Blooze Own: An F355 Six Speed N* Build Thread (Page 66/126)
RCR APR 04, 05:32 PM

quote
Originally posted by fieroguru:

Looks great except one thing... aren't they supposed to be mirror images of each other? It looks like they are an exact duplicate.



They are mirror images of each other, just depends on the plane you're speaking of. By the looks of the plans, they are straight.



With all the bends, I think it's just an optical illusion.

Bob

edit: replaced drawing with edited version per Blooze

[This message has been edited by RCR (edited 04-07-2013).]

355Fiero APR 04, 05:49 PM
Very nice Blooz;

I agree with Bob that the rails do look like they are angled to the left in the bottom picture but it appears to be only the angle of the camera that makes it look like that. Threw me the first time I looked as well.....

Keep the updates coming
Don
Bloozberry APR 04, 06:17 PM

quote
Originally posted by fieroguru:

Looks great except one thing... aren't they supposed to be mirror images of each other? It looks like they are an exact duplicate.



Bob is right... when viewed from the top, the side rails are straight as in the drawing that he reposted. The last photo in my post above does sort of look like they angle off to the left in the background, but as Don said, it's just an illusion. In my second to last photo both are lying flat on their sides on the workbench.

Edit: I've since updated the drawing that RCR quoted above to a later revision. The new revision can be found on page 16 about half way down)

[This message has been edited by Bloozberry (edited 07-26-2013).]

Yarmouth Fiero APR 04, 06:40 PM
When we get our galvanizing done, we are charged per lb of steel they dip but maybe that is because we are usually getting large structures done. I also don't know if the heat will cause distortion in smaller, lighter parts. They are very knowledgeable though and it might be worth a call atleast. You are right about welding afterwards. Its nasty stuff when it burns. Then you must use cold galvanizing to touch up. While still good, its not as good as hot dipping.

The frames look great. Your welds and material are so clean too. You'll notice that because I work so slowly, my material gets a nice oxide coating by the time I'm done fabricating.
Bloozberry APR 09, 08:32 PM
Not a lot of progress to show, but I cut up some more 2" x 3" x 1/8" wall tubing today to form the two cradle cross members:



It's not like it was a difficult task since they're only straight pieces, but I did bring them to my local metal shop for cutting because I wanted the ends to be as perfectly square as possible, and for the lengths to exactly matched. It's hard to do that in a chop saw like mine (cheap made in China), but relatively easy with an automated metal band saw. Once I got the pieces home, I mocked them up to start puzzling out how I'm going to ensure the pieces stay true while I weld them together. I'll probably take it to the professionals where they have nice solid, straight, level welding tables.
cptsnoopy APR 10, 02:58 AM
Looks awesome Dave! I can't wait to see it with the engine and suspension mounted up.

Charlie
fieroguru APR 10, 08:43 AM

quote
Originally posted by RCR:
They are mirror images of each other, just depends on the plane you're speaking of. By the looks of the plans, they are straight.



My mistake. I should have looked at the drawings vs. just looking at the photos.

Keep up the good work Blooze!
el_roy1985 APR 10, 11:12 AM
What are you going to do for the suspension now? The mounting points on the cradle have been moved outward by quite a bit, how are you going to accommodate for that? It doesn't look like you need any more track width, so if you plan on shortening the suspension arms, that will really screw with the way your car handles.
Bloozberry APR 10, 11:37 AM
Thanks Charlie & Guru.

For El-Roy, if you go back to page 16 about 1/2 way to 2/3rds down, you'll see that I designed a completely new rear control arm set-up. You're right... they are considerably shorter than the 3" extended arms I bought from HT Motorsports, but my analysis shows that the extended arms actually hurt suspension performance in several key areas. The performance of the new design is shown higher up on the same page in the graphs. The new design follows the reddish brown curves which show an improvement in every area over stock or any other modification I've studied previously, as depicted by the other colored lines in the graphs.
Bloozberry APR 10, 10:03 PM
I started looking at my drawings to determine where the cradle cross members should be welded to the side rails when I remembered that I hadn't finalized those dimensions yet. I need to take into consideration what engine and transmission mounts I'm going to use, plus have a general idea what the exhaust system layout will be, to be certain that the cross members are located optimally. So I mocked up the new cradle pieces around the engine/transmission and started figuring out where and how I would mount them to the cradle:





I did a bit of research on the internet to get a better understanding of the considerations that go into the design of modern engine mounts and was sorry I looked! It seems it's an entire field of it's own with designers calculating the engine's CofG, bending and torsional characteristics of the block(!), anticipated stresses in fore and aft, vertical, and torsional planes, vibration characteristics of the engine at various RPM's, the characteristics of the rubber in the mounts, and on and on and on! Then, a whole slew of other factors are considered with transverse engines since all the differential loads are transmitted to the mounts as well. Whew! My head was spinning.

To make things as simple yet effective as possible, I decided that the Cadillac engineers must've done their homework in this area and that I wouldn't reinvent the wheel if I could adapt the OEM Northstar mounts to my new cradle. I don't have much to go by at the moment except for two dogbones and two lower mounts and brackets. One of the lower brackets looks specifically designed to go around the automatic transmission on the aft side of the engine block so I don't know how useful it will be, but the mount and bracket on the forward side of the engine looked promising from the get go:



Once it was bolted in place, I noticed that of the two main rubber mounts I had, one was about a 1/2" taller than the other. I tried test fitting both, but the taller one just wouldn't fit between the underside of the bracket and the top of the new cradle cross member.



I don't have the option of raising the engine any further so notching the cross member would've been the way to go if I had only had the taller style rubber mount. As luck would have it, the shorter mount fit perfectly (good thing too... the taller mount was badly rusted and the rubber had failed).





This view shows that I'll have to slide the forward crossmember backwards some more if I want the mount to bolt directly to the cross member rather than to a bracket welded to it. That won't be a problem either way, so for now I'll look at what the Caddy had for a forward transmission mount before setting the forward cross member location in stone.