LFX 3.6/F23 option (Page 10/13)
Joseph Upson DEC 01, 08:53 AM

quote
Originally posted by Raydar:


There were actually some reinforcements being sold for the 88 cradles. The 88 cradles seem to be more fragile than the earlier ones. I haven't seen them in a while, however.

FWIW, My 4.9 has a 2" x 5" plate welded in where the front tranny mount bolts through. It otherwise uses the normal tranny mounts/locations, in addition to one under the crank pulley, and one on either side of the block, in the "front" corners. (i.e., 5 point mounting.)
It uses no dog bone, and I would venture to guess that you could pick up the car by the engine and shake it until the body panels fell off, and the engine would still be solidly attached. No. I didn't do the install.



On my 86 I cracked the rear tranny mount pad area running without a dog bone while using the proform interlocking poly mounts found at Autozone and Advance. They held nicely but I believe a dog bone would have helped prevent that. I tried solid mounting before and didn't like it.
jetfighterv DEC 05, 03:51 PM
what all do i need to swap the f23 into the fiero because i kave an 87 iron duke and im swaping a 3800 into it any sugestions
mender JAN 02, 11:18 PM
Made some more progress over Christmas. Coolant and fuel lines are hooked up, electronic throttle pedal installed, shifter cable brackets and arms fabbed and installed, bigger fuel cell installed, Koni struts converted to coilovers, some wiring sorted.

Here's what my F23 cable linkage looks like:



I kept the Rodney Dickman 5-speed cables that I've been using, good quality with steel ends, and modified the up-down/gate part like many others by cutting off one end and welding a tab on the other side to reverse the motion. On the fore-aft, I removed the F23 linkage assembly, drove out the pin and had a closer look. The stock arm with the weights has a rubber sleeve between it and the shifter shaft. I cut off the weights and used just the centre part of the arm. I made a steel sleeve that fits inside the centre and over the shaft with material sticking out below the centre, then cut a U-shaped arm to go around the shifter strut and welded that to the sleeve. That allowed the cable to attach about 90 degrees from the stock F23 orientation, allowing the stock cable to be used instead of the extra long custom cable that others use.

I took extra time to ensure that the cable brackets were aligned to have the least deflection and thereby the least resistance to movement. I also went through my rebuilt 4-speed shifter, removing extra pieces and again aligning the shifter cable tabs for least resistance. The result is smooth shifting with a nice positive feel, partly due to the F23 but a noticable improvement over the previous feel.

Edit: fixed! Thanks, Carbon!

[This message has been edited by mender (edited 08-31-2018).]

Steven Snyder JAN 05, 02:05 AM

quote
Originally posted by mender:
There may be a way to reinforce the stock crossmembers to handle the loads. I'm putting a fair bit of stress on them with racing so figured now would be a good time to replace them. No other mods needed to the cradle or structure of the car but I removed the hinge boxes a long time ago so there may be interference in a stock Fiero.



Make sure to box in your front cradle mounting clevises on the chassis. I nearly ripped both sides out of my car due to the lateral forces generated by 275s, and many years of track days. Half of the spot welds were cracked off and I could move the mounts by hand. Seam welding will help where possible, but the best thing is to weld a plate on top of the clevises to box them in.

[This message has been edited by Steven Snyder (edited 01-05-2018).]

mender JAN 05, 03:22 PM

quote
Originally posted by Steven Snyder:


Make sure to box in your front cradle mounting clevises on the chassis. I nearly ripped both sides out of my car due to the lateral forces generated by 275s, and many years of track days. Half of the spot welds were cracked off and I could move the mounts by hand. Seam welding will help where possible, but the best thing is to weld a plate on top of the clevises to box them in.



Good point, and I did that when I built the car in 2013 for Chump racing. It took a very solid hit on the right side at Portland that basically tore off the right rear spindle off the car. Repaired overnight and back on track the next day, cradle didn't move. I run sticky 275s as well and had about 90 hours of track time on the car before starting this next stage of development.
pmbrunelle JAN 05, 06:28 PM

quote
Originally posted by Steven Snyder:


Make sure to box in your front cradle mounting clevises on the chassis. I nearly ripped both sides out of my car due to the lateral forces generated by 275s, and many years of track days. Half of the spot welds were cracked off and I could move the mounts by hand. Seam welding will help where possible, but the best thing is to weld a plate on top of the clevises to box them in.




I think the mounting ears on the body are somewhat easily bendable to accomodate different cradle width tolerances.

So if you do box these clevises in, then your chassis may not be compatible with any cradle other than the one used during welding. But I guess that's better than having your cradle tear off the car.
mender JAN 06, 01:45 AM

quote
Originally posted by pmbrunelle:


I think the mounting ears on the body are somewhat easily bendable to accomodate different cradle width tolerances.

So if you do box these clevises in, then your chassis may not be compatible with any cradle other than the one used during welding. But I guess that's better than having your cradle tear off the car.


A partial fix to to seam weld the outer bracket to the body. Leaves the tabs movable but keeps the spot welds from getting stressed.
Will JAN 06, 04:44 PM

quote
Originally posted by pmbrunelle:

I think the mounting ears on the body are somewhat easily bendable to accomodate different cradle width tolerances.

So if you do box these clevises in, then your chassis may not be compatible with any cradle other than the one used during welding. But I guess that's better than having your cradle tear off the car.



I don't think that's a big deal. The cradles seem to be built pretty well. The ease with which one can do an '88 cradle swap into an early car illustrates this.
mender JAN 09, 10:39 PM
I tried to update the images of my F23 installation in a prior post but only get two little boxes instead of the images.

I went through the procedure a few times but no joy. I took the pictures with my phone then emailed them to myself and downloaded them into Paint. Downsized to 850 pixels wide then tried to use PIP to insert them.

Not sure what I did wrong.

Edit: fixed! Thanks, Carbon!

[This message has been edited by mender (edited 08-31-2018).]

msweldon FEB 13, 05:52 PM
So when do you plan on making more of those f23 bellhousing to lfx adapters?