Thanks for the pics and the info, but if you read my other posts you'll know that I'm a very good welder when I'm using the proper equipment. Why grind down and weaken what people won't see? That second pic is an example some "extreme overkill penetration" that you were complaining about earlier. When you're using a bad welder and can't afford better, you have to compensate for it and work with what you have. Its not like I'm even jeopardizing the functionality of my welds or work, just the aesthetics part.

 

Okay, off of the weld topic. So far as the rear end setup- It seems to me that you are leaving a lot of area for flex in the torque arm. When you are transferring that much torque over that long of a distance, it is going to be hard to build something that isn't going to flex up into your gas tank. RX-7 guys use pinion snubbers in addition to solid delrin mounts in a lot of their builds. Even then they can have issues with wheel hop. You are almost certain to have flex like crazy.

I am actually about to go back and redesign my differential mounting, but i can assure you mine is way stronger as it sits right now. I simply built a crossmember to tie the 2 framerails together at the back and made a solid mount to extend forward 6" or so and bolt to it. It leaves you with the ability to adjust pinion angle and ease of removal... and my welds are better with a gasless MIG. lol Just picking on you. The part that i am re-doing is that i can't route my exhaust past the crossbar. I am going to be making a mounting point directly to the rear subframe, and incorporate a snubber type deal to help rid any possible upward flex in even a solid mounted setup.

Just wait til you drive the car. Right now you have no clue the stresses these parts are going to take.

 

that is not extreme overkill penetration that is the proper amount. when you say extreme overkill penetration, i think extreme overkil undercut and falling out the back.....

you say you are very good but the welds I have seen, I wouldnt pay for, but that what seperates you from a backyard builder and a professional fabricator

 

The torque arm fit around the transmission mount so snugly that it almost had to be hammered on. In back of course there is no room for movement as it fits around 3 studs. The two poly mounts in back certainly aren't weak enough to allow for the differential to "flex up into the gas tank". I don't understand how you can possibly think that mounting the differential without a torque arm can be stronger then mounting one with. The length of the torque arm allows for less leverage to be put toward vertical movement as the car accelerates. With a shorter mount, more force is exerted upwards by the diff. Think about spinning a mary go round in a park, is it easier to spin by pushing it closer to the center or by pushing it on the outside? Better yet, think about preventing it from spinning. Would it make more sense to hold it toward the center or the outside? Its basic physics. You tell me how my set-up will ever allow for the diff to flex up. It will never happen.

I will say it once more, creating aesthetically pleasing welds while maintaining structural integrity with a gasless mig is extremely hard. The welds on the torque arm were done with a true mig, and came out perfectly.

On another note, after sitting for easily 5-7 months, my Ls1 cranked for no more then 2 seconds before firing up. It ran like a champ, maintaining 40 psi of oil pressure at idle, and going up to 60 at around 1800-2000 rpm. It ran perfectly, and sounded real strong and healthy. I didn't run it for too long as it only had headers and I didn't want to burn the valves, but it ran long enough to display all the characteristics of an extremely well taken care of, high quality engine. Needless to say, I am more then satisfied. Again guys, thanks for all the comments, including the criticism. Its important to me to receive input, and I enjoy responding, and standing up for my good ideas and quality work.

 

an example of some of my better gasless mig welds


Summit gauges, the engine maintained 40 psi of oil pressure at idle. These should match the black interior nicely.


Brake, and v8roadsters clutch master cylinders.


Had to extend the msd pn 6010 harness to work properly. Routing the 3 map sensor wires through the passage designated for the 2, 4, 6, 8 cyl coil pack wires worked great and looks clean.


Oil pressure sensing tube and msd cam sensor wires.


Water temp sensing device screwed into a coolent pipe mounted by wire ties to the sway bar.


Another pic


How the interior looks now


As for the fuel system, I forgot to mention that we simply removed the in tank pump, plugged the original tank outlet, and put the outlet filter onto the return inlet. Rubber hose goes from what was originally the return inlet (same size as the original inlet) to the single stock fuel line that goes to the engine bay, followed by another hose that leads to a fuel filter, Edelbrock self pressure regulated fuel pump, to the 750 carb. The stock fuel tank breather system aside from after-market clear hose is retained. As for the sway bar, the tabs had to be lengthened to clear the dampener. I MIG welded (with the REAL MIG welder) two tabs onto the original tabs to extend it 2 3/8". We also had to move foreword the sway bar mounts which are now held on by four bolts that go through the frame rails. Turned out real well.

 

Looks like a factory Miata radiator. Are planning to upgrade that one or just keep it? Think It'll be up to the job of cooling capabilities?

 

The torque arm you made will allow flex. If you want to use a physics example here ya go:

If you take a small pocket knife and try to bend the blade, it is going to take a lot force. Now take the same blade, but make it two feet longer. You would have to add so much thickness to the blade to avoid having it bend that you would do best to go with a different design all together.

So you see, by applying the same amount of torque over a longer distance, you are allowing more room for flex in the material. I know you can't bend it by hand. You also have no clue the torque that little bar is going to have to support. If you were to even take the same bar you made but cut it in half and attach it to another cross brace, you would be lessening the stress put on it. All i'm saying is that it would be easy to rebuild it now even stronger, rather than later after you have punched a hole in the bottom of your gas tank.

 

We aren't sure yet. It has two fans, and I don't expect to be in too many traffic situations with this car, where it will sit idling for long periods of time. If it isn't sufficient, we'll upgrade.

Your interest in this is greatly appreciated, I know your trying to be helpful. But that "little bar" is 2"X2" 1/4" thick box steel which is never going to bend or even warp. If having a shorter torque arm is a stronger set up, then why do the world's fastest drag cars have long torque arms? Are you saying that all drag racers including top NHRA teams who use torque arms and traction bars are wrong? Have you ever worked with tube steal? This Torque Arm is over built, take a look at some after market f-body and fox body torque arms, the steal used is lesser grade thiner metal and yet it still holds up to extreme amounts of Torque. I think you need to brush up on your knowledge of the laws physics.

 

I like the whole idea here, but I am concerned about the pvc pipe for the lower water hose.

Speaking from experience, that will deform with heat and you are going to lose the seal most likely at one clamp or another.

It may not happen sitting in the garage at idle, but it WILL happen.

Best of luck with the finsih!

 

Easy there turbo. You obviously have your own ideas of what you are going to do. Some of us have been doing this for a while, and are trying to pass along some knowledge. You can't compare an f-body straight axle to an IRS Miata. Plain and simple. You have less room for ANY ammount of flex, and there will be some. That is all i was saying.

You are young. That means that most of the people on here can teach you a thing or two... if you would be willing to listen and learn. Now go back to school and be sure to actually pay attention in class next time. You obviously have a lot to learn.

 

by the way, it's steel if you are referring to material, steal is what you do to land you in jail

 

Why not just get the water temp from the factory location? I'm sure you could get a bung adapter for your sensor. egauges.com has a lot of various sensor adapter bungs.

Frank

 

Not trying to be mean but pvc? People are very helpful here, please consider the advise they give. If not for your safety then for others on the road.

 

I may be young, but someone who mounts their differential in their 300+ horsepower car without putting the correct washers on the bottom needs to learn more then I do.

Without those washers or "plates" there is nothing that holds the differential in the car. I can't believe you're trying to argue with me about my torque arm and proper differential mounting, when you couldn't even get the most basic part of the process correct. When I looked under the diff, the first thing I noticed was that those washers you forgot to put back in, are the only things preventing the diff from falling out. Its not the poly mounts fault that your diff fell out of car while your friend was trying to beat on it. Its yours for not mounting it properly. You need to reevaluate the way you work, not the way I do.

Thank you, your probably correct the pvc will be replaced.

People who's quality of work allows for their diff to fall out of their car in fourth gear at probably over 100 mph, need to be watched out for, not me. He could have killed himself, his friend, or some innocent motorist with that incompetent blunder. The reason I'm posting here is to get advice, I never said I was an expert.

I'm not an expert speller either

Thank you, I'll look into this.

 

I'd be taking the advice of people who have already put lsX's into their miata's or the like. If they say your torque arm wont hold, it probly wont. I would probly disreguard them and find out the hard way as well as I'm pretty stubborn when it comes to my fabricating. Just saying if you keep bashing others ideas, then you probly wont be welcome on this forum much longer. Good luck with the swap! I'd love to do an LS miata

 

Edit: Taking it to PM's so as not to clutter up a good build thread. I think we all just want to see this thing on the road.

 

how old are you?

 

I'm not continually bashing the ideas of others in any means. I'm changing the pvc pipe to probably copper, will probably buy a fitting from egauges.com, am in the process of strengthening my torque arm, agree that stock suspension is unsafe to run, will box the rear subframe and yes my chassis welds aren't pretty. So far 99% of the ideas expressed on this thread I've agreed with. The only discrepancies I had were with dark_dementshun's idea about my Torque arm...Which we settled through PMs. Along with the idea that my chassis welds won't hold. I do agree I would have been better off using a proper MIG, but all those gasless mig welds will serve their purpose.

Thank you, much appreciated. Glad to see yours is already on the road and tearing up 1/4 mile drag stips with high 11 second times. Congrats

As i mentioned earlier I'm 18.

I brought my Torque arm to my shop class today and started mocking up a brace to go on top. Its a piece of 1/4" thick 2" wide flat STEEL that runs the length of the arm. I'll weld it along the entire top length of the arm upright (the 1/4" part flush with the arm) to make it look like a mohawk. With this on (correct me if I'm wrong) the question of whether it will flex shouldn't even be raised. Both my shop teacher and myself believe this is completely unnecessary, but why shouldn't I take full advantage of the resources provided for me by my school system. Furthermore some of you veterans on here seem to have a discordance with my design, so I'll take your advice. In any case it can't hurt to add strength.

Thanks again for all the input

 

I'm not trying to bash you man, just a couple quick words. Do yourself a favor and don't "rig" stuff. Just do it right the first time. You will thank yourself later when the car doesn't start falling apart everytime you go down the road. When you look back at some of these ideas 10 years down the road, you are going to say "What was I thinking??".

 

If your refering to the pvc, I know...that wasn't the best idea. But we've been doing everything else right. The way were building this car, it'll last for allot longer then 10 years. I'll post some pics of the way my torque arm looks now later on tonight. Its never going to even think about warping. But your comment is good advice to any car builder.