Hello everyone, hope all is well!
After 150k+ miles the bottom end of my 944 turbo could do with a bit of a refresh and I'm thinking that with all of the work needed to replace the piston rings (engine out) it would be rude not to bore and stroke the engine to 3.0ltr...
I've read a lot around the topic and many many builds through the different forums and while I understand a lot of what I have read it's a very new area to me! I know there are a lot of people on this forum with a wealth of knowledge and wanted to run my thoughts / plans past you guys before doing anything stupid
I am the lucky owner of Rick's (then Ben's) 944 turbo WUF, so a lot has already been done to the car and after 2-3 years of saving its time for me to try to add to their hard work which I obviously don't want to end in tears... of oil or water!!.
After reading everything that I have managed to find about 3.0 ltr conversions I believe that I know what I need to buy for it but wanted to make this post to gain any feedback, experience, thoughts, ideas or any tips you may have...
WUF has had a lot of amazing work done originally by Rick (who unfortunately I have not managed to make contact with since owning the car, Rick if you read this please send me a pm as it would be great to say hi!!).
WUF is a 1990 944 Turbo (S spec 250 bhp) and has had the following modifications made (List from Rick Cannel's site) along with a few further tweaks...
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Engine: K&N air filter on hard pipe directly in to the turbocharger (from GURU Racing stage 2 MAP Kit).
Lindsey Racing Super 75 Turbo (T04 67mm compressor, KKK #8 water cooled hot side). Remote turbo oil filter. Tial 50mm dump valve with #11 spring. Lindsey Racing stage II Intercooler.
Inlet manifold opened out, blended, matched to throttle body and cylinder head, inlet air temperature sensor installed, powder coated. Throttle body flowed and fitted with up rated seals. Custom hard pipes with charge air temperature sensors, powder coated.
CTM modified stage IV cylinder head. Big valve (48 vs. 45mm inlets). Titanium retainers. Ports enlarged and flowed. 5 angle seats. Cometic head gasket.
Modified Piper cam with higher lift. Vernier cam timing gear. Wolf cam sensor kit to trigger the engine management system and provide phase information.
Lindsey Racing engine management system comprising Wolf-3D v4+ engine management computer to replace the Bosch DME engine management computer and J&S Ultra safeguard knock control computer to replace Bosch KLR knock control. Wolf-3d programmer / monitor mounted in centre console. RandomEMS cam sensor timing kit. Wideband O2 sensor & PLX 200 data converter. J&S knock display.
72lb/hr injectors running with sequential injection. Lindsey Racing up rated fuel pump. Lindsey Racing billet fuel rail, pressure gauge, vacuum kit, adjustable fuel pressure regulator. Laust vacuum manifold.
Hayward & Scott stainless steel exhaust. 3" bore. 5" tailpipe or dual 4" dual rear tailpipe with no silencers - interchangeable. Catalytic converter removed. Tial F46mm dual port waste gate dumping to atmosphere
Lindsey Racing remote additional oil cooler kit. Lindsey Racing remote oil catch tank. Vapour purge delete. Billet oil filter with 8 micron cartridge.
Unique fully sequential ignition. The Wolf-3d provides 4 sequential ignition channels (one per cylinder). This feeds a custom 4-channel version of the J&S Ultra Safeguard that controls knock retard on a per cylinder basis by up to 10 degrees. The J&S then feeds an MSD DIS-4 4 channel ignition driver that provides up to 20 degrees burn up to 3000 RPM. This drives the individual ignition coils mounted directly on the spark plugs. The result is a 45 KV spark that is almost plasma like.
Aeroquip piping on wastegate control. Calcium battery 700 / 130 Amp. Quick shift gear change. Magnetec oil. Swepco gearbox / diff oil. Air conditioning updated to R134a. Lindsey Racing SUPERMOUNT engine mounts.
Brakes: Front 993TT big red callipers & 993 C2 turbo 3.6 322mm x-drilled discs. Rear M030 968 x-drilled discs & 4 pot callipers. Braided brake hoses. Castrol SRF fluid. EBC Red Ceramic pads all round.
Suspension: M030. Lindsey Racing Spherical castor mounts. Lindsey Racing spherical adjustable camber top mounts. 1.5 degrees negative camber front and rear. Strut brace. Wheels - Porsche 2002 Carrera 5 spoke (genuine). Front 8.5 x 18". Rear 10 x 18". Pirelli P-Zero Rosso tyres. Front 245 40 ZR18 97Y. Rear 285 30 ZR18 N4. 7mm spacers at rear.
Bodywork / Interior: Plasma headlamp bulbs 170/160w. Drive/Fog lamps fitted with Xenon Plasma bulbs. Iceshark heavy duty lighting loom. Alternator fitted with adjustable regulator - 0.5v higher voltage. 'Flamingeye' LED instrument cluster illumination.
MOMO steering wheel on removable boss. Charge air temperature gauge to measure temperature in / out of the intercooler with cross-needles. Auto Meter 20 PSI boost gauge and EGT (exhaust gas temperature) pyrometer. Custom 'A' pillar gauge pod to take boost gauge, charge air temperature gauge and exhaust gas temperature gauge. Link Electronics air/fuel illuminated gauge fed by wide-band O2 sensor & PLX200 data converter.
Porsche 931 bonnet (924 Turbo)........................................
My plans are to use the original 2.5 litre bottom end but have Darton sleeves fitted and stroke using a S2 crank to take the capacity to 3.0litr. Buy forged rods and pistons to hopefully in the end have a strong/reliable engine to play with. I have the modified head (bigger intake valves) ceramic liners intact and will fit a modified intake manifold to help with the breathing. WUF already has 72lb injectors, a remappable ECU and a stage II LR intercooler so i think... that this side is already covered?
I can buy all of the parts from LR but this is in America, costs a fair whack and will get hit with import duty and VAT.
My main questions are....
Does anyone know if the parts I need can be sourced in the UK - light weight pistons and rods (with the offset to match 2.5 engine with s2 crank)? Should I go as light and strong as possible, my understanding is that I should? Should I keep the compression ratio standard? Would like 500+ bhp/torque!
LR do a steam vent kit (need to drill the head and attach back to the coolant tank), this is supposed to cure an air pocked build up that happens in the 2.5 engine by cylinder 4 which I know is where WUF has blown gaskets before (but I am unsure as to why, reading round though could this be why?). Has anyone used this, does it work, could this help?
Will a LR stage 2 intercooler be up to the task?
What turbo should I look to use? The LR Super 75 is a beast but has quite a bit of lag, with the increased capacity though I believe it may actually get used as it should be (and work better)..? What turbos do you guys use and how do they drive? If I use a smaller turbo I know it will spool faster but I do enjoy it when it kicks in, will I lose this with this setup or is it likely to just happen quicker?
Knife edging the crank, how will this effect things? Some say to do others say not to decrease the rotating mass too much...
Clutch, any recommendations? I'm pretty certain that the NA will not be enough and WUF needs a new one anyway. It will be a street car mainly so need handle the power smoothly! LR do a lot of different kits but are there other alternatives? Has anyone used one of these SPEC "MINI TWIN" CLUTCH KIT 944T "951" how do they handle?
Please let me know any thoughts, ideas or if I'm just going about this all wrong!!
After 2 and a bit years of talking/thinking about doing this I want to make sure I do it right and end up with the car of my dreams (and do WUF justice)!!
Kind Regards
Tristan...