How to relive the thrill of IMSA’s legendary GTU class? How about this Lime Rock Historics-winning Nissan 240SX?
Consisting of an IMSA GTU silhouette body over a Speedway chassis, the Nissan is powered by a built 2.8-liter Datsun engine. (A build sheet and a recent dyno chart are included.…
Cool find, Colin. I wonder what the car’s history is. Back in the day, you saw these running at Daytona in addition to SCCA.
very cool.
Interesting that it uses the straight 6, I thought they all had turbo KA or a VG30 like this one.
Doesn't GTU mean under 2-liters? Any idea if the 2.8L (from a 280Z) has actually been destroked or if they yanked out the original motor and just stuck in this because it works? Curious use of engine in a 240SX 
In reply to j_tso :
That's a Datsun L24, a 240Z engine. Pretty old-school even when the 240SX was new.
My guess is that it started life as a Z car, and received some exterior updates as time (and perhaps contingency payouts) moved along.
I remember a local GT2 or GT3 RX-7 race car. It was bodied as an FD RX-7, but was powered by a heavily tuned carbed 12A. Asking around, apparently it started life as an early RX-7, and was rebodied as an FC, then FD. I have also seen GT4/5/L racecars with RWD 4A-power, and Tercel or Paseo bodies. 
GTU traditionally meant under three liters, not two. GTO was over three liters.
IMSA GTU was under 2.5 liters. So an L24 would make sense, but not an L28 as listed. Unless of course it never competed in that configuration, ship of Theseus paradox and all. The size rule I remember because Mazda rotaries were rated at 2x capacity, so the 12A was in GTU and 13B in GTO.
In reply to ae86andkp61 (Forum Supporter) :
Like this? I've never seen one in person and wonder how popular the chassis was.
In reply to j_tso :
Yes, very much like the white car you linked. I considered crewing for the team as they were recruiting and the guy running the car was a friend of a friend, but it didn't pan out.
So looks like this car runs in SCCA GT2, meaning it could use a range of engines. From ye olde GCR:
And the various Nissan bodies you can run in GT2:
I think there is some confusion from the wording of the original post. My understanding is that the 240SX for sale is an SCCA GT2 race car that is reminiscent of IMSA cars, and would allow one to live out an IMSA fantasy, but maybe I'm reading it wrong.
Edit: Wallens beat me to the post button!
In reply to ae86andkp61 (Forum Supporter) :
Yeah, I read it the same way: It’s an SCCA GT2 car that recalls the GTU cars of yore. And, who knows, maybe at one point it did run with IMSA.
Why no turbo(s)?
You can read the complete rules in the SCCA GCR but, basically, we’re talking about tube-frame chassis with composite bodies running on slicks. “Any classified engine may be used in a classified chassis within the same manufacturer,” the rules also state, so you can do some mixing and matching.
j_tso said:IMSA GTU was under 2.5 liters. So an L24 would make sense, but not an L28 as listed. Unless of course it never competed in that configuration, ship of Theseus paradox and all. The size rule I remember because Mazda rotaries were rated at 2x capacity, so the 12A was in GTU and 13B in GTO.
In reply to ae86andkp61 (Forum Supporter) :
Like this? I've never seen one in person and wonder how popular the chassis was.
The C&C Berettas driven by Max Jones and Tommy Kendall in IMSA GTU competition in 1988 were destroked 90 degree V6 blocks at 3.0L.
The RX-7's that ran in GTO I remember as being turbocharged. For sure the ones of Price Cobb and Pete Halsmer were in the early 90's.
In reply to racerfink :
Mazda was averse to turbo rotaries in competition. Their later GTO cars were 3 and 4 rotor.
We're both right, old IMSA rulebooks are on mulsannescorner.com. GTU rules started under 2.5, upped to 2.8 in the mid-80s, then to 3.0 by the late 80s.
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