune.

[This message has been edited by 1986 Fiero GT (edited 03-18-2010).]

quote Originally posted by 1986 Fiero GT: I talked to Lyndon yesterday. He's completely reverse-engineered the code for the '96-'00 Northstar and '96-'03 Aurora for the factory PCM. He said he's working on the '01+ stuff for the Northstar now, but he didn't give me an ETA. I wonder if he can still retain the cam phasers and such? Hmm...maybe I'll experiment with that when he's done. I just wonder exactly what I'm getting for my $500. I feel like there should be some sort of tuning suite included, because $500 seems like a lot to pay for just a tune. I guess I'll throw a few more questions at him tomorrow when I call him back to actually order a tune.

I'd like to know specifically as well but this sounds like we're moving the right direction.

As per the cost, I think that 5oo for a custom tune is well in line for what you are getting especially when there's little to no other options. You can look into the aftermarket ECM's, but they are considerably more than the cost of what it appears that Lyndon has to offer. Belive me, I know - I have an unlocked MEFI 4B and the program to play w/ the settings which set me back some pretty serious coin.

Compared to the cost for other vehicles, the tune for my A6 S-Line is 600+, and there's a number of places that have the ability to do so... Overall I think he's asking potentially a bit less than the amount of effort he's put into it but in conversations he's stated he's got long term goals with it so lower cost = more sales which = $$.

If he can deliver on the tune and code, I really think that this will be good for the N* community as a whole and much more-so for the Fiero community. It has been for the longest time the single biggest detriment for people when they are looking for potential engine swaps.

Keep us posted on what you find out and hear.

--Allen

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quote Originally posted by mcaanda: Keep us posted on what you find out and hear. --Allen

Will do. I didn't get a chance to call Lyndon back today, so I may just shoot him an e-mail here shortly so I don't bother him for an hour on the phone, haha. I'll update everyone with what I find out.