Possible new caliper for Brian's 16" wilwood kit - NOT

[tigerdog]

I'm once again mustering the fortitude to install Brian's 16" Wilwood big-brake kit that's been languishing on my workbench for 2 years. Houdini, like many, purchased the 6816 calipers so I have to buy the correct ones. Obviously, I should just buy 6806s and be done with it (nitroman's love of 6811 not withstanding). I should, but then I noticed the updated Dynapro 120-9703 caliper on Wilwoods site. Dimensions appear identical except for .07 difference vertically.

Forged_Dynalite-cm-lg.jpg

Dynapro_Lug_Mount-cm-lg.jpg

Has anyone test-fit the Dynapro calipers? I know clearance is tight; is it tight enough for .07" to make a difference? Or should I just shut up, order the 6806s and be done with it ?

[Doug]

where you gunna put the new calipers? on the workbench!?

[F1 LOTUS]

2.10" may be a typo - check the Dimension D1 calculation [left side of table] - it uses 2.03, same as Dynalite
Best to call them and ask?

[tigerdog]

2.10" may be a typo - check the Dimension D1 calculation [left side of table] - it uses 2.03, same as Dynalite
Best to call them and ask?

Nice catch! Says 2.03 in the D1 calculation section, 2.10 on the dimensioned diagram. Just to add insult to injury, the Wilwood Technical Product Guide revised 9 April 2009 shows 2.07 for both the 6806 and 9703!!!

wilwood200904catalog.jpg

Assuming the latest info is correct, you really have to wonder if we have less than 1mm to play with...

[F1 LOTUS]

Also, at the time when I was researching this stuff, I believe the Dynalite was the most compact 4-Piston Caliper - the latest info' shows the Dynapro being narrower than the Dynalite? - Proceed with extreme caution...

[bobbrown]

My reason for selecting the Dynapro radial mount was it had dust seals.
The lug mount version does not have dust seals.

Bob

[F1 LOTUS]

Bob - Do you know the actual width of the dust-seal caliper you're using? [dimensioned 1.67" in the drawing above]
I think the Dynalites are dimensioned 1.71".

[bobbrown]

The radial mount Dynapro calipers are 1.93" which is the extra thickness required to get the seals in.

Dynapro_Radial_Mount-cm-lg.jpg

These will not fit with a 12.19" (309mm) disc (16" rim)as there is not enough clearance at that diameter but they will fit a 294mm disc, all due to the curve of the spokes.

Bob

[tigerdog]

My reason for selecting the Dynapro radial mount was it had dust seals. The lug mount version does not have dust seals. Bob

Yep, an excellent choice and if I was starting over, I'd go that way. Instead, I have one of Brian's original kits, so I don't want to replace the whole thing.

For everyone else, I just spoke with Wilwood technical support; they confirmed that the 120-9703 is a direct replacement for the 120-6808. Apparently, the differences are so close that they were comfortable splitting the difference in their technical documents. As Brian and Bob have both noted, Wilwood (at least at one time) was somewhat loose with their specifications. The new calipers are actually narrower, so if anything there will be a slight clearance gain between the outer face and the 16" wheel spokes.

That being said, I'm ordering the 120-9703s and new pads. This means I have a set of 120-6816s and polymatrix Q pads up for grabs, if anyone wants them at half price.

[tigerdog]

... the latest info' shows the Dynapro being narrower than the Dynalite? - Proceed with extreme caution...

Wilwood confirmed they are narrower; that should help a bit with clearance against the wheel face. In researching pad options, I figured out why they're narrower. They use a different pad type from the Dynalite. Dynalite pads are 15mm thick. Dynapro lug mount are 12.5. So you pay more for the pads and get less useable material - part of Wilwood's positive cash flow strategy . Also means right now, only Wilwood makes pads. So I'm going back through old forums to decide between Polymatrix Q, smartpad 10 and smartpad 20. I need something that'll play nice with the greenstuff on the back.

[bobbrown]

Also means right now, only Wilwood makes pads

I think you will find EBC also make pads for the Dynapro, DP2039 green stuff DP4039 yellow stuff and and Dynalite calipers DP2038 green stuff DP4038 yellow stuff.
http://www.summitracing.com/parts/EBC-D ... refilter=1
As do Mintex, Dynapro MDB2581/M1144

Bob

[tigerdog]

I think you will find EBC also make pads for the Dynapro, DP2039 green stuff DP4039 yellow stuff and and Dynalite calipers DP2038 green stuff DP4038 yellow stuff. http://www.summitracing.com/parts/EBC-D ... refilter=1 As do Mintex, Dynapro MDB2581/M1144 Bob

Seems there's Dynapro and then there's Dynapro. The radial mount Dynapro uses type 7816 pads. The lug mount Dynapro uses 7812s, as noted above. The 7816s are thicker and won't fit the lug-mount calipers. I checked EBC's spec: their dynapro pad is the thicker one.

7816.jpg

7812.jpg

[bobbrown]

one of the lug mount dynapro's uses the 7812's and the supposed narrow lug mounted one which is a wider caliper uses the 7816's

Very confusing.................

[tigerdog]

Porterfield's excellent web site lists 7812 pads from Porterfield/Pagid, Hawk and Performance Friction. Any opinions as to which compound would be the best match to EBC greenstuff on the stock rear calipers? Street driving and maybe (just maybe) an autocross or two.

[tigerdog]

Porterfield offers a complete line of pads that mix and match with all our various brake combinations (stock front/rear, Brian's front, BobBrown's wilwood front, even this new find.) I've just ordered their R4-S street pad for the lug mount DynaPros being discussed here, with a matching set for the stock rear calipers. Bits are on the way, so hopefully Smaug will get some new stopping soon.

[F1 LOTUS]

I too preferred the R4-S to Wilwoods 'tan' or 'Q' compounds.

[tigerdog]

A better endorsement cannot be had. Let's hope these new calipers do the trick! Hey Brian, how about reliving old times with a wrenching vacation in San Diego? I serve many flavours of good .

[nitroman]

Good catch. A shame they don't make the Dynapro with a 1.62" piston! The pedal is really firm with a short travel, totally unlike the 120-6816.

[tigerdog]

Good catch. A shame they don't make the Dynapro with a 1.62" piston! The pedal is really firm with a short travel, totally unlike the 120-6816.

Or a 1.5" - IIR, BobB says that would be the ideal match. Anyway, I received the new calipers before I shipped out the old ones, so I could do a side by side comparison. Placing them back to back on a tabletop, if anything the Dynapro lug mounts appear marginally (< 1mm) shorter than the Billet Dynalites. As you can see in the photos, they're definitely narrower. They also appear to have a little nicer finish - more machine work. You'll also note the different pad retention mechanism. Instead of a single cotter pin, these have a multiple-bend clip. The clip threads through the pad, so there's no need for the pad retention fingers at the bottom.

6181v9703_b.jpg

6816v9703_a.jpg

6816v9703_c.jpg

6816v9703_d.jpg

[tigerdog]

I just checked the pads I bought from Porterfield; they're .65" thick (7816 spec) and not the .49 required by these calipers. I'll call them in the morning and hope they can make things right. Good thing I found this before disassembly.