ABS in a 240Z?

[logr]

I have been thinking about this for a while. I have added ABS to 240SX's quite a few times but never tried on a Z before.

 

What I'm thinking but would love more thoughts or ideas .

 

Take ABS SX front spindles and weld the the cut off  bottom portion of other sx spindles onto the bottom(to correct camber gain and roll center) of the ABS ones but switch the bottom portion right to left. This would give me front steer and give me a large area to weld. I could allow for ackerman by welding the bottoms on twisted. I'm thinking of cutting the 280Z strut tubes off the spindles to add ears to for the sx spindles. This way I could keep my Bilsteins.

 

I have modified SX spindles numerous times for autox cars in this way, without the switching part. I always speed up the steering at the same time.

 

I can then mount an sx abs diff in the rear which works just fine with the Giken and R200 shafts as well as the 300zx cv's now in the car.

 

I have a 99 miata power steering rack that appears to be very close to the correct length.

 

The reason is that I believe ABS in an autox car is invaluable. There was an off camber slow down last weekend that I could not do without locking up a front tire. The sx system works pretty well.

 

Thoughts?

Edited August 20, 2014 by logr

[johnc]

What are you going to do about the ABS plumbing, sensors, computer, etc.?

[RebekahsZ]

Why take a wonderful simple car and make it complicated? It's like marrying the girl you are sleeping with. Instead of sex, you get nag, nag, nag.

[logr]

John, By using the sx diff and spindles, I can use an sx puter, actuator,  m/c and sensors. Plumbing is easy. The last autox car I built had the actuator behind the passenger front seat which is probably where I would have this one though upon reflection, it might be better to move the battery and put the actuator in the batteries spot.

 

Make a Z complicated? LS, cv's, power steering, whole new rear suspension, these things and many more are done all the time and require much more work, money and complication than adding abs, but few things will improve an autox car more, imo.

 

ABS on an autox car, on expensive, easily flat spotted tires, has proven to be a real time and money saver. The National Champion SM car just added it and then wondered why he didn't do it sooner. We had been discussing it for years since I had first added it to mine but he hadn't thought it that big a deal. He is a believer now.

 

My reason is partly because I only can run 245 tires under my stock fenders( and therefore easily slide them) and partly for the challenge.

 

Anybody done it?

[logr]

Under SCCA SSM rules I can't change the suspension pick-up points but I can replace everything that bolts to it.

If this didn't work, I could always go back to what I have now.

 

My car is already 5 lug(same as an SX) and I have the big brakes that would only require a different rotor hat to work on the SX hubs.

[RebekahsZ]

Interesting. I will follow your project to learn more. One of the projects I have planned for my truck is to disable ABS, it drives me crazy and I can't get the thing stopped once the ABS starts chattering and farting. But that's my only experience with ABS. There must be better systems that perform well. On the LS, it has actually been way easier to deal with than triple carbs on an L6, very plug and play. I bet your ABS will be awesome and well done.

[G-E]

I'll chime in to say that although all my cars are non-abs, I've have to drive and diagnose many that were, and unequivocally I can say, anything older than late-90's abs systems suck as a rule, while many still sucked into the 00's

 

Perhaps you can get an external abs/traction controller box that can use the 240SX sensors and rings?

[m1ghtymaxXx]

Interesting. Rather than adapt the stock struts housing to use the 240ZX spindles, why not just use 240SX coilovers? If you have camber plates, it's pretty much a bolt in affair. 

 

I'd love to see this pan out. Autocrossing my 280Z with a Willwood 1" MC, stock calipers/drums, Hawk HP+ and slicks made me yearn for ABS as that setup was very prone to locking up. I now run BFG Rivals and have been able to modulate the brakes much better, but I can see the appeal. Of course not all ABS systems are created equal, presumably the 240SX system is a worthwhile upgrade?

[logr]

I don't much like abs in a daily. My pickup is terrible about kicking in abs when I need it least.

 

I agree that many abs systems are not great. Something other than the sx system might be better but I believe I can make this one work with the oem hardware and I have seem others that don't work as well.

 

The sx one is a simple stand alone affair and it is 3 channel. I could use a Z32 diff for a 4 channel system but doubt the output shafts would work.

 

I have experience with the sx system and know it works well enough with even huge tires and different ratios, front to rear, of piston volume. I keep the ratio as close to oem as possible. My last autox sx runs 285's and 315's with wilwod fronts and s14 rears and the abs does it's job on that. I sold it last year after a health scare.

 

The reason I was thinking of using the z strut tube is because I have no idea what length I will need it. I always had to cut down and remake the mounts on sx tubes to get everything where it needed to be so I figured a clean slate might be easier.

 

I can't start until for a couple of months, until after my last autox. I have all of the parts I believe I will need laying around already.

 

I'm thinking of pulling the z front suspension and making a jig for each side that has all the pertinent parts located exactly. Then unbolting it and bolting in the sx hub for a start. I can then get the ackerman back to original easily and maybe take a bit out since that seems to help an autox car turn better(don't want the inside tire skidding as much due to the slip angle).

 

I remember seeing once where someone put a miata rack in a z but have not been able t find any info. I am looking for 2-2.25 turns lock to lock so I need to see what the new rack would yield but it is easy enough to move the toe arm as long as I can get the rack mounted correctly to reduce oem bumpsteer. Remember I can't move the lca mounting spot so I have to modify the rack and it's mounting to reduce bumpsteer.

 

I tried to think of a better abs system to use but the ease of using a short nose diff and matching front spindle seems the simplest.

Edited August 20, 2014 by logr

[johnc]

Jason Rhoades ran the stock S14 ABS system on his SM 240SX and was very happy with it.  I have not installed ABS on a S30 myself.  It sounds like a good project.

 

The issues you are concerned with (front wheel lockup) can be dealt with in much simpler ways.  Its all about balance and most rear disk brake conversions don't have enough rear bias.  My BSP 240Z and Vic Sias' BSP championship winning 240Z both had outstanding stock brakes and neither of us had a wheel locking problem with 225, 245, and 265 width Kumho V700s and Hoosier A3s.  

[logr]

I have an adjustable proportioning valve in my z. I will try more rear bias before I go further but the system has always worked well the way I originally set it up so I didn't change in the middle of racing. I was using Z11 street tires at the event. They are not nearly as grippy as race tires but pretty dang good for the money. I doubt I would have had the problem as bad with A6's.

 

I kind of just want to do it since no one else has.

Edited August 20, 2014 by logr

[G-E]

There are people who race with no front swaybars and stiffer springs, a lot of times grip is lost it's that swaybar causing 1 wheel to lift unnaturally...  johnc is right, there's ways to tune your chassis for this.

 

But hey, if you just wanna be unique, don't let us stop you

 

BTW Q45 and skylines have the rings on the axle stubs if you want 4-channel..

[tube80z]

Lifting a front wheel isn't caused by the ARB.  It's from being too soft in the rear or too soft all round.  Personally I would look at a C6 vette for the ABS computer and tone rings.  They are a generation newer than all the 240SX stuff.  Teves sells a motorsport unit but it's going to run 5K or so.  Bosch also has a motorsport ABS but it's probably closer to 20K installed.  

 

Cary

[logr]

I know there are newer and probably better systems. The C6's that I have driven are pretty good as are a few others but I have never met any serious autoxr that wants to give up abs if it works well. There are times that no matter how hard I try, I can't keep a front wheel from locking up. I believe it is a function of how stiff an autox car is to turn quickly on rough tracks. I am running 325#Front and 400# rear springs now with 52% rear weight and no rear bar. I don't lift a front tire in turns.

 

My last car went up a level  and was much easier to drive when I added abs.

 

I realize it is the nut behind the wheel that locks up the tires and I am doing everything I can to fix that but not having to worry about flat-spotting an A6 to the cords in one over-driving moment or a touch of gravel is a great feeling.

 

Jason's S13 abs system is exactly what I am proposing using and it has worked very well for many of us. Too bad he didn't take that car a bit more. PJ and David won SM in an S14 the year I went to Nats. They have since added abs and love it. They are winning SSM sometimes as well. Nats will be interesting this year. A friend from Seattle will be going in his S13, with abs just added, as well.

[texis30O]

Why take a wonderful simple car and make it complicated? It's like marrying the girl you are sleeping with. Instead of sex, you get nag, nag, nag.

 I would appreciate it if you would keep my marriage out of a conversation about Brakes.......

[RebekahsZ]

Haha!

[logr]

I'm in the process of changing to a short nose diff. I need it for the ABS sensor as well as I would prefer the 4.08 ratio of a stock 240SX. There are some issues but nothing that can't be fixed.

 

All R200 short noses use the same pinion even though the ABS version has a longer housing. The input flange is longer, for the tone ring, and where the length comes from.

 

S13 R200 housings are solid mounted to their S13 subframes.(The subframe is rubber mounted instead.)

 

If you want the short nose to be rubber mounted using the available front diff mount. (The one from BURLEIGH.) An S14(4.08) and J30(3.9)  both use the rubber inserts in the front of the diff which will bolt to the available mount from BURLEIGH.

 

I am using a J30 diff (for the rubber inserts and the ABS) but want the 4.08 ratio. I am therefore swapping the diff guts between a J30 and a regular S13 R200. J30 and R200 long noses both have the thick spacer on the passenger side while the S13/14 have it on the drivers side.

 

This is important because the long stub axle goes on the side with the thick spacer inside the diff. This means that putting in the short nose is going to require swapping the stub axles to the other side of the car. I am using 300zx turbo CV's with CF axles so I will be swapping sides with the stub axles only(removing the inner cv and putting it on the other side of the car)

 

The difference is in the thickness of the ring gears. The J30 and the long nose R200 of a Z both have ring gears that are thicker than short nose diffs. This is why the thick spacer changes sides inside the diff.

 

I am using an OS Giken LSD which uses the open stubs and why this should all work.

 

 

******I can't find anything on this stuff but if I am just wasting space please tell me so I can finish this without all the typing.******

Edited October 2, 2014 by logr

[G-E]

Swapping the diff side stubs to opposing axles may work on the open diffs, or any "open" replacement, but it most certainly won't work with VLSD...

[duragg]

<--- walks up to the dusty old bar table and slams down a fresh drink...   Lets resurrect this thread boys!!

 

I want the BMW Mk60 4 channel system in my S30.  The only hurdle is getting the proper RPM input from the wheels.

Custom rings sandwiched with my CV axles and a bracket in the rear? 

NFC on the fronts yet...

 

I think the Mk60 BMW uses an 83mm ring.

 

BAM! 

[tube80z]

Is this a race thing or a street thing?  If it's race you really want to look at the Teve's or Bosch units.  Motorsports ABS lets you use areas of traction that are forbidden because of stability on a stock car.  Take a look at the Bosch PDFs for their ABS system (http://www.bosch-motorsport.com/media/catalog_resources/ABS_M4_Brochure_epdf.pdf)

 

Cary