FV disc brakes

[R. Pare]

The release characteristics are important regardless of the brake type - it depends on the compound, how the Cf changes with temperature, how fast the brakes heat up, how the change in temperature front to rear affects that Cf change, and then how fast the brakes and pads cool once you release the pedal.

We once went through a brake locking on release issue on an FF where no matter what the driver did to the balance bar, the lockup would change front to rear in an unexpected fashion. That was with the car fitted with LD19s and I believe PFC pads ( I could be wrong on the pads). We refitted the car with narrowed LD20's to fit the 1/4 inch rotors correctly, used the same compound pads, and the problem went away and the driver could feel a big difference in braking consistency - no more lockup on release as well as a better feel to the pedal. What we deduced as the difference between the two setups was the temperatures that the pads were going to during a braking cycle, with the larger LD20 pads going to a slightly lower temperature that stayed just below the temp that caused the CF spike upon release.

With a front disk and rear drum setup, I would expect that the temperature rise and fall of the 2 ends of the car to be very different, with the drums most likely cooling off more slowly than the front disks. Exactly how that will affect the release characteristics and brake balance throughout a lap will in turn depend on the compounds being used.

[Hardingfv32]

Release characteristics..... I learned something new today.

Thanks
Brian

[Matt Clark]

The release characteristics are important regardless of the brake type - it depends on the compound, how the Cf changes with temperature, how fast the brakes heat up, how the change in temperature front to rear affects that Cf change, and then how fast the brakes and pads cool once you release the pedal.

We once went through a brake locking on release issue on an FF where no matter what the driver did to the balance bar, the lockup would change front to rear in an unexpected fashion. That was with the car fitted with LD19s and I believe PFC pads ( I could be wrong on the pads). We refitted the car with narrowed LD20's to fit the 1/4 inch rotors correctly, used the same compound pads, and the problem went away and the driver could feel a big difference in braking consistency - no more lockup on release as well as a better feel to the pedal. What we deduced as the difference between the two setups was the temperatures that the pads were going to during a braking cycle, with the larger LD20 pads going to a slightly lower temperature that stayed just below the temp that caused the CF spike upon release.

With a front disk and rear drum setup, I would expect that the temperature rise and fall of the 2 ends of the car to be very different, with the drums most likely cooling off more slowly than the front disks. Exactly how that will affect the release characteristics and brake balance throughout a lap will in turn depend on the compounds being used.

Interesting... and I guess that would make sense.

So if someone was to use the exact same caliper and pads front/rear, would that mean possible issues, since the fronts would obviously be generating way more heat?
I ask, because a couple of us were considering doing all 4 corners the same, for 2 reasons... both to use existing caliper brackets & needing fewer different spares. Then just change the master cylinder for the rear, along with the brake balance adjustment of course.

I did not think about any issues, since the existing kits use the same now (at least as far as I know), and I have not heard this problem come up yet.

[R. Pare]

Very common in FFs and FCs to have the same calipers and rotors front and rear. The problem depends a lot on what temps the pads are getting to, and how the Cf changes during the pressure and temp cycle, so there is no pat answer.

[Daryl DeArman]

The problem depends a lot on what temps the pads are getting to, and how the Cf changes during the pressure and temp cycle, so there is no pat answer.

If you are on the brakes hard and long enough in a FV to generate the requisite heat for such an issue you're over slowing the thing.

[Matt Clark]

Very common in FFs and FCs to have the same calipers and rotors front and rear. The problem depends a lot on what temps the pads are getting to, and how the Cf changes during the pressure and temp cycle, so there is no pat answer.

Ah, ok. That's what I thought, but I was 2nd guessing myself after reading. I was thinking maybe they were all doing LD20 fronts & LD19 rears or different pad compounds then.



We had started putting together a full FV package with the Wilwood 120-10188 calipers, but were considering the 120-3277 calipers (the ones Andy Pastore used) for the rear. Both would need custom brackets, but the fronts work out to be almost flat plates. The rear would need more complex custom brackets, which can be a pain & expense, so now we are considering using these new Empi/Wilwood ones on the rear to open up bracket options. Plus, the 10188 has a 1.75 piston, so they are a bit more powerful still.

The only downside to the new calipers, is they are more expensive that the existing Wilwood options. You can buy the 10188 & 3277 parts for about $110, and the new ones are about $190.

[Garry Sharp]

Just wondering, does anybody (or everybody) put stops on their pedals?

[Garry Sharp]

These new Wilwood calipers are for use when the 4 bolt wheels are approved, right? I am considering using that Wilwood floating caliper on the rear to go with the front package I made for several reasons.

Garry

[Matt Clark]

My pedal stop is a nut on the back of the pedal against the back of the beam.


The new caliper may or may not fit on a SCCA track-width legal wide-5 brake kit, as the thickness may be too much between the rotor & the flange. Once you go to 4-bolt kit, that interference obviously goes away. Either way, it is legal on its own, if you can make it work.

[Garry Sharp]

My pedal stop is a nut on the back of the pedal against the back of the beam.


The new caliper may or may not fit on a SCCA track-width legal wide-5 brake kit, as the thickness may be too much between the rotor & the flange. Once you go to 4-bolt kit, that interference obviously goes away. Either way, it is legal on its own, if you can make it work.

I mean a stop in the other direction, coming towards you. Yeah, that caliper looks to wide to fit a "zero offset" wide-5 rotor.

Garry

[Matt Clark]

Ah, I gotcha.
I do not have a stop coming back at me. Whatever the master cylinder allows is what travel I have.

[Matt Clark]

This months SCCA Fastrack says the CRB has recommended the 4-bolt disc brakes in 2021.

"The Club Racing Board has recommended allowing the 4-bolt pattern wheels from the 1967-1973 Type 1 to permit competitors to run an off-the-shelf VW Beetle 4-bolt disc brake single-piece hub/rotor with an off-the-shelf single piston floating design that meets the caliper minimum weight rule and is in line with the price range envisioned during consideration of the FV disc brake proposal. The process of referring this recommendation to the Board of Directors allows ample time for competitors to provide comments both for and against the proposed change, which achieves the same overall goal as a WDYT. The Club Racing Board does not plan to allow the use of the existing 4-bolt drums, which are wider than the 5-bolt drums and would not permit competitors to comply with the existing track-width limitations."


I personally see 2 issues with this updated wording that we also should address. I am gonna copy & paste from a reply I had to someone else when asked about it... hopefully everyone can is getting a better idea on all this stuff.


1- Caliper Pistons:

They are currently saying to limit it to single piston calipers, sounds like they are thinking of the Wilwood 120-3277 that Andy Pastore used. Since the first SCCA proposal came out, EMPI announced their caliper. If they are currently allowing big 4-piston calipers on the wide-5 kits now, there is no reason to not allow us the 2-piston calipers. Since they mandate an off-the-shelf 1-piece rotor, the concern of a fancy, small diameter rotor & 4-piston caliper is gone. The 2-piston caliper would be good with these rotors. That would enable all the off-the-shelf kits out there. You could go buy all of that stuff today.


2- Weight:

Currently, the 5x205 brakes have weight specs per the GCR-
"The required minimum weight for the complete disc brake assembly is 16.5 lbs. The assembly includes the following components: hub assembly; rotor hat; disc (which may be in two pieces); any hat-to-disc mounting hardware; calipers; bearings (front); pads; caliper bracket; assembly hardware (not including the brake assembly to spindle hardware for the front or the brake assembly to axle housing hardware for the rear); and lugs or studs with nuts."

From Andys Pastores post here earlier, reply #375-
"The 15x4J four bolt wheels were standard on the Type 1 Beetle 67-73 . They have a greater offset than the wide 5 wheels which help to get the the front within track rules.
The 4" wheels weigh 15.4-15.6 pounds"

In a discussion on the FV USA Facebook page, Al Spadin weighed a 4" 5x205 wheel-
"I just weighed a freshly sandblasted un painted stock VW 15 x 4 and it was 13 lbs."

So, that does indicate about a 2.5 lb. increase per wheel, when you compare 4.0" widths to each other. I do know many people run a 4.5" wide 5x205 wheel, so the weight gap does shrink there. Those numbers are for the older parts, new production replacements seem to be running a little heavier. Adding a line in the GCR for 4x130 brake kits to be about 14.0 lbs. total would even us up to existing brakes at least.


For reference here, allowing 2-piston calipers would open up these following kits, and the EMPI caliper would directly bolt in & replace the cast stock ones. Without doing the work yet, I don't have exact numbers, but these could be trimmed & shaved to meet the minimum weight... similar to what Garry did with the wide-5 stuff above.

https://dunebuggywarehouse.com/link-...5zQqvwbad5wqlg

https://dunebuggywarehouse.com/vw-du...5zQqvwbad5wqlg


There will probably be a few small teething issues & massaging needed, but I think we are on the right track if we can tie down a few more things like I mention.

[Daryl DeArman]

This months SCCA Fastrack says the CRB has recommended the 4-bolt disc brakes in 2021.

"The Club Racing Board has recommended allowing the 4-bolt pattern wheels from the 1967-1973 Type 1 to permit competitors to run an off-the-shelf VW Beetle 4-bolt disc brake single-piece hub/rotor with an off-the-shelf single piston floating design that meets the caliper minimum weight rule and is in line with the price range envisioned during consideration of the FV disc brake proposal."

As long as the FV community is in the "spruce up the wording during the WDYT phase" and not trying to stuff genies back in the bottle:

The wording of the current proposal does not mandate the use of an "off-the-shelf kits" with 4 bolt pattern wheels. It simply is recommending the allowance of the 4 bolt pattern wheels in order to facilitate the option to utilize a more cost effective off-the-shelf kit.

Big difference in my eyes. Whether or not folks want to pursue clarification or exploitation is up to them.

[R. Pare]

Kinda hard to mandate an "off the shelf kit" without a lot of additional wording.

Whose shelf?

And what quantity of production qualifies as "off the shelf"? If I make a bolt-on kit, and put it on my shelf for even just 2 minutes, then it is "off the shelf" !

[Matt Clark]

As long as the FV community is in the "spruce up the wording during the WDYT phase" and not trying to stuff genies back in the bottle:

The wording of the current proposal does not mandate the use of an "off-the-shelf kits" with 4 bolt pattern wheels. It simply is recommending the allowance of the 4 bolt pattern wheels in order to facilitate the option to utilize a more cost effective off-the-shelf kit.

Big difference in my eyes. Whether or not folks want to pursue clarification or exploitation is up to them.

Do you mean it does not, because no 100% complete kit exists, or is there something else I am not picking up on?
I read it as meaning to use off-the-shelf components, not a custom billet setup like the current ones. Hence why they are going with roto-hub rears, and not allowing a Porsche 914 type 2-piece hub & rotor hat. Although, I guess without seeing their exact new proposed wording, we can't say for certain they aren't allowing the 2-piece parts.

I would prefer clarification & to do it right, so we do not have to put toothpaste back in a tube later. Or worse yet... never get it fixed.

Kinda hard to mandate an "off the shelf kit" without a lot of additional wording.

Whose shelf?

And what quantity of production qualifies as "off the shelf"? If I make a bolt-on kit, and put it on my shelf for even just 2 minutes, then it is "off the shelf" !

True.
Would something like "OEM replacement" work better? Perhaps even specify the construction & material, and VW part number they want to see it match?

[Garry Sharp]

How about this?

Front and/or rear brake drums and backing plate assemblies may be replaced with a disc brake conversion assembly as an option. The front spindle/steering knuckle, rear axle, axle tube, bearing housing
and bearing retainer/seal assembly must remain per GCR part 9.1.1. A spacer plate or a portion of the
rear caliper support may be fitted beneath the bearing retainer to replace the backing plate dimension. If
the caliper bracket is attached to the inboard side of the rear axle tube bearing casting with the bearing
cap retainer bolts, the casting area around the bolts may be surfaced to achieve an adequate contact
surface. Any ferrous alloy, unvented rotor may be used, but must have a maximum diameter of 11.75
in. and a minimum thickness of 0.20 in. The otherwise smooth rotor may have a maximum of three
pad cleaning grooves per side. Any ferrous or aluminum alloy caliper and caliper support may be used.
The caliper must have no more than four pistons. Brake pads are free. Any hub assembly may be used
as long as it can be fitted with part 9.1.1. wheels or 4-bolt pattern wheels from the 1967-1973 Type 1.
The required minimum weight for the complete disc brake assembly is 16.5 lbs. The assembly includes the following components: hub assembly; rotor hat;disc (which may be in two pieces); any hat-to-disc mounting hardware; calipers; bearings (front); pads;caliper bracket; assembly hardware (not including the brake assembly to spindle hardware for the front
or the brake assembly to axle housing hardware for the rear); and lugs or studs with nuts.

Garry

[Daryl DeArman]

Do you mean it does not, because no 100% complete kit exists, or is there something else I am not picking up on?

Yes. I mean it does not. I guess it just differs between what constitutes a kit to you and I. I don't see any requirement that a kit have a single part number, but could be a group of various part numbers from various manufacturers needed to do the conversion. "a set of articles or equipment needed for a specific purpose" is the first entry in my on-line dictionary.

I would prefer clarification & to do it right, so we do not have to put toothpaste back in a tube later. Or worse yet... never get it fixed.

With you there.

[Daryl DeArman]

Any ferrous alloy, unvented rotor may be used, but must have a maximum diameter of 11.75
in. and a minimum thickness of 0.20 in. The otherwise smooth rotor may have a maximum of three
pad cleaning grooves per side.

Sure the group doesn't wish to specify a minimum OD?

Any ferrous or aluminum alloy 4-piston caliper?

Specifying a minimum weight of all those components and then including hardware and brackets in that group, not sure that's a great idea. Maybe exclude hardware and brackets and lower the minimum weight accordingly. 15# bracket and hardware while everything else weighs 1.5# could be an issue

[S Lathrop]

The issue that Richard and I posted will be worse for 4 piston calipers than 2 piston calipers. The release time for a 4 piston caliper is longer than a 2 piston caliper. In European F3, the lap time improvement at the track where the testing was done was 1.5 seconds per lap for a car with 2 piston calipers vs. 4 piston calipers. Now there were a lot of other things that changed along with the number of pistons in the calipers.

In the development of the Citation F1000 we started with the Wilwood 4 piston caliper and replaced it with a 2 piston caliper very quickly. I would question using any 4 piston caliper on a FV.

It has been many years since I have done any work on a FV. Maybe the class has evolved to the point where what I think I know is totally outdated. And other formula car classes that I am more current with have no bearing on the issues facing FV contestants.

[problemchild]

Projecting wheel weights with two samples is hysterical, even by SCCA standards.
The 15" wheels have been made since the early 60s (probably before). That means dozens of VW and aftermarket suppliers. I use to work very hard to find light wheels and make sure my Runoff tires were on the lighter wheels and not the aftermarket heavy wheels that most people used ..... that were as much as 4 lbs heavier EACH!

[FVRacer21]

The issue that Richard and I posted will be worse for 4 piston calipers than 2 piston calipers. The release time for a 4 piston caliper is longer than a 2 piston caliper. .......

So if 4 is bad, and 2 is better, might a single piston caliper be best?

The fact that it would have to be a sliding caliper has it's own issues, as anyone in the Rust belt know with a "frozen" caliper, but assuming we maintain our race cars better than our street cars....

Will the sliding caliper affect the release time? Are we over thinking this?

ChrisZ

[Matt Clark]

Yes. I mean it does not. I guess it just differs between what constitutes a kit to you and I. I don't see any requirement that a kit have a single part number, but could be a group of various part numbers from various manufacturers needed to do the conversion. "a set of articles or equipment needed for a specific purpose" is the first entry in my on-line dictionary.

Gotcha... and the bold part is basically what I was thinking, since we may have a hard time getting a single kit p/n from companies. That is where I was coming from with my reply to Richard about wording it as OEM replacements or specifying VW part number equivalents.

Sure the group doesn't wish to specify a minimum OD?

Any ferrous or aluminum alloy 4-piston caliper?

Specifying a minimum weight of all those components and then including hardware and brackets in that group, not sure that's a great idea. Maybe exclude hardware and brackets and lower the minimum weight accordingly. 15# bracket and hardware while everything else weighs 1.5# could be an issue

I think the minimum OD issue goes away when they specified the one-piece rotors, but it wouldn't hurt to do something just to cover the bases. We would have to get some roto-hub pieces to measure for a number.
I agree on the caliper material callout. Thats the wording for FF & FC anyway, no reason we can't duplicate.
The minimum weight rule definitely needs looked at, as a few of us have brought that up, where people could get wild with weights between the rotating parts vs. the brackets & such.

I would question using any 4 piston caliper on a FV.

It has been many years since I have done any work on a FV. Maybe the class has evolved to the point where what I think I know is totally outdated. And other formula car classes that I am more current with have no bearing on the issues facing FV contestants.

Agreed... but I think it was mentioned buried in here somewhere, they had to use the 4-piston solely because of clearance issues. Otherwise, the idea was to use 2-pistons at first.
I would guess your experiences would still work with FV today. We have done a few things different, but it hasn't changed that much. Any & all input is good.

Projecting wheel weights with two samples is hysterical, even by SCCA standards.
The 15" wheels have been made since the early 60s (probably before). That means dozens of VW and aftermarket suppliers. I use to work very hard to find light wheels and make sure my Runoff tires were on the lighter wheels and not the aftermarket heavy wheels that most people used ..... that were as much as 4 lbs heavier EACH!

I would not go so far as to say as hysterical, but it is getting down to nitty gritty... which is what would be a complaint if it wasn't accounted for. I agree that that sample size is basically nothing, but it does show German vs. German wheel weights, so I just threw a number out there. If we could get more people to weigh things & increase sample sizes, then we could make a better rule. For now, there is no denying there is a rather good chunk of change, I would even be ok with saying a 1.0-1.5 difference. Fairness is the goal.

So if 4 is bad, and 2 is better, might a single piston caliper be best?

The fact that it would have to be a sliding caliper has it's own issues, as anyone in the Rust belt know with a "frozen" caliper, but assuming we maintain our race cars better than our street cars....

Will the sliding caliper affect the release time? Are we over thinking this?

ChrisZ

Andy seemed to think that single piston caliper worked, but I still say it would be better to allow the 2 pistons. FST uses them with no issue, and as I mentioned earlier... they already allow 4-pistons on the 5x205 kits, and those rotors are the same diameter. How/why would we "handicap" the 4x130 kits? And we would not need to make all custom brackets to use them now.
You definitely will have to be more on top of making sure the caliper pins are clean & free, and as someone else mentioned, your bracket will have to be much more precise on the hole locations.

[S Lathrop]

So if 4 is bad, and 2 is better, might a single piston caliper be best?

The fact that it would have to be a sliding caliper has it's own issues, as anyone in the Rust belt know with a "frozen" caliper, but assuming we maintain our race cars better than our street cars....

Will the sliding caliper affect the release time? Are we over thinking this?

ChrisZ

How much does the caliper weigh compared to a piston? Assume that the friction of the seals on the pistons and the caliper sliding on the on its mounts is close to equal. That should be enough information to give you an answer.

The release issue can be a very significant problem. I had a guy who is a mechanic with an Indy car team tell me about the problem with release on a car they were running (not the Indy car).

It may be that with a FV, you never call on the brake system to perform at the level of a FF or faster car. So this might not become an issue. Or because FV is so competitive, some small delay in the brake release, not enough that the driver really notices, the problem still cost that car a small time loss. Think about how much time some people spend tuning the brake shoes on a race weekend looking for that tiny performance edge.

[Hardingfv32]

Sure seems like you are making a simple request for low a cost system into something that is going to require costly modifications. If this solution is not 'off the shelf', then the average FV competitor is not going to be interested.

The average SCCA competitor only competes about three times a year. Is the effort to update to discs really worth the time and expense for so little usage? Talking average competitor....

Brian

[Matt Clark]

Sure seems like you are making a simple request for low a cost system into something that is going to require costly modifications. If this solution is not 'off the shelf', then the average FV competitor is not going to be interested.

We have to have parameters whether there are 100% off the shelf kits right now or not. What is costly about possibly having a couple rotors turned down some? If we lay out the groundwork for what a kit should be, to be fair & competitive, then someone could make a 100% kit for us.

But perhaps we should just leave the rules wide open... I mean, no one would ever exploit those & make an affordable item into a must-have requirement or anything.

The average SCCA competitor only competes about three times a year. Is the effort to update to discs really worth the time and expense for so little usage? Talking average competitor...

Between Challenge Cup & NEFV alone being on track way more than that (double at least), that is over half the FV entries in the US per year. There is not a lot of time or expense at all, and the kits *could* be run completely unmodded. And if it is keeping people from getting into FV, then it absolutely is worth the effort now. If the average racer only races 3 times a year, then perhaps the more serious racers that do get on track way more than that *should* be the ones to determine what happens.




The statement was made earlier in this thread "FV needed to evolve 30-40 years ago. It was managed by vendors who chose to evolve by maintaining the status quo, allowing lots of tortured modifications, and whizzy bits, without restriction".

Why is it a problem to do it now?
If it was needed 30-40 years ago, suddenly it's a bad thing when drum brakes are that much older?
Those vendors being complained about are gone. Now here we are trying to address that need, WITH restrictions, and nay-sayers in here are now trying to maintain that same status quo, when change is needed more than ever.
Is it a bad idea, because it's now our idea & not theirs? Because we are now making progress with the changes? Sure seems that way when you read back thru this post, considering almost every single younger racer, and a growing number of older guys, is on board with it.
Almost all the people against the changes have a stockpile of parts after 30-40 years of racing, or aren't going to be racing for many more years. Almost all the people for the changes would like to race affordably for 30-40 years.

[Garry Sharp]

Sure seems like you are making a simple request for low a cost system into something that is going to require costly modifications. If this solution is not 'off the shelf', then the average FV competitor is not going to be interested.

The average SCCA competitor only competes about three times a year. Is the effort to update to discs really worth the time and expense for so little usage? Talking average competitor....

Brian

Trust me, you can't have disc brakes on a Vee any cheaper than this. You start with a 100% stock system and "add lightness" as you can afford. Unfortunately, it would have been nice if 4 bolt wheels were included in the original rule. Then you would have pretty much had very combination and cost range possible.

[Daryl DeArman]

The average SCCA competitor only competes about three times a year. Is the effort to update to discs really worth the time and expense for so little usage? Talking average competitor....

Depends on how much they dislike the look, feel, maintenance, and the costs involved with running a competitive drum set up.

Not too unlike the Kent/Fit R.O.I. It takes quite a number of hours before the Fit pencils out to be a better value (assuming same performance) and most people don't race often enough to make it apparent how much sense the conversion makes. However, they'll do 3 races a year for 20 years in the class and come out many dollars behind, but too far in to change now. Much of it comes down to how much somebody dislikes messing with tuning an engine that doesn't utilize an ECU.

[Daryl DeArman]

But perhaps we should just leave the rules wide open... I mean, no one would ever exploit those & make an affordable item into a must-have requirement or anything.

That irony was not lost on me, gave me a monster of a laugh.

[Hardingfv32]

Depends on how much they dislike the look, feel, maintenance, and the costs involved with running a competitive drum set up.

It took 30-40 years to get the initial disk change and then very few were for it. It is my opinion that the average FV competitor does not dislike the drum system enough to switch to discs. Three events per year worth of brake frustration is not that big a deal, otherwise the disc option would have come much sooner. Competitor actions speak form themselves.

Brian

[Daryl DeArman]

It took 30-40 years to get the initial disk change and then very few were for it. It is my opinion that the average FV competitor does not dislike the drum system enough to switch to discs. Three events per year worth of brake frustration is not that big a deal, otherwise the disc option would have come much sooner. Competitor actions speak form themselves.

Brian

Don't confuse the lack of desire/dsilike/competitor actions with the resistance to change, especially when involving anything perceived as a competitive advantage and a class with huge participation largely because of low cost and rules stability.

[Garry Sharp]

It took 30-40 years to get the initial disk change and then very few were for it. It is my opinion that the average FV competitor does not dislike the drum system enough to switch to discs. Three events per year worth of brake frustration is not that big a deal, otherwise the disc option would have come much sooner. Competitor actions speak form themselves.

Brian

I predict that when the 4 bolt wheel option and the Wilwood caliper are available there will be a lot more people "for it".

[Garry Sharp]

I'm going to try and finish this up this weekend. (That's a wooden bracket).

The picture disappeared.

[Garry Sharp]

Picture

[Speed Sport Engineering]

Knowing that if I posted this in the runoffs thread it ran the risk of muddying that thread so I'm posting it here -

Congratulations to Chris and Andrew for their podium positions and taking home $700 in contingency money at this years runoffs for using our brakes. Way to go guys. It was fun watching and we're glad we could be a part of your efforts!

[Garry Sharp]

I finished the bracket for the rear for the Wilwood floating caliper.

[Matt Clark]

As another update on 4 bolt brakes....
We are testing a complete setup this weekend at Pittsburgh, using the 2 piston Wilwoods. I will have a write-up like Andy did next week.