ABS?

Brian74

Goblin Guru
I’m not a naysayer of ABS being a possibility. The problem with the Cobalt and newer systems is the addition of the traction control in its many forms. These newer systems utilize accelerometers to detect changes in yaw axis, braking and acceleration and they are calibrated specifically down to wheel size. They work phenomenal; if you have ever driven on snow or ice and seen it in action then you can relate.

A very basic, primitive ABS system that simply detects wheel lockup and then begins modulating to avoid skid could be ideal; even if its just for the rear wheels. May even save you on a late braking incident going into a corner.

I’m not too motivated to persue any of this, as I’ll be happy just to see the day I get my frame powdercoated at this point.
 

Desert Sasqwatch

Goblin Guru
Saw that one Jaret, as pointed out by Brad earlier - my comment about big $$$.

ABS would be a great addition to the Goblin, but the info from Lonnie appears to rule out trying to use it based on the interaction with the throttle control. Agree with Brian that even having rear wheel ABS, as found in many pickup trucks from the late 1980s, would be great - just not sure how this could be accomplished.
 

Brian74

Goblin Guru
Pick up trucks from the late 80’s was exactly what I was thinking about in that example, lol. Would need rear wheel speed sensors and programming that would communicate to an ABS actuator based on wheel speed sensor frequency threshold value.
 

Desert Sasqwatch

Goblin Guru
If I remember correctly, the ABS controller was a separate module on these trucks (GM) - I had a couple trucks back then and recall having a faulty controller replaced. A quick look at eBay for truck rear ABS controller comes up with several. This may need to have some further research to determine if it can be a stand alone and what sensor inputs are needed to make it work.
 

Brian74

Goblin Guru
The thing you have to realize (I know you’re an engineer) is do not over engineer this car, yet. The horesepower/torque to weight ratio already puts it at a HUGE advantage at the track... Literally on par with Ferarri. There are guys out there destroying other cars at the track with Goblins in stock form. That alone makes much of the other issues rather moot.

You have a great start. New engine & trans. Once you get into the actual build, you are going to find unmeasurable processes and speedbumps to get it built (especially if you are a perfectionist like me). I’ve been in this for nearly 2 years. I have a solid plan as of now. I could go further into the plan, but I am at the point where, at the same time I want to enjoy the car I envisioned. If I keep brainstorming ideas, it is only the longer I’ll be away from finishing the build & drving the car and coming up with even better ideas later that will evolve from actually drving the car and really seeing what improvements will work for me.
 
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ctuinstra

Goblin Guru
I agree withh Brian. Until you have the car built, you won't really know what you will want improve upon and make better. Locking up the brakes on this car not is not major problem. These things tend to stop on a dime! I remember one of the others members talking about how other drivers would darn near rear end the Golbin on the track because he would stop so fast going into a turn.

The cars are also very easy to work on and modify if you do decide you need to change things. Sure, customize along the way, but I would at least experience the car before re-engineering it.
 

Desert Sasqwatch

Goblin Guru
Brian and Chad, thanks for your advice and a dose of reality. Sometimes chasing an idea down the rabbit hole is a healthy mental exercise, but as you point out, may not have much relevance in the real world application.

Having rode in Rich's (RichRich) purple Goblin I experienced first hand the brutally quick stopping ability of the car with the 'stock' brakes. I did notice that during hard braking with maneuvering a wheel would tend to lock up - not dangerously as it was only a single wheel. The engineer in me asked how it could be made better and I started looking at the forum for ABS threads.

Since I have some time before I will be getting a full blown build, I will continue to look into this and post any new findings that may be relevant to the ABS thread. Appreciate your candid input and I'm fairly certain some new ideas may be forthcoming. It's all good stuff.
 

Zoidborg

Member
I'm getting ready to order a kit, and I was curious about whether the ABS could be made to work. A lot of what was mentioned here does suggest that its complexities would make it unworkable on the Goblin.

However, my donor car is a SS/SC LSJ, and the ABS system in that car is a lot simpler than the other Cobalt models for the most part. It does ABS only with Electronic Brake Force Distribution. No traction control, no stability, etc.

I am wondering whether you can just set its front channels to the rear wheels and vice versa. Considering the hubs' sensors are in the reverse position (front to back), but at the same time as others have noted, the front brakes get light compared to the rears instead of the other way around. In theory, it might work routing the rear master cylinder line to the front ABS channel to the rear wheels, and the rear master cylinder line to the rear ABS channel to the front wheels.

IF that were to work, the biggest issue might be how to keep the sensors on the Goblin's front wheels intact. It looks like they have to be taken out because of the steering piece that is on the DF front spindle.

Thoughts on this?
 

Scott #321

Well-Known Member
My experience in driving a tc/ss is the traction control and stability control would be more beneficial than ABS would, this added to the complexity of the system makes it something most are not willing to tackle. That being said, very few if any of us would have built a Goblin if not for the outstanding instructional support of DF and those that have gone before. I imagine eventually someone will figure out how to get it accomplished and it will be something that becomes more common if it can be accomplished with only minor bloodshed and shows performance or safety improvements to the origional design.
 

Zoidborg

Member
Yeah I dunno maybe it could be overkill. I guess ABS was on my mind since I've had some experiences with the Cobalt especially on track where it saved my butt on unexpected conditions. o_O

I may try to integrate it though, I'm thinking the EBCM on the LSJ car with its much simpler profile (ABS/EBFD, no TCS/Stability) might just work. I just have to make brake lines which sounds like something I can do. If it doesn't work I can always change to basic with the proportioning valve someone worked into their build.
 

k.rollin

Goblin Guru
Yeah I dunno maybe it could be overkill. I guess ABS was on my mind since I've had some experiences with the Cobalt especially on track where it saved my butt on unexpected conditions. o_O

I may try to integrate it though, I'm thinking the EBCM on the LSJ car with its much simpler profile (ABS/EBFD, no TCS/Stability) might just work. I just have to make brake lines which sounds like something I can do. If it doesn't work I can always change to basic with the proportioning valve someone worked into their build.
I think @ATMironov is working on ABS for his Goblin, but I think he's using BMW bits for that. Maybe some insight there.
 

Zoidborg

Member
Yeah, I'm using an MK60 ABS out of an E46 M3. Now I just need time to finish the **** thing
Cool I remember looking some at your build thread; I'll have to go have a look when I get off work. Did you have to keep the sensors in the hubs?

I'm thinking the biggest open question for trying this out is to make sure I can still connect the hub speed sensors to the harness connector. I gather that you have to destroy/remove the speed sensor (or at least connector) so that the rear hub will fit onto the front suspension for the Goblin. I'm thinking if I can work that out then I can try using my ABS unit.
 

Zoidborg

Member
The ABS connector should just be an issue of custom steering arms that allow more room.
I was thinking of that or maybe just some spacers and longer bolts if needed using the current ones. I don't know if they would do one-offs for this test. I do not have the skills or means to fabricate parts myself, just putting them together lol
 

Desert Sasqwatch

Goblin Guru
Keep in mind that spacing the steering arms from the back face of the uprights moves it closer to the steering rack, shortening the length of the tie rods, and will potentially affect the steering geometry. It could induce bumpsteer and change the Ackerman.
 

ATMironov

Well-Known Member
Cool I remember looking some at your build thread; I'll have to go have a look when I get off work. Did you have to keep the sensors in the hubs?

I'm thinking the biggest open question for trying this out is to make sure I can still connect the hub speed sensors to the harness connector. I gather that you have to destroy/remove the speed sensor (or at least connector) so that the rear hub will fit onto the front suspension for the Goblin. I'm thinking if I can work that out then I can try using my ABS unit.
Yes, I'm using the factory cobalt wheel speed sensors.
The Goblin rears (Cobalt Fonts) are not an issue.
The Goblin front (Cobalt Rears) are a challenge because of the steering arm.
I discuss in depth here
And show my final solution here:

Bus basically, I swapped the arms from left to right, keeping them in the same orientation, then used spacers to bring the ball joint location back to where DF intended it to be.


In conjunction with the ABS, I'm running a manual Tilton pedal rack with a dash mounted brake bias control. So I have lots of opportunities to tune the system.

I read in one of your posts that you may be swapping the brake lines front to rear... just make sure you match the sensors to the right brake lines. :)

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