I have an S14 with a CA18DET swap. I'm trying to fit a bigger turbo and I'm having issue with the brake master and the turbine housing interfering with each other. I currently have the "thicker" ABS brake booster.

The common answer seems to be to use a S14 manual, non-abs brake booster. I've found measurements for that booster and its IS thinner and will move the master cylinder back, it's also a bigger diameter by about an inch. It's already really tight in space between the valve cover and brake booster and loosing a half an inch there may not allow enough room for the down pipe.

The other answer I hear is a B13 Sentra1.6L/N13 Pulsar brake booster. It's basically the same diameter of the booster I have now, but I can't find a dimension for how "thick" it is. Pictures online make it look like it's probably thinner than the one I have now, as it's a single diaphragm and my current one is a dual diaphragm, but it would be nice to have an actual measurement.

Nobody stocks any of these things, so it's all special order and once I order them, I'm stuck with them. I'm also not 100% sure I can actually get the S14 Manual non-ABS booster. I've only called a couple places, but once they actually try to order it, it's not actually available unless I have a core to return.

sooooo, does anybody have a B13/N13 booster they can measure and tell me how "thick" it is (the distance from the firewall to the brake master)?

Ok, I bit the bullet and ordered a reman B13 / N13 booster. It IS smaller in all dimensions compared to the most of the other commons S13 / S14 factory boosters, and at least for now, you can walk into any parts store and order one.

The dimensions that I've found are as follows;
S13 non-ABS booster is 3.5" thick and 9.5" in diameter (can still be easily ordered reman from a parts store)
S14 non-ABS manual transmission booster is 2.9" thick and 9.7" in diameter (I CAN'T FIND THIS BOOSTER ANYWHERE! They're all sold out. Even used in the junkyard)
S14 ABS/Automatic booster is 4" thick and 8.7" in diameter (why would you want this? But readily available)
B13 / N13 Manual transmission booster is 3.3" thick and 8.6" in diameter. (I ordered this as a reman from Advance Auto, direct ship from the reman company a few days ago. It shipped directly to me, for just under $200. AFAIK, these are readily available)

I also found out that the booster from a particular Geo-Metro would bolt onto the firewall and a stock S13/S14/etc BMC would bolt right on. Unfortunately, this isn't new information to the hot-rod crowd and they seem to have bought them all up like we have with the non-ABS manual S14 boosters. You can't buy any remans and I couldn't find any in the junkyards anywhere online. The Cardone PN you want for the Metro booster is 53-2360. I can't find a thickness measurement, but it's a single diaphragm, so I doubt it's very thick, I'd guess around 3.5". The diameter is only 6.6"!!!

Last but not least is a booster made brand new by a company in Ireland. The brand name is "Flo's". They're an AE86 performance parts company. They make a customer booster that is TINY. The AE86 people with RHD cars have an issue when trying to run ITB's with interference with the booster and master. This company makes a booster that is only 3.3" thick (Same as the B13/N13 booster), but it's only 5.5" in diameter!!! Unfortunately, because of Pandemic things, they're out of stock. Techno Toy Tuning usually stocks them, but they've been waiting on an order for months. I went ahead and ordered that booster too, just in case I have downpipe clearance issues with the B13/N13 booster. The big thing about these is we're not limited by now many were originally made, but how quickly the manufacturer can make more. Admittedly, the amount of assist you'll get with a booster this small isn't going to be a lot, but it WILL be better than manual brakes for sure.

Yeah I'm curious to see how well the brakes perform and feel after a pretty massive booster downsizing.

I'm hoping to paint the booster tomorrow. It's like a weird gray color and I don't like it, but it's been too cold here to paint. It SHOULD be warm enough tomorrow.. barely. I gotta put a heater in the garage...

float_6969 wrote: ↑

Wed Dec 22, 2021 8:36 am

I gotta put a heater in the garage...

waste-oil-burning-stove-heater-t628073-30.html

Last winter when I had to paint my fuel rail, I ended up doing it in my water heater room on my house. It doesn't seem to drop below about 60 in there, and is a separate room from the house. Just slapped some cardboard behind it and zip tied it to a shelf in there, then let the paint fly haha.

I wish I had a space like that!... I don't take have room in the garage for a floor mounted heater, so I'm going electric so I can hang it from the roof trusses. I already have a 50A 240V outlet in there, so I'm just going to plug it into that.

Got the booster installed and it's a little less than 7/8" thinner. Plenty of room for the turbo now. It'll be a while before I can compare the brake feel as the weather is crap and I have no downpipe, lol.
Before After

Cot damn that's a huge turbo. Its still uncomfortably close to the brakes too. Any chance you could squeeze a heat shield in there?

There's going to be so much heat shielding when I'm done it'll be borderline comical. The last of it came in today. The turbine housing will get a turbo blanket. I company called Heat Shield Products makes a ton of automotive based universal heat shielding products. I'll be making a shield for the turbo manifold, downpipe, and a shield between the turbo/downpipe area an the brake booster/brake manifold area. I've already heat shielded all of the oil and coolant lines when I made them. After I watched the wiper fluid nozzle fall out of the hood of the car because it go so hot it melted and then when I pulled over and opened the hood and saw the brake fluid reservoir was deformed from the heat, I don't mess around with it anymore.

float_6969 wrote: ↑

Thu Jan 06, 2022 1:37 pm

After I watched the wiper fluid nozzle fall out of the hood of the car because it go to hot it melted and then when I pulled over and opened the hood and saw the brake fluid reservoir was deformed from the heat, I don't mess around with it anymore.

I'm picturing your wiper nozzle sinking through the hood like the Titanic and you peering through the windshield with a Clark Griswold WTF look on your face. Shame you didn't get a video. I bet it would go viral in 10 seconds flat.

VStar650CL wrote: ↑

Thu Jan 06, 2022 1:45 pm

float_6969 wrote: ↑

Thu Jan 06, 2022 1:37 pm

After I watched the wiper fluid nozzle fall out of the hood of the car because it go to hot it melted and then when I pulled over and opened the hood and saw the brake fluid reservoir was deformed from the heat, I don't mess around with it anymore.

I'm picturing your wiper nozzle sinking through the hood like the Titanic and you peering through the windshield with a Clark Griswold WTF look on your face. Shame you didn't get a video. I bet it would go viral in 10 seconds flat.

You pretty much nailed it!!!

Holy s*** that's funny haha.

Looking good. Would be nice to get a comparison between our S14s this summer once I have my brake booster delete installed. You're running Z32 calipers all around too, right?

No, not Z32's. It's a big brake kit for a Z32. I think it's still 4 piston front, 2 piston rear, but the rotor diameters are bigger, the front rotor is full floating, and the rear rotor has cooling vanes instead of being solid.

Figured I should probably update this. This is how it looks now. I'm probably going to do some heat shielding on the master itself, but I think I'm going to change the master to a RHD one so the outlet ports are on the other side before I do. I did drive it around a little and the brake feel is pretty good. Definitely firm, but not so hard that anyone would complain about it.

Nice. I snagged a cheap $20 heat shield on ebay over the weekend that I think would work pretty well as a template if you're interested.