bradthebold

Hi, I just bought an ‘88 951 that sat for ~10 years and has 117k miles and am looking to do maintenance and upgrades and want to make sure I can order as much of the stuff I need the first time around without having to place a bunch of extra orders for a missing seal or bushing that I missed or didn’t know about.

The previous owner got the car running well and replaced vacuum lines, speed and reference sensors, changed oil and coolant. Carfax says the fuel pump, filter, and lines were replaced last year, though the mileage listed was wrong, so I’m not sure if it was actually done. Edit: The damper to rail line is definitely old and cover torn, so they'll get replaced

I am most likely planning on going with a Vitesse 3rx kit with Aquamist W/M injection for proposed power level. It’ll be 95% street, possibly doing some DE. PO said compression readings were 135-140 on all cylinders. I just bought a leak down tester and will rent a compression tester and verify numbers. Oil pressure is ~4.5 bar cold idle, 1.5-1.75 bar warm idle. I’ve only driven the car on the test drive then towed it home. I noticed no issues, but have limited seat time.

Planned Maintenance items

Timing belt/roller kit $223 Zims
PS belt $7 Zims
Alternator belt $15 Zims
New Waterpump w/hardware/gasket $165 Zims - URO
Front engine seals w/races $97 Pelican
Oil pump gear, or more comprehensive seal kit with the gear
Oil Cooler Gasket Set $33 Pelican
Low temp & turbo T-stat w/seals $54 Zims
Rod Bearings $74 Pelican
Rod Nuts $20 Lindsey Racing
Throttle body reseal $20 Arnworx
Dipstick o ring $2.50 Pelican
Oil pickup tube ring $9.50 Pelican
Oil pressure relief valve ring $2 Pelican
Upper and lower oil separator rings $5 Pelican
Oil Cap Seal $2.50 Pelican
Rear Main Seal In clutch kit
Oil Pan Gasket $43 Pelican
Intake Manifold gaskets $6 Pelican
Rear balace shaft seals

Performance Parts

Vitesse Stage 3rx $4400 Vitesse
~80lb injectors ~$400 Vitesse
Boost Solenoid $100 Vitesse
V-Knock $140 Vitesse
3 bar FPR $95 Vitesse
Tial 38mm Wastegate kit $440 SFR
3” coated downpipe $375 SFR
3” test pipe $760 SFR
3” catback $700 SFR
KEP stage 1 PP w/cup clutch ki ~$800 Paragon
Clutch accessory kit $83 Paragon
Aquamist HFS-3 $715 Howerton engineering
Short Shifter $93 only944
Shift linkage $24 only944
Only 944 shifter
Exhaust gaskets beyond what comes with the exhaust/turbo???

Suspension

968 M030 sway bars w/bushings $550 LR
Front sway bar stiffeners $40 Paragon
Front control arm bushings $158 Elephant racing rubber
Spring plate bushing $120 ER rubber
Trail arm bushings $210 ER rubber
Spring plate cover mount $240 ER aluminium
29mm Torsion bars $300 Paragon
Adjustable ride height 300lb springs $265 Paragon
KLA strut tower brace $150 Paragon
Tie rod ends $57 Paragon
Koni Yellow rear struts $333 Paragon
Koni Yellow front strut inserts $443 Paragon
Rennbay ball joint kit $185 Paragon
Rear drop links

Arnworx tool kit $302
Brake lines $105
Fuel Lines if needed $202-290 Rennbay or LR
Fuel filter
Hella H4 lights and harness $260 Rennbay
Trans fluid – 3 qts MT-90 $50
Engine mounts $430 Paragon
Fill trans mount with urethane


Should I replace plug wires/cap/coil? Wil do
Should I add an oil pan baffle? Probably not for the street
Should I rebuild the torque tube if there’s no noises? Tempted to just get Black Sea bearings while it's out
Should I rebuild the LSD or wait for issues? Probably just going to change fluid
If leak down is good, should I mess with the head or internals beyond rod bearings? Leaning towards no unless I should
Similar Lindsey exhaust w/coated downpipe is $500 cheaper. Is the SFR SS system worth the extra cost?
Will the KEP stage 1/cup clutch hold that power? Should

I’m going to drop the engine to make everything easier. Any extra parts that I will need or should be replaced? Or any parts I don’t need or should go with a different brand/product? Thanks

V2Rocket

With proper weight oil filled all the way, warm idle oil pressure should be 2.5-3.5 bar
cold is 4.5-5 (pegged).

Are you sure it's topped up all the way?

fejjj

I have the WG adapter Plates if you need them.

odonnell

Jeez... for that kind of investment in performance parts you could get sorted with a real standalone and big turbo with cash left over, and have a more reliable EFI system.

bradthebold

The oil is just past the top line on the dipstick. From searching, it looked like 1.5-2 bar was a normal hot idle pressure. E.g. https://rennlist.com/forums/996-foru...ow-normal.html

I haven't seen anyone claim that high, even searching again? I did only check it the one time, but I'll double check when I warm it up to test compression/leak down.

bradthebold

I am looking to keep fabrication/modification to a minimal if I can. What other options would you recommend?

Vitesse does seem expensive, until I started looking at alternatives, like a GT(X)30R from SFR. The turbos are only $1500-2000, but when you add ~$1000 for a mount, oil lines, clamps, and water fitting, plus modify the crossover pipe or spend $1k on a new one, and modify water lines, it adds up. Minimum $2500 with crossover modification for a GT30 up to $4k for a GTX30 with new crossover pipe. And then you need a MAF kit and possibly piggyback in addition to that.

I am definitely open to other options though, this just seemed like the best route so far.

neunfünfeins

Maybe for a 996. You posted a link to a thread from the 996 forum.
2.5 bar min hot idle is what I've seen for a 951 as well.

Unless the oil pump is being starved because the oil level is too low, why would the oil level have that much bearing on the pressure developed in the system?
Is there something different about the 951 oiling system from every other kind of engine I own?

bradthebold

Oops, that was a bad link. A couple other have stated 1.5-2 bar, but others, and Clark's garage, do say the 2-3 bar warm idle. I'll check again this weekend.

V2Rocket

Dunno...but I've seen it plenty of times where a 944 has low oil pressure, check the oil and its a quart or 2 (!) low...top it off, and the pressure is fine again.

Never gave it much thought beyond that, but that's been the solution for a number of cars over the years...

Smudo

If you put 300 lb springs in front (effective rate around 280), I would go with 28 mm TB in the rear (254 lb), especially if you plan to drive the car also on a road and not only on track. Even 28 mm will be quite harsh if you do not have ideal roads where you live (I have 250 lb WM springs and 28 mm TBs, 30mm and 19mm swaybar setup for the last two years). It is good on the track and highway, although you have to be careful with the steering input due to some oversteer, however, almost unbearable in the city If you want more oversteer, you can adjust the 19 adjustable rear sway bars to middle or hard position. A lot also depends on the alignment.

neunfünfeins

I haven't quite put my finger on it, but I suspect there may be something peculiar about the oil pump / pickup design that defies 'conventional wisdom'.
Yeah a quart low would make me quite nervous, what with the infamous oil starvation issues and all.
Two quarts?? YIKES.

V2Rocket

fun fact...my 944 put down its best dyno numbers while 2 quarts low...

i promise it was the tuning, not the lower windage...

neunfünfeins

and fortunately dyno runs don't involve lateral g's.

bradthebold

Ok, so I let it warm up and it was 2.5 bar at the lowest at idle, so I must have read it wrong last time.

I compression and leak down tested. I'm not sure the rented compression gauge was accurate, but the compression numbers were 120-122 for all cylinders. Adding oil did not change the numbers. Forgot to hold the throttle body open at the beginning, but it didn't make a difference re-doing it.

Leak down was 1-3% between all cylinders, which seems unbelievable too. I only heard slight air leaking past the rings on cylinders 2 and 3 and no sounds on 1 and 4 at 100psi though.

Trans is out and engine is just held in by the crossmember bolts, so it will come out this weekend.

The turbo has seen better days.

neunfünfeins

Ouch. Almost as bad as the guts of our old Hoover upright that sucked up one too many marbles...