brake "T" fitting. 2L engine?

dave blackburn · 08-25-2002, 08:57 PM

I am going to do the bmw brake upgrade to my 75 1.8L and I am wondering if I should leave the proportioning valve in or install a T fitting instead. This will be a street car only so I would like it to be safe. Anyone have any experience with this?
Also I plan to upgrade to a 2L engine. 914's are very rare up here and the chance of finding a 2L engine is even rarer. Is there any major drawback to using a type4 from a vw bus? I will rebuild the engine this winter to porsche specs if possible? Any suggestions? Thanks for your input, Dave B

Dave at Pelican Parts · Dave at Pelican Parts's Garage

Drawbacks:

The Bus had an oil filler and dipstick sticking out the rear (front in a 914) of the engine. Hits our firewall. Gotta block off the hole, and put our filler and dipstick in. Requires drilling for the dipstick tube.

The Bus made 67 HP stock. Milder cam, low-low compression pistons.

The late-late Buses had "square port" heads, and our exhausts don't fit.

The 2.0 Buses had the smallest valves of any Type IV motor.

Other than that, not very many problems...

--DD

thesey914 · 08-26-2002, 12:39 AM

I'd like to know if anybody has fitted a "T" piece with the BMW conversion. I have done the front callipers but with the 914's light front end the brakes lock-up too early for my liking....just like to give the rears a little more bite.
Cheers

John Rogers · 08-26-2002, 06:13 AM

Yes.

thesey914 · 08-26-2002, 03:46 PM

John, would you recommend this mod? did you have any problems with the rear overtaking the front on hard braking?
Cheers

B Frye · 08-26-2002, 06:13 PM

so what IS the answer to the question ....

If you install the big ATE calipers (BMW 320i) do you or don't you need to replace the proportioning valve with a T fitting

campbellcj · 08-26-2002, 06:19 PM

The topic has been beaten-up here before, but the short answer is "yes". Do the tee; even many hardcore racer types use a simple tee vs. an adjustable proportioning valve.

With the 320i or SC calipers up front, and stock 914 front or rear calipers in back, the tee should be fine.

BTW you don't "need' to do it, but it will let your rear brakes work a little harder to match the new front capabilities. If you don't remove the prop valve then the front-rear balance will get skewed even more towards the front, compared to stock. Safe, but not optimal.

If you have some super extreme setup, like 951, 928S4, or Big Red's then think about a Wilwood valve to balance things out as needed.

anthony · 08-26-2002, 10:11 PM

B told me to go with the T setup for the Carrera calipers I will be installing. He said that every time they installed an adjustable proportioning valve on a race car they ended up running it full open.

Va914 · 08-27-2002, 05:23 AM

What is the going price for the TEE fitting?

Thanks

JWest · 08-27-2002, 05:46 AM

http://store.cip1.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=cali&Product_Code=VWC-803-611-755&Category_Code=02-06-01-02

sammyg2 · 08-27-2002, 06:27 AM

I've installed the tee on two 914s so far. Both had front caliper upgrades.
I will not recommend this upgrade to anyone because of liability reasons, but if I had to do it again I would.
The adjustable proportioning valve is probably a better way to go.
On the track I can see why it would be run wide open. Traction is optimized and most hard braking is done in a straight line, trail braking is usually not as severe.
BUT..........on the street it is a different world.
Rain, oil ,dirt, idiots, etc. can make the braking situation different.

Imagine you are driving on the street in a "sprited " manner. You go into a corner a little hot, but not so hot that you can't maintain the line. Suddenly a soccer mom in an SUV drops her cell phone and merges into your lane. You stab the brakes hard and the back brakes lock up too early. Not a pretty picture. A good driver who is well aware of the car's braking characteristics could handle the situation without too much pants soiling, but a newbie would be in trouble.

Summation: on the track we wish to maximize braking. period.
On the street we sacrifice some rear braking in the name of safety. A well set up street car should never lock up the back brakes in a straight line on dry pavement IMO. YMMV.

It's your call. Adjustable prop valves are just that. They give you the ability to dial in the brake characteristics for different situations. If it's strictly a track car the tee will probably work great. If it's also used on the street, maybe not.

BTW, the tees are readily available in junk yards, I usually snag them off the rear of VW bugs. I look for Baja bugs because the rear sheet metal is cut away and access is even easier.
You can find them on the driver's side of the transaxle. I probably still have a couple sitting in a box in my garage.

anthony · 08-27-2002, 10:57 AM

Are there different "T"s? Are some better for a 914 than others? I just seem to remember reading that one from a bus fit better or something.

dave blackburn · 08-27-2002, 03:17 PM

OK. so maybe I will leave the prop valve in just to be safe. Is there an easy way to dial a little more rear brakes with it? Is there a reliable way to test my set up and make sure it is safe? Thank you all for your input, Dave