Tilton Brake and Clutch Conversion

[daloff]

I have an early 911 that is a dedicated track car. I know some other persons have converted their brake and clutch setup to a tilton assembly. Does anyone know what is needed to do this and source for parts etc.

Thanks
David

[poorb0yw]

I have a Tilton twin disc carbon/carbon clutch. You can get the major parts for the switch from your Tilton distributor. You will most likely need to get custom bleed and adapter lines made as well as a clutch pedal stop (unless you go with tilton pedal assemblies as well)

I spoke with Taylor Race Engineering for my needs.

[Bill Verburg]

The Tilton will look like this, it replaces the whole pedal box, some minor mods will be needed to the footwell sheetmetal, replumbing is also needed, of course.

[daloff]

Bill -
Where did you get this setup ?

Thanks
David

[Bill Verburg]

Troutman, Pegasus or Tilton carry them

Troutman is specifically designed for 911s

[daloff]

Bill I think the setup you have pictured came from Troutman but they no longer are making these. Both Tilton and Pegasus just have the standard Tilton assemblies that would of course require quite bit of modification.

I don't suppose the one you have in the picture is available ?

Cheers,
David

[TRE Cup]

hi david
we sold one a few months back. i will ask my fabricator if he can make us more- just got an order from another client. they are similar to the ones troutman use to sell that mounted in the front trunk. the undercar set up is dumb. Yes, the factory used it for their rs 3.0 and rsr, but what a pita to install and service. then again a cool low spot to nail when farm excursions occur with your racer. we like the trunk mounted units that utilize the 77-89 brake booster mount. that aluminum casting along with the corresponding pedal assy, allows install in the trunk. you can inspect it easily and it is out of harm's way. ok- so it does increase your CG ever so slightly but who cares when you're working on it. i will see if i can get pix too.

[Bill Verburg]

I agree w/ TRE, Smart racing carries them, the mounting area of an early car will need to be reinforced
Smart Racing

[daloff]

Bill - I looked at the setup from Smart Racing thanks.and Dave (TRE)thank you again. As always you are most helpful. Let me know the particulars (price, time to fabricate and deliver) etc. Look forward to hearing from you. Bye the way the RSR turned out very nice. Want some pics ?

[TRE Cup]

pics of our parts on your car? why not? thanks!

[daloff]

Shameless plug - Dave

[KTL]

What a high quality setup! Couldn't ask for anything nicer than that unit to adjust the bias on your car. I can already see the seconds dropping off the lap times..............

For those curious about the brake bias issue:

Brake Proportioning

Brake Bias

[Quicksilver]

Here is a picture of the SmartRacing assembly when I was installing it in my car.


The stock reservoir works fine. A couple little tidbits… You will need an adapter for the connection from SAE to metric brake lines. The Tilton cylinders have SAE threads. You can use Ford brake light switches on the Tilton cylinders and the stock wires will plug right in.

I'm not sure about the earlier cars but on my 87 the driver's foot well heater outlet interfered with the cylinders so I blocked it off. (I would never use it anyway.)

The earlier cars require reinforcement, which is detailed here... http://www.smartracingproducts.com/pdfdocs/643100_dualmaster_cylinder.pdf

I removed the ashtray and mounted the Tilton remote bias adjuster in its place. Dialing in the bias will take forever unless you can adjust on the fly.



The last little bit. SmartRacings recommendation for cylinder sizes is way to big for earlier calipers. I have the stock Carrera calipers and I had to step it down. It is firm and rock solid. I can’t remember the sizing but If you are interested ask and I will look.

Wayne

[Quicksilver]

Originally posted by KTL
What a high quality setup! Couldn't ask for anything nicer than that unit to adjust the bias on your car. I can already see the seconds dropping off the lap times..............

For those curious about the brake bias issue:

Brake Proportioning

Brake Bias

The Stoptech proportioning article is very good but it misses an extremely important problem with proportioning valves. Pressure release from the rear system.

Say you have the perfect balance in your proportioning. You are stopping away and your front pressure is 500psi and the back pressure is limited by the valve to 300psi. Being human you screw up and lock the brakes just a touch (maybe you are going over a rise). You reduce the pedal pressure till the front pressure is 400psi. Ok, what is your rear line pressure?
(Bzzzt... thankyouforplaying)

The rear line pressure can't release at all until the front pressure drops below 300psi. Proportioning valves suck for serious braking. Porsche knew what they were doing when they carefully sized the pistons in the front and rear calipers on the earlier cars. No proportioning valves there.

(Ignore all of this for antilock brakes... They work great and no talent is required!!!)

Wayne

[KTL]

Good info. Wayne. Thanks.

So why did Porsche add the P/V to the Carreras? A substitute to resizing the brakes?

I do know the rear piston size was increased for the Carreras, which would increase rear bias. And there are other factors involved such as the vaccuum booster assist. SC is 7 in., later is 8 in. Anyway, the HBR of the Carreras is less than that of the SCs, which would make the Carreras more rear biased. I assume the P/V tries to address this?

Just curious.

Thanks,

[Quicksilver]

Yup, the proportioning valve is to reduce the increased rear braking bias but I can't figure out why they wouldn't adjust the hydraulic cylinder sizes to provide the bias. My only guess is that the weight distribution may have been different on the turbo (or some option) and they could adjust it with a valve.

I bet Bill Verburg will know the answer.

BTW, just found this option that would be the perfect piece for an early track car. It is LMK's repro 935 pedal box.


They are the makers of the really good 917 reproduction.
http://www.kraftwerkz.net/news.htm

No mention of price but it looks pretty cool.

Wayne

[blue72s]

You should change the clutch actuator to hydraulic as well. 915 boxes from middle of '73 onwards has a boss in the bellhousing which you can attach a concentric clutch slave cylinder (push-type) to it, held by 2 screws. Tilton or AP racing sells them. Of course you would have to replace the clutch disc and pressure plate from pull-type to push-type, and I think the '69S OEM clutch is the best one.

[smdubovsky]

Wayne,
Could you please measure the thickness of the aluminum block on your SmartRacing setup? Looks to be ~1/2". I have collected all the parts to machine one of these myself someday. Could you also measure the cyl to cyl spacing?

Thanks!
SMD

[randywebb]

Quicksilver - is that assy aluminum? How much does it weigh?

[daloff]

Blue -
The tilton set up requires purchasing their flywheel, clutch pak as well as the hydraulic release bearing. ~2200.00. If there is another alternative could you post more details ?
Thanks
David