Rx-792?

IanGrohse · 21 Sep 2003, 23:09 (Ref:725906)

Why was this car such a failure, or at least why did they give up on it?
What problems did it have?

Es Nes · 22 Sep 2003, 00:28 (Ref:725934)

iirc, the exhuasts liked to catch the car on fire

MulsanneMike · 22 Sep 2003, 03:05 (Ref:725964)

The economy turned and Mazda shelved it.

**FIRE** · 22 Sep 2003, 17:22 (Ref:726701)

The car looks beautifull: RX-792

**skycafe** · 23 Sep 2003, 02:20 (Ref:727235)

Weren't they also being challenged over variable inlet trumpets? I seem to remember some fracas about those.

I loved this car. It had to keep getting altered as it seemed to have some design flaws, but it really was something.

**Aysedasi** · 23 Sep 2003, 07:25 (Ref:727333)

It's a corker, to be sure.

pirenzo · 23 Sep 2003, 07:26 (Ref:727336)

Nah, i don't like it. I think that has mostly to do with the fact it has a Mazda lgo on it, but i still think it's not the best looking car ever.

**Aysedasi** · 23 Sep 2003, 07:27 (Ref:727339)

Give me one of those to an R8 any day p.

dretceterini · 23 Sep 2003, 17:38 (Ref:727937)

A very attractive car that was pretty much an engineering disaster from day 1.

**Aysedasi** · 23 Sep 2003, 17:59 (Ref:727957)

Really? Disproves the old "if it looks right...." adage then......

IanGrohse · 23 Sep 2003, 19:31 (Ref:728043)

Quote:

Originally posted by dretceterini
A very attractive car that was pretty much an engineering disaster from day 1.

But thats what im wondering, other than the catching on fire thing, what aspects of the engineering were that flawed. Based on the AERO database on this site, the numbers look very competitive with cars contemporary to it.
Did it have specific problems that anyone knows of, other than the exhaust problem. That doesnt seem like it would be too hard of a fix.

Osella · 23 Sep 2003, 22:24 (Ref:728185)

I don't know this car. Tell me more, please.

pirenzo · 24 Sep 2003, 16:11 (Ref:728839)

Ayse, it's too jelly like. It's just too japanese looking.

dretceterini · 24 Sep 2003, 22:07 (Ref:729176)

Yet another case of a project being dropped to soon because of finances. The car appeared to have all kinds of minor problems, like the MGs. A year or two of development might have turned the 792 into a superb and successful car.

ggreen29 · 28 Sep 2003, 22:06 (Ref:733301)

IIRC there was an IMSA noise limit that the 792 exceeded, therefore a bigger muffler was used to reduce the sound. The bigger muffler kept more heat than was originally planned (and IIRC rotary exhaust is hotter than piston exhaust to begin with), thus the occasional fire problems. They tried cutting a number of new holes in the body in order to get more air flowing into the rear to keep the muffler from combusting.

Also if you look at the early models vs the later models you'll see many more louvres throughout the body work (esp front wheel arches). I don't know if these were to solve a separate problem or part of the muffler cooling problem.

Then came the recession and everyone but Gurney lost interest, which was a shame because it was a great series while it lasted.

Dauntless · 29 Sep 2003, 00:07 (Ref:733382)

Beautiful doesn't do the car justice. It is a work of art...!

Magical Trevor · 29 Sep 2003, 00:13 (Ref:733387)

Hey-welcome to the forum ggreen, and thanks for the info!

Dauntless · 29 Sep 2003, 00:14 (Ref:733390)

BTW, does anyone know if this car is housed in a public museum somewhere?

Fab · 29 Sep 2003, 07:31 (Ref:733665)

Am I wrong if I say that the car didn't ever come to Le Mans ? I can't find any trace of it on the annuals... good looking, BTW... except the painting, maybe

ggreen29 · 29 Sep 2003, 16:47 (Ref:734327)

Quote:

BTW, does anyone know if this car is housed in a public museum somewhere?

It's still hauled around. At Sevenstock (a US gathering of rotary engine vehicles and enthusiasts) this year Mazda hauled out the 792P. It looked authentic and looked like it hadn't been cleaned since the last race 12 years ago. But I was surprised at how flimsy some of the parts seemed; the front nose flaps (the horizontal flaps) could be bent with thumb pressure, and I could bend the gurney flaps on the wing. Some of the aero ducts in the front could be wiggled without much force at all. Maybe flimsy isn't the right word, because I didn't break anything!, but I was surprised by how deformable they were.

And as for LM, the 792P was just for the IMSA GTP series.

And thanks for the welcome. This seems like a great source of info and discussion.

Finally, I'll try to remember to quote some info from "GTP Prototypes", by Jim Martin and Ken Wells. It's a great book, tho a little pricey (but worth it for me). Hi gloss pages with good text and quality pics covering all the GTP big'uns & li'l'uns. It confirmed the info that I provided earlier, and there's more that I'll quote.

ggreen29 · 30 Sep 2003, 04:15 (Ref:734813)

From the book Prototypes, The History of the IMSA GTP Series by JA Martin & Ken Wells:

The new GTP car was entered at Miami and Sebring in 1992 but was withdrawn because of teething problems. "We had two problems,' says [driver Pete] Halsmer. "The first was getting the sound level down to what IMSA wanted it. To do that required a lot of muffler. When you put a lot of muffler on a Mazda, you get tremendous heat, and the Mazda motor tends to flash unburned fuel through it--particularly when trying to make that much horsepower--and that fuel tends to collect in the large muffler."

Unable to solve the heat problem, the solution was to reduce its effects. Composite parts were replaced with metal parts. Airflow was increased within the body. "We used all kinds of aerospace heat barrier materials and added cooling ducts and fins, says [engineer? Max] Crawford. "The latest version had lots of louvers and ducts for air going in to induce air flow. The car was originally sealed off."

By midseason, the cooling efforts were showing results. A combination of material changes and improved air flow made heat a minor problem.

The racing program came to an end when the Japanese economy, affected particularly by weak automotive sales, began to go soft. Mazda chairman Kenichi Yamamoto, an advocate for specialty cars resigned in December of 1992.

"What seemed to happen was that Sonny Sunaguchi, acting president at the time, received a fax from Europe stating that they were pulling out of racing in Europe," says [driver Price] Cobb. "But no one said to pull out of America. But he was not a race fan, and he saw it as an opportunity to pull out of racing over here. And because they were big on the saving face stuff, no one would go back on the decision."

"The amount of money Mazda was spending was infinitesimal compared to what others were spending" says Cobb. It was a very well run package. Here's a great way to bring Mazda before the American public, to show what they were capable of, and they stopped it."

As recognition of the Mazda effort, chief mechanic Mark Olsen was awarded GTP technician of the year.

End of excerpts.

ggreen29 · 30 Sep 2003, 04:18 (Ref:734814)

To continue with more than you need to know, the 792P finished:

15 of 17 (GTP & GTP Lights) at Road Atlanta
3 & 4 of 18 at Lime Rock
6 & 9 of 18 at Mid-Ohio
16 & 18 (DNF) of 19 at New Orleans
2 & 15 (DNF) of 17 at Watkins Glen
7 & 15 of 19 at Laguna Seca
15 (DNF) & 16 (DNF) of 19 at Portland
4 & 5 of 15 at Road America
11 (DNF) of 17 at Phoenix
15 (DNF) & 18 (DNF) of 19 at Del Mar

All in all I think it was quite a good job for a first year effort. My apologies for so much information, but this series was a great age of American sports car racing, and I just couldn't stop typing. Nissan, Jaguar, Chevrolet, Toyota, Porsche & Mazda were all involved in 1992, as Toyota took the GTP title from Nissan, ending four years of Nissan's dominance and beginning their own amazing run. And every team seems to have it's own exciting or interesting story.