LSJ Supercharged Ecotec Swap (Page 7/45)
jmarek78 JUL 07, 02:34 AM
I can't believe I didn't notice this thread sooner... I've had my LSJ/F35 mocked up in the fiero cradle sitting on the floor for a good 4 months now. I tilted mine a little more than the cobalt setup to clear the cradle without any major cutting, and to keep the supercharger and the dipstick out from underneath the rear window. Then I bought a C4 and sorta lost interest in the fiero... but I'm going to start working on it again soon. Have you looked into fabricating the trans mounts yet? I've been thinking about modifying these mounts to fit the fiero: http://bwoodyperformance.co...th=23&products_id=55 ...The rear one should be real easy. The front will probably require me to cut into the cradle, but the cradle should be strengthened at that spot anyway to handle the torque load (I see you've got that covered already). The side mount will be easy to attach to the fiero frame rail and at that point my setup will be the same as what the cobalts are running, so I should be good to go.

I'm glad to see someone else is doing this so I can borrow some ideas

This images is larger than 102400 bytes. Click to view.
ccfiero350 JUL 07, 11:07 AM
Glad to have you on board.
I'm in the process of fabbing the mounts now. In fact I scanned in the poster board templete of the front tranny last night. I do believe I will be replacing the rear cross member with another 2x3 tube. Very much like fieroguru"s here.


As you have observed the rear transmission mnt for the F35 is just too far away for my tastes, from the stock subframe mnt location. And the fact the original crossmember looks like hammered crap now anyway from all the jacks through the years.

Since this is going to be a track car, it will be thrashed on a regular basis and the subframe/engine mnts are to be made to stand the rigors of racing.

------------------
yellow 88 GT, not stock
white 88 notchie, 4 banger

Austrian Import AUG 10, 04:52 PM
*bump* for updates
-M
ccfiero350 AUG 11, 09:49 AM
After a long interuption of working for a living I'm back playing in the shop.
I have replaced the rear cross piece with a strait piece of 2x3 tube. Today I'm going to mockup the engine/cradle again and fab the fore and aft trans mounts. I'm photo documenting as I go and will post the images this weekend to get everybody caught up.

------------------
yellow 88 GT, not stock
white 88 notchie, 4 banger

Austrian Import AUG 25, 03:15 PM
it's the weekend.

*bump for updates*
ccfiero350 AUG 25, 10:41 PM
Finaly sat down and orginized a little to post some updates.

After centering the engine/transmission and setting the driveline hieght the oil pan is too close to the subframe rail.



That pluged port just about touches the frame. So I'm going to cut out a section and weld back in a piece to give it clearance.



Looking down along the original 88 center mount, there is about an 1" of clearance between it and the bottom of the pan. I was hoping I could re-use it but there was any room for things like nuts, bolts and bushings.



I welded a stiffener to the bottom of the subframe to keep everything in place before the amputation.



The section was removed and a piece of 1" angle was welded back in. I capped of both ends. I left the outside wall of the subframe to weld to.



I used the plasma cutter as close as I could the side pieces.



The drivers side. Not really a whole lot of metal holding things together.



The air chisel really worked well peeling the stub sheet metal off. Also did well on removing the bulk of the welds from the good metal. I was later told from a friend two blocks away he could hear the racket inside his garage.

------------------
yellow 88 GT, not stock
white 88 notchie, 4 banger

ccfiero350 AUG 25, 11:18 PM
The factory rear transmission mount was too far away from the hard mnts on the F35 transmission. Rather then doing a funky dogleg transmission mnt it made sense to replace the rear crossmember with 2x3 tube and make a strait transmission mnt. Also raise the tube up to allow me to route the exhaust anywere under it. As a by product it makes it stiffer too.



To get all the compound cuts and notches I used the old trick of wraping the tube in poster board, taped it up and used scissors to cut the paper templete. Then you just slide it back on the tube and mark it.



The top of the new cross member sits 1" over the subframe.



The tube is slotted and fits over the web of the rear chassis mnt tower. This will stiffen it up a little bit.



Here you can see how it's been trimed to fit the back side. Later it will be all MIG welded up.



The factory rear bar and bushing has about a little over 1/8" clearance over the new piece.



Using a polypushing you can see it moves the bar up more. Addco bars use a simular bushing that you have to drill a new top hole.


I've made the front and rear transmission mounts and tacked them on the subframe. I worked on the center mnt today and I'm about halfway done with it. I should finish fabing it tomorrow and will post the transmission brackets pictures then.


Thanks for all the good words.

------------------
yellow 88 GT, not stock
white 88 notchie, 4 banger

Riceburner98 AUG 26, 10:43 AM

quote
Originally posted by ccfiero350:


There could be a very cool little black box if somebodies good with PWM circuits.

Here's the goods to make the generator do its thing all the way.

The L-termanal control signal is a 5 Volt pulse with modulated (PWM) signal of 128Hz with a duty cycle of 0-100%. Normal duty cycle is 5-95%. The either extremes are for diagnostics purposes.

The following table shows command duty cycle and output voltage of generator.
0%______0V
10%_____11V
20%_____11.56V
30%_____12.12V
40%_____12.68V
50%_____13.25V
60%_____13.81V
70%_____14.37V
80%_____14.94V
90%_____15.5V
100%____13.8V

As you can see you could make a Dail-O-Voltage box with this data, if your real good with some programing you can combine timers with inputs so you boost idle voltage when the a/c comes on or just after it cranks for 20 seconds like the factory does.

Some stand alone efi controllors have programable PWM outputs just for stuff like this.




Any idea if the input to the alt. needs to supply any sort of current, or only a few mA? The last PWM box I made with a microcontroller was in the kHZ range, 128hZ should be easy to hit with plenty of processor power left over for checking inputs. If I ever get caught up with all the projects I'm working on I'll have to try this. I printed out the post as a reminder. If anyone's built one already, feel free to let me know so I won't be duplicating work.
ccfiero350 AUG 26, 11:05 AM
I don't know about the input impedance but it's a good bet if it's a 5V logic, it would be TTL.

------------------
yellow 88 GT, not stock
white 88 notchie, 4 banger

Austrian Import AUG 29, 04:21 PM
Thanks for posting the pics. Really cool to see the progress. :-)

Would it be easier to use a non '88 cradle/Fiero, or would there be similar challenges involved in getting the engine mounted?
Would similar problems exist with the alternator when using the stock ECM? (Would have to anyways to make the car C.A.R.B. certified)