KSwap build thread?

[autox320]

just thoughts real quick using the pic



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honestly relooking at the pic i'd add a few more things; man i'd add a few tubes to that rig

hit me up brother

[AndronPrime]

If youre moving rear steering hubs to the front, to make the rear steer, my guess is that youre going to have really bad ackerman and your car will not turn well at all.

Have you checked the ackerman?

i have checked and it seems fine. I would much rather check after I have my other arms attached so the spindles are not dancing while I turn the wheel. I’ll post a picture ASAP.

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Looks like you’re right! It had been a hot minute since I looked at that, but definitely a good time for me to review it too. Here’s a good ISMA article on calculating it : https://ismasupers.com/downloads/tec...steering-4.pdf

Thanks for this link! I read through it about today but I haven’t had too much down time to finish.

[Erik Dlux]

He probably won't be able to adjust the Ackerman by moving the hole in the front though because it would put the mounting point into the tire...?

I can't wrap my head around the idea of moving the rack and changing the Ackerman. Can you explain or make a drawing? My thinking is that if the rack always gives the same amount of throw side to side, the Ackerman will always be the same. I can't think how you could position the rack so it changes the throw each time in each side.

[Erik Dlux]

i have checked and it seems fine. I would much rather check after I have my other arms attached so the spindles are not dancing while I turn the wheel. I’ll post a picture ASAP.

IMO, unless you're in some competition, don't get crazy with it.

Basically, you just want the inner tire to turn more than the outer tire. Flipping them to the front like you have, when they are designed to go to the rear instead usually does the opposite. It will make the outer turn more than the inner.

If there above is true, not only will your turning radius be horrible but you will get a ton of scrub and maybe even worse things?

[autox320]

heres how I think of it and you guys know I try to be simple and not confuse myself since beer is always involved

ackermann is just one wheel turning at more angle than the other; depending on front or rear steer is what wheel moves faster (left or right)

Lets stick to rear steer for a minute since that's what we have. This goes for rack and pinion only since pit arms etc are a bit different. Rear steer typical diagrams most will show the parallelogram lines drawn when viewed from top of the car. Through control arm ball joints and again through tierod ball joints, then connect by angle lines; theres your parallelogram; great but hard to see without animation or measuring on slip plates what you actually have. The more angled the tierod arms the more ackermann. Some call negative ackermann reverse ackermann but lets not get too confusing

Rear steer; if move the outer tierod balljoint at the hub further rearward we increase ackermann angle of the tierod arms. Same goes for moving the rack closer to the subframe we gain ackermann and make the angle more. Why do this? Well one issue with rear steer is caster. If move the hub forward your moving the tierod outer connection decreasing ackermann. So to fix this either move the outer attachment point or bring the rack closer to the subframe to restore ackermann.

Front steer; now we see how caster changes things adding caster on front steer increases ackermann ie E30/E36/E46 etc. Things are just reverse thinking since the parallelogram is in front of the subframe now.

Can see how much angle you have with a simple angle gauge setup even just printing out angles on a piece of paper. Put the car on the ground and roll the front wheels onto shopping bags ( I like walmart bags when do alignments). These are poor mans slip plates using double layer plastic allows low friction when turning wheels. I do this all the time and can see them in my pics of doing my alignments. When turn the steering wheel till one wheel is at 10deg, then go measure the other wheel and see how many degrees off it is and theres your ackermann. One wheel will turn more degrees and by how much depends on your setup.

http://www.longacreracing.com/techni...rmann%20Effect

[autox320]

parallelogram what? well got the point across with a cup of coffee

lets just say generic terms and trapezoid....there fixed

see should of waited till evening and only responded with beer

[AndronPrime]

IMO, unless you're in some competition, don't get crazy with it.

Basically, you just want the inner tire to turn more than the outer tire. Flipping them to the front like you have, when they are designed to go to the rear instead usually does the opposite. It will make the outer turn more than the inner.

If there above is true, not only will your turning radius be horrible but you will get a ton of scrub and maybe even worse things?

Im trying not to go too crazy but this project is a learning experience and even though the e21 wasn’t in my top 20 favorite cars, I’m having so much fun with the project that I want to invest more into seeing it through completely and learning as much as I can about the more sophisticated things about cars. This is my favorite car I have owned now.

Actually, even without measuring, the e36 spindles allow me much more turn angle than the e34 stuff which was rear mounted steering. Much less bundling and issues going this route. I think the most frustrating thing was not have actually e36 bottoms for my struts because the custom ones I had to make were long and caused the end link to bind. I have a true e36 bottom mount coming in the mail soon so that problem will be fully corrected.

heres how I think of it and you guys know I try to be simple and not confuse myself since beer is always involved

ackermann is just one wheel turning at more angle than the other; depending on front or rear steer is what wheel moves faster (left or right)

Lets stick to rear steer for a minute since that's what we have. This goes for rack and pinion only since pit arms etc are a bit different. Rear steer typical diagrams most will show the parallelogram lines drawn when viewed from top of the car. Through control arm ball joints and again through tierod ball joints, then connect by angle lines; theres your parallelogram; great but hard to see without animation or measuring on slip plates what you actually have. The more angled the tierod arms the more ackermann. Some call negative ackermann reverse ackermann but lets not get too confusing

Rear steer; if move the outer tierod balljoint at the hub further rearward we increase ackermann angle of the tierod arms. Same goes for moving the rack closer to the subframe we gain ackermann and make the angle more. Why do this? Well one issue with rear steer is caster. If move the hub forward your moving the tierod outer connection decreasing ackermann. So to fix this either move the outer attachment point or bring the rack closer to the subframe to restore ackermann.

Front steer; now we see how caster changes things adding caster on front steer increases ackermann ie E30/E36/E46 etc. Things are just reverse thinking since the parallelogram is in front of the subframe now.

Can see how much angle you have with a simple angle gauge setup even just printing out angles on a piece of paper. Put the car on the ground and roll the front wheels onto shopping bags ( I like walmart bags when do alignments). These are poor mans slip plates using double layer plastic allows low friction when turning wheels. I do this all the time and can see them in my pics of doing my alignments. When turn the steering wheel till one wheel is at 10deg, then go measure the other wheel and see how many degrees off it is and theres your ackermann. One wheel will turn more degrees and by how much depends on your setup.

http://www.longacreracing.com/techni...rmann%20Effect

Thanks for another great link! It’s been hectic at work so sorry for the late replies. It will definitely have extra gussets and supports welded in later after I figure out the engine mount situation unfortunately my LH threaded tube ends still haven’t been shipped so I’ll be waiting til the end of the week to set up the forward arms.. Ackermann measurements will have to wait. I also have plenty of space for adjustment for my steering to move towards the subframe. I will however tell mention that the Ackerman didn’t seem to bad from the eye test. I’ll take a video after work tonight to show how it looks at the moment when the wheel turned from lock to lock. I’ll do some more research on antisquat and antidote today to understand it much better.

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parallelogram what? well got the point across with a cup of coffee

lets just say generic terms and trapezoid....there fixed

see should of waited till evening and only responded with beer

It is ok. I understood the post anyways!

[Erik Dlux]

Good info. Thanks for sharing.

It's a whole new world with things like steering racks. Lol

[AndronPrime]

Sorry guys. I was going to do the video for the ackermann but the measurements are just weird without the the rest of the parts I need so we will wait for the time being. Also figured out that the s14, s15 and many other Nissan cars share the same inner tie rod thread pitch so I might be able to make a steering rack solution from some of their aftermarket parts. Still doing some research though.

Lastly, what other potential engine swaps do you think would be cool to see for this car?

[autox320]

Sorry guys. I was going to do the video for the ackermann but the measurements are just weird without the the rest of the parts I need so we will wait for the time being. Also figured out that the s14, s15 and many other Nissan cars share the same inner tie rod thread pitch so I might be able to make a steering rack solution from some of their aftermarket parts. Still doing some research though.

Lastly, what other potential engine swaps do you think would be cool to see for this car?

Far as steering rack can see in my thread we just ground down the outside of a e21 rack, then held by making brackets and 1.5" U bolts

Watch out for drift car aftermarket rabbit hole might not be what your after, but they sometimes have good info and interesting tuning ideas.

Man common engine swaps hmmm M20 cause so cheap and easy IMO for decent power.

[AndronPrime]

Far as steering rack can see in my thread we just ground down the outside of a e21 rack, then held by making brackets and 1.5" U bolts

Watch out for drift car aftermarket rabbit hole might not be what your after, but they sometimes have good info and interesting tuning ideas.

Man common engine swaps hmmm M20 cause so cheap and easy IMO for decent power.

I didn’t plan on doing anything too crazy. But since their tie rods can thread into the steering rack I figured if I can find something the right size it might work. I think even the e36 aftermarket tie rods are too long.

[AndronPrime]

Tomorrow the rest of the parts I need for the forward arms should be here. Hopefully not later in the day. I am thinking about going to pick up the transmission from a pick n pull tomorrow. I took a lot of measurements of the engine and the engine bay. Also made a few ideas from the measurements for the mounts and everything. This engine should be an easy fit. With the Kmiata upper coolant neck, I should be able to put the engine pretty far back in the car which should help with the balance. I should be able to get the transmission in without hammering or cutting.

Even though my plan is to eventually turbo the car I want to at least get the engine running in stock form first and focus on other parts of the build before moving on to the turbo. My mind is already overbuilding the car. (At least when I think about my power goals.) I am getting pretty excited though. going to purchase the adapter for the transmission next month sometime. It feels like this will be a never ending project. I guess all cars are though.

[AndronPrime]

Here are some pics! Sorry they are late. The wheels I got do not clear the tie rods. I also took sometime to mock up the transmission. I’m going to be using a chassis mounted shifter and a shorter DSSR to locate the shifter exactly where I need it. Plenty of room in the transmission tunnel to fit even with the location of the engine being further back. I have to save for the transmission adapter kit. I did however order a stock k series wiring harness and a ECU that I’m going to be using for the K-Pro. Still a long way to go but at least I can roll the car around.

[AndronPrime]

I have not been working on the car recently. I did however get a few deals for Labor Day. I am planning to cage the car while I wait and save for the transmission parts and other parts I’ll want to have before mounting the engine. I am also thinking on if it’s worth upgrading to a fuel cell and completely removing the stock gas tanks and making all final decisions about what I want inside so I can prep the interior for paint. Hopefully I’ll have some downtime soon and I can finally give you a call autox320 and bounce some ideas.

For it the cage, I am thinking about going with my 1-1/2in dom tubing. I am trying to decide if I want .120 or .095 wall. The cars target weight is under 2500lbs going to be keeping it within SCCA rules just Incase I decide to have even more fun with the car. The cage will be 6 points and I will be using mild steel!

[autox320]

I have not been working on the car recently. I did however get a few deals for Labor Day. I am planning to cage the car while I wait and save for the transmission parts and other parts I’ll want to have before mounting the engine. I am also thinking on if it’s worth upgrading to a fuel cell and completely removing the stock gas tanks and making all final decisions about what I want inside so I can prep the interior for paint. Hopefully I’ll have some downtime soon and I can finally give you a call autox320 and bounce some ideas.

For it the cage, I am thinking about going with my 1-1/2in dom tubing. I am trying to decide if I want .120 or .095 wall. The cars target weight is under 2500lbs going to be keeping it within SCCA rules just Incase I decide to have even more fun with the car. The cage will be 6 points and I will be using mild steel!

No problem man anytime.

On the tubing heres my post, but gist is I'd go for .095 x 1.5 cause you'll end up getting more weight out and be under the 2500. It's like crack to shed weight vs having gobs of useless power. Having ltw helps in all areas once have good suspension. Speaking of I just preliminary gross weighed+cross weighted the M3 with ballast and it's at 1860 wet. Granted I'm not done yet but for a full built M car it's already looking to be a real handful.

https://www.bimmerforums.com/forum/s...1#post29660361

[AndronPrime]

No problem man anytime.

On the tubing heres my post, but gist is I'd go for .095 x 1.5 cause you'll end up getting more weight out and be under the 2500. It's like crack to shed weight vs having gobs of useless power. Having ltw helps in all areas once have good suspension. Speaking of I just preliminary gross weighed+cross weighted the M3 with ballast and it's at 1860 wet. Granted I'm not done yet but for a full built M car it's already looking to be a real handful.

https://www.bimmerforums.com/forum/s...1#post29660361

I can’t find 1.5x.095 wall locally which is kind of lame. I’ll have to order the tube online and deal with freight cost.. I’ll search a little further than local first. This week I’ll gusset and make the engine mount points on the subframe so I can get it powder coated. I have to pick a color too. It rained randomly last week so I want to get anything with bare metal covered. I’ll likely wait on the cage in favor of getting the drive train in ASAP. With freight cost I would assume the tubing will likely cost me a ton more than I anticipated. So I’m going to just use all the money to get the transmission adapter from K-Miata. After I have that I can work on the engine mounts, transmission mounts, oil pan, wiring harness, radiator and a tons of different things needed to get the car running. I’m actually feeling pretty excited for this project to make that jump so I’ll delay the cage for the time being. Also, I have not fully welded my front end on. I was thinking of converting to a tubed front end still. But I’m not worried about that for now. I’ll show the subframe when it’s completed. I am also considering making a heavy duty jig for the subframe so it can be reproduced.

[Somjuan]

Define locally, because if you can find some up around Sac I could make that happen for you

[AndronPrime]

I will be looking into sac shortly along with some other areas that are 1-2hours away. I don’t mind renting a truck for the right price!

[autox320]

I will be looking into sac shortly along with some other areas that are 1-2hours away. I don’t mind renting a truck for the right price!

My local steel shop doesn't carry DOM tubing either. Had to drive 2hrs roughly to Denver NC, but once there they have it all as they feed Nascar and other teams. All tubing I've bought there was seamless square/round and super clean steel I call it the candy store.

Funny thing though about my local place they can order full sticks (20ft) of the sprint car tubing I like to use (3/4x.120 moly) very low cost from their connection in GA.
If cost and freight/distance is an issue then by all means go with what makes sense. If can only get .120 I'd just get local. Just make sure no ERW ie seam.

[itsbrokeagain]

Just stumbling upon this thread now. I had my eyebrows raised at the thought of a front mounted rack because this would open up options to possibly use later BMW engines that have the sump mounted in the rear. Unfortunatley to mount up an E36/46 subframe would be quite a challenge along with making sure your lower control arms are welded up in the right areas.

I managed to get my hands on an E21 for practically nothing so I'm using it as a test bed of sorts. One is involving an M57 swap but the oil pan/pickup presents some considerable issues. Making my own oil pan with baffles and somehow making a front mounted oil pickup seems much easier (despite still being a challenge) than figuring out suspension geometry lol.

[AndronPrime]

My local steel shop doesn't carry DOM tubing either. Had to drive 2hrs roughly to Denver NC, but once there they have it all as they feed Nascar and other teams. All tubing I've bought there was seamless square/round and super clean steel I call it the candy store.

Funny thing though about my local place they can order full sticks (20ft) of the sprint car tubing I like to use (3/4x.120 moly) very low cost from their connection in GA.
If cost and freight/distance is an issue then by all means go with what makes sense. If can only get .120 I'd just get local. Just make sure no ERW ie seam.

I haven't given up yet. I will continue looking for 1.5x.095 tubing. I did take a break from the car for the last few of weeks though. I did order my transmission adapter tonight. Should take about 4-5 days to get here. I have to figure out how I want to make the engine mounts now. I also thought of some other ways I could design the front subframe but I am going to keep improving my subframe until everything is set up. After that if I really want to redesign the front subframe I will do it. The only reason I would think of doing this is to make the oil pan larger for a bigger sump.

Just stumbling upon this thread now. I had my eyebrows raised at the thought of a front mounted rack because this would open up options to possibly use later BMW engines that have the sump mounted in the rear. Unfortunatley to mount up an E36/46 subframe would be quite a challenge along with making sure your lower control arms are welded up in the right areas.

I managed to get my hands on an E21 for practically nothing so I'm using it as a test bed of sorts. One is involving an M57 swap but the oil pan/pickup presents some considerable issues. Making my own oil pan with baffles and somehow making a front mounted oil pickup seems much easier (despite still being a challenge) than figuring out suspension geometry lol.

I mean, I could still figure out a way to mount a steering rack up front but I decided to go rear so I can make use of the stock E21 steering rack. After doing some measuring today I will have to make some more changes to the way my rack is mounted to the subframe. Mostly because I want to make sure the engine can go as low as possible. With the way my rack is mounted plus the subframe I will have to cut just to make the stock stuff fit underneath the engine the way I want. I think I will move the rack closer to the subframe which means I'll have to double check my steering geometry again to make sure I can get it perfect.

Lastly I will try to upload videos to youtube and try to improve the quality of them so they are actually watchable.

[AndronPrime]

Ok back again! Still as indecisive as ever. Remember I bought a car a couple months ago to cut the front end of it out to weld to my car? Now I’m leaning towards tubing the front/rear end since I found a local source I can pick up 1.5x.095 wall tubing from. The worse part is. I’m very indecisive of whether I want to get the car running as soon as possible or if I would rather complete all the chassis work first since I have a source for metal. Unfortunately while saving for a house. I don’t have the funds to make both happen at a fast pace. However, getting the chassis work done will end up cheaper than getting the engine running even though I already have the transmission adapter, engine, and ECU. Mostly because the chassis work is just labor. The metal itself isn’t all that expensive. I also finished the prototype front subframe. Of course the final version will get some more reinforcement and powder coat. With some needed adjustments. Same with the rear subframe too. List wise, this is what I have for some of the larger things that need to be done.


Chassis/Interior :
Roll cage
Front Subframe (Final)
Rear Subframe (Final)
interior/Truck sheet metal
Fuel Cell mounting
Battery mounting
Tube Front (Possibly Rear)


For paint, I have a booth I can rent so it’ll be cheap to paint the interior.


Running Car :
Radiator
Fuel System
Brake System
Drive Shaft
Exhaust
Intake/Throttle body
Hose/Sensors
Engine Refresh/Rebuild
Clutch/Clutch Master Cylinder
Fluid reservoirs
Battery mounting


There are ALOT of misc. stuff that I will probably run into and need to get the car completely running. Even after the car is running I will have to pull everything to do the chassis work anyways. A lot of people would rather see the car running first though.


Lastly, I will likely be heading to So Cal in December so if anyone may needs some parts I may have what you need. Can’t vouch for the condition of some of the mechanical things though.

[AndronPrime]

I wont be posting too much here and definitely not often so if you would like to follow the build I made a youtube channel awhile ago! feel free to see the updates here!

https://www.youtube.com/watch?v=zrnmxhUiR7I

Today I spent a fortune in metal for the roll cage and to make the interior look abit better with some new sheet metal. I also completed my engine mounts a few days ago! After that I discovered that TFworks actually made a RWD S14 with a K24. They also developed a kit that comes with a front sump pan which makes it possible to even use the E21 stock subframe for those interested in this swap! My redesigned subframe will be the final product. I decided to design it around the TF works kit! I will be working on the roll cage and the Strut towers first. After that part is done I will be doing a new front and rear subframe. I am using a similar design to the rear subframe in the pictures linked below. My build spreadsheet has gotten really long but I am loving this project more and more everyday!

[e30allday]

nice thread!

[autox320]

I wont be posting too much here and definitely not often so if you would like to follow the build I made a youtube channel awhile ago! feel free to see the updates here!

https://www.youtube.com/watch?v=zrnmxhUiR7I

After that I discovered that TFworks actually made a RWD S14 with a K24.

Thats the swap I keep referring to. They still had oil issues on track even after every baffle available for the K swap motor (mainly the front one keeping oil off the chain under braking). Still drops when going around course. IMO with a motor output like that eventually will be catastrophic rod bearing failure and game over. Needs dry sump or a solution to the issue when using wet sump when mounted inline configuration.