300bhp, 350lbs feet torque 944 3 litre turbo
Discussion
For continuity I wanted to add information to previous postings on this subject - but the search facility is currently down - so I cannot link them up - but I just wanted to draw the attention of those interested to the fact that we have finally finished the car and had it dyno and road tested with remarkable results (graphs of output included).
Without being able to add this to the previous postings - I don't see a lot of benefit in expanding the details too far today - except to say that they are all posted on the 968.uk.com web site (including bhp and torque graphs etc) for those who may have been following the story and are interested.
Baz
Without being able to add this to the previous postings - I don't see a lot of benefit in expanding the details too far today - except to say that they are all posted on the 968.uk.com web site (including bhp and torque graphs etc) for those who may have been following the story and are interested.
Baz
& 
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Nice work Baz, I have always loved the 944! We had an S2 from new when I was a kid and i have fond memories of that car.
I know it is not the Porsche forum staple, but does anyone read Precatical Performance Car (PPC) magazine?
There is a (more than) 700bhp 944 in there this month running an Audi 5-cyl, 20v turbo engine.
That must be some weapon weighing around the tonne!
I know it is not the Porsche forum staple, but does anyone read Precatical Performance Car (PPC) magazine?
There is a (more than) 700bhp 944 in there this month running an Audi 5-cyl, 20v turbo engine.
That must be some weapon weighing around the tonne!
It is not only quick but flexible and manageable - a very nice road car to drive.
On the 968.uk register - over the years - there have been many lengthy arguments about the merits of power and torque (and probably some on here) and - which is more important. Much of this has continued on that web site but I didn't realise that it was not easy to access that site if you have not joined.
Basically - to put it very very simply - it is the torque at the rear wheel that accelerates a car. Torque mutiplied by revs creates the bhp reading. If you have a lot of torque at low revs - from the engine - this will result in a lot of torque at low revs in any gear. If you can change the ratios and the diff ratio then you can alter the torque at the rear wheel - so a high revving engine with lower torque - when the torque is aplied through a greater speed reduction may have higher rear wheel torque - but if you cannot change those ratios - then just revving an engine higher to create more bhp may not make it faster since the gear ratios are the same and the relative torque at any revs must be higher to increase acceleration - and you usually reduce the power band as well.
The higher it revs the less time there is for the intake to receive the quantity of air that results in the compression pressures needed to create torque - so although it is easy to raise revs and bhp - this may lower torque.
With a fixed 5 speed gearbox (in the 944 turbo) with high final drive ratio - increasing the torque in mid range - in my view - should create a quicker car and as tuning a 2.5 with more boost usually results in a harsh power curve and difficulty controlling rear wheel spin - I thought that this creation might result in a nice quick car to drive that is also very manageable - and that seems to be the case.
Baz
On the 968.uk register - over the years - there have been many lengthy arguments about the merits of power and torque (and probably some on here) and - which is more important. Much of this has continued on that web site but I didn't realise that it was not easy to access that site if you have not joined.
Basically - to put it very very simply - it is the torque at the rear wheel that accelerates a car. Torque mutiplied by revs creates the bhp reading. If you have a lot of torque at low revs - from the engine - this will result in a lot of torque at low revs in any gear. If you can change the ratios and the diff ratio then you can alter the torque at the rear wheel - so a high revving engine with lower torque - when the torque is aplied through a greater speed reduction may have higher rear wheel torque - but if you cannot change those ratios - then just revving an engine higher to create more bhp may not make it faster since the gear ratios are the same and the relative torque at any revs must be higher to increase acceleration - and you usually reduce the power band as well.
The higher it revs the less time there is for the intake to receive the quantity of air that results in the compression pressures needed to create torque - so although it is easy to raise revs and bhp - this may lower torque.
With a fixed 5 speed gearbox (in the 944 turbo) with high final drive ratio - increasing the torque in mid range - in my view - should create a quicker car and as tuning a 2.5 with more boost usually results in a harsh power curve and difficulty controlling rear wheel spin - I thought that this creation might result in a nice quick car to drive that is also very manageable - and that seems to be the case.
Baz
How much would this conversion cost on a 944 S2 engine? Assuming that you use that engine? Or do you use the 3.0 block with the 2.5 head?
Is it a case of drive your 944 Turbo/S2 into your garage and come out X weeks later all ready for road use?
Something you can buy and fit yourself?
Thanks,
Is it a case of drive your 944 Turbo/S2 into your garage and come out X weeks later all ready for road use?
Something you can buy and fit yourself?
Thanks,
The biggest problem would be the pistons because the S2 piston does not in my opinion have enough taper for the performance planned. The 968 piston is more suitable.
The 2.7 cylinder head fits on the 3 litre block and has larger inlet ports, the 2.5 head does not fit and the inlet valves are smaller but should still work well. The 2.5 head can be welded and modified to fit. The 2.7 engine has the right bores and head and the pistons may be suitable but I doubt have enough taper either - but I have not checked out the piston ovality and taper on these.
The 968 block also has spray jets to spray oil under the piston and onto the bore for cooling and lubrication (but they could be fitted to a 2.5 or 2.7 block).
Whichever pistons are used they would have to be machined to lower the compression ratio for use with a turbo (but not if a naturally aspirated 3 litre engine was planned).
I do not have any 2.7 heads available.
We are considering manufacturing replacement liners to enable any 2.5 to 3 litre block to be repaired and if so any block could be fitted with 4 liners to suit 104mm pistons for changing a 2.5 to a 2.7 (with a 2.5 crank or 3 litre with the S2 or 968 crank). You also need bigger injectors and a re-mapped ECU.
Without that you must use a 2.7, 3.0 S2 or 3.0 968 block with 2.7 or modified 2.5 head, a 3 litre crank, probably altered 968 pistons, shorter head studds and the whole 944 turbo auxiliaries.
If youa re not using a 3 litre block (but sleeving a 2.5 with liners) it may be neccesary to machine some slots in the block to keep the oil level down with the bigger crank throw.
It begins to sound quite complicated - but was actually quite simple - but then we had all the various bits in stock and we have a machine shop to modify things in.
I think the best route might be a 968 car and an old crashed 944 turbo as a donor for various parts or a 944 turbo and buy in (or modify to) a 3 litre block and 2.7 head if using a 3 litre or 2.7 block.
Baz
The 2.7 cylinder head fits on the 3 litre block and has larger inlet ports, the 2.5 head does not fit and the inlet valves are smaller but should still work well. The 2.5 head can be welded and modified to fit. The 2.7 engine has the right bores and head and the pistons may be suitable but I doubt have enough taper either - but I have not checked out the piston ovality and taper on these.
The 968 block also has spray jets to spray oil under the piston and onto the bore for cooling and lubrication (but they could be fitted to a 2.5 or 2.7 block).
Whichever pistons are used they would have to be machined to lower the compression ratio for use with a turbo (but not if a naturally aspirated 3 litre engine was planned).
I do not have any 2.7 heads available.
We are considering manufacturing replacement liners to enable any 2.5 to 3 litre block to be repaired and if so any block could be fitted with 4 liners to suit 104mm pistons for changing a 2.5 to a 2.7 (with a 2.5 crank or 3 litre with the S2 or 968 crank). You also need bigger injectors and a re-mapped ECU.
Without that you must use a 2.7, 3.0 S2 or 3.0 968 block with 2.7 or modified 2.5 head, a 3 litre crank, probably altered 968 pistons, shorter head studds and the whole 944 turbo auxiliaries.
If youa re not using a 3 litre block (but sleeving a 2.5 with liners) it may be neccesary to machine some slots in the block to keep the oil level down with the bigger crank throw.
It begins to sound quite complicated - but was actually quite simple - but then we had all the various bits in stock and we have a machine shop to modify things in.
I think the best route might be a 968 car and an old crashed 944 turbo as a donor for various parts or a 944 turbo and buy in (or modify to) a 3 litre block and 2.7 head if using a 3 litre or 2.7 block.
Baz
I guess Billy that it is not too bad if you already have one car or the other or can wait while you source the parts from various breakers.
The performance is superb (into 996 territory) and all I wanted to convey was that you can get that relatively easily and relativley inexpensively without a huge number of special parts being manufactured, or great technical difficulties and without the frustration often associated with the technical problems getting many other project engines running and performing acceptably.
I have grafted in Stuart Cooksons reaction to driving the car last week - posted to another web site.
"Today I needed to run some errands so a perfect excuse to use the 968 and one of those errands had me in north Manchester, so I thought I'd pop over to see Barry's 944 Turbo project. I've been to Hartech before but while I was there Barry gave me a guided tour round the new features of the premises, parts and spares all indexed and itemised in racking and the new engine building department which is being made bigger due to the amount of work they are dealing with on Boxster and 911 engines(and some of the problems are factory generated).
While we were chatting about the development of the Turbo Barry suggested we go for a drive, Barry drove the 944 out and down the straight from the industrial estate.
Barry used the accelerator to good effect between the speed bumps.
Initial response from me was 'bloody hell'(or words to that effect) this is quick, I mean very quick.
We got onto the main road, keeping in mind we were on public roads so some amount of caution was necessary but again Barry used the accelerator to good effect.
We got to a layby and Barry turned the car round to let me drive it back.
I waited for the traffic to clear on the road ahead and then gave it some beans. I would say that the car behaves quite normally below 2000rpm and then you get a steadily increasing surge up to 3000rpm and that's when you really notice a huge amount of torque and the acceleration far far exceeds that of a 968.
We were running out of clear road very quickly and weren't really able to explore the full potential of speed but the massive amount of torque through the midrange gave an idea of what the car was capable of so I really wanted to see how the car would do in higher gears but still low revs so we continued with the 'seat of the pants' road test accelerating from around 2500rpm in 3rd and then in 4th. Again the amount of torque is outstanding from 3000rpm. The problem is that in the higher gears we were doing silly speeds so curtailed the test.
I had said to Barry that I reckoned there was a huge amount of torque available over and above the 968 and that we had at least 50% of that available torque at 3000rpm so when we got back to his office we checked and sure enough the Dyno figures confirmed it. Max torque on a 968 is 225lbs ft, and on this turbo it's closer to 350max, with about 210lbs ft available at 3000rpm as opposed to around 180 for the 968.
Over the next 1000rpm up to 4000rpm is the big difference, the 968 gains another 45 up to 225 whereas the Turbo gains around 130 to get close to 350.
So the car is able to be driven around town very smoothly at pretty low revs but with lots of reserve. The car is very sedate, no that's the wrong word, it isn't sedate but it is under control and feels pretty normal to drive until you start accelerating hard.
Barry wanted an honest opinion on the car and what it feels like to drive, I think I hit the nail on the head when I said that you wouldn't know it wasn't a production car(apart from the extra torque and power) and I think Barry appreciated the comment. I said this because the engine bay looks just like any other 944 Turbo and because it drives like a normal car, no dramas, no running problems etc. After all, if you can put together something that works very well in normal driving conditions and there doesn't appear to be any problems with it's running, yet has the potential to obliterate almost anything else on the road, and do it with standard parts, that has to be an achievement. As Barry has already mentioned he is going to do something about the suspension because the car does pitch down at the rear quite a bit under heavy acceleration. He also wants to get it onto a track and explore it's performance a bit more, there really is no way you can do it on a public road without endangering your licence. It will be interesting to be in it at high revs in high gears although from the figures around 6000rpm the torque and the bhp is on a par again with a 968, but in a straight line drag race Barry's Turbo would already be way ahead. The overtaking potential in this car is phenomenal.
We discussed the timing of the completion of the project and it is apparent that had Barry completed this project years earlier he would have had a whole lot of people qeueing at the door for the conversion, as it is people inevitably move onto newer models and the big market for it may have diminished significantly.
Well done Barry and thanks for the drive.
Stuart.
Our track test day is now booked but we don't expect it all to go smoothly as the car is bog standard apart from the engine and stronger lsd - and not at all prepared for track testing.
Baz
The performance is superb (into 996 territory) and all I wanted to convey was that you can get that relatively easily and relativley inexpensively without a huge number of special parts being manufactured, or great technical difficulties and without the frustration often associated with the technical problems getting many other project engines running and performing acceptably.
I have grafted in Stuart Cooksons reaction to driving the car last week - posted to another web site.
"Today I needed to run some errands so a perfect excuse to use the 968 and one of those errands had me in north Manchester, so I thought I'd pop over to see Barry's 944 Turbo project. I've been to Hartech before but while I was there Barry gave me a guided tour round the new features of the premises, parts and spares all indexed and itemised in racking and the new engine building department which is being made bigger due to the amount of work they are dealing with on Boxster and 911 engines(and some of the problems are factory generated).
While we were chatting about the development of the Turbo Barry suggested we go for a drive, Barry drove the 944 out and down the straight from the industrial estate.
Barry used the accelerator to good effect between the speed bumps.
Initial response from me was 'bloody hell'(or words to that effect) this is quick, I mean very quick.
We got onto the main road, keeping in mind we were on public roads so some amount of caution was necessary but again Barry used the accelerator to good effect.
We got to a layby and Barry turned the car round to let me drive it back.
I waited for the traffic to clear on the road ahead and then gave it some beans. I would say that the car behaves quite normally below 2000rpm and then you get a steadily increasing surge up to 3000rpm and that's when you really notice a huge amount of torque and the acceleration far far exceeds that of a 968.
We were running out of clear road very quickly and weren't really able to explore the full potential of speed but the massive amount of torque through the midrange gave an idea of what the car was capable of so I really wanted to see how the car would do in higher gears but still low revs so we continued with the 'seat of the pants' road test accelerating from around 2500rpm in 3rd and then in 4th. Again the amount of torque is outstanding from 3000rpm. The problem is that in the higher gears we were doing silly speeds so curtailed the test.
I had said to Barry that I reckoned there was a huge amount of torque available over and above the 968 and that we had at least 50% of that available torque at 3000rpm so when we got back to his office we checked and sure enough the Dyno figures confirmed it. Max torque on a 968 is 225lbs ft, and on this turbo it's closer to 350max, with about 210lbs ft available at 3000rpm as opposed to around 180 for the 968.
Over the next 1000rpm up to 4000rpm is the big difference, the 968 gains another 45 up to 225 whereas the Turbo gains around 130 to get close to 350.
So the car is able to be driven around town very smoothly at pretty low revs but with lots of reserve. The car is very sedate, no that's the wrong word, it isn't sedate but it is under control and feels pretty normal to drive until you start accelerating hard.
Barry wanted an honest opinion on the car and what it feels like to drive, I think I hit the nail on the head when I said that you wouldn't know it wasn't a production car(apart from the extra torque and power) and I think Barry appreciated the comment. I said this because the engine bay looks just like any other 944 Turbo and because it drives like a normal car, no dramas, no running problems etc. After all, if you can put together something that works very well in normal driving conditions and there doesn't appear to be any problems with it's running, yet has the potential to obliterate almost anything else on the road, and do it with standard parts, that has to be an achievement. As Barry has already mentioned he is going to do something about the suspension because the car does pitch down at the rear quite a bit under heavy acceleration. He also wants to get it onto a track and explore it's performance a bit more, there really is no way you can do it on a public road without endangering your licence. It will be interesting to be in it at high revs in high gears although from the figures around 6000rpm the torque and the bhp is on a par again with a 968, but in a straight line drag race Barry's Turbo would already be way ahead. The overtaking potential in this car is phenomenal.
We discussed the timing of the completion of the project and it is apparent that had Barry completed this project years earlier he would have had a whole lot of people qeueing at the door for the conversion, as it is people inevitably move onto newer models and the big market for it may have diminished significantly.
Well done Barry and thanks for the drive.
Stuart.
Our track test day is now booked but we don't expect it all to go smoothly as the car is bog standard apart from the engine and stronger lsd - and not at all prepared for track testing.
Baz
I don't have a set of printed results for a chipped twin port waste gate 944 2.5 turbo but if you E-mail me yours I can graft them on to the previous graphs for comparison.
However none of the similar cars I have driven have had anything like the bottom end torque or indeed bhp and were relatively difficult to drive quickly because the turbo response had built in lag both spooling up and after backing off - which this engine does not have - being more like a naturally aspirated very big engine.
Baz
However none of the similar cars I have driven have had anything like the bottom end torque or indeed bhp and were relatively difficult to drive quickly because the turbo response had built in lag both spooling up and after backing off - which this engine does not have - being more like a naturally aspirated very big engine.
Baz
Wow really pleased you got her finished and working ok. Can't beleive I didn't even know you were on here.
You supplied the 2.7 head for my 3.2 turbo (built by Jon M) and showed me around the factory when I brought it up to show you after it was finished. Unfortunately it was raining heavily that day so you/we weren't able to go for a drive (or there wouldn't have been any point as even a standard 44T doesn't keep traction in the wet)
What turbo does your 3.0 run? Is it all standard except the capacity change? With the cars ageing now, still holding a strong following and given the cost of a new short engine from Porsche for a 944 (£10,000 I believe)..Have you considered offering a sleeved solution to the 944 block similar to the 911 process you showed me? Could a 3.0 capacity be achieved in a 2.5 block with a 2.5 head and 3.0 crank or would the head not be suitable for the larger bores?
I think with larger capacity 944 turbo's we (as a comunity) really have stumbled onto something quite amazing. The combination works so well that you end up with a reliable, potentially very serious road and track car; For far less outlay than anything else that could hope to come close to that level of performance. The low down torque really helps prevent the traction problem suffered with other modified 2.5ltr 944s.
Regards,
Ben
You supplied the 2.7 head for my 3.2 turbo (built by Jon M) and showed me around the factory when I brought it up to show you after it was finished. Unfortunately it was raining heavily that day so you/we weren't able to go for a drive (or there wouldn't have been any point as even a standard 44T doesn't keep traction in the wet)
What turbo does your 3.0 run? Is it all standard except the capacity change? With the cars ageing now, still holding a strong following and given the cost of a new short engine from Porsche for a 944 (£10,000 I believe)..Have you considered offering a sleeved solution to the 944 block similar to the 911 process you showed me? Could a 3.0 capacity be achieved in a 2.5 block with a 2.5 head and 3.0 crank or would the head not be suitable for the larger bores?
I think with larger capacity 944 turbo's we (as a comunity) really have stumbled onto something quite amazing. The combination works so well that you end up with a reliable, potentially very serious road and track car; For far less outlay than anything else that could hope to come close to that level of performance. The low down torque really helps prevent the traction problem suffered with other modified 2.5ltr 944s.
Regards,
Ben
Edited by Niffty951 on Friday 6th November 09:51
Hi Ben - yes everything else is standard and in my opinion it really has produced a quite remarkable car for comparatively little money and nice to drive as well (as you will already know from yours).
If you refer to my answers up the page you will see that we probably will make a liner to suit all models - as the pattern is not so expensive and it would solve a problem long term for those seeking to repair and existing engine or modify one.
I don't see why the standard 2.5 head would not work if we sleeved a 2.5 block and there are plenty of 944 turbos still around at reasonable costs.
I also think for those more adventurous - a 968 with perhaps a damaged engine - turned into the equivalent of a turbo S - would have some high value when finished - although I guess it may be better not to graft a 944 turbo set of auxiliaries on to it but to fit a larger turbo and intercooler and a more modern engine management system from the outset?
Baz
If you refer to my answers up the page you will see that we probably will make a liner to suit all models - as the pattern is not so expensive and it would solve a problem long term for those seeking to repair and existing engine or modify one.
I don't see why the standard 2.5 head would not work if we sleeved a 2.5 block and there are plenty of 944 turbos still around at reasonable costs.
I also think for those more adventurous - a 968 with perhaps a damaged engine - turned into the equivalent of a turbo S - would have some high value when finished - although I guess it may be better not to graft a 944 turbo set of auxiliaries on to it but to fit a larger turbo and intercooler and a more modern engine management system from the outset?
Baz
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