PorSTi Project Thread…, Well that was fun, time to make some upgrades! Options

[DBCooper]

My MR2 shifter was modified to sit flat and fit, but my son mounted his a little higher with some home improvement store brackets so it just bolted up:

(IMG:http://www.914world.com/bbs2/uploads_offsite/i379.photobucket.com-2618-1422818516.1.jpg)

(IMG:http://www.914world.com/bbs2/uploads_offsite/i379.photobucket.com-2618-1422818516.2.jpg)

Pretty clever, cheap, works well, and no need to cut anything. He's apparently smarter than I am.

[Amenson]

Pretty clever, cheap, works well, and no need to cut anything. He's apparently smarter than I am.

That looks wonderfully simple and effective, unfortunately my unrelenting need to over engineer everything will result in a solution significantly more effort that that. I really want the shift knob to be located adjacent to the steering wheel. I am considering using only the pivot block and linkage from the MR2 and putting it on an elevated base like this:





I have also considered changing the motion ratios and having a much longer shaft like this:



I am concerned that the second option would really magnify any slop in the linkage/cables.

How is the slop in your son's car?

Cheers,
Scott

[DBCooper]

How is the slop in your son's car?

It was good before and he says it's better now, but since I haven't driven since then I have to say I don't know. Mine's very good and I think probably good enough to work well with your long lever. Too bad you're so far away, when people ask me questions like that I usually give them my keys and ask them to try to not hit anything. Unless they're drooling or I'm pretty sure they're nitwits, those guys just get a ride.

[Amenson]

Too bad you're so far away, when people ask me questions like that I usually give them my keys and ask them to try to not hit anything. Unless they're drooling or I'm pretty sure they're nitwits, those guys just get a ride.

You are a brave man letting people drive your car. The only people who have driven the PorSTI are my wife, father, mother and buddy Jake. The only reason Jake got to drive it was he helped build my garage...and he is the most careful guy in the entire world. (IMG:style_emoticons/default/driving.gif)

Does anybody have a tail shift engine mount laying around that they would be willing to sell? I am looking at reworking the engine mount to correct the slight lean and thinking that I should get rid of the huge cast side shift bar while I am at it. The tail shift bar seems like it should be much lighter. I am also considering making a bar but really do not need another project.

Cheers,
Scott

[DBCooper]

You are a brave man letting people drive your car.

Ha ha, I think you actually meant "foolish", no?

The only people who have driven the PorSTI are my wife ... mother... (IMG:style_emoticons/default/driving.gif)

Well now if you ask me THAT was pretty brave.

[Amenson]

The only people who have driven the PorSTI are my wife ... mother... (IMG:style_emoticons/default/driving.gif)

Well now if you ask me THAT was pretty brave.

Not really, the wife knows that if anything happens to the car it will result in extended garage time. My Mom's daily driver in the summer is an E-Type, she is classic car approved.

Cheers,
Scott

[ruby914]

Scott,
I am working on a pitch mount of sorts. It looks like you may have this area of your car clear to look at so I thought I would show you what I have come up with. I don't hear much chatter on the need for it but I think I will feel better with it tied in on top.
I picked up an aftermarket VW bug urethane motor mount. The plan is to weld some mounting points to both sides of the rear firewall, bolt the motor mount to that and then to the trany. I will have slotted holes for and aft at the trany and a nut plate with slotted holes up and down at the fire wall. The fire wall has a joggle in it so I will use a partial spacer there.
I will try to up date my thread as this progresses...
Oh, and I made a 1/2" tube frame riser for my shifter.

[914GTSTI]

Scott, has anyone used the plastic MR2 shifted ?
Randy

[DBCooper]

Not really, the wife knows that if anything happens to the car it will result in extended garage time. My Mom's daily driver in the summer is an E-Type, she is classic car approved.

Wow, good taste, good sense and good genes. Good job on all counts!

[Amenson]

Scott,
I am working on a pitch mount of sorts. It looks like you may have this area of your car clear to look at so I thought I would show you what I have come up with. I don't hear much chatter on the need for it but I think I will feel better with it tied in on top.

Oh, and I made a 1/2" tube frame riser for my shifter.

Your shifter is what got me thinking about improving the shift knob placement!
Unfortunately I do not have your composite skills so I have to make sure whatever I build is aesthetically pleasing...although your tube frame is pretty nice looking too.

I think with factory rubber Suby mounts, the pitch stop could be beneficial. I am replacing the engine mounts that I busted with the J-west urethane part and the mounts that I am making in the back are nearly solid so I should not have much engine motion at all. (IMG:style_emoticons/default/wacko.gif)

Scott, has anyone used the plastic MR2 shifted ?
Randy

I think that the stick to cable motion is not correct with the plastic shifter.

Cheers,
Scott

[914GTSTI]

Thanks Scott.

[Amenson]

Finally took the time to remove the STI DOJ's from the axles. They are in really good shape and both fit the LSD!



It is amazing how much plunge the joints have. Definitely do not need floating axles with this type of joint.

I started pulling apart my extra suby trans so I took the oportunity while the center diff and other parts where off to weight it. Came in at 105 lbs. Measured a 901 and it is 80 lbs. Both were dry.

I decided to make my own engine cross bar. Considering using 1x1.5" rectangle tubing .120" wall (A513). Any FEA geeks out there want to provide feedback if this will be strong enough? Engine should weigh ~300lbs + a bit for exaust, intake etc.

Still looking for another phone dial or two.

Cheers,
Scott

[914forme]

Do you want the Lotus approach - its to heavy. Weight is not the only stress it has to endure. You have torque and forces induced by engine rotation. The arms become a huge lever. With out putting it through modeling or real world trails its just a guess.

My approach is go stronger, because not knowing your design, means I have to compensate for things beyond my current understanding. I just built my transmission hangers, well they are in mockup and tacked together. I used 1.5" DOM with a 0.125 inch wall. It is most likely over kill, but I had it and well thats the best metal to use, free!!! I ended up using the factory bar from a tail shifter because I had it around, and I bored the bolt holes out for 1/2" bolts, because thats what my Energy Suspension bushings required. It is also most likely over kill. But the engine mounts I picked up where built from 3/8 inch plate. The original ones I was building was 3/16" So I might have been wrong or Small Car, decided they wanted the no pictures of it yet.

But here are my trans hangers. Still need a little fitting, the gap is a little wider than I like. I now know why Ian went with Angle for his trans hangers. Hold it in place, mark, cut, and done. I am a masochist when it comes to working with metal. So much pain for so little pleasure. (IMG:style_emoticons/default/headbang.gif)





I might be adding the Subaru mount piece to them also, to tie them together. Not needed, but I am thinking of using it for a place to mount a wheel, just in case I need a wheelie bar. (IMG:style_emoticons/default/lol-2.gif) In reality, it would be to have a location for a caster to make the engine easier to move about.

[Amenson]

Do you want the Lotus approach - its to heavy. Weight is not the only stress it has to endure. You have torque and forces induced by engine rotation. The arms become a huge lever. With out putting it through modeling or real world trails its just a guess.

My approach is go stronger, because not knowing your design, means I have to compensate for things beyond my current understanding.

Still need a little fitting, the gap is a little wider than I like. I now know why Ian went with Angle for his trans hangers. Hold it in place, mark, cut, and done. I am a masochist when it comes to working with metal. So much pain for so little pleasure. (IMG:style_emoticons/default/headbang.gif)

Ya, about those gaps... (IMG:style_emoticons/default/barf.gif)... (IMG:style_emoticons/default/lol-2.gif)
I see one of the tube mockup thingies in your picture. Does it help?

I am in the same boat. I know that the current bar works but is way beefy. Something lighter will work, just don't want to risk going too light. Luckily somebody (IMG:style_emoticons/default/shades.gif) is providing a tail shift engine bar for me to use or reference for material selection! See you Thursday.

Cheers,
Scott

[914forme]

Ya, about those gaps... (IMG:style_emoticons/default/barf.gif)... (IMG:style_emoticons/default/lol-2.gif)
I see one of the tube mockup thingies in your picture. Does it help?

I am in the same boat. I know that the current bar works but is way beefy. Something lighter will work, just don't want to risk going too light. Luckily somebody (IMG:style_emoticons/default/shades.gif) is providing a tail shift engine bar for me to use or reference for material selection! See you Thursday.

Cheers,
Scott

Quick answer Nope thus the reason for the gaps!!!!! I hate copying others work, but Ian had the right idea here. Easy to mockup, scribe a line, cut, and well, weld in place. It could also allow the brackets to be smaller. Which would help with leverage on the mounts and other factors. With out going into a bunch of force calculations, it becomes basic physics. Less leverage on a given point if it can be avoided, means less stress on the given point, thus lighter materials can be used.

The issue with the tube tool is keeping it oriented correctly, keeping a constant angle on the tube that matches the finale angle of the production piece. Then be able to get it in there. So I marked a line on the tube. Marked a line on the tool, always keep the two on the marked lines. And still got a gap. (IMG:style_emoticons/default/headbang.gif) It was closer than if I had done it with a pencil, and just guessing, but not close enough for me to say it was easier.

If some one has an easier way, I am open to suggestions. Wood dowels, build a prototype, and then recreate it with metal. I used to do it with a roll of tape, and a sharpie, it works. I have also used a holes, but that works in fitting two tubes. This should have been a simple angle calculation.

(IMG:style_emoticons/default/idea.gif) I could weld up a box section, two sides to build the angle then make a pattern and for the other two sides and fill it in. (IMG:style_emoticons/default/welder.gif) That would have been way easier, and could be made just as strong or stronger do to better joints. And I would have been done, when we had a nice day to weld outdid yesterday (IMG:style_emoticons/default/headbang.gif)

Tube is just so sexy though, I keep going back to it.

[76-914]

If you want "lighter" go with 4130 .095" chromoly.

[mgp4591]

Have any estimates about the weight of your homebuilt cradle? I'm thinking of using rectangular tubing also because it may be easier to mock up and provide some great torsional rigidity...

[914forme]

Chromoly lol, Im a CSOB, I had the 1.5 in my metal bin.

BTW, I just got done talking plasma CNCs with a co-worker, when we started talking my pipe fitting issue. He said I need this book, it solves all my issues. Pipe Trades Pocket Manual head to Amazon, no new ones in stock, one used. Okay, well, easy enough I am willing to learn.

Then I was walking away and thought oh crap, I know how to do this!!!! (IMG:style_emoticons/default/headbang.gif) 4 hours of frustration would have been ended with a few steps.

Mark the plate with where you want the center of the tubes to land. Drill a hole big enough for you to pull a piece of wire through.

Bolt everything up

Pull the wire down and pass it through both holes. 2 points create a line.

Now I have all the information I need, measure the angles. Duplicate it in tube form.

Am I correct in this thinking?

Still might be easier to do it in flat sections and build the box.

Sorry for the thread hijack here Scott.

I'll start a new thread to see if I get better answers.

[Amenson]

Sorry for the thread hijack here Scott.

I'll start a new thread to see if I get better answers.

This is a good discussion. I will be doing something similar once I get my engine square with the chassis again.

[Amenson]

Moving along with progress, just stockpiling parts now.
I am considering using the AL front 911 cross member when I swap the front struts. I know, it is supposedly less stiff, but...I kind of like it so I may use it. Unfortunately my suspension setup was missing the bracing straps, or whatever they are called.
The think pointed to below:



Anybody have a pair that they want to sell or measure so that I can make them?

Thanks,
Scott