heavy85

And the best for last. This is what happens when you are pushing down on your wonky floor trying to make it meet the rails and then proceed to spot them in from the bottom. You think your hand is not on top of the weld and well your wrong

I agree with Pete that's 0.065 is plenty strong enough but I was concerned with kinking it with a jack or jackstand or curb etc which is the only reason I went with 0.083. Im my oppinion 0.065 is borderline for that use but I haven't done any testing to prove that out. Here's a crack I found in factory subframe right at the base of the firewall. Appeared to have been jacked by a small jack which caused the crack. If you look close you can see where the were beat up in other places - they actually looked pregnant since the sides bowed out from being bent up by jacking on them .... granted they are a little less than 0.065. Cameron

Yeah that's what I meant. Somehow I missed the page with the mounts themselves so now I can picture the end result. Did you end up attaching the engine to the frame rails on both sides liked you indicated or just to the K-member? Thanks Cameron

Jeronimo - I've looked at your site many times as I'm looking to do something similar but you never show the finished product at least as far as I can see. Do you have a picture of the finished mounts .... preferrably with the engine out. Lastly, looks like you used the factory rubber mounts no? Thanks Cameron

I put them in the top since it's redundant steel with the floor .... kind of like the factory rails only had three sides to make most efficient use of the floor. Actually the only reason I did this at all was because my factory rails were trashed as it's not the most efficient way to add stiffness to the chassis. Regardless I'm not sure I agree with you for all load cases in this application. You are correct that the more the metal is from the center the stiffer the beam will be ... high moment of inertia .... however, I'm more worried by the yield case if you were to bottom out on a sharp object, jack in the wrong place, etc since the section is relatively thin vs the potential normal force that could be placed on it. I wanted to minimize the chance of screwing up (off road, slipped jackstand, etc) and kinking the beam. 1" tall tube is not much then start adding holes and well if you look up at my cracked factory frame rail pic and you can see where I'm coming from. This is the reason I went with 0.083 vs .065 wall was to prevent a jack or jackstand or curb from denting them otherwise this thick stuff is just dead weight. I just wish my factory rails weren't beat up so I didn't even have to mess with this ... and they didn't even have spec of rust on them. Cameron

I believe it's the cheater way for classes that do not allow seam welding. Anyway here's the subframe. It connects to a 2x3 that sandwiches the factory subframe in the rear and the T/C bucket in the front. Overall I'm pretty happy with it other than it took forever to get square and level and symetric. Main thing I'm contemplating is how to lighten it as it's close to 25 lbs. As you can see I've drilled some holes but pissed the wife off in the process and killed a bit so no more big holes anytime soon for me otherwise I would have kept going. The rear crossmember is intended to add some strength by tying the two sides together and also double as a driveshaft safety hoop but once I get to the exhaust I realize it'll probably have to be modified or even made into a bolt-in. The front crossmember is just tacked in to keep it square while I welded the rest but it will be repositioned and will become the transmission mount. Hopefully in then next week it'll be welded to the car. Cameron

Faster than full slicks? Since I'm classed there anyway do you see an advantage other than maybe in the cold? I'm currently running 9.5x22.5x15 R35 Hooiser slicks and am debating what to get next year. Thanks Cameron

Thanks guys for the replies. I guess I'll have to try a smaller blade and make the initial cut then reposition thing ... I dont think I could go much slower as I'm limited now by not tripping the 15A breaker so I have to take it easy whether I want to or not. Subframes are nearly complete without it so later I'll play with this stupid cut-off saw. Cameron

I've got a 14" Dewalt chop saw that's about as worthless as a football bat. First of all the fence is cast at an angle .... on purpose which is OK if you are cutting at 90 degrees both otherwise it holds the metal crooked. Next the blade flexes soo much that you end up about an 3/16" longer on the bottom than the top. I'm so frustrated by it that I've banished it to a $170 pile of scrap taking up valuable garage space. I'm mosting trying to cut 1x3x.083 and 2x3x.083 mild steel for my subframe connectors but I've given up and just use my 4 1/2" angle grinder with a cut-off wheel. What could I be doing wrong as I can't believe this thing could be so useless? Thanks Cameron

Here she is in all her glory on jackstands - the LS1 is under the tarp Crack I found in subframe right at the base of the firewall. Appeared to have been jacked by a rather small bottle jack on the corner which caused the crack. Another misc crack I found. Subframe connectors in progress. I found another crack at the base of the firewall in the lip and a spot weld broken but you cant tell from the pic. Lastly is that the doubler plate had rust behind it on both sides so I removed them and now have to decide how to fix - NOTE this one is tricky in that there is no seam sealer so water is free to get between the base plate and the double and you cant see the rust unless you dig in from the top. I would bet that nearly all Z's have this if you look close enough. Had to remove the front seat bracket which I was planning to anyway since it pushed the floor down just enough the SFC wouldn't sit flush. There was absolutely no evidence the bracket ever moved just manufacturing tolerances. New favorite tool for cutting metal - air chisel but it really sucks for cutting spot welds as it tends to punch through the wrong side. Cutting the factory subframes off really sucked and took forever and the floor still has too many holes in it. I'm finding this to be the biggest piece of crap I own. I can't get a straight cut to save my life. I'm starting to omit the year when I say it'll be on the road on May Cameron

Yes it is a recognized rule of thumb in the engineering world. Cameron

Yeah but 10mm shorter than what. I'm looking for dimensions here and not just 10 mm shorter than stock .... 'cause I dont know what stock is. Thanks Cameron