Hello all -- long time ITS racer, now building EP TR8

J

Jeffyoung

Well-known member
Hello...see some familiar names here.

I've raced an ITS TR8 since 2003, numerous races wins and the 2011 SEDiv championship. Love the car, other than brake maintenance. Lots of common knowledge out there about these cars that is wrong, including and most importantly the FI system v. carbs.

In any event, I'm taking the plunge and turning my coupe chassis that I intended to build into an "ultimate" ITS car into an EP car. Have spent a few weeks studying the rules, and reading up on what else is out there in EP and I think the car can be competitive.

Initial question -- brakes. The rules clearly allow a rear solid disc conversion, no bigger than the fronts. I am fine with that and can work with it. The rules also allow me a larger alternate front rotor (10.5 v. 9ish for the stock solid disc) but there is no provision for an alternate caliper and no way the stockers will work with the vented.

Quandary? Misstep in the rules?

It seems the intent was to allow the bigger vented rotor but it won't work without an alternate caliper.
 
Perhaps it did not carry over? 30 years ago the Production TR8 was allowed a brake kit that was that size rotor and included a specific alloy 4 piston AP caliper. This was exactly the same stuff as was allowed for the similarly 13" wheeled Jensen Healey. You could probably get info from Tom Kraft or Joe Huffaker.
 
Thanks but doesn't really answer the question.

The spec line allows a 10.5" front vented rotor.
The spec line does not allow for an alternative caliper
The rules say stock caliper only
The stock caliper will not work

The 10.5" vented is probably the rotor off the SD1 which used an AP-Lockheed 4 pot caliper. I bet that is what was intended but rule doesn't say it.

I don't think this is a Joe Huffaker problem, it is an SCCA rule writing problem.
 
I think the point is that Kraft or Huffaker might know more detailed history being one that raced/prepped one of these cars in the past and can provide more detail.

Some things like this have happened through the frequent revisions of the GCR and the generational updates to an entire ruleset. some of the small comments like "must use AP 4 piston caliper with this allowed 10.5" rotor" were lost in translation where it currently just says "10.5" rotor OK".

If you can dig back umpteen years of GCR rewrites and find the previous rule where it said the caliper was allowed, then send that to the GCR under an E&O issue, they can get it updated rather quickly. Maybe this is where someone like Kraft or Huffaker can help out.. ??
 
I don't know where that rotor allowance even came from, as I don't recall ever talking about it on the PAC calls regarding this car. Hmmm, will need to look into it.
 
THanks guys.

Like I said, I'm pretty sure I know what those guys were using -- there is a 10.5ish (slightly smaller) vented rotor and 4 pot AP Lockheed caliper that bolts right up from the Rover SD1. My guess is that is it.

Kevin, thanks on looking into this. The car is not, in my opinion, raceable without vented fronts in EP trim. with the 9.5 solids it has now, it's a tough row at 190 whp in ITS.

Should I write in to the PAC with what i've found? RIght now, the TR7 is allowed the same alternate rotor with a reference to an old Jaguar Rover Triumph caliper, which I suspect is the Rover SD1 4 pot. The Z cars get a similar allowance to go vented up front.

Thanks all!
 
Sorry I couldn't help you put a square dowel in a round hole :D just trying to help.

Some unsolicited advise: get a different caliper approved than the AP of old. That part number will cost $1000 ea, if you can even find them. They are needed by historic formula and sportsracing restorers desiring to be vintage correct.
 
Hey, no worries, appreciate the help! I'm on the ITAC and know a bit about SCCA rule making but Prod world is news to me.

Actually those calipers are available now from Rimmers for about $140 each. Not bad. If I get this approved, I'll buy three sets and go from there.
 
Hi Jeff -

I'm a lurker on the Sandbox (RRAX forum), have exchanged a few emails with you, etc, but am fairly active here.

As you obviously already are doing - ask lots of questions of Prod folks. As you know, SCCA rules are not always perfectly drafted and sometimes aren't interpreted as one might think, so if in doubt ask. The rewrite of a few years ago did make things better but I still think there are some cloudy areas.

I have some old GCR/PCS laying around and will see if I can see what the CP TR8 brake specs were. If anyone else has the books from the early 80s they should be in there.

Prod is tons of fun and the people are great. This forum can occasionally be a bit surly as it is essentially 100% unmoderated aside from spam control but even here 98% is well intentioned.

I converted an ITC VW Scirocco to HP and have greatly enjoyed the project and racing and continuing to develop the car.

Welcome to Prod! The TR8 should be a blast!

Al Seim
HP VW Scirocco 1.6
 
Jeffyoung":vemqvk8q said:
Kevin, thanks on looking into this. The car is not, in my opinion, raceable without vented fronts in EP trim. with the 9.5 solids it has now, it's a tough row at 190 whp in ITS.

Should I write in to the PAC with what i've found? RIght now, the TR7 is allowed the same alternate rotor with a reference to an old Jaguar Rover Triumph caliper, which I suspect is the Rover SD1 4 pot. The Z cars get a similar allowance to go vented up front.

Thanks all!
Click to expand...

As I was told when I started asking about allowing a simple four piston caliper for all Prod racers, you just have to work around the limitations of your given platform. Otherwise pick another platform. "SCCA does not guarantee competitiveness of any specific model". (of course I call BS on that, but the current spirit of the class is what it is.) Want big brakes, Fuel injection, etc, race a modern car.
 
I certainly get that, but the question here is a bit more complicated:

1. An alternate rotor is allowed already that won't work with the stock caliper, with no allowance for any other caliper.
2. The TR7, a much slower car, is allowed the same alternate rotor, and an alternate caliper.
3. Some of the natural competitors for this car, like the Z cars, are allowed alternate rotors and calipers.

It seems pretty clear to me that something was intended with the brakes on the car, but the alternate caliper was left off, I would suspect accidentally.
 
Looked at 81 PCS...page 94, TR8 in CP....

front brakes: 9.75" disk/Std, 10.5: vent disk/Alt, 11" disk/alt, 1.1" width.
under alternate specs: alternate brake kit: Lockheed disk, front: PN CP2271; Lockheed disk, rear: PN CP2382.

didn't say a thing about calipers, specifically...so, perhaps that's covered in those "kits"

Guess you need to get the Triumph/Leyland competition prep. sheets from that time to see what parts were included in the "kits". Don't think I have anything that new in my Leyland factory competition "archives"... (bet 79 was my last, where it is, who knows?)

Another idea would be to check with Ken Slagle, Ted Schumacher, or even Kas Kastner to get more information, from a historic standpoint.

But, think the letter to CRB, as Jesse suggested, is best... makes no sense to allow big brakes that don't fit the allowed calipers, and if those are antique items, then modern alternative/equivalents are logical...

note: in '81, a difference in wt. 2136# w/carb, 2300# with FI... Holley carb, required restrictor plate, FI had a bunch of alt. parts, too.

Good luck.

Bob L.

edit.... oh yeah, the TR7 showed the same 10.5" vented rotors, listed alternative brake kit: STN 000068, .... different #
 
EXACTLY. Those CP numbers are the part numbers for the calipers themselves. Follow Jesse's advice but ask for something different and available as I suggested. Or get ask in tech to prove you have that exact part in tech. :doh:

My experience, if anybody cares :roll: was that i could buy an equivelent caliper for a lot more than $140 but that it wasn't going to have that part number and so not be legal. Maybe AP started reproducing them in last few years but you couldn't buy them in 05
 
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