Filed under: Auction Action, Etc., Buick, Mazda
eBay find of the week: Mazda FD RX-7 equipped with Grand National turbo'd V6
Here's another example of liking the individual hardware pieces, but being repulsed by the idea of the ultimate combination. RX7s are cool. Grand Nationals are cool. But a vehicular mash-up of a 1993 RX-7 powered by a Buick GN's V6 seems a little weird. Weird to think that it even gets past regulatory agencies, as it's an older, totally alien engine in a newer car, which might make it interesting to register in a state with California emissions. The swap is well done, though, even if we'd question the handling a heavier and much more powerful engine in the snout brings with it. It's fast, but does it understeer like a pig and snap the tail out? The seller seems to have focused on posting low elapsed times in the quarter mile, so think about that when you conjure what the dynamics may be. Follow the jump for more.
[Source: eBay via Carscoop]
Gallery: GN powered RX-7
3rd-generation RX-7's are not only the zenith of the model's performance abilities, they're also the end of the line (so far) for the 2-door Wankel sports car. Turbo models were fitted with a staged turbocharger system that used two different compressors to boost power across the entire rev range. It was effective in stock trim, though it's less than celebrated by the crowd that likes to tweak on their 7s. Grand Nationals, too, were the baddest of badass A/G body GMs. The 231 V6 with a Garrett snail hung off the front was impressive in stock form, is capable of silly-to-ridiculous power levels when fiddled with, and still returns reasonable fuel mileage,which mirrors the seller's claim. As much as we recoiled at the initial thought of this particular swap, the car is obviously fussed over. Shoot, it's got a Dana 44 rear from a Viper for crying out loud, and it is an appropriate shade of GN black. Gather something north of 16 grand together and bid away!
Reader Comments (Page 1 of 3)
stefan 12:37PM (8/19/2007)
What kind of idiot thinks a buick v6 is better than a twin turbo 13B.
Reply
Justinmx6 4:40PM (8/20/2007)
The kind that likes tons of power.
The 13B is great, but if you want more power other engines are needed. Ang the GN engine will make more power then a 13B.
If it was my car I wouldnt do it, I ove the 13B, but it just cant compare with big numbers
Tim P 3:26PM (8/19/2007)
Apparently you've never driven a turbo buick.
500 1:51AM (8/20/2007)
What a waste of a perfectly good Grand National engine.
why not the LS2LS7? 12:38PM (8/19/2007)
It's likely not heavier. Because the transmission in the RX-7 is so heavy, you can replace the rotary and stock transmission with a Chevy small-block V8 and transmission and end up with roughly the same weight distribution as before.
The GN V6 might be even lighter.
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Xcountryflyer 12:53PM (8/19/2007)
Tragic...they ruined a brilliant car.
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Alex 1:00PM (8/19/2007)
the car's ruined
i dun have the funds to maintain a twin turbo rotary
but if i did, i'd definitely pick a rotary over a V6 or any piston engine, no matter who built it.
no seriously... the car's been ruined.
put the rotary back in that thing
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stefan 1:52PM (8/19/2007)
Are you crazy a LS in a RX7 that thing would be way too heavy, i rather have a high reving twin turbo rotary than a fat V8.
And if you want more power than the RX7 has just drop the twin turbo 20B in from the JDM cosmo.
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Chris 3:15PM (8/19/2007)
Ignorance is bliss eh? The LSX converted FDs weigh about the same as the rotary ones. Quoted directly from Hinson Super Cars(they specialize in the LSX conversions, link below):
"The aluminum GM LS1 and LS6 engines are extremely light power plants. With the complete removal of the 13B and the sequential turbo assembly, the project car's final weight is less than the total gross vehicle weight of a stock Mazda RX7. "
and
"The converted car handles and behaves the same as a factory car. The shop car is outfitted with aftermarket struts and front and rear sway bars for performance higher than that of the stock Mazda Touring suspension. Our customers should expect their vehicles to handle just as well as it did prior to the install."
and
"Depending on the level of engine modification, our customers should expect even a stock LS1 conversion to perform better than a C5 Corvette Z06. All of this for less than 1/3 the cost. Most of our stock LS1 RX7s will run between an 11.9-12.5 second 1/4 mile pass. The range is based on track conditions and driver ability"
So lets see the LSX converted cars are weigh about the same as a stock RX-7, are plenty fast, handle just as well, are more reliable and get better mileage. Hmmm...
Go to this site: http://www.hinsonsupercars.com/faqFD.htm
maybe you'll learn a thing or two
Nick 3:16PM (8/19/2007)
First off, this isn't an LS swap, it's a V6 from a GN (illiterate much?).
Second, an LS swap is -not- heavier than the rotary, it comes out with essentially the exact same weight distribution as stock, with a hell of a lot more power, and a hell of a lot better fuel economy and durability. The LS is the engine the RX7 wished it had from the start.
Preston M 4:09AM (8/20/2007)
Nick, i believe he was responding to me about the LS. And i mentioned both the LS and Grand National block.
Rocket Punch 8:19PM (8/19/2007)
The misconception that the Rotary is a very light and superior engine is both funny and sad.
Yeah, It is so good only one car company in one of their model uses it. Its all PR stuff, stop watching racing cartoons and drooling over import tuner pictures.
I am sure Ferrari is planning on replacing their V8 in their F430 with a Rotory very soon.
Mike 3:34PM (8/19/2007)
NEWSFLASH: Rotary's suck...unless you like quirky engines that cost a ton of cash due to rebuilds...
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787b 11:19PM (8/19/2007)
You, sir, are a moron.
The twin-turbo FD may not be the most reliable, but I'll put my normally-aspirated 12A up against any V8 for longevity. I've been racing it for a decade wide-open, always finishing in top-10 of 30 or more cars, have 147,000 miles on the clock, and still pulling strong.
The NA rotaries are pretty-much bulletproof and always good for 200,000+ miles, so long as you hit red line *every* day. How many V8's can hit red line every day for 20 years?
Justin 11:55PM (8/19/2007)
"How many V8's can hit red line every day for 20 years?"
Umm, they don't need to hit redline to make power. Its called a flat torque curve.
787B 10:38AM (8/20/2007)
Justin, that' really funny, because the rotary torque curve is flatter than a V8's. Just showing your ignorance.
stefan 3:51PM (8/19/2007)
@Mike
Rotary's don't suck, not all people like low tec 7liter V8 truck engine's.
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Nick 5:04PM (8/19/2007)
Or idiot fanboys just don't like to admit that a 'low-tech' lump of American metal is better than the rotary...Maybe? Let's see, a V8 that has more power naturally aspirated than a twin-turbo rotary, is more reliable, more durable, weighs the same if not less, and is more efficient both with fuel and oil, all while still being able to rev to ~7,000 RPM, handle forced induction into quadruple digit horsepower, and provide a more livable power band...Where is the rotary better again?
787b 11:32PM (8/19/2007)
Nick, don't be a jerk.
The Buick Turbo V6 isn't very low-tech. And especially this one is not low-tech. This is a heavily-modified, fuel-injected, custom-built engine.
I love Turbo Buicks. I go to Bowling Green every year. But it ain't revving to any 7000 rpm. My 12A technically red lines at 7000, but as anybody will tell you, it's more of a "suggestion" than hard limit. If the track calls for it, just keep your foot into it until it's convenient to shift. Most of the time that's 7500, but I've seen 8000. No big deal.
The twin-turbo has a *hard* fuel cut at 8000, which is still 1000 higher than your "~7,000 RPM". But you can run it at 7500 all day.
Nick 1:41AM (8/20/2007)
787b, maybe go re-read the post I replied to. Every comment I made was referring to the "V8 truck engines" mentioned in said post, not the Buick engine (since that wasn't mentioned).
As far as RPM are concerned, a modern SBC is capable of surpassing 8,000 RPM when built right, but in lesser forms there really isn't any need to do so, since 6,500-7,000 will suffice just fine in most any situation, especially considering there is ample power all the way through the rev range (unlike the rotary).
Really though, your old NA rotary has no bearing on anything in this thread, since the car in question came with a TT 13B, not a 12A. And in the case of durability this is a rather significant point, since as you have said, the NA rotaries are pretty solid, but once you introduce FI, that all goes out the window.