Rack and pinion exploration. Building a bolt in conversion

[Lockleaf]

For anyone who might be interested in this crossmember plus a VG, the Infiniti M30 uses a front sump oil pan and pickup tube on the VG30. Not guaranteeing that its perfect, but it gets you to front sump.

[datsunfreak]

 the Infiniti M30 uses a front sump oil pan and pickup tube on the VG30. Not guaranteeing that its perfect, but it gets you to front sump.

 

The Nissan Quest also uses a front sump pan, and you can buy them new on ebay for $40.  :thumbup:

[Lockleaf]

The Nissan Quest also uses a front sump pan, and you can buy them new on ebay for $40. :thumbup:

This seems better than what I said :)

[datsunfreak]

Sorry, wasn't trying to one-up you.  Hope it didn't come off that way.   ^_^

[Lockleaf]

Not at all. I said "here's a hard way to do this." You said "here's the easy cheap way". I thought to myself, yeah his way is better that mine. I wish I had known that when I was looking to go front sump on a vg. Took me forever to find the m30 stuff.

[datsunfreak]

I wish I had known that when I was looking to go front sump on a vg. Took me forever to find the m30 stuff.

 

If it's any consolation, I think they've only been on the market for maybe a year.   ^_^

 

http://www.ebay.com/itm/New-Oil-Pan-for-Nissan-Quest-Mercury-Villager-1994-2002-/231178161193?fits=Make%3ANissan%7CModel%3AQuest&hash=item35d34acc29&vxp=mtr

 

I looked for an M30 pan for awhile too, then a buddy with lots of VG swap experience told me a Villager/Quest pan was a front sump too. So for giggles I looked on ebay and there it was!  :thumbup:

[Lockleaf]

Sorrry icehouse datsunfreak and I are done now [/threadjack] :)

[onekickkawi]

I toyed with the MR2 Rack a little but then went back to stock. To many side projects with the car and I will never finish. One thing I was going to try was pulling the rack out and sticking it on a lathe to trim down each end .25" (I think rack was .5" longer then our pivot points, don't remember the exact number). 

[Big_E-Dog]

all vg powered maximas do as well. the 85-86 ones have a lil shoulder that sticls out for an extea .5 quarts of capacity

[dscottdatsun]

Any update on this too cool project?

[Icehouse]

Not really.  We have been working on other things.  Soon we will have the prototype in the test front end though.  

[Icehouse]

Modified and test fitted!  unfortuantly it needs more work.  An end is in sight though!  

 

 

[q-tip]

Looks like progress to me!

[Icehouse]

We have a goal set, the last auto cross is one month from now. We want to drive both are cars with the prototype rack setup in it. Seems like an easy goal... Well after getting all the bump sorted out we realized that the steering would be terribly slow. The rack travel is less than the box. We wanted faster steering! So the only option was to make new steering knuckles. The knuckles dictate the amount of ackerman by moving the inner tie rod pivot point inboard. Which in effect changes the bump..... Serious rabbit hole!!! We decided to go with neutral ackerman, 100% or whatever you want to call it. The good news is Sam figured out how to get us 2 turns lock to lock! Zero bump, added caster, neutral ackerman! While he was doing that I drew the power steering bushings haha. I was busy with some family stuff that week or I wouldn't have been more involved.   To give you an idea of how different a steering knuckles can be, the left arm is off a 300zx and the right is off a 510.

 

 

 

 

 

 

 

 

 

 

 

[tr8er]

Can't wsot

[510T]

That looks so great!  And sounds like it will be a huge improvement,  I would love to get on the purchase list. ;)

 

I hate the steering on my 510!

 

I have a question, how does the ball joint location relative to the strut center line and tie rod affect the geometry? 

[Icehouse]

That looks so great!  And sounds like it will be a huge improvement,  I would love to get on the purchase list. ;)

 

I hate the steering on my 510!

 

I have a question, how does the ball joint location relative to the strut center line and tie rod affect the geometry? 

 

 

I can only guess why Nissan changes things.  The 300zx runs more strut angle as well.  So my guess is they are trying to improve the scrub radius since the Z ran wider tires.  The tie rod length does effect bump steer.  A little change makes a difference small or big they add up.  I've driven many 510s, some drive nice and some don't.  None have driven as nice as a super dialed in S13 I had.  Well none with a steering box.  My 68 with rack and pinion was my all time favorite car ever.  We want to recreate the crossmember so everyone can enjoy it :)  

[DrRocks0]

68 crossmember MR2 rack. 

[Laecaon]

That rack is way too ride for no bumpsteer with any set of Nissan knuckles. I know because my MR2 rack has been cut down a lot for no bumpsteer.

 

At this point I am drastically changing the front of my car.

[Z23T]

We have a goal set, the last auto cross is one month from now. We want to drive both are cars with the prototype rack setup in it. Seems like an easy goal... Well after getting all the bump sorted out we realized that the steering would be terribly slow. The rack travel is less than the box. We wanted faster steering! So the only option was to make new steering knuckles. The knuckles dictate the amount of ackerman by moving the inner tie rod pivot point inboard. Which in effect changes the bump..... Serious rabbit hole!!! We decided to go with neutral ackerman, 100% or whatever you want to call it. The good news is Sam figured out how to get us 2 turns lock to lock! Zero bump, added caster, neutral ackerman! While he was doing that I drew the power steering bushings haha. I was busy with some family stuff that week or I wouldn't have been more involved.   To give you an idea of how different a steering knuckles can be, the left arm is off a 300zx and the right is off a 510.

 

 

 

 

 

 

 

 

We have a goal set, the last auto cross is one month from now. We want to drive both are cars with the prototype rack setup in it. Seems like an easy goal... Well after getting all the bump sorted out we realized that the steering would be terribly slow. The rack travel is less than the box. We wanted faster steering! So the only option was to make new steering knuckles. The knuckles dictate the amount of ackerman by moving the inner tie rod pivot point inboard. Which in effect changes the bump..... Serious rabbit hole!!! We decided to go with neutral ackerman, 100% or whatever you want to call it. The good news is Sam figured out how to get us 2 turns lock to lock! Zero bump, added caster, neutral ackerman! While he was doing that I drew the power steering bushings haha. I was busy with some family stuff that week or I wouldn't have been more involved.   To give you an idea of how different a steering knuckles can be, the left arm is off a 300zx and the right is off a 510.

 

 

 

 

 

 

This is one of those threads that when I see an update I'm excited to see what the progress is. I love the idea of being able to buy a well engineered, bolt in, R&P steering setup. But I do have one concern. It kind of freaks me out to think of the additional stress of the steering loads being applied to those four little bolts that hold the cross member on. Most 510's have already added additional stress to these bolts with heavier, more powerful engines, spring rates that are 2 to 4 times higher than stock, suspension with heim joints, and tires with super sticky rubber. I was thinking that a plate, welded to the cross member, that ran vertically up the inside of the front rail, with a couple of bolts running through a tube welded into the rail, horizontally, just like what the steering gear and pitman arm bolt to, would really make it strong. Maybe I'm wrong in my concern, but I thought I would mention it.

 

Thanks, Cam.

[thisismatt]

This is one of those threads that when I see an update I'm excited to see what the progress is. I love the idea of being able to buy a well engineered, bolt in, R&P steering setup. But I do have one concern. It kind of freaks me out to think of the additional stress of the steering loads being applied to those four little bolts that hold the cross member on. Most 510's have already added additional stress to these bolts with heavier, more powerful engines, spring rates that are 2 to 4 times higher than stock, suspension with heim joints, and tires with super sticky rubber. I was thinking that a plate, welded to the cross member, that ran vertically up the inside of the front rail, with a couple of bolts running through a tube welded into the rail, horizontally, just like what the steering gear and pitman arm bolt to, would really make it strong. Maybe I'm wrong in my concern, but I thought I would mention it.

 

Thanks, Cam.

 

Except that the engine w/trans, as well as the steering rack load, are mounted to the crossmember, not to the body or frame rails.  Those 4 bolts only have to steer the rest of the body around.

[Icehouse]

That rack is way too ride for no bumpsteer with any set of Nissan knuckles. I know because my MR2 rack has been cut down a lot for no bumpsteer.

 

At this point I am drastically changing the front of my car.

 

Did you test bump steer with the stock width rack and the narrowed rack?  Our data shows a MR2 rack to lower the bump steer if placed in the right position.  What you really loose is turning speed/radius and ackerman.  

 

 

 

 

This is one of those threads that when I see an update I'm excited to see what the progress is. I love the idea of being able to buy a well engineered, bolt in, R&P steering setup. But I do have one concern. It kind of freaks me out to think of the additional stress of the steering loads being applied to those four little bolts that hold the cross member on. Most 510's have already added additional stress to these bolts with heavier, more powerful engines, spring rates that are 2 to 4 times higher than stock, suspension with heim joints, and tires with super sticky rubber. I was thinking that a plate, welded to the cross member, that ran vertically up the inside of the front rail, with a couple of bolts running through a tube welded into the rail, horizontally, just like what the steering gear and pitman arm bolt to, would really make it strong. Maybe I'm wrong in my concern, but I thought I would mention it.

 

Thanks, Cam.

 

 

I used to think the same thing until Dillon hit a man hole cover and it ripped the crossmember itself leaving the bolts unscathed attached to a small chunk of crossmember.  Tim did the same thing.  Didn't harm the bolts at all.  Actually Hainz did a structural test as well.  I think I have some pictures.  

 

 

 

 

[Laecaon]

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.

[Dime Dave]

 

 

Jeff,

 

You are going to have an issue caused by the steering shaft u-joints. The angles are not equal and opposing. This will create an uneven rotational speed at the rack. The severe angle of the u-joint at the firewall needs to have an opposing angle at the rack to transmit a constant rotation to the rack (think phasing and angles on a driveshaft).

 

 

The large first u-joint angle will induce a varied rotational speed into the intermediate shaft. Having the joints phased on the intermediate shaft and with an equal and opposing angle at the rack will cancel out the rotational variances. The nearly straight thru angle of the u-joint at the rack will not cancel out the rotational variances induced by the extreme firewall u-joint angle. 

 

 

I had this condition on my tube frame 510 on the first build. The rack end u-joint was virtually straight thru and the firewall u-joint was angled about the same as yours is. Because of how the u-joints were clocked on the shaft at straight ahead, it took 1/4 turn of the steering wheel right to match nearly 1/2 turn to the left to steer the car off straight ahead in equal amounts.

 

 

On my car it was extreme enough that I had a track worker come to me after a race and ask if the car was OK. He could see the front wheels on turn-in jerking as I turned the steering wheel going into his turn. Even with smooth steering wheel input, the tires looked jerky like something was coming apart.

 

 

I replaced the single u-joint at the firewall with a double u-joint from Borgenson. This required adding a support bearing on the lower shaft to keep the double u-joint from flopping around. This was enough to make the steering input matched left to right.

 

Here is a graph showing what I'm talking about.

 

[Icehouse]

Thanks for the info Dave! I didn't even think of that. The good news is they are closer to the same angle than the look in the picture. We will make adjustments to fix the issue.