ABS controller relocation

[90BLKTALONTSI]

I recently got a Magnus SMIM and have no clearance now for my intercooler pipes, the manifold sits low and is hitting my ABS controller. Is it possible, instead of removing completely to relocate it? Would braided lines instead of the hard lines make a difference? Thanks in advance...

 

[jtmcinder]

The people I have talked to WRT deleting my ABS unit have had no strong arguments against braided lines, as long as they are done right.

- Jtoby

 

[Ludachris]

On a 92? I'd just remove it altogether. That's just me. I would think that relocating it would be more of a pain in the ass than the system is worth on these cars (1G at least).

 

[jtmcinder]

Your opinion also applies to at least one of the two systems tried in 2Gs. The funny thing is, half of the people I've talked to hate the Bosch and like the Nippon, while the other half are just as adamant in the opposite direction. Given the weight and location, I decided to pull it.

The one thing that doesn't get enough attention in all this is bias. A lowered and stiffened DSM would almost always benefit from moving some braking force to the rear. This is doubly or triply true for those of us with a lot more front camber than rear. So, instead of going through the hassle of replacing your lines with those from a non-ABS car, start over with an adjustable prop-valve in the cabin.

- Jtoby

 

[shleppy]

So exactly what parts did you use in eliminating the abs from your car. I'm interested in doing this in the next few months and am starting to research the best way to do it and where to get the parts from-thanks!

 

[jtmcinder]

Hasn't been done yet. Still talking to people, to do it right, once. The original plan of making a piece that simply replaces the hydraulic unit is out; too much fancy CNC piece and no option for an adjustable prop valve. The second plan to just swap in some flexible lines for the rest of the season never happened; too much other stuff that are all more important than, maybe, 30# off the nose.

I promise to post details when it actually happens.

- Jtoby

 

[shleppy]

Thats cool, I was just wondering if you had another suggestion besides using a stock non-abs unit which as you mentioned would be a little too front biased for a stiff lowered car.

 

[jtmcinder]

I suppose you could start hunting around for the specs for valves from other cars. Pulling numbers from my nether regions, I'd look for one that splits at about 500 psi with a 20% reduction. But I'd wash off that suggestion before using it.

- Jtoby

 

[underradar92]

The one thing that doesn't get enough attention in all this is bias. A lowered and stiffened DSM would almost always benefit from moving some braking force to the rear. This is doubly or triply true for those of us with a lot more front camber than rear. So, instead of going through the hassle of replacing your lines with those from a non-ABS car, start over with an adjustable prop-valve in the cabin.

- Jtoby

This subject has been floating around in the back of my mind for a while now. The wall I keep running into is where to find the correct tubing, flare nuts, tee's & a metric flaring tool. I think a Wilwood or similar adj. valve should work, if I could find 1/8 pipe to 10mm metric flare adaptors.

 

[1991GSXAWD]

Remove the ABS all together, its nothing but problems on DSM's and doesn't work that well anyways, I've removed mine because it would not clear my manifold and a PITA to pull codes with a analog meter, you need the proportioning valve and front brake lines from a donor car that does not have ABS, I might have all the parts to do it and can have it done here in my shop on a weekend, PM me if interested.

 

[jtmcinder]

If you are going to switch to an adjustable prop valve in the cabin, then the entire system needs to be changed. The brakes can't be LF&RR vs RF&LR anymore (which is for safety when one half of the master fails). Instead, you feed one half of the master to the fronts and send the other half to the prop valve.

Option 1: connect one of the master's to the fronts where the ABS hydraulic unit was using some kind of T. Fab a line from the master's other output to the cabin and, then, after the new prop valve, feed it into the existing rear lines somewhere under the car.

Option 2: same as above, but eliminate the rear lines completely and fab new lines all the way to the rear calipers.

Option 3: as Option 2, but use non-ABS front lines and fab a T for the first master's ouput at the center of the firewall, instead of where the ABS hydraulics were.

- Jtoby

 

[underradar92]

Other cars without the dumb diagonal bias, have only 1 brake line to the rear of the car, then a tee. I've done this exact mod on a Barracuda I had & it worked great, so I know it will work. I just haven't located the aforementioned metric pieces yet.

 

[Todd TCE]

Remember that just removin an ABS controller and fitting the prop valve won't shift bias to the rear. You haven't made any brake changes. Under panic stops the controller prevented lock up, but that's not going to get you more rear brake by simply removing it.

 

[underradar92]

Wouldn't (theoretically) removing the abs and prop valve altogether give an equal hydraulic balance to all 4 calipers, thereby leaving mechanical advantage to determine bias? Then adding the adjustable prop. valve to tune pressure distribution to taste?

 

[jtmcinder]

Yes, of course. But don't even try driving the car with no prop valve at all. I assume that what Todd was warning about was how the mere back-dating the car to non-ABS will not move any bias to the rear. In fact, given the split point of the non-ABS valve, back-dating moves bias to the front, which is why I, for one, have no interest in doing this. If you're going to use a Mitsu valve, the one you want is that from an ABS car, even if this requires some fabricating.

- Jtoby

 

[Todd TCE]

Take the ABS issue out completely. It's not a brake bias or propotioning tool. Nor should it be used as one if you've ever had the pedal pulse at speed- most would rather have a butt dyno feel and tune that way!

Removing the prop valve will not increase rear pressure. What it will do is prevent it from being limited. Depending upon the current brake set up on each end that could or could not help or hurt. If you have 'way mondo' front brakes now you might do ok with more rear pressure.

But...it's not a pressure increasing tool, it's a reduction tool Meaning if you have no valve you get equal psi on all four corners. With the adj valve you'll make the presure point (knee point) a variable based on how much input pressure you give it.

So....depending upon the required pressure to work the fronts to your satisfaction you might need to reduce the rear pressure to prevent lock up. Or you might be be able to get more rear brake than you think if you're fronts are not requiring a lot of psi to function. Hard to visualize I guess. If the fronts are over biased now with large piston area and calipers then they don't take a lot of psi to work. Here the rears work only to the same level with no valve. If that's low psi you may have even less rear brake than you can actually use.

I suppose you're right that removing it elevates rear brake pressure, dynamic bias, but given it's pressure related the same thing is happening up front now too. What you might do is to replumb all this and then try some high Cf pads in the rear. Static bias (most common in ref) is simply a math result of parts relation- dia, piston, pads etc. and is not truly altered.

Setting the adj valve sets the pressure point that the rear line pressure is reduced. This might be low or might be high depending upon the requirements of the fronts to slow the car also. And given it's pressure relate any change in input pressure also changes output pressure. At low psi the rears get full pressure, at higher pressures the rears get less. You just tell it when and where.

 

[underradar92]

I'm pretty sure we are in agreement now on these points. (?) I've located a place that makes (supplies) metric flare nuts, tees, tubing, etc. http://www.fedhillusa.com/brakelinenutsfittings.html Now I just have to wait for winter to tear into this mess.

 

[jtmcinder]

Todd -

We're not idiots. Of course we meant dynamic bias or, in my case, the desired bias at threshold. I'm sorry if the default use of "bias" means static, but I thought it was pretty clear what we were talking about. A lowered 2G - especially with 2.5* of front camber and less than 1* in the rear - needs to move some braking to the rear if it wants to slow down in the least time possible, as I do. And you do a lot less damage to your tires locking a rear than a front.

With that said, I'll try to remember to use a modifier in front of "bias" from now on. Thanks for explaining the usage of the term.

- Jtoby

 

[jtmcinder]

I'm pretty sure we are in agreement now on these points. (?) I've located a place that makes (supplies) metric flare nuts, tees, tubing, etc. http://www.fedhillusa.com/brakelinenutsfittings.html Now I just have to wait for winter to tear into this mess.

Good find! Now, does anyone know the size of the fittings going into and out of the hydraulic unit, saving me the hassle of getting up from my chair?

- Jtoby

 

[underradar92]

Good find! Now, does anyone know the size of the fittings going into and out of the hydraulic unit, saving me the hassle of getting up from my chair?

- Jtoby

Ask.com is my friend. The flares are 10mm flare. I'm not sure on the banjo's, although I think those could be eliminated

 

[jtmcinder]

Ask.com is my friend. The flares are 10mm flare. I'm not sure on the banjo's, although I think those could be eliminated

No banjos at the hydraulic unit on my (Bosch) car; just six 10mm flares.

- Jtoby

 

[Todd TCE]

Sorry if I offened anyone...that wasn't the point at all!

Before tear into all this and cut and hack on things, why not consider a change to the rear brakes? And why?

Changing the rears to a more rear biased design will net the same goals and in a more controlled manner in a lot of ways. Fitting a rear brake kit or at least high end pads will elevate the rear tq values for bias. And 'why' is that under lower pressure applications the total braking will be improved. Then under hard braking where the prop valve kicks in you'll reduce pressure to the rears as needed. If the ABS kicks in you'll be at the limit and know it.

That plan gets you the same result as all the cutting and tuning with the valve. In either case all you'll get it max tq until the rear wheels lock. If you've changed the front a whole lot you may be leaving something on the table out back. But adding more pressure to them alone may not be the single best way.

Ok...so what's the thought? The rear brake kit. If you're running any front BBK with track pads for example you may have shifted front bias into the car. Fit the rear kit to the car and tune it to spec with some pads! And get the benefit of more rotor mass where you're less likely to over heat them as you may a more pressure design.

If you've never tried it, the calculators on the web page will give you some ideas on both bias and tq but also at various line pressures.
http://www.tceperformanceproducts.com/brake_bias_calculator.html
Bet I can put 7-8% more brake into the car real quick with the right pad!

 

[jtmcinder]

Todd -

I'd agree if we were planning to keep our ABS. But many of us are in the process of dumping the ABS, so we have to do something to the lines, anyway, and putting a non-ABS prop valve into a 2G is a step backwards, as the split point is lower than the ABS prop valve. In my case, I also want to experiment and that is much easier to do with an adjustable prop valve than trying to do three pad swaps between runs at an autocross. Plus, I just like messing with things.

edit: would you happen to know if Metal Masters have a high mu than R4-Ss? If they do, I might do as you suggest as a stop-gap, since I have my old, rear Metal Masters somewhere in the garage. Thanks.

- Jtoby

ps. I wasn't that offended, but thanks

 

[underradar92]

My abs is also a vestigial appendage since I had to cut off the trigger wheels to install my longer lugstuds. Now its just taking up room. I am trying to tune bias with pad selection, but there are limited pad chioces for my f/r caliper combo.