Yun's rear brake upgrade - Part 1

[POWERBRAKEBOB]

I am sure you will need a larger bore master to feed all those caliper pistons. Unfortunately, larger masters will not bolt on to the original vacuum booster.
I recommend my Hydroboost system, which will have unbelievable stopping power, AND clean up the engine compartment.
The computer and wiring harness can be rerouted UNDER the Hydroboost, and the battery relocated to the rear compartment.
HUGE improvement in stopping power, a better master, and cleaned up engine compartment

[secondchance]

Thanks for the info.
So far OEM set up seems to work fine. My front conversion is on hold until my 380 build is completed.
After I convert the front I'll be able to asses if I need larger master. Another option is to graft on Tahoe master - we shall see.

[ZZZZZR1]

I have C6 Z06 front / rear calipers with a stock master and no issues

But I'd consider an upgrade there if here is a benefit!



David

[Daniel_Mc]

Originally Posted by ZZZZZR1

I have C6 Z06 front / rear calipers with a stock master and no issues

But I'd consider an upgrade there if here is a benefit!



David

David,

The F body MC is a great alternative and will give you much better petal feel.

-Daniel





http://www.corvetteguruforum.com/mod...post_id=194228

[batchman]

Good luck with the full conversion Yun (and the rest of the build).

Daniel, thanks for the excellent link. Are the pics of your car, if so what brakes are you using and how did the rear bias work out?

I really need a 1" master if I'm staying with the PBRs, which should be adequate for my racing. Same stuff stopped my Cobra on a dime.

Thanks,
- Jeff

[Daniel_Mc]

Originally Posted by batchman

...Are the pics of your car, if so what brakes are you using and how did the rear bias work out?

I really need a 1" master if I'm staying with the PBRs, which should be adequate for my racing. Same stuff stopped my Cobra on a dime.

Thanks,
- Jeff

Jeff, no these were on a 85 running 6 piston Wilwoods up front and 4 Piston Wilwoods out back the GN III design. I've had the F body master in the attic for a year or so and never put it on my 89. The 89 is running the Wilwood GN III's as well. I purchased the set up I am running now from the Rippies and Randy has been telling me I need to do the F-Body MC to get the full benefit on the system. I need to find the time and do this mod. One thing the article does not mention and I have heard mixed reviews about is you have to drill out the hole in the MC for the Corvette rod to fit. The rod is a slightly different diameter on the Corvette than it is on the Camaro. I ditched the J55's when they failed on me at TWS running CCW going into turn one (pucker factor ). Depending on what racing you are doing getting a set of good brakes will be great not to mention much safer (or could change the class be careful and read your class rules).

Our ZR-1 has AP Racing brakes and the Camaro master with a bias valve however I cannot comment on the install the builder of the car did this but works great on the street (I do not track this car). However I can get you pictures if you are interested.
-Daniel

[batchman]

Originally Posted by Daniel_Mc

Depending on what racing you are doing getting a set of good brakes will be great not to mention much safer (or could change the class be careful and read your class rules).

Our ZR-1 has AP Racing brakes and the Camaro master with a bias valve however I cannot comment on the install the builder of the car did this but works great on the street (I do not track this car). However I can get you pictures if you are interested.
-Daniel

Not to steal Yun's thread completely, but for autocross the J55s with appropriate pads and braided lines should be just fine (my 99 Cobra had essentially the same caliper and braking was excellent with 250 lbs more weight and a lot less tire). Runs are usually under a minute and only 2-3 real braking points, then 20 minutes to next run. In fact I sometimes think of swapping to 12"s to reduce weight.

My concern with the F-body MC is rear bias. No way to increase the rear bias, adjusters only work as limiters. I have significant understeer under braking, meaning I need more rear bias. Since I really need a firmer/faster pedal (ie 1" master bore) I'm hoping to hear from someone with j55s had to limit rear braking with the F-body MC.

Looking forward to Yun's next chapter!

Cheers,
- Jeff