Icehouse Posted February 19, 2016 Author Report Share Posted February 19, 2016 I really only have 1 place to put my MR2 rack in the car. Transmission says how forward the rack goes, engine says how far down it goes. Mounted the rack using a jig I made for adjusting everything. I just turned the pinion to put the rack at different "widths" to simulate a few different scenarios. With the inner tie rod out where it would be on a stock rack, and tie rod lengths to make the wheel straight, tested with both 510 and 280ZX knuckles, I had massive bumpsteer. And this makes sense as the length of the LCA and tie rod were very different and moved in different arcs. So I made the tie rod the same length as the LCA, moved the inner tie rod pivot inset from the LCA pivot the same as the outer tie rod pivot is inset from the ball joint, and bam no bumpsteer. I had switched to the ZX knuckle to gain steering speed/radius (and ackerman, but less concerned about this). Right now I have S13 front knuckles under my car, just to mix it up some more. Yeah the amount of space for the rack is lacking. There is still enough room to make placement challenging. Did it still feel slow with the ZX knuckles? One car I did like that felt slow IMO. I can imagine the S13 knuckles being faster but drastically lowering the roll center. I test fit a car that way but ended up putting the older style struts back in before I drove it. Is this with your L series still? Quote Link to comment
DrRocks0 Posted February 20, 2016 Report Share Posted February 20, 2016 I should take a picture of my input shaft. We cut the tube back all the way to the firewall to lengthen the intermediate shaft and decreasing the angle on the top u joint. We cut down the output shaft coming from the steering column to keep the threads in the column in good contact. We also machined and moved the connection at the rack down closer to the rack to get the most angle we could. The picture I posted was when I was doing a motor swap, not the rack install. Changing the angles made a big difference. Quote Link to comment
heywier427 Posted February 21, 2016 Report Share Posted February 21, 2016 Taking that a step further, you could cut down the shaft at the rack and turn it into a "double D" design pretty easily. We also machined and moved the connection at the rack down closer to the rack to get the most angle we could. Really. how did i skip that entire sentance :) !!! Quote Link to comment
Icehouse Posted February 25, 2016 Author Report Share Posted February 25, 2016 We recheck the column to rack shaft angle. I don't know why it looks so bad in the pictures. maybe it sagged out something before I took the shot. Because the angles are basically the same. Started modifying the crossmember for the second time. This is for sure going in the car before our next auto cross! Which is in less than 3 weeks. I took a few pictures. 1 Quote Link to comment
Laecaon Posted February 25, 2016 Report Share Posted February 25, 2016 No, I have a Ca18det going in. With a custom pan to keep it mid sump. S13 knuckles will indeed shove the roll center below ground, but then you use the 68/69 crossmember or move the lca pivots up. Which as you showed is normally bad on a stock 510, but when you choose where the rack goes... 1 Quote Link to comment
Stoney Posted March 10, 2016 Report Share Posted March 10, 2016 There is a company is Aus that has just released a complete bolt in kit to suit the Datto 1600 Facebook only page www.facebook.com/largeautomotiveindustries/ Appears to be RHD and LHD compatible Quote Link to comment
Stoney Posted March 10, 2016 Report Share Posted March 10, 2016 Another option to overcome bump steer issues would be to use a centre pivot rack and pinion, like something from a Saab 9-3. I know nothing more about them, such as for turns lock to lock etc, but you can easily modify them to change the centre pivot points to suit whatever. I'd say there is a hotrod style one out there with different ratios and what not to work with older suspension that initially ran a steering box without the need to change steering knuckles. Quote Link to comment
Icehouse Posted March 10, 2016 Author Report Share Posted March 10, 2016 There is a company is Aus that has just released a complete bolt in kit to suit the Datto 1600 Facebook only page www.facebook.com/largeautomotiveindustries/ Appears to be RHD and LHD compatible Damn $2500!!!!!!!!!!!!!!!! Quote Link to comment
Draker Posted March 10, 2016 Report Share Posted March 10, 2016 Comes with the rack crossmember, column, tie rods, lower control arms.. but still spendy!! Quote Link to comment
Stoney Posted March 10, 2016 Report Share Posted March 10, 2016 That's Aussie $$, so roughly US $1900, you look at the kit that Datsport sells, and its nearly $1.5k for a fitting kit, and still uses stock steering setup, albeit a bit more modern (200b stuff) I'm not supporting this product, but in Aus at least, it will come with complete engineering paperwork, be legal, etc Nothing is cheap these days, and by no means was I saying this product is the way to go, but it does show you that an AE86 rack can be used, and this is the way they went about it. For some of people, not having to do all the trial and error work, along with sorting out bump steer etc is well worth the asking price, I'm sure if you employed a third party to install a R7P kit to your datto, it'd cost this much. But that's what I love about this site, and the work you guys do. You get in there and have a go, along with documenting it for all to see. 1 Quote Link to comment
Laecaon Posted March 10, 2016 Report Share Posted March 10, 2016 Also its front sump only. Something I do not like. I have actually converted my CA18DET to mid sump. I have decided in making my own crossmember though. Waiting on a plasma cutter to come in. Quote Link to comment
Icehouse Posted March 16, 2016 Author Report Share Posted March 16, 2016 Also its front sump only. Something I do not like. I have actually converted my CA18DET to mid sump. I have decided in making my own crossmember though. Waiting on a plasma cutter to come in. I've never minded front sump. I've had plenty of low rigs with front sump pans and never had an issue. Mild steel is great that way. It bends out of the way with no issues. I bent my SR pan so bad once it broke the pickup tube off. Didn't leak a drop. 1 Quote Link to comment
Icehouse Posted March 16, 2016 Author Report Share Posted March 16, 2016 We did it! Finally installed and just in time for our last autoX! Sounds like they are going to put on some summer events so maybe I'll get to race more this year! We finished installing the crossmember at about 4am and had to be up at 7:30..... So lets just say I didn't race as well as I'd hoped to. New quick steering with only the drive to the track to get used to it. Then it poured rain most of the day. My summer tires don't like the rain one bit. Sleep deprived and all I somehow pulled off 3rd in RWD. I don't quite understand how. My car was very unpredictable in the standing water. I'm really getting used to the new steering setup and loving it more by the day. So quick and stable. We didn't check the bump on our suspension jig, just not enough time. I'm going to bring my car to my bro's work so we can do some laser testing on there fancy alignment rack. I can't wait to see the bump steer graph. Here are some pics of the progress. It's cool in the autoX pic how you can see the lower unused LCA hole. Its pretty bad ass how you can draw all the parts on the computer and design the suspension and have it work so well in the prototype. I ended up welding all the shafts. With the power rack and a modified down pipe the U-joint was really close to the exhaust. Front sump goon! Had to slightly bend my TC rods because I machined the tappers to deep :( 9 Quote Link to comment
thisismatt Posted March 16, 2016 Report Share Posted March 16, 2016 Sweet! I'll just leave this here... 1 Quote Link to comment
q-tip Posted March 16, 2016 Report Share Posted March 16, 2016 So that's what the wolfman lives on! Jelly beans and coke! 1 Quote Link to comment
Draker Posted March 16, 2016 Report Share Posted March 16, 2016 That is so awesome! Damn dude.. nice work. 2 Quote Link to comment
INDY510 Posted March 16, 2016 Report Share Posted March 16, 2016 That looks great .. :cool: how much did you raise the LCA's? .. if they're one inch higher you can raise the T/C rod pivot like this: Quote Link to comment
Z23T Posted March 16, 2016 Report Share Posted March 16, 2016 Nice job! It will be interesting to see how the bump steer comes out. Quote Link to comment
heywier427 Posted March 16, 2016 Report Share Posted March 16, 2016 Dats the way, uh huh, uh huh, we like it, uh huh, uh huh. Do lots of driving and tweaking :) What it your ground to fender height (gtf) and ground to center of hub (gtc) You guys rock! Would you entertain a "build it yourself" price. You supply the cut pieces, and the person can weld up themselves at a humongous discount :) Quote Link to comment
Insitu_az Posted March 27, 2016 Report Share Posted March 27, 2016 Wow... Nice Rack :-) I really like how this project is progressing. I have been interested in R/P for a while. Keeping the original turbo location would give such a nice stock appearance to the engine bay for an SR510. -Guy Quote Link to comment
GUS-GUS Posted March 27, 2016 Report Share Posted March 27, 2016 So sweet!! I've been a stalker of this thread since day one and I'm amazed with the work!! Keep it up man!! Quote Link to comment
510T Posted May 23, 2016 Report Share Posted May 23, 2016 Bump for an update... ;) Quote Link to comment
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