Which Stop Tech kit (Gen 2)

[72hemi]

Alright I am having a hard time deciding which big brake kit to get for my 2001 ACR. I do not want the SRT brake conversion kit, so please no recommendations for that. I am trying to decide between the 4 piston front and rear kit or the 6 piston front 4 piston rear kit. What are the pro's and con's of each?

[TexasTonka]

Alright I am having a hard time deciding which big brake kit to get for my 2001 ACR. I do not want the SRT brake conversion kit, so please no recommendations for that. I am trying to decide between the 4 piston front and rear kit or the 6 piston front 4 piston rear kit. What are the pro's and con's of each?

I had a 2001 RT/10 set up for track use with KWv2 suspension, custom sway bars, blah blah blah... so I used my brakes quite a bit... I had the ST60 front and ST40 rear set up with slotted rotors for quite a while (REAL break in is a MUST to get any performance advantage) and I really enjoyed the 60/40 set up. When I sold that car I kept the 60/40 set up and swapped in a set of ST40/ST40 stoptechs and honestly felt ZERO difference. Granted I did not go out and do 60-0 runs to test but seat of the pants 'spirited driving' I felt nothing different than the ST60 fronts. The ST60 are a little bigger but unless you held them side by side you wouldn't know either.
If you can get the ST60/ST40 set up for same money as 40/40 then go for it. If it is several hundred more I don't think I would do it again, would stick with the 40/40 and use the money saved for more pads.

[Leslie]

I have the Stoptech 6 piston front/4 piston rear, purchased from Jonb on group purchase a few yrs. ago.
I would have been fine with the 4 piston fronts if he had them, pads are cheaper. I use hawk dtc 70/60 pads.

I do about 8 track weekends/yr, have plenty of brake so am sure 4 piston fronts would be good.

[Will at RSI]

Also consider Brembo kits. Give me a call if you are wanting to discuss your options.

[XSnake]

I have the 4/4 setup on my non ABS car and never had an issue once I got the fluid switched over to SRF.

[72hemi]

Thanks for the input so far. I had thought about the Brembo's but in the end I think I may be paying more for the name than the extra performance.

[JonB ~ PartsRack]

Thanks for the input so far. I had thought about the Brembo's but in the end I think I may be paying more for the name than the extra performance.

You did your research! Nice that you have an ACR, because the BBS OE wheels will clear the 6 or 4 piston kits. The StopTech BB kits were engineered at a time when StopTech's owner had a Viper. He haded the 1997 Brakes. So he made BBKs even tho low production numbers. A magazine test in 2001 of BBKs rated Brembo, Wilwood, Baer, StopTech, and one other mfr (drawing a blank.) Tested On a VIPER, due to its Gen 2 crummy OE brakes.

In the various categories, StopTech 4/4 BBK won "most improved Stopping Distance from 100mph - 0mph "
It alo won "easiest install" and also the "best value" in that 2001 Test.

the 4/4 option gives you a LOT of economical pad options that the 6 piston just does NOT have. The 4/4 vs 6/4 braking performance only shows up in sessions longer than 45 minutes...not a HPDE benefit.

Id recommend a 4/4 kit unless the 'cosmetic' benefit of big-6 matteres, but you already showed that cosmetics (Brembo) are not primary in your mind. And the 6/4 is about $500 more than the 4/4 kits....

JonB

[XSnake]

the 4/4 option gives you a LOT of economical pad options that the 6 piston just does NOT have. The 4/4 vs 6/4 braking performance only shows up in sessions longer than 45 minutes...not a HPDE benefit.

Id recommend a 4/4 kit unless the 'cosmetic' benefit of big-6 matteres, but you already showed that cosmetics (Brembo) are not primary in your mind. And the 6/4 is about $500 more than the 4/4 kits....

JonB

Agree with this. Unless you are doing some longer sessions/enduro stuff the 6 piston front is just not needed. I've done Daytona multiple times in my car where I'm hitting the brakes at over 180mph twice per lap. With the right pads and fluid the 4/4 can put you in the windshield.

[Ricketts]

I'd contact Jon B, he is very knowledgable on Stoptech products.

[Dan Cragin]

Alright I am having a hard time deciding which big brake kit to get for my 2001 ACR. I do not want the SRT brake conversion kit, so please no recommendations for that. I am trying to decide between the 4 piston front and rear kit or the 6 piston front 4 piston rear kit. What are the pro's and con's of each?

The six piston front, four piston rear is the best kit. The bias is better and the six piston front can take much more heat, so it is more repeatable. If you want the best kit out there, the Brembo kit is by far the best. The components are higher quality and the rotors will last much longer. Obviously, it is much more expensive. I worked directly with Stoptech when they developed those kits, they are a good setup for the price. I do have a couple suggestions, use the slotted rotors not the drilled ones. They will last longer and will be less likely to crack. Also,instead of using the Stoptech parking brake kit, order the parking brake brackets for the earlier 1996-2000 kit and get the earlier rear caliper to use as a parking brake. They hold better and the parking brake handle does not need to be pulled up too high.

[Will at RSI]

Great Info Jon and Dan!

I would like to ask a few questions.

• What type of modifications have you done? Horsepower increase? Aerodynamic improvements (more down force with rear wings or front splitters)? Strip the vehicle for weight reduction? Race Compound Tires? What pad compounds currently used? Dedicated race car or dual purpose car?
• Do you track your car? What type of events? Autocross, High Performance Driving Events, Time Attack or Road Racing (Club Racing or )? How often?
• Are you an aggressive driver (late braking and high speeds into the corners)? Driver experience (Professional, Advanced, Experienced or Inexperienced)?

[72hemi]

Thanks Jon and Dan great information! Will for your questions see my answers below:

• What type of modifications have you done? Horsepower increase? Aerodynamic improvements (more down force with rear wings or front splitters)? Strip the vehicle for weight reduction? Race Compound Tires? What pad compounds currently used? Dedicated race car or dual purpose car? So far horsepower increases have been minor with only a Borla 2 muffler cat back system. I also have upgraded the rear differential with 3.55 gears and Penske 8300 shocks installed. The car is dual purpose, mostly street but I do take my car to the track. No aero upgrades or weight reduction. More horsepower increases will be in my future.
• Do you track your car? What type of events? Autocross, High Performance Driving Events, Time Attack or Road Racing (Club Racing or )? How often? Most of the track events I do are road course and only a couple a year currently but that will increase when more free time becomes available.
• Are you an aggressive driver (late braking and high speeds into the corners)? Driver experience (Professional, Advanced, Experienced or Inexperienced)? I would say that I am definitely an experienced driver, but I tend to be a more conservative driver on the track.

[Troublemaker]

This could end up being a great thread with alot of brake information in one place. Brakes are actually going to be winter project for me. I was looking at just doing the SRT upgrade, but maybe the outcome of this thread could have me spending a little more money to do it right the first time.

[moparracing]

I have the 60/40 stoptechs on my GTS, a must over stock brakes & JonB can get ya a great deal too. The other advantage over other BBK's is there's no need to add a proportioning valve with the stoptechs. Never have a brake lockup since I put the stoptechs on. Great, balanced kit & worth every penny. You will need 18" wheels with this kit at a minimum.

[Leslie]

I have the 60/40 stoptechs on my GTS, a must over stock brakes & JonB can get ya a great deal too. The other advantage over other BBK's is there's no need to add a proportioning valve with the stoptechs. Never have a brake lockup since I put the stoptechs on. Great, balanced kit & worth every penny. You will need 18" wheels with this kit at a minimum.

brake lock up-good point, never have had that. I don't race, but I do like to brake late (instructor group) and I love confidence of the stoptechs. Most braking I have ever done at the track is 140 to 80 on back straight at Mid Oh.

Thanks Jonb! Best upgrade I ever made.

[JonB ~ PartsRack]

brake lock up-good point, never have had that. I don't race, but I do like to brake late (instructor group) and I love confidence of the stoptechs. Most braking I have ever done at the track is 140 to 80 on back straight at Mid Oh.

Thanks Jonb! Best upgrade I ever made.

Leslie: MoparRacing Randy does NOT have ABS....... vs you DO have ABS in 2001+. The "Balancing Act" is done by the computer on abs and by the Driver on a 92-2000, so proper bias-proportioning is more critical pre-2001.

Thank You

[Leslie]

Leslie: MoparRacing Randy does NOT have ABS....... vs you DO have ABS in 2001+. The "Balancing Act" is done by the computer on abs and by the Driver on a 92-2000, so proper bias-proportioning is more critical pre-2001.

Thank You

that makes sense, thanks Jonb!

[moparracing]

Leslie: MoparRacing Randy does NOT have ABS....... vs you DO have ABS in 2001+. The "Balancing Act" is done by the computer on abs and by the Driver on a 92-2000, so proper bias-proportioning is more critical pre-2001.

Thank You

yeah, more critical to have a manual prop valve on other BBK kits on non-abs cars....... not required with the stoptechs.

[jrkermode]

72Hemi,

I had these same questions when I first started tracking my car years ago (before the 6 piston StopTechs were available). What I learned along the way is a lot of the kits, and unfortunately a lot of the advice, have more to do with looks or brand loyalty than performance. I'd be happy to share what I tried along the way, perhaps at our first NorCal VOA meeting. Suffice to say either StopTech kit, or even the front only kit (what I have) will do a fine job stopping a Gen 2. So, you will not regret either of those options.

[viperfred]

I my opinion the first question to be answered is why modify the brakes?

Serious open tracking or racing?

Fred

[Troublemaker]

I my opinion the first question to be answered is why modify the brakes?

Serious open tracking or racing?

Fred

Basically, Gen2 brakes suck.

[Leslie]

Basically, Gen2 brakes suck.

Omg they do! I started upgrading with GenIII's, wish I would have jumped right to Stoptechs (Jonb!)

[72hemi]

Basically, Gen2 brakes suck.

This is why I want to upgrade them.

[1997Viper]

Maybe not as popular but I did the Front StopTech's long ago before all the market options and kept the rears stock but upgraded the pads and slotted rotors. As bulk of issue was front's this made all the difference plus left the parking brakes and was 1/2 cost and lets me still use 17's for track. The other option explored on the rear was the bigger 40mm bore stock that balances with fronts (Search Tom's 40mm, though not sure still available).