RE: 500hp Cayman GT4!

Wednesday 2nd January 2019

500hp Cayman GT4!

New York tuner DeMan Motorsport has made a 4.25-litre, 8,000rpm road rocket out of the flagship Cayman



Given a Porsche Cayman GT4, most people would be pretty content. As was made evident again in our Christmas twin test with a BMW M2 Competition, it's a superb sports car: exciting, engaging and hugely satisfying to drive. But for those not content, DeMan Motorsport in the US has a solution...

Its take on the Cayman GT4 sees the 3.8-litre flat-six bored and stroked to 4.25-lites; with new pistons, rods and crank, plus software work and a rev limit raise to 8,000, the Porsche is delivering 488hp and 360lb ft at the wheels - see the dyno vid below for proof. Assume a 15 per cent drivetrain loss and that's 561hp and 414lb ft at the crank, which are huge gains over standard. Apparently with titanium internals the DeMan GT4 could rev to 8,500...


Now if you're thinking that all this sounds quite pricey, you'd be right: $28,500 is the asking price, or about £22,500 at current exchange rates. That's without the Cobb access port or 'free-flowing exhaust' also required. But since when has modifying Porsches been an affordable undertaking?

DeMan apparently has five engines ready built ahead of announcing the package; those buyers wanting to keep their original block will have to wait six weeks. Perfect time to add in the Sharkwerks GT4 regearing as well, right? What a machine stands to be created then. And while this sort of investment will surely mean spending well into six figures on a Cayman - given the most affordable UK cars are still £70k plus - the prospect of a small, mid-engined, manual Porsche with GT3 RS performance does sound absolutely incredible. If any US-based PHers do take the plunge then we'd love to hear about it...





Author
Discussion

Burwood

Original Poster:

18,709 posts

246 months

Wednesday 2nd January 2019
quotequote all
I’m sure it’s thrilling but large brave pills needed to weather the write down in value, surely?

RumbleOfThunder

3,554 posts

203 months

Wednesday 2nd January 2019
quotequote all
Burwood said:
I’m sure it’s thrilling but large brave pills needed to weather the write down in value, surely?
I get the impression the US market are not so precious about such a thing.

SidewaysSi

10,742 posts

234 months

Wednesday 2nd January 2019
quotequote all
Burwood said:
I’m sure it’s thrilling but large brave pills needed to weather the write down in value, surely?
Who cares if you plan to keep and enjoy it? Values, values, values etc. Zzzz.

Bright Halo

2,966 posts

235 months

Wednesday 2nd January 2019
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That would make an awesome track weapon!

Maldini35

2,913 posts

188 months

Wednesday 2nd January 2019
quotequote all
anonymous said:
[redacted]
My thoughts exactly!

samoht

5,712 posts

146 months

Wednesday 2nd January 2019
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£22k doesn't seem that expensive for a fairly comprehensively rebuilt motor with quite a lot of specially made parts.

Question is, this or a 458 ? Sounds like they would be evenly matched in a straight line. 458s seem to start around £130k.

PistonBroker

2,419 posts

226 months

Wednesday 2nd January 2019
quotequote all
Agreed, it doesn't seem too bad price-wise considering.

I had a feeling it might have been the standard US method of shove a heavy V8 in there before I read it, so I'm pleased it's much better than that.

Bright Halo

2,966 posts

235 months

Wednesday 2nd January 2019
quotequote all
I wonder how good their warranty is and how it dovetails with the Porsche one. Hopefully there isn’t a no mans land in the middle somewhere.

Edited by Bright Halo on Wednesday 2nd January 16:36

J4CKO

41,549 posts

200 months

Wednesday 2nd January 2019
quotequote all
PistonBroker said:
Agreed, it doesn't seem too bad price-wise considering.

I had a feeling it might have been the standard US method of shove a heavy V8 in there before I read it, so I'm pleased it's much better than that.
Arent the LS conversions no heavier than the normal flat 6 engine ?

there is an impression that American V8 engines are heavy old boat anchors, they may have been in the past but nowadays they are fairly light for the power they offer.

SidewaysSi

10,742 posts

234 months

Wednesday 2nd January 2019
quotequote all
samoht said:
£22k doesn't seem that expensive for a fairly comprehensively rebuilt motor with quite a lot of specially made parts.

Question is, this or a 458 ? Sounds like they would be evenly matched in a straight line. 458s seem to start around £130k.
Not sure I would trust a 458 as much as a GT Porsche for hard use TBH.

RedAndy

1,230 posts

154 months

Wednesday 2nd January 2019
quotequote all
I'll admit I'm not in to Porsche that much to know where this thing sits in the model hierarchy, but wouldn't you just buy a 911 Turbo or an GT3 thingy in the first place?



Frogmella

153 posts

90 months

Wednesday 2nd January 2019
quotequote all
RedAndy said:
I'll admit I'm not in to Porsche that much to know where this thing sits in the model hierarchy, but wouldn't you just buy a 911 Turbo or an GT3 thingy in the first place?
Good point but the Cayman is the only mid engine option. I have never driven a GT3 but I have driven a 991.1 Turbo S and whilst it was mind-bendingly fast it felt a little dull and cumbersome.



anonymous-user

54 months

Wednesday 2nd January 2019
quotequote all
RedAndy said:
wouldn't you just buy a 911?
Depends whether you want your engine in the "right" place!

RedAndy

1,230 posts

154 months

Wednesday 2nd January 2019
quotequote all
Frogmella said:
Good point but the Cayman is the only mid engine option. I have never driven a GT3 but I have driven a 991.1 Turbo S and whilst it was mind-bendingly fast it felt a little dull and cumbersome.
ah right yes, fair enough! thanks smile

Nerdherder

1,773 posts

97 months

Wednesday 2nd January 2019
quotequote all
Needs an audio clip of that engine revving out really..

SydneySE

406 posts

260 months

Wednesday 2nd January 2019
quotequote all
Burwood said:
I’m sure it’s thrilling but large brave pills needed to weather the write down in value, surely?
there are two types of owners- those that can only afford a car on finance IF the residual value (or future value) is relatively high (making for smaller monthly payments). These owners pay a lot of attention to the miles the car is driven and do nothing to affect its future value. These owners also do no modifications to the car, as the finance documents generally don't allow it (as the car is not usually owned until a certain number of payments are made, if ever).

The 2nd type of owner generally buys the car outright, as it allows them to modify the car to their heart's content, as they are legally allowed to, and also they are not worried about the future value of the car; they tend to drive/track their cars as well...

IanJ9375

1,468 posts

216 months

Wednesday 2nd January 2019
quotequote all
J4CKO said:
Arent the LS conversions no heavier than the normal flat 6 engine ?

there is an impression that American V8 engines are heavy old boat anchors, they may have been in the past but nowadays they are fairly light for the power they offer.
The last conversion I read the LS V8 was lighter than the pork that came out, so yes you're right

WCZ

10,523 posts

194 months

Wednesday 2nd January 2019
quotequote all
RumbleOfThunder said:
I get the impression the US market are not so precious about such a thing.
yep, people buy cars to drive them there and aren't bothered about mods

IanJ9375

1,468 posts

216 months

Wednesday 2nd January 2019
quotequote all
WCZ said:
yep, people buy cars to drive them there and aren't bothered about mods
And they seem to have a different approach to crash repaired metalwork to us

anonymous-user

54 months

Wednesday 2nd January 2019
quotequote all
Lol, gotta love those Americans for making up power numbers!


488 bhp from 4.25 litres at 8k rpm (114 bhp/litre) is 435Nm (102Nm/litre) which is 12.9 Bar BMEP.

This is juuust about achievable and is broadly in line with what Porsche themselves make on their GT-3 engine (GT3 4.0 is 493 bhp at 8250 rpm, with the extra 250 rpm giving them a small edge in terms of specific output)


But the absolutely ridiculous 561 bhp figure (132bhp/litre & 118 Nm/litre - 14.8 bar), er nope, not a chance (unless they've got a turbo or two hidden away somewhere..........)