Which Manthey Engine Conversions Are There?

[PRO 5T]

I'm currently looking at a couple of 996 GT3 that have Manthey engine conversions, one a M410 and one a 3.9 displacement conversion.

Am I right i saying a K400 is what is done on a 996.1 GT3, a K410 is a 996.2 GT3 and an M devotion means it was built by Manthey and not built from a kit?

There's surprisingly little online about the various versions.

[TDT]

Has mainly been killed off because of the Manthey/Porsche official link up so they no longer develop drivetrain upgrades.

K400 and K410 were available for 996.1 and 992.6 respectively
Cup air filter, new engine cover inner to mate to filter, Ecu upgrade with tune, new full exhaust system. Slippydiff will know much more as this was his era.

There were also M designation kits, as far as i can tell these were for the turbo cars such as GT2 M600.

They also used to offer some capacity kits for N/A Mezgers in the form of 3.9, 4.2 and 4.4L. That all stopped after 997.

They have done some recent conversion on 996 and 997 but these require special sign off now as a project.

[blackmamba]

TDT said:

Slippydiff will know much more as this was his era.

Brilliant!

They are great conversions and I very nearly bought a K400 a few years back and wish I did. Adds a bit of extra edge to the powertrain and sounds glorious when at full chat. All 996 GT3s are good to drive and these are just that little bit extra.

[993rsr]

PRO 5T said:

I'm currently looking at a couple of 996 GT3 that have Manthey engine conversions, one a M410 and one a 3.9 displacement conversion.

Am I right i saying a K400 is what is done on a 996.1 GT3, a K410 is a 996.2 GT3 and an M devotion means it was built by Manthey and not built from a kit?

There's surprisingly little online about the various versions.

The 3.9 was referred to as K440. I had a K400 on my Mk1 GT3, then the K440 done by Manthey at Muespath.

Shame they don't do these any more - especially the 4.4! I'd be back there in a flash.

Edited by 993rsr on Saturday 20th January 19:22

Edited by 993rsr on Saturday 20th January 19:42

[PRO 5T]

The 3.9 I’ve test driven and still looking at was north of €30k I think and that was maybe ten years ago-I dread to think what a 4.4 would be by Manthey now!

[Slippydiff]

blackmamba said:

Brilliant!

They are great conversions and I very nearly bought a K400 a few years back and wish I did. Adds a bit of extra edge to the powertrain and sounds glorious when at full chat. All 996 GT3s are good to drive and these are just that little bit extra.

I know where there's a K400 Mk1 available if you should be interested.

The K400 is indeed the 996 Mk1GT3 conversion, and the K410 the 996 MK2 GT3 conversion.

The early 3.9 conversions carried out by Manthey on the Mk1 996 using Perfect Bore (which subsequently became Capricorn) liners and pistons were somewhat sub-optimal initially, but they got them sorted and they produced good horsepower and torque increases.

The Mk2 K410 conversion wasn't as popular, it was basically gilding the lily, as the Mk2 996 GT3 engine was pretty well optimised compared with the Mk1 unit.
A large part of that came courtesy of the Variocam Plus system which enabled infinitely variable valve timing on the inlet cam, as opposed to the cruder, "stepped" adjustment utilised on the Mk1 engine. The Mk2 engine used considerably lighter internal components and a far more powerful ECU too.

The Mk1 engine clearly had a lot more "left on the table" as Manthey managed to extract close to 50hp with the Mk1 K400 conversion by using some decent exhaust manifolds, high flow cats and freer flowing silencers along with some fairly crude (but effective) modifications to the induction system and engine ECU.

Engine kit K400

· GT3 (up to M.Y. 2001)

· manifolds, sport catalysts, rear mufflers, tail pipes, Cup air filter, MM motronic

· more power, more torque

· weight reduction by 6.7 kg (exhaust system)

· increase of acceleration, performance, top speed

· developed on the latest MAHA dyno

· tested on the Nürburgring and in every day use

· original onboard diagnosis systems are not affected

· individual dyno run incl. if fitted at Meuspath

· TÜV only inhouse

· special noise reduced version with additional silencer (minus 3 dB) available (surcharge 603,00 EUR)

Manthey quoted a 35hp gain, but it's suggested that the Mk1 engine didn't make the full 360hp claimed by the factory.
Depending on the rolling road used, figures seem to vary between 395 and 405hp for the conversion, what's not in doubt is the improvement in breathing at the top end and the vastly improved induction and exhaust noise.

Wayne at Chip Wizards can extract 395-400hp from a Mk1 engine if you fit a decent set of exhaust manifolds/cats and system from M&M exhausts in Germany, and get him to remap the ECU.

It won't have the wonderful induction noise the full K400 kit provides, but it will save you a lot of money and avoids having to cut the inside out of the very expensive engine cover away to facilitate fitment of the carbon fibre cold air ducting required when the 996 BMC Cup air filter is used.

The K410 kit for the Mk2 looks familiar ... :

Engine kit K410

· GT3 (from M.Y. 2004; incl. RS)

· manifolds, sport catalysts, rear mufflers, tail pipes, air filter, MM motronic

· more power, more torque

· weight reduction by 6.7 kg (exhaust system)

· increase of acceleration, performance, top speed

· developed on the latest MAHA dyno

· tested on the Nürburgring and in every day use

· original onboard diagnosis systems are not affected

· individual dyno run incl. if fitted at Meuspath

· TÜV only inhouse

· special noise reduced version with additional silencer (minus 3 dB) available (plus 603,00 EUR)

Manthey quoted a 30hp gain, but as most Mk2 owners would have you believe the engines produced closer to 400hp than the 380 claimed by the manufacturer, it leaves one wondering what the real gains were with the K410 kit ...

Manthey also offered a 3.9 litre K440 kit for the Mk2 996 GT3 and RS :

Engine kit K440

· GT3 (incl. RS, M.Y. 2004)

· complete engine conversion incl. increase of capacity to 3.9l (pistons, cylinders, sports clutch, Cup fly wheel,

complete sports exhaust system, air filter, MM motronic)

· weight reduction by 6.7 kg (exhaust system)

· great increase of performance (0-100 km/h: 3.8 sec. / top speed limited: 333 km/h)

· developed on the latest MAHA dyno

· tested for two years on the Nürburgring and in every day use

· street version of MR’s most successful 3.9L race engine (GT3-MR)

· minus 600,00 EUR for RS version

· individual dyno run incl. if fitted at Meuspath

· the total conversion needs app. 2 weeks

They quoted + 60 hp / + 70 Nm gains.

They also produced the K480 (a 3.8L 480hp conversion for the Gen 1 997 GT3/ and RS) along with the M600 conversion for the 997 GT2. you guys mentioned.

I have features on both the latter conversions in PDF form, but being a halfwit (and some would say that's being generous) I have absolutely no idea how to extract them from my PC and onto the worldwide interwebz.

So anyone wanting copies of the features, drop me a PM with your email address and I'll send them through. If you can scan them and then post the scans in this thread, it would make a good reference source for all to refer to in the future.

Edited by Slippydiff on Saturday 20th January 19:41

[TDT]

TDT said:

Slippydiff will know much more as this was his era.

Slippydiff said:

Knowledge….

Lol… told ya!

[Caddyshack]

My friend has one that Flemke had a hand in developing, I think? It has over 500hp.

[PRO 5T]

Slippydiff said:

I know where there's a K400 Mk1 available if you should be interested.

Slippy, if you could send me some info I'd be incredibly interested, plus thank you so much for all the info. If you could forward any PDF info that would be amazing too. Your name came up last week while I was viewing a certain 3.8 engined 997.

[ChrisW.]

TDT said:

TDT said:

Slippydiff will know much more as this was his era.

Slippydiff said:

Knowledge….

Lol… told ya!

PH gold

I do wonder how safe Porsche played it with the 996 Mk1 GT3 ... it was a proof of concept that has become a brand in its own right ... and yes, the MkII was better in so many ways, but only by building on the shoulders of the Mk1 ....

[Slippydiff]

PRO 5T said:

Slippy, if you could send me some info I'd be incredibly interested, plus thank you so much for all the info. If you could forward any PDF info that would be amazing too. Your name came up last week while I was viewing a certain 3.8 engined 997.

Ah yes, a deeply impressive 3.8 that. The work of Silverstone's Mezger whisperer. 478hp on the dyno sheet seems to ring a bell.
No more than a fag paper between that car and my 997 Cup engined Mk1 GT3 built by the same Mezger whisperer. I'd guess the Mk1 996's smaller frontal area would be more efficient on high speed circuits, but there wouldn't be much between them at all.

[993rsr]

You had a beast with my old 996 Henry!

[TDT]

[TDT]

This is Nicolas Abbouds car.. 4.2L


Someone else that a few of us know, (UK based), also recently had his car a 996 GT3 MR come Cup car completed with a 4.0L upgrade.
List of other tweaks is extensive.

Edited by TDT on Saturday 20th January 23:49

[TDT]

Slippydiff said:

Ah yes, a deeply impressive 3.8 that. The work of Silverstone's Mezger whisperer. 478hp on the dyno sheet seems to ring a bell.
No more than a fag paper between that car and my 997 Cup engined Mk1 GT3 built by the same Mezger whisperer. I'd guess the Mk1 996's smaller frontal area would be more efficient on high speed circuits, but there wouldn't be much between them at all.

Ahh.. Zanicup.... where is that car now?

[993rsr]

TDT said:

Slippydiff said:

Ah yes, a deeply impressive 3.8 that. The work of Silverstone's Mezger whisperer. 478hp on the dyno sheet seems to ring a bell.
No more than a fag paper between that car and my 997 Cup engined Mk1 GT3 built by the same Mezger whisperer. I'd guess the Mk1 996's smaller frontal area would be more efficient on high speed circuits, but there wouldn't be much between them at all.

Ahh.. Zanicup.... where is that car now?

With Mr S Rance 🙂

[isaldiri]

TDT said:

......
They also used to offer some capacity kits for N/A Mezgers in the form of 3.9, 4.2 and 4.4L. That all stopped after 997.

I thought it was a 3.9, 4.1 and 4.4 (which iirc was started out as a project for flemke's car as mentioned)? when I was at Mantheys I think in 2014 or 15, they had mentioned that the 4.4 was having some road use resonance issues which never came up on track so it was down sizes to a 4.2 which was going to be the final possible offering.

[TDT]

isaldiri said:

TDT said:

......
They also used to offer some capacity kits for N/A Mezgers in the form of 3.9, 4.2 and 4.4L. That all stopped after 997.

I thought it was a 3.9, 4.1 and 4.4 (which iirc was started out as a project for flemke's car as mentioned)? when I was at Mantheys I think in 2014 or 15, they had mentioned that the 4.4 was having some road use resonance issues which never came up on track so it was down sizes to a 4.2 which was going to be the final possible offering.

I didn’t know about 4.1.

As for 4.4. There are some conversions around. In fact Manthey have been featuring a 997 3RS with 4.4 on their social media channels over the last few weeks.

Edited by TDT on Sunday 21st January 00:26

[Andyoz]

Just a note on the K and M designations as I understand it...

...M designated kits were fitted at Manthey.
...K designated were fitted by their agents.
EDIT: that's BS above !!!

996.1 Manthey ups the redline from 7800 to 8200 (matches the Mk2). As mentioned above, Mk2 Manthey kits miss out on the Cup style intake which does sound tasty and barks...anyone into flat 6 sounds, really should try one out and visit that redline.

Friend just did a teardown on his 130k mile 996.1 GT3 Manthey ready for 3.8 conversion. Bores still showed original honing marks, piston skirts like new, zero cam wear, big end bearings were good, etc, etc..LOTS of hard track work but properly cared for.
There's a reason these engines cost a bomb.

Edited by Andyoz on Monday 22 January 12:55

[Cheburator mk2]

Andyoz said:

Just a note on the K and M designations as I understand it...

...M designated kits were fitted at Manthey.

...K designated were fitted by their agents.

996.1 Manthey ups the redline from 7800 to 8200 (matches the Mk2). As mentioned above, Mk2 Manthey kits miss out on the Cup style intake which does sound tasty and barks...anyone into flat 6 sounds, really should try one out and visit that redline.

Friend just did a teardown on his 130k mile 996.1 GT3 Manthey ready for 3.8 conversion. Bores still showed original honing marks, piston skirts like new, zero cam wear, big end bearings were good, etc, etc..LOTS of hard track work but properly cared for.
There's a reason these engines cost a bomb.

Edited by Andyoz on Sunday 21st January 00:55

Not sure about the designations... I have the first K400 car, call it the prototype if you will - a LHD MY 2000 CS delivered new to Olaf Manthey on the 3 Jan 2000 and in the German Fahrezeugbrief that I still have the engine mods are listed as K400...