991 GT3 Premiere - Tues 05 March @ 09:45 GMT

[majordad]

You mean you 're missing the RS Day, and I was going to let you attempt to put my brakes on fire again !

Enjoy the snow. Show.

PS, I've you rumbled, you're getting one for the PCGB Series ? Or, there's a problem with the engines already and Porsche have summoned Baz !

[Sierra Mike]

IanHug said:

Manks said:

For want of a better description it is a 991 Carrera S+

Feels like to me like what the Carrera S should have been. Difficult to see it holding its value like the previous GT3s – not different enough and you can imagine some of the current differentiators making it onto the 991.2 in a couple of years.

I think the best description of this car is a 991 GTS. It's missing some key GT3 attributes but that doesn't mean it's a bad car as I'm sure it will be great. For once I think they got the pricing right and this car is value for money. However, I'm more concerned with residuals on the 991 GT3 than I was with the 997 since everyone expects it to be built in greater numbers.

[HokumPokum]

fioran0 said:

Anyone bothered to look at the gearing chart?
It's geared pretty much the same as the 3.8RS/4.0 over the first 6 gears with 7th then longer on top.
Not really how it was described in the blurb.

That's already better than the previous gt3 if so. the next RS will be shorter geared?

[HokumPokum]

anonymous said:

[redacted]

I think you may be right on the above. But what separates previous GT3s/RS was the race proven engine derived from the Cup cars. Because the motorsport link is currently missing, you have a lot of fans questioning why. There is always the lingering question of "if it is better, why is it not in the CUP?". "If it is better, can you commit to a future date?" No CLEAR answers on these 2 questions. I don't know of any car bar the 7.2 RS that drove from the factory to nurburgring, completed the nurburgring 24 hour race (with Chris Harris as one of the drivers) with just tyre and brake pad/disc changes in stock form and then drove back home to the factory. To me, that means something.

Maybe, porsche will subject the next RS to the same test using the same engine and drivetrain and electronics. but as Fiorano says, it's a completely new book. Yes, GT3 fans normally do cling on to the older proven stuff that doesn't break EASILY on track. As MTR succintly puts it, we'll see. By the time the next RS comes, these doubts may well be removed. But, rumours persist that the cup cars may use the flat 8 from the super cayman.....

anyway, history matters for the track guys re Gt3s. Not for generic Porsche fans.

[Joe911]

fioran0 said:

Very curious to see them, with max power at 8250rpm there's a real question mark over the extra 750rpms purpose beyond top trumps. Torque i saw falls like a stone past 8k.

Huh. Shirley you would not want peak power at max. revs - you would expect that if you rev to the limit when you change up you are back in (well, near) peak power again.

[PorkaFly]

So in reality Porsche is appears to be testing the new engine for the 2014/2015 cup car in the new GT3...it won't be Motorsport derived but it will end up in Motorsport use if successful.

Is this the new reality?

They thinks its good but just don't know yet...has the same internal treatment as the old engine, so it should be a cracker, and they hope it will be, but staying with the current engine until the new one is proven was less of a risk in the 991 Cup.

It's what I think is going on...

PF

[RatBoy M3CSL]

Andreas talked about the new engine, and its finger type valvetrain to let it rev to 9, did he mean a normal cam + finger rocker to valve arrangement ie BMWS54 M3 engine or a Desmo set up..? surely not..? .. ;o)

[Joe911]

RatBoy M3CSL said:

Andreas talked about the new engine, and its finger type valvetrain to let it rev to 9, did he mean a normal cam + finger rocker to valve arrangement ie BMWS54 M3 engine or a Desmo set up..? surely not..? .. ;o)

He certainly didn't say it was desmodromic.

[Ian_UK1]

fioran0 said:

Anyone seen the engine dyno curves yet anywhere? I've seen torque but not hp.

You can calculate the HP from the torque figure easily at any given rpm. From memory, HP(KW)=Torque(NM) x rpm / 9549

[Joe911]

Ian_UK1 said:

You can calculate the HP from the torque figure easily at any given rpm. From memory, HP(KW)=Torque(NM) x rpm / 9549

Surely that can't be right - that would imply that torque is always fixed in relation to RPM - and yet some engines have more torque than others, or more torque at lower RPM, etc.

[Ian_UK1]

Joe911 said:

Surely that can't be right - that would imply that torque is always fixed in relation to RPM - and yet some engines have more torque than others, or more torque at lower RPM, etc.

No, it just means that for an engine to produce more torque at a given rotational speed, it also has to be producing more power at that rotational speed too. Logical if you think about it.

Edited to add: This link explains it quite well.

http://www.epi-eng.com/piston_engine_technology/po...

If you look at the equation for deriving HP from known torque/rpm figures, you'll note that the number you divide by is different depending on the units of measurement you use (BHP/KW/Ft-LB/NM).

Edited by Ian_UK1 on Thursday 7th March 10:40

[N24]

lumpystew said:

Silly question - but will you be able to get rear seats on new GT3

I was wondering if that would be an option too.

[sidsideways]

Is that pinnacle of GT3s the one with the wheels falling off and the engines blowing up?

[cayman-black]

sidsideways said:

Is that pinnacle of GT3s the one with the wheels falling off and the engines blowing up?

HaHa.So to lighten things up a little what special colours are we going to see on the new RS then, any one care to guess?

[fergus]

Ian_UK1 said:

No, it just means that for an engine to produce more torque at a given rotational speed, it also has to be producing more power at that rotational speed too. Logical if you think about it.

Edited to add: This link explains it quite well.

http://www.epi-eng.com/piston_engine_technology/po...

If you look at the equation for deriving HP from known torque/rpm figures, you'll note that the number you divide by is different depending on the units of measurement you use (BHP/KW/Ft-LB/NM).

Edited by Ian_UK1 on Thursday 7th March 10:40

Torque / BMEP figures are the ones you want to compare engines. This will give max BHP at a specific RPM.

BMEP is a product of volumetric efficiency (how much air you can get in), AFR (how well you use the air you've got into the cyl head to combust the fuel) and fuel conversion efficiency (how well you use the energy in the fuel). All of which are needed to generate torque at a specific RPM.

"for an NA engine, BMEP is a measure of how clever you are, for forced induction it's a measure of how brave you are" (LJK setright)

[stefan1]

anonymous said:

[redacted]

When I met Preuninger at the launch of the 4.0 he said GT3 engines have always been quoted conservatively - for the 4.0 he expected 510 - 515hp after a few thousand miles. So I think the figures are probably comparable because Porsche are being consistently conservative.

[APOLO1]

My 991s 3.8 400BHP, engine now on 5k miles, feels way more torquey than that of 4.0.RS. Its also faster 0-60 20-70 30-90, On track that is.....

[cayman-black]

APOLO1 said:

My 991s 3.8 400BHP, engine now on 5k miles, feels way more torquey than that of 4.0.RS. Its also faster 0-60 20-70 30-90, On track that is.....

Really?

[APOLO1]

PDK...The 4.0 does not feel…like super fast through the gears. There is a vid on YT up against a M6, the M6 kills it. No doubt in the right hands on track the 4.0 is epic…..

Edited by APOLO1 on Thursday 7th March 13:47

[Robbo66]

APOLO1 said:

PDK...The 4.0 does not feel…like super fast through the gears. There is a vid on YT up against a M6, the M6 kills it. No doubt in the right hands on track the 4.0 is epic…..

Edited by APOLO1 on Thursday 7th March 13:47

So it's £100k more than the 3.8 and needs to be in the right hands to make it sing....quite telling really.