LS4 / F40 swap - fieroguru (Page 183/216)
fieroguru NOV 26, 04:02 PM
Here is a general layout of the clutch disks, HTOB range of motion, pressure plate fingers and release zone.
Trinten NOV 26, 04:54 PM
That is so cool. Damn I am envious of your technical skills (and just general life choices to where you have things like a freakin' lathe.... lol )
85-308 NOV 28, 12:51 PM
Wow. Go away for 10 years and they change everything around on you!
I'm WAYYY back near the start after taking almost 10 yrs off my build due to life and work and other issues, but they're over now and I'm in shape to purse that - the 'straightforward' LS4/F40 swap. (No turbo - I need to get caught up on this, too!)
Anyway, a basic question I hope nobody minds: I'm back nearly on page 1, adapting an LS2 intake over the DoD valley plate and (10 years, sigh) parts have somehow gone missing. I can't find THIS, and I can't come up with a name that Rockauto or Summit or anyone can source it by. Does anyone have a name/link etc for this please? It's 5 pin and I've tried all kinds of names. Any help appreciated!!
And thanks to fieroguru, ongoing, for his impeccable documentation.
Edit; not sure the image is showing. It's the pressure sensor that mounts under the TB end of the intake manifold. Guru did a fair bit of mods to get it to fit in that tight space.

[This message has been edited by 85-308 (edited 11-28-2022).]

fieroguru NOV 29, 08:59 AM
That connector is part of the Valve Lifter Oil Manifold Assembly. I don't think gm sells it individually.

You only need it if you are planning to keep Displacement on demand. Lots of people delete displacement on demand and replace the valley cover with one from an LS2.
85-308 NOV 29, 09:07 AM

quote
Originally posted by fieroguru:

That connector is part of the Valve Lifter Oil Manifold Assembly. I don't think gm sells it individually.
That explains much! Thanks.

You only need it if you are planning to keep Displacement on demand. Lots of people delete displacement on demand and replace the valley cover with one from an LS2.


Exactly what I am doing. Again, thanks for the prompt reply. Saved me hours (this AM) trying to figure out what it was/did/is named. Much appreciated!
GP

PS: I'll be ordering a few more things as soon as I get a complete order together for you. The passage of time has made a few of the things I got 'lose' parts... sigh.
fieroguru DEC 18, 01:53 PM
Flywheel and twin disc clutch are now done.

Sequence of installation
Flywheel:

Bottom Disc:

Floater Plate:

For some reason I missed taking a picture of the top disk.

Pressure plate:


Transmission installed:



With my quest for weight offsetting for the turbo bits, the twin disc clutch is definitely heavier than my last setup.
However, like the turbo, the additional weigh is needed to hold up to 800 hp while keeping the car daily driver friendly, but the additional weight was still kept to a minimum.

For comparison, a stock 2.8 fiero setup is about 15 lbs for the flywheel and 15.6 lbs for the clutch/pressure plate = 30.65 lbs.
LS4/F40 Spec Stage 4+ combo is 11.2 lbs for the flywheel and 28 lbs total after 55K miles of use.
Stock 2000 LS1 is 24 lbs for the flywheel and 32 lbs for the clutch/pressure plate = 56 lbs and this weight is spread over a 2" larger diameter.
LS4/F40 flywheel/twin disc clutch combo is 13 lbs for the flywheel, and 21 lbs for the clutch discs, floater plate, pressure plate and all bolts. = 34 lbs So the setup will be about 3.5 lbs heavier than stock Fiero and 22 lbs lighter than a stock LS1 clutch setup.




The clutch did come with this plate so that it could reuse the stock flywheel/pressure plate bolt patterns... I tossed it as it wasn't needed. This saved 2.5 lbs off the clutch kit as delivered.




Here is a history of my LS4 flywheels:
Original prototype (after 55k miles) - fabricated with manual lathe and mill:


CNC version of original from small batch run:


Protype of the twin disc version - fabricated with manual lathe and mill:


The twin disc version is heavier as there is minimal material taken off the backside:


Now it is pretty much time to start cleaning things, sand blasting them and starting to make then look pretty.

[This message has been edited by fieroguru (edited 12-18-2022).]

Trinten DEC 19, 10:50 AM
Wicked stuff, man!

I'm guessing because of how particular dimensions are between engine/trans combos, this isn't something that would make it to your products page, except for LS4/F40 folks?
fieroguru DEC 19, 09:44 PM

quote
Originally posted by Trinten:

Wicked stuff, man!

I'm guessing because of how particular dimensions are between engine/trans combos, this isn't something that would make it to your products page, except for LS4/F40 folks?



Vince, right now, my primary focus with this flywheel/clutch setup is getting something that will work (streetable and hold) in my car so I can get it back on the road in 2023. Finding a viable manufacturing plan for it is a rabbit hole I am not going down anytime soon. It will likely require a different pressure plate, which likely will require a flywheel redesign.
fieroguru JAN 02, 09:02 PM
I was notified my mill is about 2 weeks from shipment and made the final payment. Started reading through the assembly instructions... going to take quite a bit of work.

ericjon262 JAN 02, 09:17 PM
out of curiosity, why didn't you get a CNC conversion for your existing mill?

------------------
"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

I invited Lou Dias to trash me in my own thread, he refused. sorry. if he trashes your thread going after me. I tried.