930/965 Upgrades
Discussion
Probably needs its own thread....
Also, I am thinking of importing some K27 HighFlow turbo's. These seem to be the turbo of choice in the USA at the moment. They are basically a new K27 with the internals thrown away. The cold side is CNC'd and 'new technology' internals added. The bottom line is, it spools about 300 rpm slower than a K27 quick spool, and flows similar to a K29. Approx. £1000 after importing.
If you're interested let me know....
Also, I am thinking of importing some K27 HighFlow turbo's. These seem to be the turbo of choice in the USA at the moment. They are basically a new K27 with the internals thrown away. The cold side is CNC'd and 'new technology' internals added. The bottom line is, it spools about 300 rpm slower than a K27 quick spool, and flows similar to a K29. Approx. £1000 after importing.
If you're interested let me know....
The current list price of the K27/11 from KKK is £1935+VAT, so it would seem that these are a reasonable deal. However.....
9m are now packaging a new bolt-on ballrace turbo with an independent cooling system for the 930/965 that will spool up at 1500rpm and will flow enough air for engines from 400 to 1000bhp depending on the build.
9m are now packaging a new bolt-on ballrace turbo with an independent cooling system for the 930/965 that will spool up at 1500rpm and will flow enough air for engines from 400 to 1000bhp depending on the build.
I was desperately trying to ignore this thread 'cos things could get expensive fast and the girlfriend wants a new bathroom. However, I can't resist finding out more.
On a 930, what other mods would you want to couple with either of the new turbos mentioned? My car is currently bog standard apart from a stainless sports exhaust system and a Ruf sticker in the back window.
Particularly interested in the fueling side of things. Do you need to ditch the K-Jet for Motec for instance? Suspect the costs of that would put me off.
Cheers,
Chris
On a 930, what other mods would you want to couple with either of the new turbos mentioned? My car is currently bog standard apart from a stainless sports exhaust system and a Ruf sticker in the back window.
Particularly interested in the fueling side of things. Do you need to ditch the K-Jet for Motec for instance? Suspect the costs of that would put me off.
Cheers,
Chris
The RUF sticker adds 10bhp.
Re fuelling, nah, the standard system tends to run rich, so I beleive that it is retained and can cope happily with up to 450bhp or so.
Basically, boost spring can get good gains straight off. Then you need to uprate to a K27, but this gives more lag and can be less driveable (I know of a 965 owner who switched back to the smaller turbo after having this done).
ATB
Domster
Re fuelling, nah, the standard system tends to run rich, so I beleive that it is retained and can cope happily with up to 450bhp or so.
Basically, boost spring can get good gains straight off. Then you need to uprate to a K27, but this gives more lag and can be less driveable (I know of a 965 owner who switched back to the smaller turbo after having this done).
ATB
Domster
If you have the standard turbo on your 930, then the K27 is a good upgrade, and it will spool faster than your original 'K26'.
I have spent a reasonable amount on my car doing simple mods, but having them done well. There are plenty of people who will bolt on all sorts of stuff and pay no attention to fuelling for example...
The first things I would do is K27, 1 bar or EBC, K&N, cat bypass. If you have an O2 sensor unplug it and get rid of the air injector stuff. This made a massive difference to my car. Then cams, port/polish.... Then EFI + bigger turbo.... Then sell house to fund next phase....
All I would say is treat BHP claims with caution, most people talk absolute boll*cks. Get your car dyno'd and treat the numbers as a benchmark for you to work with. If you want to settle 'my car is faster than your's', just get them down to Brunters...
Oh, and have a plan. Last thing you want to do is spend hard cash having a mod done, only to replace it later because it doesn't fit with new mods...
I have spent a reasonable amount on my car doing simple mods, but having them done well. There are plenty of people who will bolt on all sorts of stuff and pay no attention to fuelling for example...
The first things I would do is K27, 1 bar or EBC, K&N, cat bypass. If you have an O2 sensor unplug it and get rid of the air injector stuff. This made a massive difference to my car. Then cams, port/polish.... Then EFI + bigger turbo.... Then sell house to fund next phase....
All I would say is treat BHP claims with caution, most people talk absolute boll*cks. Get your car dyno'd and treat the numbers as a benchmark for you to work with. If you want to settle 'my car is faster than your's', just get them down to Brunters...
Oh, and have a plan. Last thing you want to do is spend hard cash having a mod done, only to replace it later because it doesn't fit with new mods...
What I should probably add, is that I don't know anything about anything and just read a lot of forums. You may like to try:
www.turbo911.com
www.rennlist.com
www.c2turbo.com
Lots of back posts to read......
www.turbo911.com
www.rennlist.com
www.c2turbo.com
Lots of back posts to read......
Sorry Dom but you should stick to Badger baiting. Here's a copy of a post I made on another forum which should enlighten all who can be bothered to read it. If anyone wants more than the stuff mentioned ask again.
First of all, it is possible to significantly improve response and low end torque by re-engineering the exhaust system, doing away with the "round the houses" design of the original 930 & 965 that contributes to most of the problems. In simple terms there are four aspects of exhaust gas energy that will result in acceleration of the turbo, i.e. temperature, pressure, velocity and resonance: the rule is that if you can get the gas to the turbo with more energy it will boost earlier, period. Looking at the standard system the longest path from head to turbo is around 9ft, so in travelling this far the gas can do nothing but lose heat, diffuse any resonant waves (generated by valve opening/closing) and due to the large diameter of the collector pipe, lose velocity. The result is that the turbo is mainly driven by back pressure in the exhaust system. Now, if by turning small header (manifold) pipes backwards, merging each bank of three into two small bore pipes and nozzle-ing the pipes seperately towards the turbine, you can spool up the turbo with a high velocity impulsive exhaust flow that is hotter and carries more energy. This header design works without fail, our independent tests on the 930 showed a 22% increase in torque with peak torque 500rpm lower in the range and boost beginning at 2500rpm. Typically they can make as much as 50bhp gain on all 930/965 engines. This design of system is well known and has been sold for years by PowerHaus/B&B/GHL and around two years ago we (9m Racing) also tooled up to make our own from a high grade of stainless steel with a thicker tube section after having occcasional cracking problems with high hp motors. Any free flow silencer/cat will also help response, since power generated by the turbine is proportional to the pressure drop across it.
Secondly there is the issue of boost. Most 930/965 engines run happily on 1.0 bar and will be more responsive as a result. The reson for this is that the stiffer spring counteracts the build up of pressure on the wastegate for longer, holding the wastegate valve shut until a higher boost level is reached and thus allowing the turbo to achieve peak boost earlier. However since the wastegate is nothing more than a spring/diaphragm and will start to open early no-matter what spring is fitted, the better way to control the valve is with electronics. Modern electronic boost controllers can be used to cut off the pressure to the wastegate until the desired boost pressure is reached, thus allowing a slight (or flash) overboost to maximise response (this is called an underdamped system). We sell the HKS EVC4, although there are others that work just as well or maybe better.
Next we come to the turbo. I will blow away a myth first: no factory 930 ever made has a K26 turbo, they were fitted with the mother of all turbos, the 3LDZ unit which was initially designed by KKK for a marine diesel engine. The 3LDZ unit is immensely strong but it is dynamically heavy and old, so any of the 930 models will benefit from the fitting of the more modern and dynamically lighter K27 design as fitted to the 965. The best overall variation of the K27 is the K27/11, i.e. with the #11 exhaust housing. By fitting a smaller #10 housing you can get the turbo to spool up quicker and hence produce more bottom end, but the trade off is increased back pressure at high rpm and thus less power. Overall I would say that up to 400bhp the K27/11 is the ideal choice. Beyond 400bhp the hybrid turbo is king, hence the K28/27 and K29/27 units where larger compressor wheels can be grafted onto the #11 exhaust housing in order to move more air, in which case the usual route is to angle grind the outlet of the turbine wheel in order to reduce the back pressure at high rpm whilst maintaining low end performance.
The rule with intercoolers is the bigger the better, the turbo will fill a larger capacity in an instant. The 965 cooler is a good one and is fine up to 400bhp, also a nice one to fit onto a tweeked 930 if you can find used one in a breakers yard. Intercoolers will not help response though. The 965 recirculation system can be incorporated onto the 930, this mod does improve response between gears slightly and also saves weight off the engine.
Finally we come to the engine itself. For low end response the standard 930/965 cams are the best but they will ceiling the power potential of the engine at sub 400bhp. Small intake/exhaust ports maintain velocities and REDUCE back pressure seen by the engine so leave the heads standard please. So all that is really left to go at is the compression ratio, fuelling and ignition timing. Goodness knows why Porsche set the compression of the 930 at 6.5:1 with 0.8bar, these engines will work so much more efficiently at 7.5 or 8:1 it is untrue but unfortunately this requires an engine rebuild and new pistons, so it is not exactly a quick-fix option. The stock (euro) K-Jet system of the 930 is diabolically ineficient and over-rich, having enough fuel in it for just about 400bhp, so forget about extra injectors until you are into serious power. The ignition system is a good one although limited by its preset curves, adding a programmable controller to the system helps, although gains are mainly to be had at the top end with 3 or 4 extra degrees of timing giving 10-20bhp in some cases.
First of all, it is possible to significantly improve response and low end torque by re-engineering the exhaust system, doing away with the "round the houses" design of the original 930 & 965 that contributes to most of the problems. In simple terms there are four aspects of exhaust gas energy that will result in acceleration of the turbo, i.e. temperature, pressure, velocity and resonance: the rule is that if you can get the gas to the turbo with more energy it will boost earlier, period. Looking at the standard system the longest path from head to turbo is around 9ft, so in travelling this far the gas can do nothing but lose heat, diffuse any resonant waves (generated by valve opening/closing) and due to the large diameter of the collector pipe, lose velocity. The result is that the turbo is mainly driven by back pressure in the exhaust system. Now, if by turning small header (manifold) pipes backwards, merging each bank of three into two small bore pipes and nozzle-ing the pipes seperately towards the turbine, you can spool up the turbo with a high velocity impulsive exhaust flow that is hotter and carries more energy. This header design works without fail, our independent tests on the 930 showed a 22% increase in torque with peak torque 500rpm lower in the range and boost beginning at 2500rpm. Typically they can make as much as 50bhp gain on all 930/965 engines. This design of system is well known and has been sold for years by PowerHaus/B&B/GHL and around two years ago we (9m Racing) also tooled up to make our own from a high grade of stainless steel with a thicker tube section after having occcasional cracking problems with high hp motors. Any free flow silencer/cat will also help response, since power generated by the turbine is proportional to the pressure drop across it.
Secondly there is the issue of boost. Most 930/965 engines run happily on 1.0 bar and will be more responsive as a result. The reson for this is that the stiffer spring counteracts the build up of pressure on the wastegate for longer, holding the wastegate valve shut until a higher boost level is reached and thus allowing the turbo to achieve peak boost earlier. However since the wastegate is nothing more than a spring/diaphragm and will start to open early no-matter what spring is fitted, the better way to control the valve is with electronics. Modern electronic boost controllers can be used to cut off the pressure to the wastegate until the desired boost pressure is reached, thus allowing a slight (or flash) overboost to maximise response (this is called an underdamped system). We sell the HKS EVC4, although there are others that work just as well or maybe better.
Next we come to the turbo. I will blow away a myth first: no factory 930 ever made has a K26 turbo, they were fitted with the mother of all turbos, the 3LDZ unit which was initially designed by KKK for a marine diesel engine. The 3LDZ unit is immensely strong but it is dynamically heavy and old, so any of the 930 models will benefit from the fitting of the more modern and dynamically lighter K27 design as fitted to the 965. The best overall variation of the K27 is the K27/11, i.e. with the #11 exhaust housing. By fitting a smaller #10 housing you can get the turbo to spool up quicker and hence produce more bottom end, but the trade off is increased back pressure at high rpm and thus less power. Overall I would say that up to 400bhp the K27/11 is the ideal choice. Beyond 400bhp the hybrid turbo is king, hence the K28/27 and K29/27 units where larger compressor wheels can be grafted onto the #11 exhaust housing in order to move more air, in which case the usual route is to angle grind the outlet of the turbine wheel in order to reduce the back pressure at high rpm whilst maintaining low end performance.
The rule with intercoolers is the bigger the better, the turbo will fill a larger capacity in an instant. The 965 cooler is a good one and is fine up to 400bhp, also a nice one to fit onto a tweeked 930 if you can find used one in a breakers yard. Intercoolers will not help response though. The 965 recirculation system can be incorporated onto the 930, this mod does improve response between gears slightly and also saves weight off the engine.
Finally we come to the engine itself. For low end response the standard 930/965 cams are the best but they will ceiling the power potential of the engine at sub 400bhp. Small intake/exhaust ports maintain velocities and REDUCE back pressure seen by the engine so leave the heads standard please. So all that is really left to go at is the compression ratio, fuelling and ignition timing. Goodness knows why Porsche set the compression of the 930 at 6.5:1 with 0.8bar, these engines will work so much more efficiently at 7.5 or 8:1 it is untrue but unfortunately this requires an engine rebuild and new pistons, so it is not exactly a quick-fix option. The stock (euro) K-Jet system of the 930 is diabolically ineficient and over-rich, having enough fuel in it for just about 400bhp, so forget about extra injectors until you are into serious power. The ignition system is a good one although limited by its preset curves, adding a programmable controller to the system helps, although gains are mainly to be had at the top end with 3 or 4 extra degrees of timing giving 10-20bhp in some cases.
As an afterthought:
Stock 3.3 turbo engine with:
964 cams
9m ported intake manifold/injector blocks/heads
500 cu in intercooler, long neck conversion, 965 recir valve
9m header set
9m K27/28 hybrid turbo
std wastegate & spring
HKS EVC4 boost controller
7th injector
Ignition/fuel computer for partially mapped fuel/ign
Twin outlet silencer
So not exactly a stupidly expensive engine to build at around £11k +VAT, but the result was a collosal 461bhp & 650Nm flywheel or 429bhp at the wheels if you prefer at just 1.0 bar boost (that's 996 GT2 power). We built this conversion in 2000 on a 5000 mile engine, now done over 15,000 miles of road and heavy track use without a glitch.
The point here is that this engine started out totally standard and we initially just added set of headers and a K27. We later added the cams and intercooler for 400bhp, then did the turbo and mapping for the final push. It now utilises the same parts that we recommend for the most basic upgrades of a standard engine and the only part that had to be changed was the turbo, but since we started with a K27 rebuilt it into the K27/28 for the same end cost as a new one. Subsequently if things go to plan with our new ballrace turbo, we may actually be able to configure a suitable package that covers all applications from 350 to 500bhp.
This reflects the 9m approach to tuning where you buy everything just once and build on it through logical steps. In my mind if anyone tries to tell you otherwise be very suspicious.
Incidentally, never done Motec on a 930 or 965 but it would make a fantastic conversion with more power, less lag and better consumption. Unfortunately after the conversion was done I would expect a bill of £7k or more due to the work involved changing the entire intake & fuel system for a modified 3.2 unit.
>> Edited by ninemeister on Friday 17th October 19:12
Stock 3.3 turbo engine with:
964 cams
9m ported intake manifold/injector blocks/heads
500 cu in intercooler, long neck conversion, 965 recir valve
9m header set
9m K27/28 hybrid turbo
std wastegate & spring
HKS EVC4 boost controller
7th injector
Ignition/fuel computer for partially mapped fuel/ign
Twin outlet silencer
So not exactly a stupidly expensive engine to build at around £11k +VAT, but the result was a collosal 461bhp & 650Nm flywheel or 429bhp at the wheels if you prefer at just 1.0 bar boost (that's 996 GT2 power). We built this conversion in 2000 on a 5000 mile engine, now done over 15,000 miles of road and heavy track use without a glitch.
The point here is that this engine started out totally standard and we initially just added set of headers and a K27. We later added the cams and intercooler for 400bhp, then did the turbo and mapping for the final push. It now utilises the same parts that we recommend for the most basic upgrades of a standard engine and the only part that had to be changed was the turbo, but since we started with a K27 rebuilt it into the K27/28 for the same end cost as a new one. Subsequently if things go to plan with our new ballrace turbo, we may actually be able to configure a suitable package that covers all applications from 350 to 500bhp.
This reflects the 9m approach to tuning where you buy everything just once and build on it through logical steps. In my mind if anyone tries to tell you otherwise be very suspicious.
Incidentally, never done Motec on a 930 or 965 but it would make a fantastic conversion with more power, less lag and better consumption. Unfortunately after the conversion was done I would expect a bill of £7k or more due to the work involved changing the entire intake & fuel system for a modified 3.2 unit.
>> Edited by ninemeister on Friday 17th October 19:12
Really interesting thread - thanks UV and 9m, lot's for me to digest. This could be the beginning of a slippery slope! Some of these things do sound like a lot of money but if you add up the purchase price of a tidy 930 or 965 then the price of the mods and compare to what else you could get for the money it begins to look quite sensible! Best part of 500bhp for the price of a BMW 330Ci anyone?
See, I'm beginning to start justifying it to myself already!
See, I'm beginning to start justifying it to myself already!
I must admit I was always of the amateur opinion that if you move to a bigger turbo then you will increase lag. I know that many 944 Turbo owners move from a K26 to a K27 but I have not heard of any doing so with a ballrace design. I'd be very interested if this could be done and also reduce the lag that comes as standard with the 944.
Sorry to hijack a 930/965 thread but when Colin starts waxing lyrical regarding Turbo upgrades
I tend to get a bit excited and can't help myself 
and also reduce the lag that comes as standard with the 944. Sorry to hijack a 930/965 thread but when Colin starts waxing lyrical regarding Turbo upgrades
I tend to get a bit excited and can't help myself 
I'm booked in to Oulton on Saturday so do please come along, it would be nice to give the old RS a good thrashing before the winter sets in. I should have a few customers there in a some "different" Pork of some kind or other, will be an interesting day for sure.
As for 964 cams versus 911SC, yes I prefer the 964 cams since the turbo can use the extra lift and duration to extend the top end power without sacrificing response. Piston to valve clearance is adequate with standard pistons.
We could look into a ballrace turbo conversion for the 951 for a customer if requested, but until someone walks through the door with a couple of thousand beer tokens in their pocket it will have to wait. I will guarantee that it will work though!
As for 964 cams versus 911SC, yes I prefer the 964 cams since the turbo can use the extra lift and duration to extend the top end power without sacrificing response. Piston to valve clearance is adequate with standard pistons.
We could look into a ballrace turbo conversion for the 951 for a customer if requested, but until someone walks through the door with a couple of thousand beer tokens in their pocket it will have to wait. I will guarantee that it will work though!
Now, i quite like the sound of my 965 with the cat replacment pipe, will putting the 'g-pipe' on make it into a noisy machine or will it be bearable for road use? i only think about changing it as it should unleash a few more horses. I still want to be able to cruise along gently if i have to.
EW having just got the car it may do you good to get used to what you have....
This way you can work out what you think needs improving first,,new tyres,exhaust,suspension,boost etc
This way any mods you do will give you more satisfaction as you realise how much better the car is than before the mods.
Also consider that most after market noisy exhausts prohibit use at anything other than rare loud trackdays.
This way you can work out what you think needs improving first,,new tyres,exhaust,suspension,boost etc
This way any mods you do will give you more satisfaction as you realise how much better the car is than before the mods.
Also consider that most after market noisy exhausts prohibit use at anything other than rare loud trackdays.
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