ALFAGTV6.COM

[bmacf]

Hey Everyone, as a follow-up to my earlier post, Jim at Whoa Brakes
(www.whoabrakes.com) is thinking about making a front brake upgrade kit for our Alfa V6's. I've volunteered to do some testing for him and check out what arrived at my front door:

Jim sais this is just a prototype, but it has Wilwood Dynapro calipers, Wilwood Polymetrix pads, and some braided stainless hoses (not a bad still life for one of my photoclass projects).

For the testing I'm going to first test my stock system then the WHOA system. I've got a Gtech, so I'll evaluate stopping distance, abs activation, pedal pressure & height, and potential for fade.

I'm headed out for a Mid-Atlantic AROC driving school event at VIR at the end of the month, and then another driving school at Summit Pt. in May. So that should give me a feeling of how the WHOA system compares to the stock system. Look for more information soon.

Thanks,
Bill in Maryland

[Greg Gordon]

This looks pretty exciting Bill. Our stock brakes are pretty good, but modern tires and track conditions have made them somewhat obsolete. Plus the original calipers are getting really expensive. This could be a great alternative.

[enzo]

specs?

[Zamani]

With stock rotors? Our rotors are pretty small for a pretty heavy car. Even Integras have bigger rotors I think.

[MALDI]

Do Integras have bigger rotors because they need bigger rotors or because 'bling' sells in that market???

Some Integras have big rear wings too!

[la_strega_nera]

Even the little light weight poxy 4 cyl alfettas need bigger rotors if they're being driven hard enough!

I think Z was using the tegra as an example of a lamo slow budget car that has bigger brakes.

[Greg Gordon]

It depends on what you are using the car for. On the street the stock sized rotors are just fine. They are large enough to dissapate the heat and provide plenty of leverage for the calipers for just about any realistic street situation. At the track bigger rotors would be an improvement, but the stock rotors are certainly good enough for club events and other things. Plus stock sized rotors are required for many classes of racing in the SCCA.

[Mats]

Even the little light weight poxy 4 cyl alfettas need bigger rotors if they're being driven hard enough!

I think Z was using the tegra as an example of a lamo slow budget car that has bigger brakes.

You would have to have some serious power before you actually need bigger brakes. A friend with a 200Hp TS engine in a very light GTV with 235mm tires have used stock calipers (brembos) and stock sized rotors up until now without any problems at all and believe me, it is being driven hard.
He even ran it a couple of seasons on slicks without problems.

I'm not saying I would turn down a brake upgrade but I think there is a certain *bling* factor involved here. Race styling!
Don't get me wrong, some cars needs bigger brakes but 4-cylinder Alfettas without monster engines don't. Even my stock weight 75 T worked fine at the track with the stock setup.

[Zamani]

Stock brakes are fine, even for spirited track driving. But when you are trying to cut down time as much as you can, you really need the bigger brakes.

I was just at the track last weekend, and while the my brakes held up fine, you couldn't make the car slow down quick enough. Instead of braking for 1 second you need to brake for 1.5-2 seconds. That's 0.5-1 second out the window right there. Multiply that by 2-3 turns with that scenerio, that's it, good bye class win.

With the wilwoods, one strong jab on the brakes and the car just slows down.

[Micke]

Sorry to say Z but that doesn't make sense.

Bigger brakes do NOT shorten the braking distance. They only provide more heat storage and cooling. The OE brakes in good shape have all the braking power any tires can use. Then again the key is that the brakes have to work like they should (good fluid and pads are obvious here).

I raced my GTV with the original small brakes (not the GTV6/75 ones) for some years. They had as good braking as my new set but could only keep it 3-5 laps before they couldn't cope with the heat anymore. I really couldn't concentrate on driving as I feared in every corner whether I have brakes or not.

I rode two of Ron's cars at the ring. They used the OE brakes and there was no fade or problem with the braking distance whatsoever.

PS! Most guys brake like shit anyway. Too long and not hard enough.

[Zamani]

Micke,

I realize that area is not a function of friction, but as a heat sink it is. Also maybe the pads in my stock brakes aren't that good as the ones in the wilwoods. The mu is probably very different.

[Mats]

Not trying to pour gas on the fire here but if you brake for 2 seconds longer you don't lose 2 seconds, but maybe you meant per lap?

Longer pad contact means higher pad temps though and is what Micke talks about when he is talking about people not braking properly.

[Micke]

hear, hear!


PS! I once caught myself for sloppy braking as well. I analyzed my driving and realized that I'm standing pretty long on the brakes in one (scary) corner. Then I did a simple calculation. I come in at ~150 km/h and need to do the corner at ~110.

Next time I told myself that YOU DON'T BRAKE MORE THAN A 1 SEC BLIMP! And goddammit it worked great. Spent less time braking and did the corner faster as well.

What can we learn from this! Analyze your driving. There's a lot of space for improvement for all of us. Datalogging could probably improve lap times more than any gizmo to tune the car with.

[MALDI]

First, after re-reading my post I want to say that I was not trying to insult our youthful colleagues who enjoy Japanese-engineered products, BUT much of what appears on the cars of enthusiasts under 30 is for style and not for performance. Take what you see with a HUGE grain of salt. (Both stock and aftermarket "performance" parts.)

RE: rotor size. It would seem to me that larger rotors are necessary primarily for heat dissipation. If you have pads that can take the heat then there's no need for bigger rotors. (Check out those red hot rotors on long distance racers). By "take the heat" I mean that the brake pad material does not degrade (i.e. glaze, fragment, or delaminate from the plate backing) AND it's coefficient of friction does not drop precipitously when hot.

Testimonial: my stock brake system on my stock GTV6 sucked until I upgraded to track/street pads (Porterfield R4S) and high temp fluid (Motul 600 RBF). Now no probelms, even at Summit Point with its hard breaking zones (before turns 1, 5 and 10, especially turn 5 which is down hill and into a 30 mph turn). On the other hand, I have overshot a stop sign or two on those cold winter mornings on the way to work (and before coffee).

Last: Everyone knows that the problem with the transaxle cars is cooling the REAR brakes. Design some ducting that works and we'll beat a path to your (proverbial) door.

[Jim K]

Micke, the Ring is not a demanding track on brakes, there's plenty of cooling periods in-between braking, so I wouldn't consider that track a valid brake testing ground. Now down here, we have a 2.3km track with 4 heavy brake points. With laptimes around 1'12" and speeds of ~170km you NEED BRAKES!!!
At 1400kg I KNOW what you mean about not knowing whether you'll stop or not! Huge brakes are a blessing here as well as cooling and in the summer things are even worse.
Re rear brakes overheating, I have yet to see this happen! I have warped the front Wilwoods a number of times, but this was because I used the Ultralites and not the HD discs (Wilwood's opinion and I respect it) plus I had no cooling. 30 fast laps will do it every time. Warping started from about lap #3 to be precise, not enough heat removal there. And of course, with warped brakes forget about laptimes, you have to pump 2-3 times and hope!
Jim K.