Project: #becauseracejeep

[Vanimal]

Cross drilled rotors are about as bad as it gets - less surface area for the pad to bite and they're more prone to cracking.

I'll be sure to alert NASCAR.

 

[sidewaysstarion]

I'll be sure to alert NASCAR.

Check out those awesome drilled rotors... oh wait...

 

[IXNAYXJ]

Slotted is fine...drilled, not so much. We run solid rotors on our *actual* race car, as does just about any real race car I can think of.

 

[CobraMarty]

No problems with the rotors so far. No fade or cracks. Autocrossing less than 1 minute at a time is the most abuse they see.

 

[Talyn]

There are cross drilled rotors then there are cross drilled rotors. Companies such as Porsche has the drilling cast into the rotors. They last. Every rotor that I have seen that has had cross drilling drilled has developed cracks along the circumference of the hole. Even the expensive set of Porterfield cryo'd rotors I tried had cracks.,

Not to mention removing area from an already too small rotor.

Not to pick nits, but if it's a race car, why do you care about brake dust? As far as pads go, try blackmagicbrakes.com. And get rid of those silly drilled and slotted rotors, lol.

I run the Raybestos Advance Technology on the ZJ and Porterfields on the XJ. They both stop well, the XJ better. Both dust like a bitch, but I prefer better stopping.

 

[yossarian19]

I missed something. Where did you get the mounting kit to put the M62 on your intake?

 

[JohnX]

I have cheapish drilled rotors on my Miata. Track days are fairly regular for me, no cracks, no fading, and most importantly for me....no pulsating when I drive it on the street.

I also have them on my tow rig. Appears to make little to no difference in stopping distance or feel. 3/4 ton, usually pulling a jeep on a trailer and sometimes a slide and in camper. Again....no pulsation after severe use. Also no cracking.

You guys can say what you want but I'm very happy with my drilled and slotted rotors.

 

[urban yan]

If there's little or no stopping difference than you just answered your own question. They're not worth it.

 

[CobraMarty]

Drilled and/or slotted rotors are not measured by stopping distance alone.
2' difference might seem 'little' but is significant when it comes to braking.

 

[IXNAYXJ]

If there's little or no stopping difference than you just answered your own question. They're not worth it.

I think what he was saying is that he wasn't warping rotors as much...but I've warped drilled rotors just as easily, so I'm not convinced personally. Where I have seen drilled rotors fail (a lot) is on race tracks. Which, given the title of this thread, is what I assumed I'd be reading about. You know, "because racecar?"

Took this a while back...how are those drilled rotors working now?

 

[urban yan]

WOW; you don't see that everyday.

I had drilled rotors on my previous car. No major failures, but the braking wasn't any better. I consider them a total waste of money (especially when you add the possibility of warping, cracking, etc...)

 

[JohnX]

If there's little or no stopping difference than you just answered your own question. They're not worth it.

Stopping difference wasn't my goal.

Drilled and/or slotted rotors are not measured by stopping distance alone.

^this^ Sometimes the difference is after repeated abuse and they still work because they haven't overheated.

I think what he was saying is that he wasn't warping rotors as much

^nailed it!^

I really wasn't trying to stir the pot....just sharing my personal experience on 2 vehicles that have drilled and slotted rotors. The point was this....my rotors used to "warp"....now they do not. And cracking hasn't been an issue.

 

[GSequoia]

Stopping difference wasn't my goal.

^this^ Sometimes the difference is after repeated abuse and they still work because they haven't overheated.

^nailed it!^

I really wasn't trying to stir the pot....just sharing my personal experience on 2 vehicles that have drilled and slotted rotors. The point was this....my rotors used to "warp"....now they do not. And cracking hasn't been an issue.

A good question would be how much improvement could be had from ducting cool air to the brakes verses just slapping drilled/slotted rotors in place.

You have your assignment John. I expect to see a spreadsheet with detailed results including temperature readings at six points of the rotors, calipers, and pads in two weeks time.

 

[yossarian19]

Ducting cool air to the brakes would be more effective at Lemons than in autocross, I'd think, due to the higher sustained speed. Still - yeah, I'd be curious to see what could be accomplished by doing that.
I'd also like to see stopping distances from 60 recorded over 6 trials with solid rotors vs drilled, but now I'm getting data-greedy.

 

[CobraMarty]

Using the drivers side fog light opening for CAI scoop/duct. This mod is not for offroad use.

 

[CTeunuch]

I just read through the build, and you've given me some terrible ideas. I have a couple of questions too. Where did you get those monoleafs, and how much drop did they get you? How do they ride? Also, what did you do to drop it up front besides the coils? It didn't look like you dropped the coil mounts into the tube at all, but it definitely sits low, I like it. Had a chance to dyno it with the blower yet?

 

[bpas328xii]

I just read through the build, and you've given me some terrible ideas. I have a couple of questions too. Where did you get those monoleafs, and how much drop did they get you? How do they ride? Also, what did you do to drop it up front besides the coils? It didn't look like you dropped the coil mounts into the tube at all, but it definitely sits low, I like it. Had a chance to dyno it with the blower yet?

The monoleafs are from Flex-Form http://www.flex-form.com/. We added another monoleaf under the FF leafs to increase spring rate. You can also find these springs in certain Astro vans. As it sits right now, it's about a 4" drop from stock with the springs mounted "upside down", Rough Country shackles and a 1.5" block. It could easily go MUCH lower with these springs, but major mods would have to be done to the chassis and fenders for clearance.

The front was dropped using 3" lift coils (heavier spring rate) and I just cut coils off until it sat right. (due to the design of the springs, you can cut coils without any problems).

The ride is a little bouncy/harsh because it hits the bumpstops a lot (working on fixing this problem). Other than that, the springs are decently stiff and the Jeep handles and drives like a sports car. No complaints on the monoleafs at all.


I haven't had the chance to dyno it with the blower on yet. Still have to put meth on it, put the boost gauge on, and tweak the tune... Racejeep is on the back burner a little bit mostly because of college. Plus I'm also working on my Sprintex XJ (DD) at the same time... Haha

 

[GTIdocjones]

Experience any wheel hop/axle wrap with this setup?

 

[bpas328xii]

Experience any wheel hop/axle wrap with this setup?

Nope. Launches hard and grips like crazy. No drama from the rear axle whatsoever. I'll eventually get around to making some videos of me launching it after I finish it. The axle also seems to be pretty solid laterally which was one of my main concerns. Lol. These fiberglass leafs are really proving themselves to be a great mod.

 

[GTIdocjones]

Very nice. I might have to go with some of those leaves for my project next spring. What spring rates/part numbers do you have?
I was planning to go spring under, but I like your set up because it leaves more room for longer shocks.