LS4 / F40 swap - fieroguru (Page 9/216)
Will JAN 10, 09:40 AM

quote
Originally posted by 1fatcat:


Not easily. The F40 uses an input shaft and 2 main shafts. The main shafts BOTH enguage the differential gear (the equivalent of a ring gear in a RWD differential) at all times. To change the final
drive ratio, you would have to change the diff gear and both of the shaft gears. 1st gear is part of one of the main shafts, and 2nd gear is part of the other main shaft. So to change the ratio of 1st or second, new shafts would be needed at the very least, and they would be very expensive...if you could even find someone willing to make them?



GM built a version with 3.94 final drive in the 03-04 Saab 9-3's.
The 1st and 2nd input gears are integral to the input shaft.
dobey JAN 18, 03:37 PM
So did you get her fired up yet?
fieroguru JAN 18, 03:55 PM
Nope... been busy parting out the 2.8/Getrag for funding and room. I did finish the test fit and put everything back on the cradle fixture to finish all the mount tabs, but haven't touched it in a could of weeks.

I also spent a couple of days turning down a Spec LS1 168 tooth billet flywheel to accept the 142 tooth ring gear. I am thinking about making one LS4/Getrag (92-94 HTOB) flywheel and starter mount and put it on ebay to help fund the LS4/F40 swap...

[This message has been edited by fieroguru (edited 01-18-2011).]

mwhite JAN 19, 03:55 PM
Any thoughts about making a LS4 to F40 Flywheel? I was going to have SPEC make one for me, but if you have the ability to make one at a reasonable price I would be interested. And it would be nice to help someone out on the forum too.
fieroguru JAN 19, 04:13 PM

quote
Originally posted by mwhite:

Any thoughts about making a LS4 to F40 Flywheel? I was going to have SPEC make one for me, but if you have the ability to make one at a reasonable price I would be interested. And it would be nice to help someone out on the forum too.



I have no interest in making more LS4/F40 flywheels... they are just too thick and require to much work. The LS4/Getrag is much simplier and easier to get the needed flywheel to start with.

I have kicked around the idea of having spec make me one... but too cheap...
blackrams JAN 19, 07:39 PM

quote
Originally posted by fieroguru:

... but too cheap...



Maybe, but you're rich in talent.

Ron
mwhite JAN 26, 01:35 PM
FieroGuru,
I have a question about exhaust manifolds, and spacing. The LS4 rear manifold angles way from the engine block, and gives plenty of room for the trans and passenger side axle. Using the LS7 manifold that hugs the block more, is there an issue with interference between the down pipe from the manifold and the passenger axle? I am thinking of using some LS2 manifolds, which would be similar in style, but I have concerns about the down pipe. If you could, please post a picture from the from the passenger side wheel well with the axle installed. Thanks a lot.
Mike
fieroguru JAN 26, 01:40 PM

quote
Originally posted by mwhite:

FieroGuru,
I have a question about exhaust manifolds, and spacing. The LS4 rear manifold angles way from the engine block, and gives plenty of room for the trans and passenger side axle. Using the LS7 manifold that hugs the block more, is there an issue with interference between the down pipe from the manifold and the passenger axle? I am thinking of using some LS2 manifolds, which would be similar in style, but I have concerns about the down pipe. If you could, please post a picture from the from the passenger side wheel well with the axle installed. Thanks a lot.
Mike


The LS7 manifolds are similar to most corvette manifolds, they typically do not hug the block at all, just exit straight down from the heads. I do not have any LS2 manifolds to compare them too, but probably the next best would be the 97+ formed stainless manifolds from the Vette and cut the collector bend off of them. They are a formed stainless manifold with integraded heat shields/insulation and are quite compact. Just cut the collector bend off of them and install some band clamps.

There is about 2" of clearance between the exhaust and the intermediate shaft with the LS7 manifolds. It isn't the easiest to see in this picture, but you can make out the closest edge of the manifold to the intermediate shaft.

[This message has been edited by fieroguru (edited 01-26-2011).]

qwikgta JAN 26, 03:00 PM

quote
Originally posted by mwhite:

FieroGuru,
I have a question about exhaust manifolds, and spacing. The LS4 rear manifold angles way from the engine block, and gives plenty of room for the trans and passenger side axle. Using the LS7 manifold that hugs the block more, is there an issue with interference between the down pipe from the manifold and the passenger axle? I am thinking of using some LS2 manifolds, which would be similar in style, but I have concerns about the down pipe. If you could, please post a picture from the from the passenger side wheel well with the axle installed. Thanks a lot.
Mike



Guru, sorry to crash your thread,

Mwhite, Archie uses stock LS3 mani's for those who don't want to use his headers. I went with the headers and have a set of new, never used LS3 manis (for sale). I'll pass some photos of them. They are the Corvette ones not the Camaro ones, and yes there is a differance.

Rob

------------------


88 Coupe, CJB T-TOP, LS376 and a GT clip

fieroguru JAN 27, 06:44 PM

quote
Originally posted by mwhite:

FieroGuru,
I have a question about exhaust manifolds, and spacing. The LS4 rear manifold angles way from the engine block, and gives plenty of room for the trans and passenger side axle. Using the LS7 manifold that hugs the block more, is there an issue with interference between the down pipe from the manifold and the passenger axle? I am thinking of using some LS2 manifolds, which would be similar in style, but I have concerns about the down pipe. If you could, please post a picture from the from the passenger side wheel well with the axle installed. Thanks a lot.
Mike



Here is a better picture of the clearance: