GT3 Engine - questions!
Discussion
Hi Guys,
In the wake of the fantastic GT3 vs. CSL thread (thanks everyone!)...I've got a couple more questions before I take the plunge and shell out 50k for a Mk1 (craving your indulgence here!)
1. I've read that the GT3 engine is quoted as a non-turbo version of the GT1 motor...what are the major differences between this and a stock 996 motor?
2. 996 engines seem to be very prone to oil leaks (to the point where a (major) main dealer salesman quoted with a smile 'oil leaks are almost obligatory')...is the GT3 motor less prone (and thus more reliable?) Any owners willing to share their experiences out there?
3. How much difference does a lightweight flywheel (as fitted to GT3 RS, CS cars etc.) make in driveability terms? Worth going for?
Thanks in advance...
A
In the wake of the fantastic GT3 vs. CSL thread (thanks everyone!)...I've got a couple more questions before I take the plunge and shell out 50k for a Mk1 (craving your indulgence here!)
1. I've read that the GT3 engine is quoted as a non-turbo version of the GT1 motor...what are the major differences between this and a stock 996 motor?
2. 996 engines seem to be very prone to oil leaks (to the point where a (major) main dealer salesman quoted with a smile 'oil leaks are almost obligatory')...is the GT3 motor less prone (and thus more reliable?) Any owners willing to share their experiences out there?
3. How much difference does a lightweight flywheel (as fitted to GT3 RS, CS cars etc.) make in driveability terms? Worth going for?
Thanks in advance...
A
shotokan said:
Hi Guys,
1. I've read that the GT3 engine is quoted as a non-turbo version of the GT1 motor...what are the major differences between this and a stock 996 motor?
2. 996 engines seem to be very prone to oil leaks (to the point where a (major) main dealer salesman quoted with a smile 'oil leaks are almost obligatory')...is the GT3 motor less prone (and thus more reliable?) Any owners willing to share their experiences out there?
3. How much difference does a lightweight flywheel (as fitted to GT3 RS, CS cars etc.) make in driveability terms? Worth going for?
You might want to read this as it answers some of your engine questions....
www.titanic.co.uk/GT3/GT32e.htm
but basically...
1. The Mk1 GT3 engine is a detuned and de-turbo'd version of the GT1 engine and prepared for mass-production (although still hand-built!). It is based on the 964 engine block, which carried through the 993 series and got a water-cooled head for the GT series. It's got a reputation of being pretty much indestructible. It has light-weight titanium con-rods and lots of bits are plasma-nitride hardened. Its limited at around 7,800 rpm but could quite easily have been 9,000rpm - this makes it ultra-reliable. I've heard of one which was "buzzed" to 13,000rpm then stripped down and no damage was found. The engine also has full dry-sump lubrication compared to the semi-dry in the 996 engine - which is very good news if you intend to do trackdays.
The stock 996 engine is of the M96 engine design (as with boxster, new boxster, 997) and is a unit built and designed with mass production in mind (read cost!). Not to say the 996 engine is fundamentally bad - it is better than 99.9% of engine designs out there - it is still a porsche engine after all. To give you an idea of the difference, a 996 engine will cost about £10K to replace, a GT3 engine will cost £28K.
2. The GT3 engine being a totally different design is not prone to any oil leaks, in fact there are precisely zero common defects in the engines.
3. The lightweight flywheel does make a difference - the car revs much more freely, the noise is a bit different and some people have likened it to having an extra 10 to 20bhp...however it is more expensive to replace and more difficult to drive - it stalls VERY easily at low speed and the revs drop very quickly between changes, so you need to get practising your rev-matching between changes. Definitely worth going for if you intend to do any trackdays.
rubystone said:
Re Q2: GT2,3 & Turbo's have dry sump engines and as mentioned above are different to "regular" Boxster & 996 Carrera engines so no RMS issues.
Out of idle curiosity, did Porsche then move to a wet sump design with the 986 and 996 cars
Not completely - it's what they call "semi-dry". They say it is fine for normal trackday use, but you should not use slicks as the extreme g-forces produced could damage the engine. However I do know of a couple of people who have run boxsters/996s with slicks with no problem.
GreigM said:
Hi Guys,
1. I've read that the GT3 engine is quoted as a non-turbo version of the GT1 motor...what are the major differences between this and a stock 996 motor?
2. 996 engines seem to be very prone to oil leaks (to the point where a (major) main dealer salesman quoted with a smile 'oil leaks are almost obligatory')...is the GT3 motor less prone (and thus more reliable?) Any owners willing to share their experiences out there?
3. How much difference does a lightweight flywheel (as fitted to GT3 RS, CS cars etc.) make in driveability terms? Worth going for?
You might want to read this as it answers some of your engine questions....
www.titanic.co.uk/GT3/GT32e.htm
but basically...
1. The Mk1 GT3 engine is a detuned and de-turbo'd version of the GT1 engine and prepared for mass-production (although still hand-built!). It is based on the 964 engine block, which carried through the 993 series and got a water-cooled head for the GT series. It's got a reputation of being pretty much indestructible. It has light-weight titanium con-rods and lots of bits are plasma-nitride hardened. Its limited at around 7,800 rpm but could quite easily have been 9,000rpm - this makes it ultra-reliable. I've heard of one which was "buzzed" to 13,000rpm then stripped down and no damage was found. The engine also has full dry-sump lubrication compared to the semi-dry in the 996 engine - which is very good news if you intend to do trackdays.
The stock 996 engine is of the M96 engine design (as with boxster, new boxster, 997) and is a unit built and designed with mass production in mind (read cost!). Not to say the 996 engine is fundamentally bad - it is better than 99.9% of engine designs out there - it is still a porsche engine after all. To give you an idea of the difference, a 996 engine will cost about £10K to replace, a GT3 engine will cost £28K.
2. The GT3 engine being a totally different design is not prone to any oil leaks, in fact there are precisely zero common defects in the engines.
3. The lightweight flywheel does make a difference - the car revs much more freely, the noise is a bit different and some people have likened it to having an extra 10 to 20bhp...however it is more expensive to replace and more difficult to drive - it stalls VERY easily at low speed and the revs drop very quickly between changes, so you need to get practising your rev-matching between changes. Definitely worth going for if you intend to do any trackdays.
Great answer Gregg. Just to add that I know of two GT3 engines that were stripped down last year, one was from a leading German Supercup car that had a full season on it and the other was a road GT3 with 40,000 miles on it, much of which were track day miles. Both engines dyno'd power over quoted output levels and neither had any discernable bearing wear at all. In fact the road engine was so good it was re assembled with the original bearings! Amazing...
Steve R
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