GregBBRD

Worth watching, one of "my" 5.9 liter equipped GT's is for sale on Bring a Trailer.
If anyone has ever wondered how people rationalize having us build a super trick 928, the proof of value is in the resale.....

Speedtoys

https://bringatrailer.com/listing/19...sche-928-gt-5/

linderpat

unicorn car, and will set a new record for a GT. It may be there already at $130K. I think there is still much value on the table with it, but we shall see if that first big bid was a knockout bid. I hope not.

GregBBRD

There is a boadload of value left there.
That "starting" GT, with the low miles, has to be worth ~75K, today.
Toss another 125K+ at it and there's 200K of "hard money", right there.
Add in the fact that there isn't any possible way to duplicate that car, without waiting for years (if at all.)
And you have the true value.

It will be fun to see if there is more than one person, who figures out the above....

FredR

The all time record for a Corvette at auction is US$3.85 million and it still remains the "thing" it was in 1967!

US$130k will get you a [wonderful] fully loaded 2023 Corvette but I doubt US$130k would get you Neil Armstrong's lunar landing underpants were they available!

I doubt there can be more than a handful of "equivalent spec" 928's in existance given the history and they are probably "nailed down" by their current owners yet alone available for purchase.

That 928 is arguably a "bargain" at twice the current bid!

slownrusty

400hp with a stock exhaust.
What's the power with headers, X-pipe and a well fabricated mandrel exhaust (cat-less)?

Cheburator

A 5.4ltr stock GTS engine - the last one ever made, hence with drilled Kolbenschmidt pistons and factory alusil liners, with Mark Anderson's headers, GT cams, custom X-pipe into a stock GT exhaust made 410bhp after some SharkTuning. I would hazard an educated guess that Greg's GT is good for at least another 50 on top if not more, based on the fuel available...

bubba928

Yes. Fun to watch since I have a 91GT in excellent condition, and almost totally stock.

GregBBRD

I'd guess that 400hp would be a little bit "generous".
If the heads, cans, and exhaust will support it, displacement power increases are darn near linear.
And the heads and cams are up to that task. Depending on the age and condition of the cat, the exhaust system is also capable.
Pure displacement math (330÷5.0=x÷5.9) gets you 375. There's a couple fistfulls of tricks inside this engine...some for reliability, some to reduce internal friction, some to keep the oil where it belongs, some to increase efficiency, some for tuning, and some because that's how I engineered the components.
What actual power do those add, versus the limitations of the stock exhaust system and the dyno that tests the engine?
Unknown, but likely not 400hp, unless one finds an "optimistic" dyno.

Once the exhaust system is no longer a factor, all the internal modications can really shine. Since the stock heads will flow enough air to make the full 400hp, with zero inertial cylinder filling, suddenly there's a little bit "sitting back on the table". The expectation would be to get another 5-10% increase in power at various rpms, once the heads, cams, and exhaust are not a limiting factor.
....Which, BTW, is certainly very close to the limit of a very fresh stock GT clutch.

There's a bit of the "slippery slope", at this point...which is the primary reason there's not one of our exhaust systems already on the car. (Business had turned fairly sour for the owner who was building this car, limiting exhaust and clutch expenditures, and leading to him selling the car upon completion.)

Matt-R20

I think in the auction I said “close to 400HP” as we don’t know, maybe that is a bit too optimistic? The reality is its the torque that you really feel and this car has gobs of it. When not hustling, I frequently am a 1 / 3 / 5 shifter given the torque and simplicity of the dog leg pattern.

GregBBRD

Matt, of course, is completely correct. The actual horsepower number is almost completely moot, which is why we don't stress about measuring it. Almost no one drives a tall geared 5 speed 928 near redline, very often. 380 horsepower at 7,000 rpms or 400 horsepower at 7,000 rpms is a really subtle change.
The beauty of these 5.9 engines is the massive amount of torque. It's really easy to find yourself cruising down the road, in 5th gear, at 2,200 rpms....and be able to drive around the car in front of you (quickly), only using the gas pedal.

Without doing something stupid (like using a camshaft ground to work on the top end, only or by making the port/valves in the heads too large), it is difficult to do anything to "kill off" the torque in a 928 engine.
We work with that.
Torque comes with displacement. Until we designed our latest clutch, we did not build 6.5 Liter versions of our "GT" engines for use in 5 speeds...the stock clutch was not up to the task (with the '87 to '95 intake manifold.)

So, at this point in time, nothing external that could be done to Matt's engine would do anything to hurt torque.
Exhaust (and intake manifold improvements) would only increase the torque.....everywhere.

Torque and horsepower at tied together.
Any increase in torque, at a given rpm, raises the horsepower, at that rpm.

ALKada

Matt,
Clearly your dreaming….. I read the BAT auction description and if you think it’s going to stop raining in SoCal anytime soon……..

Matt-R20

Actually sun is out this afternoon and supposedly clear skies till the end of the auction!

JBT3

@Matt-R20 For God's sake, man. Give us a video of this monster being put through its paces.

Oh, and best of luck with the auction. Incredible machine. Must be hard to part with it.

GregBBRD

I don't think a video of it driving will tell much....you won't be able to feel the extra "grunt" or the freshness of the chassis.

It drives just like all 928's...just a bit crisper than most.