Final started chassis stiffening ...

[heavy85]

I notice many people who use 2x3 tubing lay it flat (2in high x 3 wide) I assume that this is to lessen the protursion through the floor, but wouldnt you actually want it the other way from a structural point of view? I imagine much more vertical load the horizontal.

 

Short answer is ground clearance. 1x3 and you dont have to cut into the floors (reason I chose this), 2x3 and you need to cut a slot and recess into the floor, 3x2 and you'ld have big bumps under your feet but your right 3x2 would be the best for this application if it would fit. If I had not needed new subframes I probably would have tied a 3x2 or 3x1 or similar into the rockers (see other threads for examples) and left the subframes alone.

 

Well you probably don't want to here this but I would have tried to tie the K frame back into the frame rails and not the TC cups.

 

I am actually confident with the SFC tied into the TC buckets and a tube from the TC area to the rockers (yet to be installed ... need to order some steel) along with a gusset from the TC to the framerail (yet to be installed in pics) that tying into the TC cup is better from a load path standpoint.

 

I am not sure what engine you are putting in or why you need a K frame

 

LS1 and I 'need' a k-member because I strongly believe that to be the most efficient method and will add the most stiffness to the chassis with a side benefit of mounting the engine. No offense as your mount is probably effective to mount the engine but I dont believe does a lot for stiffening the chassis and appears to be heavier.

 

My header on the passengers side comes out just behind the motor mount on my cross member. In fact, you can see the left and right sides point in opposite directions. That is because I had to move the passenger's side mount forward an inch just to get clearance for the JTR LS headers.

 

That sucks 'cause if that's the case then plan B may be in order. Hopefully the UPS man will be kind and deliver my headers tomorrow and well see for sure.

 

Cameron

[Pop N Wood]

No offense as your mount is probably effective to mount the engine but I dont believe does a lot for stiffening the chassis and appears to be heavier.

 

There is nothing to be offended about. I chose to copy Mark Ickards mounts because it looked like they would give me the most flexibility in mounting the motor. They were never indended as anything structural. As for weight, I keep wondering if I made it heavy enough.

 

Will be interesting to see what your header and starter clearances turn out to be. I think the passenger's side exhaust flange will end up pointing right at that cross piece. I know my starter is sitting not a half inch from the TC cup.

 

If you mount your motor higher and a little farther forward then mine you might be able to run the exhaust next to the rail and under that cross piece. Hard to tell without looking at it in real life though. Mine is so far back I am moving the heater hose penetrations.

[heavy85]

Well I still dont have my JTR headers - apparently they shipped just not to me so it'll still be a few days. It'll be tight to get the exhaust through there but I'm still holding hope it'll work. Starter fits fine

 

 

Since I'm waiting on headers to start the engine mounts I moved on to the transmission mount. It's tied into the subframe as I'm of the opinion the tranny tunnel weakens the middle of the car so tying the sides together is a good thing. I obviously still have to cut the arches for the exhaust and figure out a way to attach to the vertical plane of the tunnel to get the full benefit of tying the sides together. Anyway here it is in process.

 

 

Cameron

 

PS - this is something new as for some reason spell check is now on as I type?

[LLave]

Very nice. Keep the updates coming:)

[1 tuff z]

cameron, now i know why you haven't been working on the q45 front diff mounts. u been a buzy boy! tons of progress, got the headers yet?

[heavy85]

cameron, now i know why you haven't been working on the q45 front diff mounts. u been a buzy boy! tons of progress, got the headers yet?

 

Must be a different Cameron as I'm still using the 300ZX LSD R200. No luck on the headers as they've (JTR) screwed up twice now. First they sent them to someone but it wasn't me and then they lost my order when they were suppose to send them the second time and now they were suppose to go out on Tuesday with four day shipment so we'll see if they get here on Monday. Friday will be three weeks from initial order.

 

Cameron

[heavy85]

Woohoo the passengers side JTR header will clear the k-member ... barely but close enough

 

 

Now to the engine mount. It took a lot of pondering to get to this. You quickly realize that the mounts have to be fairly far forward - especially on the passengers side once you get the headers on. I started with the SBC to LS adapter plates on the drivers side (e-bay) then built a tower from the cross-member up to the mount. I will go back and add a leg down to the k-member for more support. The passengers side is a whole different story but I'll post that later when I get it done. I could have just tied into the frame rails instead but for efficient load path reasons I wanted to keep the engine mounted to the cross-member.

 

Top view

 

Front view

 

Bottom view - this is where you can see where I will tie in from the main mount back into the k-member.

 

PS - for exhaust I decided to go with a cross-over in the middle and two round Magnaflow straight through mufflers that will exit just in front of the rear tires. Should look and sound bad-a$$ ... I just hope it's not so loud I want to wear ear plugs going down the highway.

 

Cameron

[trwebb26]

Lookin good, Cameron.

[heavy85]

It's been almost a year since the last update so now I'm done with the front end ...

 

Connecting rockers to upper frame horn and to SFC and a little rust repair (the shark in the middle).

 

 

And the finished k-member / engine mounts and strut tower to firewall bars (although a little hard to see in the light). With a combination of the k-member and the SFC to rocker bars it really makes for a nice straight way to distribute input loads (from suspension into crossmember) into the main structure.

 

 

And the money shot. It's now running.

 

 

Now that the front is about done I'm mostly happy but would probably do something different with the SFC next time. Now time for the back-end. Since everything is so much closer relatively it already seems worlds better than the front. I'm at least adding a harness bar and eventually a rollbar but otherwise nothing is really coming to me yet.

 

Cameron

[heavy85]

So probably the last installment to this thread. Added a rear strut & harness bar. That rollbar tubing is heavy stuff! It's also a lot easier to weld than the thin sheet metal on the rest of the car. This is all I'm doing to the rear at least for a while until I have a rollbar installed ... some year from now. Obviously I'm anxious to see how all the works out on the track but I'm sure I'll have future posts on that.

 

 

Cameron

[EMWHYR0HEN]

Looking good Camron, Fast progress!

That reminds me, I need to get to work as well!

 

by the way, have you gotten the engine running yet?

[jeromio]

My car is back up on jackstands and I am doing massive amounts of chassis work. Mostly rust abatement. My front chassis "torque boxes", which lie below the vent drains, are totally rusted out on both sides.

 

In the dreaded "while-I'm-at-it" death spiral, I am pondering an alteration to my mount scheme. I too have the K and I have almost 100% of the tower mounts on the arms of the K, using the stock fbody motor mounts. I do have some latereal "stabilizer" arms that tie to the upper part of the (re-enforced) frame rail to squelch any side to side movement. Trouble is that these arms will interfere with headers - I have stock FBody manifolds on now. I like your variation and it shouldn't be too hard to adapt to it from what I have now.

 

You said that you used "SBC to LS adapter plates". Which rubber (or poly) mounts did you use: stock LS1 fbody style or SBC units? What did your passenger side end up looking like - the same SBC adapter plates used?

 

If possible, I would love to see more pics of the headers and how they fit - I think my K is almost identical to yours, but I can't imagine headers fitting - there's barely enough room for the 2 1/4" pipe off the manifold on the pass side to run betw frame rail and starter as it is.

[heavy85]

You said that you used "SBC to LS adapter plates". Which rubber (or poly) mounts did you use: stock LS1 fbody style or SBC units? What did your passenger side end up looking like - the same SBC adapter plates used?

 

If possible, I would love to see more pics of the headers and how they fit - I think my K is almost identical to yours, but I can't imagine headers fitting - there's barely enough room for the 2 1/4" pipe off the manifold on the pass side to run betw frame rail and starter as it is.

 

OK so I was halfway though typing a reply when the power went out. Ice followed by sustained high winds which are still howling in the background. Any ... I used Energy Poly SBC mounts. They seem easier since they have ears that go around the frame mount as oppose to the fbody that require the mounting ears to be on the frame if you know what I mean. I bought generic adapter plates that bolt on with the factory LS four mounting bolts but use one of the front mounts to also attach the SBC mount. The plates have two tapped holes for the other two SBC mounting bolts. The look like a square with a triangle attached to the front. Anyway I used them pretty much as is on the drivers side. If you are using the JTR headers you will quickly figure out the passenger side the the tricky one and the mounts have to be far forward of the stock location. For this side I slid the adapter plate forward so it only used the two front factory LS mounting bolts then welded on ears to the plate to pickup two additional mounting holes near the front of the block similar to the John's mounts. This also require drilling and tapping a couple extra holes in the plates. Here's a front shot:

 

 

If you look up several posts you can see the headers come with a nifty 2.5" adapter that is mitered at a fairly sharp angle. These were key in getting the 2.5" exhaust through there. This is also pretty good pic that shows the exhaust and mount.

 

 

 

Looking good Camron, Fast progress!

That reminds me, I need to get to work as well! by the way, have you gotten the engine running yet?

 

Ha Ha - fast progress ... only a year behind schedule. My target was May '07. Looks more like March '08. It's running and only a driveshaft away from being drivable which if all goes well should get it back by end of this week .

 

Cameron