GM High Value LZ9 Swap? (Page 7/11)
ChuckR SEP 11, 04:09 PM


quote
Originally posted by Joseph Upson:


The motors come out complete with wiring harness and PCM so the number of sensors are not important as they are already wired and plugged into the PCM, it's the chassis interface end of the harness that has to be worked with and the associated BCM for both will expect to see pretty much the same essential inputs.

bmwguru has what is probably the most impressive and successful similar swap involving the turbo 2.8L version of the 3.6L motor from a Saab swapped in. I didn't review the entire swap thread, but the only complaint about mounting I saw early on involved the difference in the Saab F40 vs. the G6 F40 and having to make new mounts as a result. We have seen nearly every GM motor offered over the past 15 years, or a version of them swapped into the Fiero and some how the 3.6L is not friendly enough to swap, but the 4.6L DOHC Northstar and other V8 motors are? I don't buy it for a second in the absence of EXACTLY what this alleged snafu is to discourage such an effort.

Again it's a swap and will require some far from impossible custom work. With all of the madness I've created, this is exactly the kind of reasoning I would use, get the most out of my effort the first go around, to avoid more time and money fiddling with it later on.



This is a very sound argument. However I have read all of that post, and BMWguru is seasoned in the arts of custom and swaps, and even he did not get his to run properly on the stock ECU, he ended up going stand alone on that build it also took him several years to complete. Yes he did get it to run on the stock ECU but it wasnt right. I do agree that the 3.6 is the better motor and it would be better to swap that one in, I would not have the issues bmwguru had since I would be using mated engine trans ecu tcu bcm. But it is out of my league right now.

My Fiero is my hobby. I do this swap and enjoy it, learn more. Get tired of this swap and go for the 3.6 or next great V6 out there. enjoy that move on. Any heavily modified car is not done for the value monetarily It is done for the value the owner gets from the experience. There is a big enough difference in the 2 that with my modest skill set the 3.6 is not feasible now. It will be, just not now.

Maybe the next swap is not even a V6 at that point, maybe get a totaled Bolt and do an electric Fiero, that is the future anyway. Electric motors. Instant torque, no curve just a flat line of instantaneous torque. Wouldn't that be something?

But none of that has to do with this swap. I do enjoy this exchange of ideas and I totally understand your point of view. I have it myself. And I know that while I could be spending my time and money on the best swap that might not ever get completed, or even worse I do complete and dont get the modifications to fit the 6 speed auto done correctly and end up crashing.

The 3900 will require some custom motor mounts but that is about it. I am not even sure if I will have to remove the hinge boxes for it. the trans already has been hashed out even as far as the shift cable bracket. The trans mount locations are set, drive axles are already figured out, this also already locates the engine as well.

The 3.6/ 6T70 will have a ton more work in these areas that I would have to figure out all on my own. I am not confident that I know enough to make sure I get it right to where I dont drop a shaft from wheel travel, or have binding, or crash in a wall due to bump steer from mounting the trans to far left right front or back.... This ultimately is why I have decided to forgo the power and a better transmission. Also with the LFX will the combined intake/exhaust manifold cause fitment issues? No one knows, I would be blazing a new trail on that and I dont have the required skills or knowledge for those kind of builds.

Will SEP 11, 04:39 PM

quote
Originally posted by Joseph Upson:

The motors come out complete with wiring harness and PCM so the number of sensors are not important as they are already wired and plugged into the PCM, it's the chassis interface end of the harness that has to be worked with and the associated BCM for both will expect to see pretty much the same essential inputs.

bmwguru has what is probably the most impressive and successful similar swap involving the turbo 2.8L version of the 3.6L motor from a Saab swapped in. I didn't review the entire swap thread, but the only complaint about mounting I saw early on involved the difference in the Saab F40 vs. the G6 F40 and having to make new mounts as a result. We have seen nearly every GM motor offered over the past 15 years, or a version of them swapped into the Fiero and some how the 3.6L is not friendly enough to swap, but the 4.6L DOHC Northstar and other V8 motors are? I don't buy it for a second in the absence of EXACTLY what this alleged snafu is to discourage such an effort.

Again it's a swap and will require some far from impossible custom work. With all of the madness I've created, this is exactly the kind of reasoning I would use, get the most out of my effort the first go around, to avoid more time and money fiddling with it later on.



Dude... it's a scale.
Easy: Order brackets, bolt in place, done in a weekend
Medium: Carve the stock crossmember, make some brackets you can't buy
Hard: Blow the cradle apart and frankenstein it back together, build exhaust manifolds from scratch, make your own flywheel

Results tend to go along with the difficulty.

You're saying they're all the same, so why not go for the biggest result. That's completely discounting the extra work involved--for a beginner in this case--which is a silly point of view.

I've seen BMWGuru's work on a different car in person. It is *NOT* impressive.

Yeah, the newer architectures mount the PCM to the engine. Does it clear the decklid?

[This message has been edited by Will (edited 09-11-2019).]

Will SEP 11, 04:44 PM

quote
Originally posted by ChuckR:

The 3900 will require some custom motor mounts but that is about it. I am not even sure if I will have to remove the hinge boxes for it. the trans already has been hashed out even as far as the shift cable bracket. The trans mount locations are set, drive axles are already figured out, this also already locates the engine as well.




GM has had essentially the same accessory configuration in FWD V6 cars since the Gen II V6's right after the Fiero was built. The waterpump is offset forward of the crank, the A/C compressor is low on the front side of the engine with the PS pump right above it. The alternator is on the back side of the engine.

The difference between the normal FWD stuff and Fieros is that the FWD cars mount the alternator so high on the back side of the engine that it interferes with the Fiero decklid. It's also pretty much in the same space as the Fiero dogbone mount.

3800 swaps require a "low mount" alternator bracket and a dogbone mount to connect to the Fiero dog bone bracket. That's a component that hasn't been made yet because the 60 Degree V6 swaps were never as popular as the 3800 swaps. I got started on a Gen II component that would be both low alternator mount and dogbone bracket... it shouldn't take much to update it to a Gen IV version. I can help you out with the design work on that, but I'll own the design afterward.
ChuckR SEP 11, 05:07 PM

quote
Originally posted by Will:


Check out this thread: http://www.60degreev6.com/v...rations-for-swap-use

The car engines have manifolds with dual cats. The minivan engines have older style manifolds with a crossover pipe that should be much easier to adapt to a Fiero than the car style manifolds.

Since AFM/DOD doesn't work without a BCM, don't waste your time with an AFM engine.



I have read that thread too... I have been silently cyber stalking 3900 threads, and there are not a lot of them. I dont think I finished all of that thread though. I might get the Uplander as my donor for this reason. but that will come down to best salvage price with lowest miles I can find more than any certain car.

I know I will need to get my hands on the FSM for both the donor and the 1988 Fiero. I bought the Haynes / Chilton For the Fiero. I also got from eBay a "Pontiac Service Manual" That doesnt look any different than the Haynes when going through it says Bishko Automotive Literature GM Restoration Parts on it but it does say copyright 1987 Gernal Motors Corp on it. So if this isnt the FSM and someone has one for the 1988 GT then I would love a copy please.

Joseph, what all from your experience am I missing or not thinking of that would be needed on the 3900 for a straight swap? Since you went back to ODBI you didnt have to worry about drive by wire, I will have to figure out a mount for a gas pedal. do the 3100/3400/3500 manifolds fit the 3900? if they do do they restrict flow from being smaller passages? can they be ported if that is the case? This is only if the 3900 manifolds will not work in a way I want them to just looking for options. I know you had to worry about turbos on your builds so it may not cross to my project.
ChuckR SEP 11, 05:31 PM

quote
Originally posted by Will:


GM has had essentially the same accessory configuration in FWD V6 cars since the Gen II V6's right after the Fiero was built. The waterpump is offset forward of the crank, the A/C compressor is low on the front side of the engine with the PS pump right above it. The alternator is on the back side of the engine.

The difference between the normal FWD stuff and Fieros is that the FWD cars mount the alternator so high on the back side of the engine that it interferes with the Fiero decklid. It's also pretty much in the same space as the Fiero dogbone mount.

3800 swaps require a "low mount" alternator bracket and a dogbone mount to connect to the Fiero dog bone bracket. That's a component that hasn't been made yet because the 60 Degree V6 swaps were never as popular as the 3800 swaps. I got started on a Gen II component that would be both low alternator mount and dogbone bracket... it shouldn't take much to update it to a Gen IV version. I can help you out with the design work on that, but I'll own the design afterward.




That would be great. I am fine with that.
Hywil has this installed with a 5 speed i forgot which but here is a picture of his install



He did have to delete his hinge boxes, not sure what else he had to do though. But i think he kept the stock alternator mount. I can ask him later.
Will SEP 12, 10:19 AM
Looks like he had to remove the right hinge box because he mounted his alternator high on the front of the engine.
I don't see a reason why it couldn't go basically where it is on the Fiero 2.8.
ChuckR SEP 26, 11:09 AM
So with the 4T65E, is the gearing pretty much the same as the TH125 and just adding an OD and stronger internals with electronic controlled shifting?
Will SEP 26, 11:46 AM
There are a couple different final drive options available inside the transmission as well as at least three chain ratios available.
ChuckR SEP 26, 12:17 PM
So with this motor and trans being set up to push over 1000 pounds more than the Fiero, what ratios would be best for the Fiero? I guess I could spend some time digging through 3800SC threads to find this info, but if you know it off hand that would be great.
Will SEP 26, 03:27 PM
I'm neither a 3800 guy nor a 4T65E(HD) guy. I just know the options are there.
If you turbo it, you probably want the tallest gears.
If you throw rod bolts, cam, pushrods and valvesprings in it and spin it to 7000, you probably want the shortest gears.
If you don't mod the engine, leave the transmission alone too.