brake question ; v8 350 HP, stock vs BMW vs 911 Options

[got914?]

OKay ive searched and read every topic I can find and there seems to be a bit of conflicting information. Now I realize obviously the 911 5 lug is going to be the best option I have but is it really necessary ? And again yes im spending all this money on a v8 swap why not go full out but...
Yes I also realize tires play a big factor in braking as well. I will be running 8 inch wide tires so no worries there.

Can I get any info from people who have done the actual swaps.

[Bruce Hinds]

It depends on what kind of driving you're going to be doing.
The standard 914 brakes are okay for regular driving but it's real easy to go 911 on front and just drill the rears for 5 lugs. Unless you're going racing, you really don't need much more than that.
It's more about the big wheels and tires than the power or weight of the car. The SBC chevy conversion is only 250 lbs more weight, but bigger wheels and tires have more rotating mass and a lot more grip.

[Mike Bellis]

My car had a V8, now it has a 4 cyl with more power. I have 930 turbo brakes. They are not the lightest option but they work extremely well.

If you stay with stock brakes, plan on a full rebuild at least. There is debate over the benefit of BMW calipers. Why not spend the money on a 5 lug conversion? It will cost more but it's money well spent.

[jim_hoyland]

(IMG:style_emoticons/default/agree.gif) 5 lug conversion, 911 calipers. The BMW calipers are a little better than the stock, but not that much - from my experience.

Another thought; don't tailgate.... (IMG:style_emoticons/default/smile.gif)

[shoguneagle]

7in17's in front; 9in 17's in rear. 911 Carrera brakes all corners with 23mm master cylinder. As said before, "DO NOT tailgate!!". Reasoning is not because of the brakes which are more than adequate but because the master cylinder requires a strong leg.

One of these days I will put an electric brake boost on the master cylinder and a hydraulic clutch.

Car is a very nervous one which requires everything to be set just right. But, so enjoyable.

Steve

[mgp4591]

Is the Volvo option for brakes the same as the BMW being as they're both ATE calipers?

[MikeInMunich]

7in17's in front; 9in 17's in rear. 911 Carrera brakes all corners with 23mm master cylinder. As said before, "DO NOT tailgate!!". Reasoning is not because of the brakes which are more than adequate but because the master cylinder requires a strong leg.

One of these days I will put an electric brake boost on the master cylinder and a hydraulic clutch.

Car is a very nervous one which requires everything to be set just right. But, so enjoyable.

Steve

Steve, I have a 23 mm master cylinder from a 450 SL Mercedes and have yet to try it out, as the car is still in CA and being sent to Germany next month. I have only found one other comment about a 23mm MC and it was negative; regarding lack of range in the pedal and potentially locking up more easily. I will be riding on Toyo Proxes RA1, 225 50 15s with 944 turbo brakes in the front and RX7s in the rear. Any feedback?

Mike in Munich

[r_towle]

Is the Volvo option for brakes the same as the BMW being as they're both ATE calipers?

Volvo calipers offer a real dual circuit design which requires the right type of master cylinder, but they are really the best choice for safety and racing.

For the OP, are you serious?

You may have over 200 hp pushing a car around that was originally designed for a 100 hp motor.

it may be in your best interest to consider getting larger brakes with vented rotors up front.

Rich

[matthepcat]

I am running a 23mm unit from a Mercedes with Wilwood super light 2's.

Brake feel is almost zero travel requiring a heavy foot. This was a race car however, so I believe that is the feel that many racers are looking for.

Matt

7in17's in front; 9in 17's in rear. 911 Carrera brakes all corners with 23mm master cylinder. As said before, "DO NOT tailgate!!". Reasoning is not because of the brakes which are more than adequate but because the master cylinder requires a strong leg.

One of these days I will put an electric brake boost on the master cylinder and a hydraulic clutch.

Car is a very nervous one which requires everything to be set just right. But, so enjoyable.

Steve

Steve, I have a 23 mm master cylinder from a 450 SL Mercedes and have yet to try it out, as the car is still in CA and being sent to Germany next month. I have only found one other comment about a 23mm MC and it was negative; regarding lack of range in the pedal and potentially locking up more easily. I will be riding on Toyo Proxes RA1, 225 50 15s with 944 turbo brakes in the front and RX7s in the rear. Any feedback?

Mike in Munich

[CptTripps]

The bigger MC just makes for a harder pedal. I'd still stick with the 19mm (or maybe even the 17mm if you're going with the 911 brakes.)

[pdlightning]

The bigger MC just makes for a harder pedal. I'd still stick with the 19mm (or maybe even the 17mm if you're going with the 911 brakes.)

A lot of people have had great luck going the 19 mm and 911 vented calipers/rotors. Eric Shea EMER brake 308 calipers in the rear allow vented 911 rotors and stock mechanical emergency brakes (308 style).

[rick 918-S]

Volvo calipers add a shit load of un-sprung weight. Bad. A full 911 brake conversion is the best.

With the stock tire diameter and contact patch a fresh set of 914-4 brakes are great.

Increase the tire width/contact patch and weight of the wheels, add engine weight and change the balance of the car and you need to increase the clamping force of the calipers.

Contact patch increases the traction but also changes the modulation at the peddle. Increase the tire size and it adds weight to the spinning mass. This requires an increase in clamping force at the rotor.

Bigger brakes have nothing to do with hp. Take the Wankel three rotor for instance. Lighter than the type VI but capable of serious hp. numbers. What have you changed? Now add contact patch for traction, heavier rubber and wheels....

You choice for stopping power has everything to do with the type of engine, tires and wheels you select. As is the 914-4 stops very well.

With that said my Alien has BMW 2002 4 piston calipers on stock 914-4 rotors up front 19mm master and p-valve delete.

[a914622]

With out trying to sound snotty, the rear 993 caliper fits the SC front rotors. The calipers need the bolt holes widened 1mm and 1mm needs to be milled off to inset the caliper to center over the rotor.
The rear 993 has the small pistons but the big pads the fit the big rotor. So the pedal feel with the 19mm or even the 17mm master is great. But you do need the 911 struts in front. It's all about dissipating heat on the high speed stops. Any brake system should be good at 55. But the stopping distinse and heat are much greater at 80-100mph, even in our light cars.

Jcl

[mgp4591]

Volvo calipers add a shit load of un-sprung weight. Bad. A full 911 brake conversion is the best.

With the stock tire diameter and contact patch a fresh set of 914-4 brakes are great.

Increase the tire width/contact patch and weight of the wheels, add engine weight and change the balance of the car and you need to increase the clamping force of the calipers.

Contact patch increases the traction but also changes the modulation at the peddle. Increase the tire size and it adds weight to the spinning mass. This requires an increase in clamping force at the rotor.

Bigger brakes have nothing to do with hp. Take the Wankel three rotor for instance. Lighter than the type VI but capable of serious hp. numbers. What have you changed? Now add contact patch for traction, heavier rubber and wheels....

You choice for stopping power has everything to do with the type of engine, tires and wheels you select. As is the 914-4 stops very well.

With that said my Alien has BMW 2002 4 piston calipers on stock 914-4 rotors up front 19mm master and p-valve delete.

You have solid rotors with 4 piston calipers? What about the heat dissapation at speed? Do you have any longevity in your pads or do you fade out quickly after a couple of higher speed stops? I've always heard (and it's been my experience) that vented front rotors work better, 'specially with your v8 I thought you'd have the big brake package...

[rick 918-S]

Volvo calipers add a shit load of un-sprung weight. Bad. A full 911 brake conversion is the best.

With the stock tire diameter and contact patch a fresh set of 914-4 brakes are great.

Increase the tire width/contact patch and weight of the wheels, add engine weight and change the balance of the car and you need to increase the clamping force of the calipers.

Contact patch increases the traction but also changes the modulation at the peddle. Increase the tire size and it adds weight to the spinning mass. This requires an increase in clamping force at the rotor.

Bigger brakes have nothing to do with hp. Take the Wankel three rotor for instance. Lighter than the type VI but capable of serious hp. numbers. What have you changed? Now add contact patch for traction, heavier rubber and wheels....

You choice for stopping power has everything to do with the type of engine, tires and wheels you select. As is the 914-4 stops very well.

With that said my Alien has BMW 2002 4 piston calipers on stock 914-4 rotors up front 19mm master and p-valve delete.

You have solid rotors with 4 piston calipers? What about the heat dissapation at speed? Do you have any longevity in your pads or do you fade out quickly after a couple of higher speed stops? I've always heard (and it's been my experience) that vented front rotors work better, 'specially with your v8 I thought you'd have the big brake package...

If I were racing the car I'd have a different setup entirely. But for an occasional blast through some twisties they have preformed well. I have run thousands of miles zigzagging cross country an still have the same pads and rotors I installed in 2004.