Track Video: Eclipse chasing M3 at MAM

[Slow old poop]

That's what I think it is, anyway.

I haven't seen it, because my ancient Windows 98 laptop won't play the video, so I won't be able to see it until I get home, sometime this weekend, and can play it on my PC. Somebody tell me how it turned out.

Here's the link: http://media.putfile.com/Rich-at-MAM---FTL-6-2006

With luck, the video will show me following an M3 out onto the track, then a full lap at Midamerica Motorplex near Council Bluffs, Iowa. The camera car is Damien dela Huerta's Mazda RX7 One Lap car, and he was kind enough to upload the video to putfile for me. He was also kind enough NOT to pass us, since he is about 7 seconds a lap quicker. He was in the top 5 during One Lap until it rained.

The M3 is a fully modded car with a $6000 head, unknown engine mods, cage, adjustable suspension, and was used as a model for race car prep at a NASA seminar at Orr Motorsports in Minneapolis.

I am only running 10 psi boost during this session, because it was our first outing of the year, and we were getting the bugs out.

You may see the brake lights flashing like crazy -- that's because I was pumping the brakes to get pedal pressure. Once I got pedal pressure, the car stopped OK, but it sure messes up the braking points. You never know when it's going to stop. So you may see me braking kinda strangely.

Maybe when we kick the boost to 20 psi, I'll catch that M3.

I hope the video is interesting and I didn't do anything stupid.
(I may regret putting this video up without watching it first.)

Rich

 

[Slow old poop]

Finally saw my own video. Not very exciting, is it?
I thought the RX7 would be closer, and that he had the entire lap on tape.
Sorry about that
Rich

 

[schemauer]

Rich-

Any ideas on how to cure your brake issues? I have the same problem with my Archer Talon. In some corners I need to jab the brake pedal before the actual braking point to get a solid pedal. If I don't the pedal will drop lower, but still work fine. It's just a bit unnerving to have this happen and to remember to hit the brake pedal to avoid it.

The car runs stock rotors and calipers using Porterfield R4E pads. I've heard this is due to the pads moving away from the rotor in the calipers? Not sure why this would happen - possibly a slightly untrue rotor might push them back? That's just a theory I've heard.

Scott

 

[mavisky]

Not too bad, at least there was footage at all as opposed to no footage.

 

[olmytsi]

Yeah, good enough for me! Thanx for sharing.

 

[Slow old poop]

It's called pad knockback. The rotor flexes during cornerign, and pushes one of the pads back into the caliper, so the first pump of the brakes moves the pad into position, and the second pump (allegedly) sees a full pedal. The bigger the rotor on a stock hub, and the more cornering force, the bigger the problem. I am pumping like crazy to get pedal pressure.

There is a complete discussion of the phenomenon at the stoptech web site.

I got rid of some pad knockback last year by replacing the front hubs. They tend to wear out (tired iron) and allow more flexing.

There are theories about bracing the master cylinder or replacing some of the components with 3000GT parts.

My next fix will be to install residual valves, which keep 2 psi pressure to the pads at all times. This allegedly will be enough to overcome the pad knockback. All we have to do is figure out where to put them: at the master cylinder? At the calipers?

If it works, I'll post all the gory details.

Rich

 

[Ludachris]

Nice smooth lines. We need to get more road race DSMers to post some videos from their in-car cameras... I need to get a video camera myself!

Ad for the brakes, I didn't realize this was such a big issue. I haven't experienced it, or if I have it hasn't been very noticable. I know MachV sells a brace for the master cylinder. It's a little expensive though - $119:
http://www.machv.com/brakboosbrac.html

Wonder how tough it would be to fabricate a brace?

 

[mavisky]

I'd seen that before, and I've got to imagine that a brace wouldn't be too terribly difficult. It looks to have a "cup" to receive the end of the master cylinder and then an area to bolt it to the shock tower at a near 90degree angle. I'd imagine a bent piece of steel and some angle iron would make something just as effective, but not as cool looking.

 

[Slow old poop]

I just discovered that the video IS a complete lap of MAM.
All you gotta do is be patient, and let the whole thing load.
It ends when the camera car pulls off

Rich

 

[Zero Bar]

Hmmm...I can't see the video. I waited about 20 mins for it but it never worked for me. I guess I'll try it again later.

 

[Slow old poop]

Just a black screen, right? that's what happened to me last night in the hotel. It seems the hotel network was blocking codecs or something techie like that. As soon as i got to a different wireless network, it worked.

I also downloaded the latest version of Media Player, which you must have to see the video.

Rich