So rad, I can't believe how far back you've gotten the engine.
So rad, I can't believe how far back you've gotten the engine.
Impressive build. I'm also really impressed with how you're making your own tools like that rolling tailshaft support!
Inspires me to figure out what useful things I could build in my own garage with some spare "stuff" and a welder...
Shavarsh said:So rad, I can't believe how far back you've gotten the engine.
Thanks, I'm stoked to say the least, definetly fun to see it coming together
nlevine said:Impressive build. I'm also really impressed with how you're making your own tools like that rolling tailshaft support!
Inspires me to figure out what useful things I could build in my own garage with some spare "stuff" and a welder...
Thanks, having tools is almost as much fun as when you think of something and decide you need another tool. Welder is a great tool to have, always good to know that you can always (almost) put it back together if you mess it up
Last week was a slow week for car work due to other commitments, but found some time over the weekend to make some progress.
Been working to figure out how to address a clearance issue with the engine/oil pan and the steering rack. I finalized my engine location without the rack installed, knowing it would need an adjustment of some sort
here was my interference issue, you can see wehre i had already ground a tab off the casing
Untitled by fouckhest, on Flickr
rev 1 of adjusting the position was down and forward, you can see the factory mounting places, it would be ~2" up and back...
Untitled by fouckhest, on Flickr
still didnt get me the proper clearance to get the engine far enough back to meet my desired location, so as any reasonable person would do, i took the nuclear approach, ground off the OEM mounting points and made some rudimentary brackets for a revision 2 test fit...this would bring the rack as far back as i could get it and also decided to shift to to the drivers side ~1"
cleaned up
Untitled by fouckhest, on Flickr
new brackets for mock up
Untitled by fouckhest, on Flickr
this is the new position, but it has created an interference with the oil pan, so i am current noodling on how to address that, not sure if moving the steering rack a little further towards the drivers side, or dropping it down a little? I want to avoid lowering it much more as it is already lower than the subframe
Untitled by fouckhest, on Flickr
I am happy the ending location is still in a decent spot i think, feeling confident that i am close to calling this its final home and begining to work on the engine mounts
Untitled by fouckhest, on Flickr
Will you be using power steering? If not is it possible to make a lower profile cap for that section of the pinion?
Shavarsh said:Will you be using power steering? If not is it possible to make a lower profile cap for that section of the pinion?
I am going to try and keep power steering, not married to it, but removing the PS pump will pose its own set of challenges b/c it is driven from the back of the engine from something in the timing chain system
I think I have finally found the "best" location for the steering rack, however, it leaves me with a question that i dont fully know how to address. the steering rack is needs to be "offset" by ~2.5", this will result in unequal length tie rods....i've dont some research and i think a combination of e90/e36 inner/outer tie rods and ends may account for the difference in length to get me on the ground, but still looking into that
Question for any suspension guru's, how bad is this going to impact steering geometry, I think specifically it will have an impact on bump steer, but not sure about ackerman angle? I need to do some more research, but i've been trying to solve the mechanical issues of locating the rack first....I also might call flaming river and see what their thoughts are and if a custom rack could be made to over come this.
Any input/feedback would be greatly appreciated
some photos of the rack shifted and clearance off the oil pan. I really like how it fits, just really dont want to compromise suspension geometry too adversly
Untitled by fouckhest, on Flickr
Untitled by fouckhest, on Flickr
Untitled by fouckhest, on Flickr
Untitled by fouckhest, on Flickr
I don't know about the geometry issue but is it possible to find a wider rack that would slot the pinion assembly into the correct location?
I would try your hardest to find another rack that fits and matches the width of your lower control arm inner joints to tie rod distance as close as possible. And that also fits in the space for the pinion of course. Smarter ones than me here will probably have more to add, but an offset rack like that is going to make your bumpsteer be different per side, which is even worse than just normal bumpsteer. Its going to feel very weird and unstable.
SpeedAddict502 said:I would try your hardest to find another rack that fits and matches the width of your lower control arm inner joints to tie rod distance as close as possible. And that also fits in the space for the pinion of course. Smarter ones than me here will probably have more to add, but an offset rack like that is going to make your bumpsteer be different per side, which is even worse than just normal bumpsteer. Its going to feel very weird and unstable.
Yeah, I am coming to that realization...womp womp....lol
Looks like I'll be looking into modifying the subframe to see if I can get the rack in a better spot, or contacting flaming river and letting them light some of my money on fire...
I wouldn't be calling flaming river. Rock auto says an e90 rack is 39ish inches wide, while a 5 series of similar year is 45 inches wide. You could do some digging around to find one that's a width you could fit while still being off the shelf OE.
Not a bad thought, the call to flaming river is free, just to get an idea of cost
I'll have to see if there is a 5-series in the junk yard that I could go take some measurements from
Can the whole subframe drop down a bit?
Call to flaming river was fruitful and cheap.
The guy in tech support suggest having an extension bar machined the same length that would be needed to compensate for the offset. He said they do this when making custom racks, seems simple, logical and effective. Now to pull the rack apart and measure the threads
Shavarsh said:Can the whole subframe drop down a bit?
In theory it could, but this is more about side to side than up/down. Also, control angle is in a nice spot now, and making it lower would adversely impact that geometry...seem my post above, I think this is the route that I am going to take for now
Sorry for blowing up my own thread...but apparently this is a thing for folks that do anything from custom builds with mustang racks to what i am guessing are drift guys.
guess him using my labor day coupon at HF to buy a tie rod removal tool kit this weekend
makes me feel good that speedway motors sells something like this: https://www.speedwaymotors.com/Inner-Tie-Rod-Extention-Kit-Speedway-Mustang-II-Manual-Rack,8066.html
So, I am going through this with my rx8 swap. When I moved the rack down (still centered) the bumpsteer was crazy bad. Even with a bumpsteer correction kit.
I am currently going to New mounts for the rack that only move the position 3/4 inch instead of about 1.5 inches. In order to do this, I raised the engine about 1 inch.
The car was NOT fun to drive with the bumpsteer. I would recommend doing everything you can to minimize bumpsteer now.
wvumtnbkr said:So, I am going through this with my rx8 swap. When I moved the rack down (still centered) the bumpsteer was crazy bad. Even with a bumpsteer correction kit.
I am currently going to New mounts for the rack that only move the position 3/4 inch instead of about 1.5 inches. In order to do this, I raised the engine about 1 inch.
The car was NOT fun to drive with the bumpsteer. I would recommend doing everything you can to minimize bumpsteer now.
Thank you for that feedback, this is exactly what I want to avoid, the car will primarliy be a mtn/backroad car, so dont need any "wonkiness" on spiritied drives
Yeah offsetting the rack is bad for steering geometry. Bumpsteer is the search word. Good luck with this. Enjoying the build.
amg_rx7 (Forum Supporter) said:Yeah offsetting the rack is bad for steering geometry. Bumpsteer is the search word. Good luck with this. Enjoying the build.
Understood - any thoughts/concerns with using one of those tie rod spacers? This is new/news to me, but when talking to the guy at flaming river, he brought it up, so I cant imagine they would use/promote that if it would not be effective?
the concern with offset rack is purely a result of unequal length tie rods, correct? so with a spacer, that will be a non-issue, so i should be back to square one, right? or am i still missing something?
Bumpsteer happens when the pivot points of the tie rods don't align with the pivot points of the suspension.
Adding those spacers, or just 1 to make the rack equal length side to side, will probably mess with bumpsteer, but help keep the Ackerman the same on each side. I am not sure if it will change Ackerman from stock.
Basically, if at all possible, you want the steering pivots to be in the same plane, and same length as the suspension pivots.
Moving a front steer rack down will impact bumpsteer. (Correctable with tie rods that can change the pivot point location of the outer tie rod pivot down) Moving a front steer rack forward will impact Ackerman. Changing the steering rack pivot locations can mess with both.
Can you just move the rack down like 1 inch? Does that get you what you need and then keep it centered? Then just get a bumpsteer correction kit (adjustable pivot outer tie rod.)
I also recently learned that there are offset inner tie rod mounts as well. These can allow you to move the rack down, but keep the inner tie rod pivot in its stock location.
Like these: https://store.partsshopmax.com/shop/Z32R32/Multilink/RSPCR.html
Not sure this thread will answer your questions, because my situation was slightly different, but lots of smart people jumped in.
https://grassrootsmotorsports.com/forum/grm/need-tech-help-with-swap-stuff-video-call/257017/page1/
fouckhest said:Sorry for blowing up my own thread...but apparently this is a thing for folks that do anything from custom builds with mustang racks to what i am guessing are drift guys.
guess him using my labor day coupon at HF to buy a tie rod removal tool kit this weekend
makes me feel good that speedway motors sells something like this: https://www.speedwaymotors.com/Inner-Tie-Rod-Extention-Kit-Speedway-Mustang-II-Manual-Rack,8066.html
Functionally, that looks like it would work fine to me. It goes on between the inner TRE and the rack correct? Effectively making the rack wider? Clever idea. I don't think I'd run it like that if I could find a different width rack but it's a damn simple solution.
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