Trials and tribulations of a Porsche tuner..
- Thread starter Indi9xx
- Start date
Indi9xx
New member
I have seen 944 NA 8V engines that have produced 175 bhp at the crank when the valve guides are under 20,000 miles old but everything else stock, but with typical mileage without new guides they more often than not are closer to 150 bhp.
In the UK, the whole tuning market tends to be air filters, exhausts, MAF kits, chips and fluffy dice these days, which is a bit sad, I am from an era of cams, individual throttle bodies and head work. But that is how the market shifted about 20 years ago, with the advent of all cars having EFI and the majority of tuners seeing it as voodoo made the market change to bolt on bits which didnt need altered fueling and ignition.
Unfortunately, the mindset of the average tuner that sells boxes of bits rather than someone who can alter the ecu software and maps, as well as altering the whole engine package, has not changed.. Meanwhile, the consumer base sees cars as a much more temporary item, and therefore is reluctant to delve into modified heads.
With the 2.0 924 8v NA and 944 2.5 8v NA cylinder heads, the corrective modifications I worked on would have had back then a price tag of about £1500 plus vat just for the headwork, plus fitting etc, so was not something that an owner back when the cars were selling for under £1k to £3k would consider.. Now the values have gone up, the buying power is probably there, but those paying top money for the cars want them to be absolutely stock, so my feeling is the market still isnt there and the costs involved will probably be 25% higher now or closer to £2000 plus vat.
We did a few of the 924 heads, which were a spectacular success on the cars they were fitted to, with a massive improvement in torque from very low down in the rev range and great through the midrange and a peak bhp of around 145 bhp with relatively mild cams, a slightly larger throttle body and standard injection and ignition system. I always wanted to convert one to the 944 DME and EFI/Ignition, where its tune could be perfected, but there was never really the market there for that either.
I still have some projects I want to do for myself, which may turn into there being additional products to offer, in particular I want to build a Motronic 924 Turbo with a complelte rethink of the the entire top end, manifolds and plumbing (which will produce nothing really to offer anyone else), I want to finish developing my MAF kit for one of my turbos which may turn into a MAF kit, I need to finish off some work on my classic stealth chips for the 220 and 250 944 turbos, which will be honed towards specific chips, for those specific cars, with standard turbos and wastegates, as well as adding some new code to the original chips for those models which are a hotter tune and a bit of a swiss army knife, and then I have a load of prototypes I want to finish... All of this is for my own cars, but may turn into products... For product development everything new will be really for the Boxsters, 996/ 997 / 981 etc.. Unless of course I come up with any mad plans, but they will probably be for my own benefit and if anything comes of them, then so be it.
What I would really like to do is to buy cars, modify them as a specific package and then sell them and move onto the next fun project.. But as a business model that rarely works unless you get a following like Magnus Walker or Singer.
In the UK, the whole tuning market tends to be air filters, exhausts, MAF kits, chips and fluffy dice these days, which is a bit sad, I am from an era of cams, individual throttle bodies and head work. But that is how the market shifted about 20 years ago, with the advent of all cars having EFI and the majority of tuners seeing it as voodoo made the market change to bolt on bits which didnt need altered fueling and ignition.
Unfortunately, the mindset of the average tuner that sells boxes of bits rather than someone who can alter the ecu software and maps, as well as altering the whole engine package, has not changed.. Meanwhile, the consumer base sees cars as a much more temporary item, and therefore is reluctant to delve into modified heads.
With the 2.0 924 8v NA and 944 2.5 8v NA cylinder heads, the corrective modifications I worked on would have had back then a price tag of about £1500 plus vat just for the headwork, plus fitting etc, so was not something that an owner back when the cars were selling for under £1k to £3k would consider.. Now the values have gone up, the buying power is probably there, but those paying top money for the cars want them to be absolutely stock, so my feeling is the market still isnt there and the costs involved will probably be 25% higher now or closer to £2000 plus vat.
We did a few of the 924 heads, which were a spectacular success on the cars they were fitted to, with a massive improvement in torque from very low down in the rev range and great through the midrange and a peak bhp of around 145 bhp with relatively mild cams, a slightly larger throttle body and standard injection and ignition system. I always wanted to convert one to the 944 DME and EFI/Ignition, where its tune could be perfected, but there was never really the market there for that either.
I still have some projects I want to do for myself, which may turn into there being additional products to offer, in particular I want to build a Motronic 924 Turbo with a complelte rethink of the the entire top end, manifolds and plumbing (which will produce nothing really to offer anyone else), I want to finish developing my MAF kit for one of my turbos which may turn into a MAF kit, I need to finish off some work on my classic stealth chips for the 220 and 250 944 turbos, which will be honed towards specific chips, for those specific cars, with standard turbos and wastegates, as well as adding some new code to the original chips for those models which are a hotter tune and a bit of a swiss army knife, and then I have a load of prototypes I want to finish... All of this is for my own cars, but may turn into products... For product development everything new will be really for the Boxsters, 996/ 997 / 981 etc.. Unless of course I come up with any mad plans, but they will probably be for my own benefit and if anything comes of them, then so be it.
What I would really like to do is to buy cars, modify them as a specific package and then sell them and move onto the next fun project.. But as a business model that rarely works unless you get a following like Magnus Walker or Singer.
Indi9xx
New member
One thing I do agree on, the standard Motronic DME does not need to be thrown away when tuning, it has 30 years or more of evolution.
Yes the processor is old hat today, but for what it has to do, it isnt taxed, and much of its time is wasted because Bosch wanted it to be a one size fit all product with limited memory capacty, with half its ROM taken up with maps for the whole world markets, yet much of the processor time is working with compressed tables (tansfer functions) because Bosch did not have the memory space to put in a complete table for the airflow meter (just as one example), whereas if you hone the chip for one market, one specification, one fuel range (say 94 to 100 Ron), then you end up with more space for software, more space for more refined maps and the processor still spends much of its time twiddling its thumbs.
Oh, it cant connect to an Android phone though.. oh ok.. I guess I can live with that
What I can't live with is a car which runs rough just because it has not been mapped with a specific weather, humidity or air pressure, and struggles to run properly on a certain kind of morning, which Porsche spent hundreds of thousands of miles to fine tune.. Improve the wheel, don't reinvent it, unless there is something really needed that the old wheel can't be modified to do..
The only thing about the 944 8v na airflow meter is its bore size, but to be honest, I am not entirely sure it strangles the engine that much, and if it was found to do so, fit a 944 Turbo one and adjust the chip to work.. the fuel pump is good for 320 bhp (in good condition), the injectors are good for over 200 bhp worth of fuel and the exhaust isnt the problem either except for weight.
Yes the processor is old hat today, but for what it has to do, it isnt taxed, and much of its time is wasted because Bosch wanted it to be a one size fit all product with limited memory capacty, with half its ROM taken up with maps for the whole world markets, yet much of the processor time is working with compressed tables (tansfer functions) because Bosch did not have the memory space to put in a complete table for the airflow meter (just as one example), whereas if you hone the chip for one market, one specification, one fuel range (say 94 to 100 Ron), then you end up with more space for software, more space for more refined maps and the processor still spends much of its time twiddling its thumbs.
Oh, it cant connect to an Android phone though.. oh ok.. I guess I can live with that
What I can't live with is a car which runs rough just because it has not been mapped with a specific weather, humidity or air pressure, and struggles to run properly on a certain kind of morning, which Porsche spent hundreds of thousands of miles to fine tune.. Improve the wheel, don't reinvent it, unless there is something really needed that the old wheel can't be modified to do..
The only thing about the 944 8v na airflow meter is its bore size, but to be honest, I am not entirely sure it strangles the engine that much, and if it was found to do so, fit a 944 Turbo one and adjust the chip to work.. the fuel pump is good for 320 bhp (in good condition), the injectors are good for over 200 bhp worth of fuel and the exhaust isnt the problem either except for weight.
edh
New member
blade7 said:edh said:I would also quite like a Michael Mount built 3.0 N/A 400hp motor though [
What would it cost and how long would it last though. And is it run on Unicorn p*ss.
Who knows? It's completely out of my price range anyway, I'm sure of that.. and if I could afford it, I could also afford the running costs.
924Srr27l
New member
PSH said:blade7 said:edh said:I would also quite like a Michael Mount built 3.0 N/A 400hp motor though [
What would it cost and how long would it last though. And is it run on Unicorn p*ss.
No idea... but I bet it comes with a fully working saratoga roof....
It's a 968 Crankshaft 3.2 steel lined Twin Cam, dry sump, ITB's, screamer with a power band 5500 - 8000rpm
Gave 316bhp at the wheels.
R
Neil Haughey
New member
ISTR one of the cars on those days made 219 Bhp or so and was completely stock (from memory it was Oli?). I bet many of the cars making more than 211 have weak midrange torque and conversely those making less that 211 which aren't kippered probably made really strong torque. The whole cam timing thing is something I have discussed with Jon before as both Kevin Eacock (EMC) and Andy Duncan (NineX) checked my cam timing as spot on but I have those dyno graphs showing the torque curve far too far to the right with a peak torque rpm way higher than factory figures. I don't know for sure but I believe S2s have a bit of variation in the cam gear giving misleading cam timing. This may also explain why the MR Performance guys said to me years ago that they prefer to road test cars and tweek the cam timing if possible to get a nice kick rather than just believing the dial gauge.
Anyways Wayne was fairly adamant with Andy that it is waste of time mapping S2s as all you can do is fiddle around with where it makes power and torque (if he didn't say this we would have taken my car up to him as he has made massive gains with other Porsche race cars and racers down the years).
Ed NineX have been pushing the limits of what you can get from a 968 the past couple of years and of course very successfully in AMOC Intermarque.
Anyways Wayne was fairly adamant with Andy that it is waste of time mapping S2s as all you can do is fiddle around with where it makes power and torque (if he didn't say this we would have taken my car up to him as he has made massive gains with other Porsche race cars and racers down the years).
Ed NineX have been pushing the limits of what you can get from a 968 the past couple of years and of course very successfully in AMOC Intermarque.
Indi9xx
New member
Variations in combustion chamber volumes are also interesting on the non turbo 944/924S engines (both the 16v S2 and the 8v non turbo)
We recently measured several 8v non turbo heads for example and found wild variances with combustion chamber volumes. All the heads had casting numbers of ROW heads, ranging from early through to the last manufacturing runs and found that there wasnt much or a pattern. We even compensated for any previous skimming by measuring the heads deck dimensions.. Our main purpose was to look at substituting 944 NA heads for use on a hybrid version of a 944 turbo engine for port re-profiling (so we didnt want the ceramics in the way) but it goes to show how much variation of compression ratio there could be from what may seem to be identical cars, and therefore performance if the engine builder was not on the ball.
The 16v heads I checked many and compared them to 928 heads many years ago and found the 16 944 s2 heads varied more than I would expect also but did not get to the bottom of one suspicion that the cars built with catalytic converters had lower volume combustion chambers, which would explain why I used to find that Cat equipped cars that had been de-catted and chipped made more power than cat equipped cars, but I also suspect this could be down to also how the cars would have "run in" with the cat equipped cars having a closer to perfect AFR during running in due to the o2 sensor closed loop nature of the beast.
With cam timing, there is a big part of art to it on the 16v heads, I prefer to use the dial gauge on road cars, just so no one can say I have not timed it up properly. For a race engine it would be down to consultation with the driver and potentially even different cam timing for different tracks and potentially choosing between a worn/slightly stretched cam synchro chain (if the chain tensioner mod is outlawed in that series) to alter the relationship between overall exhaust cam timing (adjustable) and the inlet timing (fixed in relation to the exhaust) depending on the track about to come up or the drivers preference. But I do not have the time to be involved with 944 race cars much these days, its mostly the GT3 racers, but I cant elaborate on that very much.
We recently measured several 8v non turbo heads for example and found wild variances with combustion chamber volumes. All the heads had casting numbers of ROW heads, ranging from early through to the last manufacturing runs and found that there wasnt much or a pattern. We even compensated for any previous skimming by measuring the heads deck dimensions.. Our main purpose was to look at substituting 944 NA heads for use on a hybrid version of a 944 turbo engine for port re-profiling (so we didnt want the ceramics in the way) but it goes to show how much variation of compression ratio there could be from what may seem to be identical cars, and therefore performance if the engine builder was not on the ball.
The 16v heads I checked many and compared them to 928 heads many years ago and found the 16 944 s2 heads varied more than I would expect also but did not get to the bottom of one suspicion that the cars built with catalytic converters had lower volume combustion chambers, which would explain why I used to find that Cat equipped cars that had been de-catted and chipped made more power than cat equipped cars, but I also suspect this could be down to also how the cars would have "run in" with the cat equipped cars having a closer to perfect AFR during running in due to the o2 sensor closed loop nature of the beast.
With cam timing, there is a big part of art to it on the 16v heads, I prefer to use the dial gauge on road cars, just so no one can say I have not timed it up properly. For a race engine it would be down to consultation with the driver and potentially even different cam timing for different tracks and potentially choosing between a worn/slightly stretched cam synchro chain (if the chain tensioner mod is outlawed in that series) to alter the relationship between overall exhaust cam timing (adjustable) and the inlet timing (fixed in relation to the exhaust) depending on the track about to come up or the drivers preference. But I do not have the time to be involved with 944 race cars much these days, its mostly the GT3 racers, but I cant elaborate on that very much.
924Srr27l
New member
[style="background-color: #ffffff;"]Q & A 's in RED[/style]
[/quote]
924Srr27l said:Jon Mitchell
The last one we built was last year for the Chairman of TiPEC who has a couple of 924S examples, one standard, the other we installed a 968 3.0 16v engine and DME with the engine loom modified to plug into the original 924S electrical system, so completely reversible, with adapters for the 924S fuel line location and a cone filter, we used a single mass flywheel and sprung clutch rather than the unsprung 968 one (still genuine), and the brakes were bigger disks on the front and rear and four pot Porsche brembo's all round. Litterally every part was a Genuine Porsche part except for the engine loom (standard 968 modified to plug straight into the 924S body looms), DME chip, and the 968 fuel rail to 924 fuel line adapters.
I considered a 968 Lump but the installation looked more expensive at the time, did you also fit the 968 Torque Tube and 6 Speed Gearbox?
Rather than chase the largest amount of Power, as that would of been far far easier with a Turbo Lump, the Main theme and ethos for the project was to remove as much weight as I could muster, in combination with as much power as my budget would go with a N/A Engine. So although at first I also wanted to keep everything standard and Porsche Components this soon became not possible as for example the brakes I went with the stock size discs front and rear, not Heavier and larger and also the Wilwoods are lighter than the Brembo Porsche items, which would of needed different stub axles etc...
Whenever we do something like that, we try to make it so anyone with (in this case) a 968, 924S/944 Factory workshop manual could work on the car, including main dealers, and all the parts are marked and available from the main dealer network as well as the aftermarket.
The customer then complimented it with a GAZ coil over kit, but with our springs and solid top mounts, some 968 16 inch cup one wheels.. So if you see a red 968 at shows, with Martini graphics and a 968 engine, say hi to the owner, he is a really nice chap and would probably be really interested in your project, not to mention would be happy to take you out so you can experience the road noise from the top mounts.
Because of the 250KG Weight loss the Gaz and all the other Suspension kits are way too hard for ROAD use, they are ok for standard heavier car's but the Spring rates are too high and harsh for the road, hence I fitted
much lower spring rates (190Lb's Front / 220Lb's rear) than the array on offer from aftermarket companies
Yes I'm keen to try other transaxles (Stock & Modified) after doing nearly 3000 miles in the 2.7 lightweight to compare, I did have a run in a 3.8 997 C4S the other week but I prefer the 924!
Performance should be in the ball park of about 240 BHP and 225 ft-lbs of torque, I would not hazard to guess his actual output, the engine had a head rebuild with new guides as part of the work (which can loose 968s about 20 bhp when worn beyond 20,000 to 30,000 miles) and the intake adapters and cone filter were not parts we would usually use with the 968 when we install our off the peg chip, but they tend to get around 260bhp and 255 ft-lbs (calculated flywheel figures) on a DD Chassis dyno.
[style="background-color: #ffffff;"]Yes my calculations worked out the Power to Weight Ratio would be and is higher than any production 924 (Inc Carerra GT), 944 (Inc turbo) and the 968 (except the 968 turbo S / RS) or even a 924 with a 968 engine) unless this was extensively lightened? [/style]
If it were my car, I would probably have seen if some 16inch late offset 944 teledials coud have been made to fit somehow and mounted the cone filter a little like yours, but we wanted to keep it as "Porsche parts bin" as possible and the throttle body to MAF sensor adapter was sourced from another Porsche model, but in testing we found almost equal under bonnet temperatures either in the inner wing or counter intuitivey near the radiator on previous projects (except when stuck in traffic)
I tested some 16" Teledials but they were heavier than the Cups, and I could feel the difference was a performance disadvantage so I didn't fit them.
Actually, thinking back, this was one of the less painful customer projects, with the owner fully following our advice, the plan was pretty much set from the moment he made the decision to go 968 powered and because it is about the 10th 944S2 or 968 powered 924S/pre-86-944 conversion we had done, much of it was quite straight forward, with the pre-86 944 using the same fuel lines and pretty much the same fuse box and dashboard connectors for the engine loom to tie into.
Oh my project kept escalating more and more and the goal posts were ever moving, 3.5 years and the car went to 5 different UK Companies for different types of work etc.. It was a tough venture I wouldn't relish doing again, my own fault because once I started fitting superior products it kept revealing "Weaker" areas that had to be addressed, otherwise the car would not be as complete as it's turned out to be.
One other part that was modified or manufactured was a aluminium bracket to allow the use of the 968 header tank, which was critical because we wanted the customer to be able to use Genuine 968 hoses and front coolant rail on his car, so if anyone else ever works on it they can pretty much know that "If its under the bonnet its 968, if its not under the bonnet it is 924S, apart from the brakes, which are a cunning mix of Porsche parts which is a slight secret)
I took off my header tank and the Washer bottle and didn't want to put them both back, so I made a special header which sits where a Power steering reservoir would normally do, and put a much smaller washer bottle near the servo...(Both saved weight)
This is with the old 2.5 Engine in at the time, that was soon taken out.....
R
[/quote]
Indi9xx
New member
That particular car used the 924S torque tube and transmission, the aerodynamics of a 924S would mean the top speed with the 968 transmission would have been a bit hairy so probably not of any benefit.
Interesting that you comment on the coil overs from GAZ etc are too hard for the road, this is down to the spring rates which are, like with KW, always in the area of 400lbs/inch, which especially with a lighter car would have been a bone shaker on the road. Our spring rates were calculated to give the car the ride height we desired with the height adjusters set mid way, but with a spring rate that was closer to standard.
This can be controversial as on the road, the thing that most people are trying to achieve with suspension upgrades is to control body roll and improve damping for something more sporty, which should really be done with more suitable anti roll bars and good dampers valved and setup correctly.. With the right selection of parts you should be able to have your cake and eat it, a car that is flat through the corners, stable, yet still rides well.
The other downfall of using the off the peg springs that come with the coil over kits from GAZ, KW etc is that they stop you from benefiting from weight transfer during acceleration and deceleration, which is important for good traction during both of those phases.
The teledials would from my point of view have been purely for aesthetics to make the car still look standard (teledials) but to have a big enough wheel to house the brakes.
Every car has to be a balancing act of weights, aesthetics, costs, performance and everyones view would be different for what they want. For all out lightness a set of magnesium wheels would be lighter than aluminium but very expensive, on the other hand Fuchs are reasonably expensive, but in any given size lighter than any other Porsche wheel, such as the 7J 16" Cup 1 being 7.5kg and the same diameter and width Fuchs wheel being 6.4kg or the 15" version at only 4.8kg but the offsets would put the wheel outside of the arch on the front, unless the 6J fuchs were used which would be a bit narrow for the additional power and more importantly less traction under braking.
If budget is no issue, it would be possible to have aluminium stub axle assemblies made for unspring weight reductions, but that would not help with the wheel gyroscopic rotating mass problem, but on that subject you could remove a kg from the middle of the wheel and it would not make as much difference as choosing a tyre which had a fraction of the reduced weight with gyroscopic effect, but would make more of a difference to unsprung mass, which many people confuse the difference in performance of.
If the standard brakes are being used and aesthetics are not the main concern (making it still look like a 924S), you could use the 15 inch fuchs wheels which are really light (across the entire radius not just the centre) you could fit the 15" Fuchs, benefit from sub 5kg wheels which are light on the rim as well as the centre, change the front wings for carbon fibre 944/CGT items, cut out and reseal the rear arches for carbon fibre CGT rear arches and you would have a car which had lost lots of weight from the shell and from the wheels, wheels that would benefit from gyroscopic improvements as well as unsprung mass, on a car that had lost weight from the shell as well.. Ad a carbon bonnet and a polly rear screen and the weight reductions just keep coming.. But, then again, if you are going to completely change the look of the car with no concern for aesthetics then there are lighter weight cars in the world you could start with, such as a Lotus Elise, a Crossbow or Atom, so anyone tuning a 924S is doing so because they like the Aesthetics.. So Aesthetics do play a big part in the big picture.
Interesting that you comment on the coil overs from GAZ etc are too hard for the road, this is down to the spring rates which are, like with KW, always in the area of 400lbs/inch, which especially with a lighter car would have been a bone shaker on the road. Our spring rates were calculated to give the car the ride height we desired with the height adjusters set mid way, but with a spring rate that was closer to standard.
This can be controversial as on the road, the thing that most people are trying to achieve with suspension upgrades is to control body roll and improve damping for something more sporty, which should really be done with more suitable anti roll bars and good dampers valved and setup correctly.. With the right selection of parts you should be able to have your cake and eat it, a car that is flat through the corners, stable, yet still rides well.
The other downfall of using the off the peg springs that come with the coil over kits from GAZ, KW etc is that they stop you from benefiting from weight transfer during acceleration and deceleration, which is important for good traction during both of those phases.
The teledials would from my point of view have been purely for aesthetics to make the car still look standard (teledials) but to have a big enough wheel to house the brakes.
Every car has to be a balancing act of weights, aesthetics, costs, performance and everyones view would be different for what they want. For all out lightness a set of magnesium wheels would be lighter than aluminium but very expensive, on the other hand Fuchs are reasonably expensive, but in any given size lighter than any other Porsche wheel, such as the 7J 16" Cup 1 being 7.5kg and the same diameter and width Fuchs wheel being 6.4kg or the 15" version at only 4.8kg but the offsets would put the wheel outside of the arch on the front, unless the 6J fuchs were used which would be a bit narrow for the additional power and more importantly less traction under braking.
If budget is no issue, it would be possible to have aluminium stub axle assemblies made for unspring weight reductions, but that would not help with the wheel gyroscopic rotating mass problem, but on that subject you could remove a kg from the middle of the wheel and it would not make as much difference as choosing a tyre which had a fraction of the reduced weight with gyroscopic effect, but would make more of a difference to unsprung mass, which many people confuse the difference in performance of.
If the standard brakes are being used and aesthetics are not the main concern (making it still look like a 924S), you could use the 15 inch fuchs wheels which are really light (across the entire radius not just the centre) you could fit the 15" Fuchs, benefit from sub 5kg wheels which are light on the rim as well as the centre, change the front wings for carbon fibre 944/CGT items, cut out and reseal the rear arches for carbon fibre CGT rear arches and you would have a car which had lost lots of weight from the shell and from the wheels, wheels that would benefit from gyroscopic improvements as well as unsprung mass, on a car that had lost weight from the shell as well.. Ad a carbon bonnet and a polly rear screen and the weight reductions just keep coming.. But, then again, if you are going to completely change the look of the car with no concern for aesthetics then there are lighter weight cars in the world you could start with, such as a Lotus Elise, a Crossbow or Atom, so anyone tuning a 924S is doing so because they like the Aesthetics.. So Aesthetics do play a big part in the big picture.
924Srr27l
New member
Indi9xx said:That particular car used the 924S torque tube and transmission, the aerodynamics of a 924S would mean the top speed with the 968 transmission would have been a bit hairy so probably not of any benefit.
Yes, this is also why I kept my stock 924S FDR @ 3.889, I also prefer a car that's short geared and does 120-130 tops, although I have been to 120mph which is rare as I don't do three figures much. It's currently geared at 3000rpm in top gear @ 80mph, 4000 @ 100, 5000 @ 120 and so on...
Interesting that you comment on the coil overs from GAZ etc are too hard for the road, this is down to the spring rates which are, like with KW, always in the area of 400lbs/inch, which especially with a lighter car would have been a bone shaker on the road. Our spring rates were calculated to give the car the ride height we desired with the height adjusters set mid way, but with a spring rate that was closer to standard.
Yes, normally any suspension kit would be fine, although even then still pretty harsh but the dramatic diet makes this more difficult to sort. I'm hoping to try some 160lb's springs (2.5ID Hyperco Race coils) and Bilstein B6 Inserts in my standard legs next year and see how that feels, although I'm also looking at competing in the Porsche Speed championship (Hill climbs & Circuit Venue Sprints etc..) so I may have to lump the harder road ride to be more competitive on track.
This can be controversial as on the road, the thing that most people are trying to achieve with suspension upgrades is to control body roll and improve damping for something more sporty, which should really be done with more suitable anti roll bars and good dampers valved and setup correctly.. With the right selection of parts you should be able to have your cake and eat it, a car that is flat through the corners, stable, yet still rides well.
I've got the Turbo / S2 / 968 26.8mm front ARB and an 18mm Rear one, it does roll but reasonable on the road and even the Oulton track day in November was ok too as it was wet and greasy to start with. So yes it is a good compromised road and track set up, but ideally I want softer for the road and harder for the track.
But I didn't design the car for track use, hence Rubber Bushes everywhere. Only after 2000 miles of Road burning up hot hatches my ambitions to show modern machinery the old girl's quicker than they think! were fulfilled but it's too risky to continue at this pace on the road! Hence why I'm considering the production class in the speed championship and I'd drive to the venue's and back!
The other downfall of using the off the peg springs that come with the coil over kits from GAZ, KW etc is that they stop you from benefiting from weight transfer during acceleration and deceleration, which is important for good traction during both of those phases.
Because they are too stiff?
The teledials would from my point of view have been purely for aesthetics to make the car still look standard (teledials) but to have a big enough wheel to house the brakes.
Every car has to be a balancing act of weights, aesthetics, costs, performance and everyones view would be different for what they want. For all out lightness a set of magnesium wheels would be lighter than aluminium but very expensive, on the other hand Fuchs are reasonably expensive, but in any given size lighter than any other Porsche wheel, such as the 7J 16" Cup 1 being 7.5kg and the same diameter and width Fuchs wheel being 6.4kg or the 15" version at only 4.8kg but the offsets would put the wheel outside of the arch on the front, unless the 6J fuchs were used which would be a bit narrow for the additional power and more importantly less traction under braking.
I would of liked to stay with 15" Wheels but they wouldn't fit over the 6 or 4 Piston Wilwoods, so i had to g
16" and I did not want to make a mess of the handling and fit an incorrect ET23 Fuch's so the 16" Cups were the lightest i could find, so i bought 3 sets and made (1) set all 7x16 for Road and (1) set all 8x16 R888 for track and the other 4 were bent!. The road versions also got machined and drilled to remove weight and the Pilot Sport 3 Road Tyres are much lighter than the Stiff sidewalled R888's so each 7x16 road wheel 7 Tyre is about 16kg from memory
including 1kg of air!
If budget is no issue, it would be possible to have aluminium stub axle assemblies made for unspring weight reductions, but that would not help with the wheel gyroscopic rotating mass problem, but on that subject you could remove a kg from the middle of the wheel and it would not make as much difference as choosing a tyre which had a fraction of the reduced weight with gyroscopic effect, but would make more of a difference to unsprung mass, which many people confuse the difference in performance of.
Yes I'd be interested in Aluminium Hubs, Quote me Happy? I've got Aluminium wishbones, Hub caps and calipers. I'm looking to get some quotes for a pair of Aluminium Struts to be made if your interested? Also both Wilwood calipers do not use all the disc, so I was thinking have some Aluminium Bells and Rotors made to suit which would be a smaller diameter then I could consider 15" Wheels
If the standard brakes are being used and aesthetics are not the main concern (making it still look like a 924S), you could use the 15 inch fuchs wheels which are really light (across the entire radius not just the centre) you could fit the 15" Fuchs, benefit from sub 5kg wheels which are light on the rim as well as the centre, change the front wings for carbon fibre 944/CGT items, cut out and reseal the rear arches for carbon fibre CGT rear arches and you would have a car which had lost lots of weight from the shell and from the wheels, wheels that would benefit from gyroscopic improvements as well as unsprung mass, on a car that had lost weight from the shell as well.. Ad a carbon bonnet and a polly rear screen and the weight reductions just keep coming..
It has all Lexan windows doors, quarter and rear hatch, and fibre panels: bonnet, badge panel, front wings front and rear bumpers, Sunroof , GTS Lightweight Light Binnacles setc...only the doors left to do!
But, then again, if you are going to completely change the look of the car with no concern for aesthetics then there are lighter weight cars in the world you could start with, such as a Lotus Elise, a Crossbow or Atom, so anyone tuning a 924S is doing so because they like the Aesthetics.. So Aesthetics do play a big part in the big picture.
No Aesthetics had and have no part in this project at all, everything has been designed and executed for maximum Road performance. I only got bored whilst waiting for several companies to complete work and hence got carried away with the bonnet decals, and stickers etc...
R
Neil Haughey said:
You remember well Neil. Yes, my car was the one that managed 219 and was completely stock at that time. Peter's did better but had had work done on it.
Your comments about BHP vs Torque are interesting, particularly given that Torque is a far more valuable commodity in a road car than power. On that basis maybe I should have hoped for less BHP rather than more from the dyno day!
Oli.
924Srr27l
New member
zcacogp said:
It's either a very rare situation where a car produces more power than the manufacturer spec suggests, which is virtually unheard of, and especially with car's 20 30 + years old, However I've owned many cars that I mapped and sold on, and I wouldn't be surprised if your car has also been as without any receipts there's no way of knowing without checking the ECU etc...
What was the Torque figure out of interest?
R
Posts made and opinions expressed are those of the individual forum members
Use of the Forum is subject to the Terms and Conditions
