ACR vs LimeRock

[ACR steve]

Well I had my baby out for its first track day on Sat. All I can say is thank you to Ralph and the whole Viper design Team. The car was 2 seconds a lap faster (58seconds) driving it 7/10 of what I know I could drive it at. Unfortunately I never got to drive it alone for some laps. IT made such a big impact everyone wanted to go as a passenger. I must have had 10 people with me during the course of the day.

We smoked all the Z06's , GT3's ,600hp full raceEVO's and everything else that showed up.

I did have a problem with the brakes getting soft after 3 laps. I have Motul in it so I am guessing that it is a pad issue and I need to upgrade them.

That leads me to the question of should I put in the Comp. Coupe brakes? and if so where can I get them?

With the brakes working like I know they are capable of I bet this car would be a 56 second car around LimeRock which puts it in the league of some veryyyyyy fast race cars and might I dare say never achieved by a stock factory car.

 

[ACRBruce]

...
With the brakes working like I know they are capable of I bet this car would be a 56 second car around LimeRock which puts it in the league of some veryyyyyy fast race cars and might I dare say never achieved by a stock factory car.

You're probably right Steve as 7:22 was never achieved by any other stock factory car at the 'Ring before the ACR roamed there.

 

[CCBrian]

I have the same problem with our ACR as well. I also am running Motul. These are the same brakes as the Comp Coupe. I think the issue is the extra weight of the ACR and cooling ducts. In my Comp Coupe I run Motul and Mintex pads-at the same track I have zero fade or softness.Yes there are some ducting to the wheels, but nothig like what is on a Comp Coupe. I am going to change pads next time out to see if that helps-but I believe its the extra weigt/smaller cooling ducts that are at play here.Even though they appear soft, they do still stop very well though. We just had both cars out at Thunderhill Raceway here in Norcal this past weekend.

 

[ViperTony]

Hey...how did you get on Lime Rock? Can you sneak a few of us in next time? I have to imagine that even with the track improvements made at Lime Rock that the Viper still can't fully stretch its legs on that course although if there's anyone that knows how to work the limitations on that course it's you Steve. Cool update, thanks.

 

[mike & juli]

Nice write-up on your new ACR and LimeRock Track, Steve. And, good observations on your brakes too. If ANYONE would know what's needed on these cars at the track, it'd be you. NO DOUBTS either on beating anyone, even with your passengers you took along...you're 'in it to win it'~! KUDOS...juli

 

[ACR steve]

CCBrian- Let me know how the Mintex pads work out. It may be without brake ducts the stock pads get to hot and cool fast enough. When the pedal gets soft the brakes get notchy during that lap almost like a bad pad . Then once they cool down they are back to normal.

 

[Bugeater]

I posted a separate thread, but where do you guys get your mintex pads at? Also, any use of a different composition on the rear for less bite/torque?

 

[fireball]

Hey, ACR Steve - about the soft pedal. I had the same problem on my first track day. By the second track day everything had worked itself out and the brakes were excellent. Since then I've switched to Castrol SRF and the brakes continue to feel excellent.

Greg

 

[plumcrazy]

Steve, i was waiting to hear this from YOU...very kool

sounds like with a little time and braking, its gonna be dangerous to others if they race ya.

ya might wanna consider keeping it BONE STOCK for a while till you get that time down where you think a BONE stock ACR can go....and THEN mod the brakes or whatever else

 

[YellowViperSRT10]

I have 0 fade. I am using our Euroteck rotors and Porterfield R4 race pads and stock fluid!!! I just came back from Sebring and it was awesome. You guys should really try the R4 pads, you will love them!

 

[CCBrian]

We are going to try the stock pads in rear, and Mintex up front. Fireballs Castrol SRF idea is a good one too (we used to run it in our Panoz GTS)-I think we will go to that fluid as well. We have 4 track days on the car so far...while the pedal gets soft is does still stop-just a little un-nerving! We get Mintex pads from Viper Headquarters.

 

[ACR steve]

Cool thanks guy. I really do not think its a fluid issue since I had new motul and only 3 laps of nowhere near what I would consider threshold braking (I didnt hit ABS ).The wet boiling point on Castrol is higher but Motul should still be able to take the 3 or 4 laps. After the pedal was soft on there would be the weird pedal feel almost like the pad was deforming.

I think the way to go might be try the from CC pads as the fronts and go stock in the rear. Anybody have any bad feedback with two different compounds from and rear? How can I order the pads from Viper Headquarters?

 

[YellowViperSRT10]

Cool thanks guy. I really do not think its a fluid issue since I had new motul and only 3 laps of nowhere near what I would consider threshold braking (I didnt hit ABS ).The wet boiling point on Castrol is higher but Motul should still be able to take the 3 or 4 laps. After the pedal was soft on there would be the weird pedal feel almost like the pad was deforming.

I think the way to go might be try the from CC pads as the fronts and go stock in the rear. Anybody have any bad feedback with two different compounds from and rear? How can I order the pads from Viper Headquarters?

I think it is only a pad issue you are having. Trust me! try the R4!!!!!!!!!! My pedal is very firm even after many laps and braking is excellent.

 

[fireball]

I think it is only a pad issue you are having. Trust me! try the R4!!!!!!!!!! My pedal is very firm even after many laps and braking is excellent.

How's the rotor wear?

 

[YellowViperSRT10]

How's the rotor wear?

Very good so far. I have put 11 track days on my rotors. I went threw 3 sets of R4 pads.....2 of those days were on stock pads which **** in contrast to the R4s. The R4s will eat up the rotors faster if you plan to use them on the street though.

 

[Tom F&L GoR]

In my dreams I hoped for a sub-minute lap at Lime Rock (OK, with a tricked out Gen 1 setup that beats Gen 1/2/3 in autocross.) Getting under a minute has to be 150-ish braking to 70-ish into the decreasing radius Big Bend turn. Pucker power.

Then to be around 56 seconds, you are talking about lap records for Shelby Cobras and other real race cars. I'm more than impressed, I am hiding!

 

[Boxer12]

You can get Mintex pads from Archer Racing, and most guys (me included) use BM3's on the rear with them. Very nice combo. I have also used R4's, and IMO they are inferior to the Mintex in the initial stages of braking. Here is something to shoot for (54 sec in a 1974 RSR-3.6L): [media]http://www.youtube.com/watch?v=JdHXfHu1L0M[/media]

 

[REDSLED]

I have 0 fade. I am using our Euroteck rotors and Porterfield R4 race pads and stock fluid!!! I just came back from Sebring and it was awesome. You guys should really try the R4 pads, you will love them!

What times are you posting at Sebring?

 

[REDSLED]

Jon B also stocks the Mintex pads. He had a huge sale on them a few months back.

 

[YellowViperSRT10]

What times are you posting at Sebring?

It was a DE event, and I did not actually have my lap timer with me....

 

[cheryl mccally]

I love the PFCs on the track. They are very predictable and linear. I melted a set of OEM pads to the rotors in one session on a pad eating track we have around here. Drove straight off and up a hill. The pedal was still good and firm but no stoppee the ACRee. On this particular track you better have good brakes or bad things happen. Neither of my ACRs like bumps on the track either. It will really send the back end around with you doing nothing else wrong. One bad bump if you are really fast and it will let that rear wing act like a propeller.

 

[ACR steve]

Boxer, I know Chris's car and I know Spencer who held the lap record in a 944 until Chris broke it. They have incredible times at the track.All I can say is that I am very confident that the new ACR in stock may just be the ticket to braking more then the "Rings Production Car Record"

Tom- this car is awsome .Last year in my 99ACR the best time I had was a minute flat with Toyo Proxi's on the car. This new car is just in another league

Thanks Yellow,Cheryl, Red, Fireball and CC.I think I am going to try the CC brakes up front and see how it reacts.
Thanks for everyones feed back

 

[YellowViperSRT10]

Boxer, I know Chris's car and I know Spencer who held the lap record in a 944 until Chris broke it. They have incredible times at the track.All I can say is that I am very confident that the new ACR in stock may just be the ticket to braking more then the "Rings Production Car Record"

Tom- this car is awsome .Last year in my 99ACR the best time I had was a minute flat with Toyo Proxi's on the car. This new car is just in another league

Thanks Yellow,Cheryl, Red, Fireball and CC.I think I am going to try the CC brakes up front and see how it reacts.
Thanks for everyones feed back

goodluck, and let us know how it feels.

 

[Viper X]

Went down the brake improvement road with my GTS ACR - with SRT brakes of course.

It's a pad issue.....the Brembo brakes themselves are great. Try PFC's up front, part number 7780.01.18.44 and Porterfield R4s on the back (Brakeman 3's work about the same but cost more). You will need 4-inch brake ducts up front with these pads as they transfer more heat into the rotors and Motul 600 RBF.

With this set up, the limitation becomes our tires.

On the Mintex pads, I tried a set and they worked pretty well but were harder on the rotors than the PFCs IMHO.

You can get all of the above brake pads from Archer Racing.

Now, go out and beat up on those Ferarris, Porsches and Vettes.

Dan