what is an 'early' 3.4 996?
Discussion
PRO5T said:
Very interesting, thanks.Am I right in thinking that peak bhp on the 3.9 is 428 PS which is 422 bhp, up from 360 bhp standard?
If so, that's huge!
Would love to know what they do to the engine to get that power and rev to 8,000 rpm - the GT3 has titanium rids etc to allow it to rev higher, doesn't it?
BandOfBrothers said:
Very interesting, thanks.
Am I right in thinking that peak bhp on the 3.9 is 428 PS which is 422 bhp, up from 360 bhp standard?
If so, that's huge!
Would love to know what they do to the engine to get that power and rev to 8,000 rpm - the GT3 has titanium rids etc to allow it to rev higher, doesn't it?
It’s a Mk 2, so has 381 hp standard, not 360.Am I right in thinking that peak bhp on the 3.9 is 428 PS which is 422 bhp, up from 360 bhp standard?
If so, that's huge!
Would love to know what they do to the engine to get that power and rev to 8,000 rpm - the GT3 has titanium rids etc to allow it to rev higher, doesn't it?
Maximum looks to be 456 PS and 341 torques, which ain’t too shabby (but most of those gains will be offset by the barn door manacled to the engine cover …)
Mk1 had Ti rods, Mk 2 didn’t.
Slippydiff said:
BandOfBrothers said:
Very interesting, thanks.
Am I right in thinking that peak bhp on the 3.9 is 428 PS which is 422 bhp, up from 360 bhp standard?
If so, that's huge!
Would love to know what they do to the engine to get that power and rev to 8,000 rpm - the GT3 has titanium rids etc to allow it to rev higher, doesn't it?
It’s a Mk 2, so has 381 hp standard, not 360.Am I right in thinking that peak bhp on the 3.9 is 428 PS which is 422 bhp, up from 360 bhp standard?
If so, that's huge!
Would love to know what they do to the engine to get that power and rev to 8,000 rpm - the GT3 has titanium rids etc to allow it to rev higher, doesn't it?
Maximum looks to be 456 PS and 341 torques, which ain’t too shabby (but most of those gains will be offset by the barn door manacled to the engine cover …)
Mk1 had Ti rods, Mk 2 didn’t.
BandOfBrothers said:
Oh right, so whats the service interval/longevity on the Manthey GT3 3.9 - seems like they've tuned the balls off it?!
I don’t think Manthey raised the rev limit, so you just keep chucking oil and filters at it (regularly) and it’ll run just fine for many, many thousands of miles without any issues whatsoever.Slippydiff said:
BandOfBrothers said:
Oh right, so whats the service interval/longevity on the Manthey GT3 3.9 - seems like they've tuned the balls off it?!
I don’t think Manthey raised the rev limit, so you just keep chucking oil and filters at it (regularly) and it’ll run just fine for many, many thousands of miles without any issues whatsoever.It's an already highly fettled engine that's been pulled apart, bored, stroked and rebuilt.
In my secondhand experience, those types of rebuilt engines take a lot of TLC.
BandOfBrothers said:
Is that last bit sarcasm?!
It's an already highly fettled engine that's been pulled apart, bored, stroked and rebuilt.
In my secondhand experience, those types of rebuilt engines take a lot of TLC.
No, no sarcasm at all.It's an already highly fettled engine that's been pulled apart, bored, stroked and rebuilt.
In my secondhand experience, those types of rebuilt engines take a lot of TLC.
They're bullet proof engines if you maintain them properly, and that maintenance centres on fresh oil (and filters) and lots of both, if tracking the car.
It's not that highly fettled. A near 10% increase in capacity should see a similar horsepower increase alone.
Most 996.2 GT3 engines are actually credited with closer to 390hp, add 10% to that and you're in the 430hp ballpark.
Manthey no doubt fit their M&M exhaust manifolds, hi-flow HJS 200 cell cats and better flowing silencers. Garnish with a live remap and you end up with 456hp. The result of increased capacity and improved breathing courtesy of the better flowing exhaust system, no black magic, no changes to cams etc.
The 3.8 engine (which is intrinsically the same) in the 997.2 produced 450hp, so the Manthey conversion isn't taking the engine outside of its design brief.
Edited by Slippydiff on Sunday 9th June 16:07
Or... you go off piste :
This is a Porsche Motorsport supplied 997.1 GT3 Cup engine (the final 3.6 Evolution) It's basically a 997.1 GT3 3.6 engine with the Variocam system removed, big port heads, a pair of very long duration, very high lift, big overlap exhaust cams along with a 997.2 GT3 RS 4.0 Ltr inlet manifold/plenum and inlet runners ) :
Shoehorned into the back of Mk 1 996 GT3 :
Add in some inconel RSR "esque" exhaust manifolds :
Some suitably large bore tubing and a pair of very light, hi-flow Titanium silencers (and a distinct lack of cats) :
Then tweak with a suitable map and inlet manifold/plenum resonance flap opening and closing strategy, and you end up with 465 very angry, very cammy, somewhat intractable below 4500rpm, but absolutely ballistic from there to the 8,100rpm redline, horsepower (the engine is built to rev to 8,400rpm, but we clipped its wings to ensure its longevity)
More in this thread :
https://www.pistonheads.com/news/ph-spottedykywt/p...
This is a Porsche Motorsport supplied 997.1 GT3 Cup engine (the final 3.6 Evolution) It's basically a 997.1 GT3 3.6 engine with the Variocam system removed, big port heads, a pair of very long duration, very high lift, big overlap exhaust cams along with a 997.2 GT3 RS 4.0 Ltr inlet manifold/plenum and inlet runners ) :
Shoehorned into the back of Mk 1 996 GT3 :
Add in some inconel RSR "esque" exhaust manifolds :
Some suitably large bore tubing and a pair of very light, hi-flow Titanium silencers (and a distinct lack of cats) :
Then tweak with a suitable map and inlet manifold/plenum resonance flap opening and closing strategy, and you end up with 465 very angry, very cammy, somewhat intractable below 4500rpm, but absolutely ballistic from there to the 8,100rpm redline, horsepower (the engine is built to rev to 8,400rpm, but we clipped its wings to ensure its longevity)
More in this thread :
https://www.pistonheads.com/news/ph-spottedykywt/p...
Edited by Slippydiff on Sunday 9th June 16:11
Slippydiff said:
BandOfBrothers said:
Is that last bit sarcasm?!
It's an already highly fettled engine that's been pulled apart, bored, stroked and rebuilt.
In my secondhand experience, those types of rebuilt engines take a lot of TLC.
No, no sarcasm at all.It's an already highly fettled engine that's been pulled apart, bored, stroked and rebuilt.
In my secondhand experience, those types of rebuilt engines take a lot of TLC.
They're bullet proof engines if you maintain them properly, and that maintenance centres on fresh oil (and filters) and lots of both, if tracking the car.
It's not that highly fettled. A near 10% increase in capacity should see a similar horsepower increase alone.
Most 996.2 GT3 engines are actually credited with closer to 390hp, add 10% to that and you're in the 430hp ballpark.
Manthey no doubt fit their M&M exhaust manifolds, hi-flow HJS 200 cell cats and better flowing silencers. Garnish with a live remap and you end up with 456hp. The result of increased capacity and improved breathing courtesy of the better flowing exhaust system, no black magic, no changes to cams etc.
The 3.8 engine (which is intrinsically the same) in the 997.2 produced 450hp, so the Manthey conversion isn't taking the engine outside of its design brief.
Edited by Slippydiff on Sunday 9th June 16:07
My understanding is that this is mainly because the aftermarket parts have never been through the R&D, testing, manufacturing and assembly processes that the oem parts have and on top of that are being pushed harderthan the oem parts, which leads to all sorts of issues.
I've been into modifying cars for 20 years (latest is a 600 bhp 996T) and have spoken to several people who have either stroked, bored or both their engines and wished they'd never opened up the engine.
Presumably both the rods and pistons on the GT3 3.9 engine have been swapped?
BandOfBrothers said:
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Lieutenant George : How, how do you mean, Sir? Do you mean, do you mean take her home at weekends to meet your mother ?
Lord Flasheart : No, I mean get inside her five times a day and take her to heaven and back.
Captain Blackadder : I'm beginning to see why the suffragette movement want the vote.
Lord Flasheart : Hey! Any girl who wants to chain herself to *my* railings and suffer a jet movement gets *my* vote!
BandOfBrothers said:
From what I've read of others' experiences, it's not so much the power or capacity increase that borks an engine's reliability, but opening up and replacing the internals, specifically bearings, rods, pistons and piston rings.
My understanding is that this is mainly because the aftermarket parts have never been through the R&D, testing, manufacturing and assembly processes that the oem parts have and on top of that are being pushed harderthan the oem parts, which leads to all sorts of issues.
I've been into modifying cars for 20 years (latest is a 600 bhp 996T) and have spoken to several people who have either stroked, bored or both their engines and wished they'd never opened up the engine.
Presumably both the rods and pistons on the GT3 3.9 engine have been swapped?
Pistons and liners IIRC, ‘cos it’s only bored to get to the 3.9 capacity.My understanding is that this is mainly because the aftermarket parts have never been through the R&D, testing, manufacturing and assembly processes that the oem parts have and on top of that are being pushed harderthan the oem parts, which leads to all sorts of issues.
I've been into modifying cars for 20 years (latest is a 600 bhp 996T) and have spoken to several people who have either stroked, bored or both their engines and wished they'd never opened up the engine.
Presumably both the rods and pistons on the GT3 3.9 engine have been swapped?
Early iterations of the Perfect Bore (subsequently bought by Capricorn) pistons and liners were “sub-optimal” for road use, but as they evolved they improved hugely.
Then Porsche released the 4.0 997 GT3 RS, and everyone started using the crank from the 4.0 race cars along with the Mahle 3.8 pistons and liners, and that became the way to build a big capacity Mezger.
BandOfBrothers said:
From what I've read of others' experiences, it's not so much the power or capacity increase that borks an engine's reliability, but opening up and replacing the internals, specifically bearings, rods, pistons and piston rings.
My understanding is that this is mainly because the aftermarket parts have never been through the R&D, testing, manufacturing and assembly processes that the oem parts have and on top of that are being pushed harderthan the oem parts, which leads to all sorts of issues.
I've been into modifying cars for 20 years (latest is a 600 bhp 996T) and have spoken to several people who have either stroked, bored or both their engines and wished they'd never opened up the engine.
Presumably both the rods and pistons on the GT3 3.9 engine have been swapped?
It’s very dependent on who builds the engine …My understanding is that this is mainly because the aftermarket parts have never been through the R&D, testing, manufacturing and assembly processes that the oem parts have and on top of that are being pushed harderthan the oem parts, which leads to all sorts of issues.
I've been into modifying cars for 20 years (latest is a 600 bhp 996T) and have spoken to several people who have either stroked, bored or both their engines and wished they'd never opened up the engine.
Presumably both the rods and pistons on the GT3 3.9 engine have been swapped?
There aren’t many I’d trust, but there are a few good Mezger builders out there
Slippydiff said:
Pistons and liners IIRC, ‘cos it’s only bored to get to the 3.9 capacity.
Early iterations of the Perfect Bore (subsequently bought by Capricorn) pistons and liners were “sub-optimal” for road use, but as they evolved they improved hugely.
Then Porsche released the 4.0 997 GT3 RS, and everyone started using the crank from the 4.0 race cars along with the Mahle 3.8 pistons and liners, and that became the way to build a big capacity Mezger.
Very interesting, so do OEM porsche pistons have removable gudgeon pins?Early iterations of the Perfect Bore (subsequently bought by Capricorn) pistons and liners were “sub-optimal” for road use, but as they evolved they improved hugely.
Then Porsche released the 4.0 997 GT3 RS, and everyone started using the crank from the 4.0 race cars along with the Mahle 3.8 pistons and liners, and that became the way to build a big capacity Mezger.
I seem to recall a lot of the issues around retaining standard rods and replacing pistons (or vice versa) was oem pistons often use friction fit gudgeon pins that one use only/ weren't really workable with aftermarket pistons?
Interesting chat and good questions from band of brothers…
With mine, I guess it’s worth pointing out exactly who did the engine rebuild-Manthey Racing really know and knew back then what they were doing so it’s worth putting a bit of trust in them. The first Grellow was a 2004 GT3 and by the time mine was converted in 2010 they were well on their way in building special GT3s.
But then as Slippy says, it sounds an obscene amount of power and torque but up from standard it isn’t that crazy.
Compared to what the engines are tuned to in the cup cars it’s no great shakes, it’s designed to do what it’s doing just keep looking after it and it’ll look after you.
The Castrol Manthey recommend is less than £120 off Amazon and a filter is £15. It takes nowt to drop the oil.
Then you consider the way you drive the engine compared to standard with all the extra torque-you really only rev it out when a gear change gets in the way. The torque is almost like a turbo engine, just one that also revs to 8k if you want it.
I usually find myself pulling another gear at 7.5k on tack and in all honesty never seeing 7k on the road.
It might have a barn door strapped to it but it’s jettisoned it’s carpets and frunk etc amongst other light weight options, it really pulls!
With mine, I guess it’s worth pointing out exactly who did the engine rebuild-Manthey Racing really know and knew back then what they were doing so it’s worth putting a bit of trust in them. The first Grellow was a 2004 GT3 and by the time mine was converted in 2010 they were well on their way in building special GT3s.
But then as Slippy says, it sounds an obscene amount of power and torque but up from standard it isn’t that crazy.
Compared to what the engines are tuned to in the cup cars it’s no great shakes, it’s designed to do what it’s doing just keep looking after it and it’ll look after you.
The Castrol Manthey recommend is less than £120 off Amazon and a filter is £15. It takes nowt to drop the oil.
Then you consider the way you drive the engine compared to standard with all the extra torque-you really only rev it out when a gear change gets in the way. The torque is almost like a turbo engine, just one that also revs to 8k if you want it.
I usually find myself pulling another gear at 7.5k on tack and in all honesty never seeing 7k on the road.
It might have a barn door strapped to it but it’s jettisoned it’s carpets and frunk etc amongst other light weight options, it really pulls!
PRO5T said:
Interesting chat and good questions from band of brothers…
With mine, I guess it’s worth pointing out exactly who did the engine rebuild-Manthey Racing really know and knew back then what they were doing so it’s worth putting a bit of trust in them. The first Grellow was a 2004 GT3 and by the time mine was converted in 2010 they were well on their way in building special GT3s.
But then as Slippy says, it sounds an obscene amount of power and torque but up from standard it isn’t that crazy.
Compared to what the engines are tuned to in the cup cars it’s no great shakes, it’s designed to do what it’s doing just keep looking after it and it’ll look after you.
The Castrol Manthey recommend is less than £120 off Amazon and a filter is £15. It takes nowt to drop the oil.
Then you consider the way you drive the engine compared to standard with all the extra torque-you really only rev it out when a gear change gets in the way. The torque is almost like a turbo engine, just one that also revs to 8k if you want it.
I usually find myself pulling another gear at 7.5k on tack and in all honesty never seeing 7k on the road.
It might have a barn door strapped to it but it’s jettisoned it’s carpets and frunk etc amongst other light weight options, it really pulls!
Great to hear first hand experiences of these unique cars from their owners. With mine, I guess it’s worth pointing out exactly who did the engine rebuild-Manthey Racing really know and knew back then what they were doing so it’s worth putting a bit of trust in them. The first Grellow was a 2004 GT3 and by the time mine was converted in 2010 they were well on their way in building special GT3s.
But then as Slippy says, it sounds an obscene amount of power and torque but up from standard it isn’t that crazy.
Compared to what the engines are tuned to in the cup cars it’s no great shakes, it’s designed to do what it’s doing just keep looking after it and it’ll look after you.
The Castrol Manthey recommend is less than £120 off Amazon and a filter is £15. It takes nowt to drop the oil.
Then you consider the way you drive the engine compared to standard with all the extra torque-you really only rev it out when a gear change gets in the way. The torque is almost like a turbo engine, just one that also revs to 8k if you want it.
I usually find myself pulling another gear at 7.5k on tack and in all honesty never seeing 7k on the road.
It might have a barn door strapped to it but it’s jettisoned it’s carpets and frunk etc amongst other light weight options, it really pulls!
Would love to see some pictures if you have time?
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