60-0 Braking...
 

Got a G-tech Pro performance meter over the Xmas holiday and decided to test my 60-0 braking performance tonight.

Conditions: 48*, all-season Bridgestones tires on stock wheels, 1/3 tank of gas. My car was equipped with stock rotors and Auto-Specialty semi-metallic brake pads. Each run was done 3 minutes apart.

Did two timed runs on the same remote flat stretch of road and braked at approximately the same point on the road.

My first attempt was scratched due to a mistake on my part (still threshold braked from 60mph though). Next two runs had the stopping distances of:

124ft

128ft

In the next 2-3 weeks I'll be ordering slotted only rotors and Axxis semi-metallic pads (front & rear) from Ben at RaceConcepts. I'll then repeat this test (with conditions as similar as possible) to see if there is any measurable improvement in braking performance. Should be fun!

-Chike

P.S. BTW, stopping from 60mph in 124ft felt pretty darn cool. Just proves that the SVX with factory rotors can still stop in distances which are excellent by today's standards. :cool:

how much for the rotors?

With the special Ben is running until the beginning of March, you can get Race Concepts slotted rotors F&R for $189 before shipping. The pads are another $70.

This is the thread where Ben talks about his deals:

http://www.subaru-svx.net/forum/show...threadid=23598

-Chike

P.S. Just to be clear, my current braking distances are on stock rotors only.

Went back this morning...
 

...and repeated my testing from last night. Temps were 30*, but everything else was the same.

1st stop: 120ft

2nd stop: 117ft

http://www.subaru-svx.net/photos/fil...etkd/24351.jpg

http://www.subaru-svx.net/photos/fil...etkd/24352.jpg

-Chike

Cool photos Chike, looks like fun!:D

Chike,
Interesting! Looks like the cooler temps bumped up your coefficient of friction - 11 foot shorter stoping distance is a big difference!
-Bill

Yeah it is. I would have thought that a colder tire would result in less friction. After all, why do drag racers and such heat their tires if not for stickier launches. Braking should do the same I would think. All things considered between the tests done by Chike and I would have to consider some widely varying inaccuracies in Chike's G-Tech. :confused:

Johnny

Was the ABS operating?

Harvey.;)

Re: 60-0 Braking...
 

Chike,
Great test. I am wondering also why the big difference in distance in the two events. Very interesting. And it would be cool too to test the braking with race tires too. With those, Johnny, a higher temp would definitely help.

BTW, Chike, I think you can probably get those AXXIS pads cheaper elsewhere. Seems like the last ones I bought were about $50, but my memory isn't all that good these days - old age, you know. I really like my AXXIS pads, but went with the Green Stuff pads at the beginning of last season's autocross events. I think the AXXIS pads were better. Even at Summit Point Raceway and VA International Raceway, I had NO fade with the AXXIS pads and STOCK rotors (a MAJOR factor is changing to high temp brake fluid too!!). I also had an interesting comment from one of the track instructors who drove several laps in my car Showing me the proper turn-in points, etc). Going into Turn One at Summit approaching 120 MPH and braking very hard for the hairpin turn (taken at maybe 50 MPH), the instructor said, "Wow! This car has brakes". The instructor, BTW, drives a race prepared VW GTI (very lightweight) at this track and several other SCCA associated tracks. As you said, the brake performance of the SVX isn't that bad even compared to "modern" standards. I have never understood why some SVX'ers bad mouth the SVX brakes. I bet they have never changed the brake fluid ?

Anyway, looking forward to seeing the results of the AXXIS pads and new rotors.

Harry

Remeber to bed the brake pads and give them 100 miles or so to go throught some heat cycles, and ive read your only spouse to change the rotors our pads at one time then the others, better for braking them in.

It would be interesting to 0-60 around 5 times in a row to see the diffrence in fad resistance between the two setups becasue i bet thats were most of the gains will come from.

My guess is the difference was more due to the condition of the road versus Mr. Chike's tires. I think Mr. Harvey also has a point as to whether the ABS is working in Mr. Chike's car.

Wow thats a pretty good price.

Harvey,

My ABS was operating properly both times. I really love the Subaru ABS system compared to the ones I've experienced in Nissan (former '90 300ZX TT) and Ford (former '00 SVT Lightning). Those systems kicked in way too early. The Subaru only kicks at impending lock-up and the rapid pulsing is really awesome.
The difference in my stopping distances is more attributable to the road surface being cleaner the second time. The area where I braked at was a bridge near my house. I used the bridge as it is completely flat and there would no gradient to influence my results.

This was a picture of the bridge I took just last Saturday (1/22):

http://www.subaru-svx.net/photos/fil...etkd/24210.jpg

Basically, after the snow melted, there was a bunch of sand and salt everywhere. Some rain did fall between my first and second test which obviously dissolved the salt and moved the sand towards the edge of the bridge (drainage). The cleaner road surface definitely helped.

-Chike

Re: Re: 60-0 Braking...
 

Thanks for the comments Harry. I used my all-season Bridgestone m+s tires for this test, and I'll use the same rubber once I install the raceconcepts rotors and pads. When it warms up again, I'll switch over to my sticky Dunlop SP Sport 8000 summer tires (tread wear of 200). I'm sure the extra sticky rubber will help braking even more!

-Chike

BTW guys & gals...
 

I should mention that my brake pedal is extra firm as I have zip-tied my entire front brake lines. I'm also running high temp Valvoline Syn power brake fluid.

-Chike

P.S. Sorry for the delay in responding to your posts, but I was at a Kenny Chesney concert last night. Charlottesville, VA was the first stop in his '05 Keg in a Closet' tour. :cool: