I'm going out on a limb here...

tom_sprecher

tom_sprecher

Super Moderator
Dear Abby,

Since Mazda no longer produces 12A rotor housings, and finding serviceable used pieces is proving to be an exercise in futility, what chances are there that either the IT7 divisional or the SCCA advisory committees would allow the 13B in stock form or with Weber carbs like found in any FM to be substituted? I do not know what the HP numbers are, or how much of a percentage difference it makes since I do not have a high enough security clearance to know the highly classified and crucial to our nation's defense formula otherwise know as "The Process". That being said something must be done. Lord o’ mercy, can’t anyone help this poor man?

Will we see the hundreds of 1st gen Rx-7 racers rapidly disappear? Will racing regions, already struggling to break even, be able to maintain solvency? Can I even switch to ITS with an ’83 model. Heaven forbid, do swim with the sharks in Prod? What the freak am I going to do with my car that’s 20-30% down on power? Do I try to sell the car at a big hit and sit out for 3-4 years while I save up for another car? As much as I, and probably most of the other IT7 drivers don’t want to do, is unfortunately switching to NASA in our future. Help!

Signed,

Dazed and confused
 
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Off the cuff response is that the request isn't within the IT Intent. Lack of parts has caused other cars to lose popularity in IT... RX3 is the first to come to mind.

Looking up the ITS 13B RX7, any idea if that engine is the same as in the later (extremely competitive) 3nd Gen RX7's?
 
RX-7's:

Gen 1
12A: 101hp
13B from 84-85: 135hp

Gen 2 NA
13B from 86-88: 146hp
13B from 89-91: 160hp

Gen 3
13B TT not listed in IT. 255hp.

If you want to do the swap (it is more than you think), then ask for the GSL-SE to get relisted in ITA. Probably around 2545lbs via napkin math.
 
It kind of sucks but we have to watch out for the bigger picture, and any allowance outside of the general plan sets a precedent. Enough of those and we lose control of the most important control we've got over the category.

ON THE OTHER HAND, there's nothing to keep a region - or regions - from defining a spec class that does exactly what you describe. I personally think it would be nice if it wasn't called "ITx" to avoid confusion but why not...?

K
 
Hmmmmmmm.......................................................

Remove the carbed 12A and install a 13B in a 1st gen with a Megasquirt...................................................................
 
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I kinda wondered what sort of weight it would come in at in ITA... probably more viable there than in ITS.
 
Andy Bettencourt said:
RX-7's:
If you want to do the swap (it is more than you think), then ask for the GSL-SE to get relisted in ITA. Probably around 2545lbs via napkin math.
Click to expand...

I know quite a few IT7 owners, and even looked at purchasing one myself. This seems like the most viable option. The GSL is not competetive in ITS, but would breath enough life into the IT7's to keep em going.

The local contingent of mazda owners are very competetive. There are usually 7-9 cars every weekend.


hoop
 
I've honestly always wondered why a to the hilt GSL-SE wouldn't be competitive in S at 2300 lbs.

That said, the IT7 guys I know around here don't have any problems getting housings just yet. Call Eustis White, I bet he could hook you up. It's going to be a problem at some point, but we aren't (as best I can tell) there yet.
 
In this part of the country IT7 is a divisional class with simple rules: 1st gen Rx-7 build to ITA rules running the Toyo RA1 or R888 as a spec tire. We have a lot of them too. With the situation only bound to get worse maybe a divisional rule change is the easiest and cleanest way to go.

Ricky gave me a name and I need to call Eustis White as well. Anyone know his number? Also, since posting this I have received some promising emails from a couple of rotary engine builders about alternate sources for new and re-furbished housings. Not as cheap as Mazdaspeed (OEM $330 each, I should have bought 4 when I wanted to), but not too bad all things considered.

Even still, that beating a dying horse thing keeps coming back to mind. The 13B would breathe new life into it for quite some time.

On edit: We had 58 IT7 drivers compete for points in the SCCA Southeast Division in 2007 and a total of 362 entries nation wide at regional races that same year. Spec Rx7 had 382 and Pro-7 had 142. That's a lot of entry fees.
 
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I've heard of people making 12A housings out of 13B ones by milling them down on each side. Not exact replacement though, since I think the exhaust port will then be wider.
 
12a Housings

Tom...I feel your pain. I have 2 ist gen race ready 12a rx 7's myself. Anyone know the appr. life span for the housing under race conditions?

Thanks,

Bruce
 
intakes

IIRC, the RX7 GXL-SE had a very different intake than the 2nd gen 7s 13Bs. I could be wrong. making the no-VIN swap to a 5-letter car would be prohibitive only in this respect (and the harness...)

as for a "spec" IT RX7 with the 13B and a mikuni, sounds pretty cool, but I don't see it going anywhere without a very large number of cosigners and a package proposal with supplier agreement a'la spec miata suspension.
 
The intake is different, but it still is a 13B so rotor housings are moot. There are a few choices for ITA 12A drivers:

- Stay as is.
- Do the research and convert to ITS in GSL-SE configuration.
- Request the CRB reclass the ITS GSL-SE to ITA at the process weight of around 2545lbs and THEN do your conversions.

Those cars were fairly rare so you may be jumping out the frying pan and into the fire, but it would add options.
 
It's Soul Searching Time...

Andy Bettencourt said:
The intake is different, but it still is a 13B so rotor housings are moot. There are a few choices for ITA 12A drivers:

- Stay as is.
- Do the research and convert to ITS in GSL-SE configuration.
- Request the CRB reclass the ITS GSL-SE to ITA at the process weight of around 2545lbs and THEN do your conversions.

Those cars were fairly rare so you may be jumping out the frying pan and into the fire, but it would add options.
Click to expand...

Like I've said before I don't want to beat a dying horse and the "84 - '85 6 port 13B would only be putting the damn thing on a ventilator. It will only work if we can use the 2nd gen 13B, otherwise it's EP, STU (and I have neither the time nor the $$$ for either at this point and would guess neither do the rest of the IT7 crowd) or NASA for me.
 
tom_sprecher said:
Like I've said before I don't want to beat a dying horse and the "84 - '85 6 port 13B would only be putting the damn thing on a ventilator. It will only work if we can use the 2nd gen 13B, otherwise it's EP, STU (and I have neither the time nor the $$$ for either at this point and would guess neither do the rest of the IT7 crowd) or NASA for me.
Click to expand...

Help me here. How does a move to NASA help you when the core of your motor is in shortage?

If it was me, and I saw a dead future, I would try and get a STANDARD ruleset with the 146hp S4 ITS motor as the core. It's a regional only class anyway. Create teh groundsweel, create the leadership team and run it like SM.
 
Andy...any idea as to the lifespan of a 12a housing under race conditions?
Idemitsu makes the only engine oil made especially for rotary engines,plus a premix.Any good?

Thanks,

Bruce
 
Ps..i just bought the 4 new 12a housings that were on this website for quite some times(still in the original boxes and packing)
 
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