Plan for (inexpensive) 300+ hp SC motor

[Packy]

This is my plan for an inexpensive 300-350 hp/tq motor. Please leave the "buy a 3.6 at home" and we all know the differences in turbo charging and supercharging and have heard that conversation. This is a multiple stage project that will allow me to fund it in little chunks instead of dropping 5 to 10 grand all at once. The first stage will allow for a lot of power without opening up the case or removing the motor from the car. I will do intake with EFI first then ignition then exhaust then supercharger with intercooling. Doing it this way will allow me to trouble shoot easier. Next stage will be beefing up the guts of the case. after I do this I should be able to get 500 to 800 hp. Have fun. This should spark some good conversation.

Engine:
90k miles on an early 3.0L 911 SC motor with larger ports and lower 8.5:1 stock compression ratio with a 915 tranny. – boy am I glad I bought the early 911SC instead of a later SC with the smaller ports and higher compression ratio.

Upgrade Plan (stage 1):
Eaton m62 supercharger – $100, bought from a friend.
This supercharger only takes about 25hp to turn it to full boost and it is a roots type blower. The snout goes bad on these but there is no catastrophic failure. When the snout goes bad, I will hear it and send it in for a rebuild. Use a breather tube from crank case to supercharger. The major issue is finding manifolds.
I have info from TurboKraft, Supercharging of Knoxville and TPC.
Water to air intercooler – $400
Extra weight but small and more compact in engine bay. Also has higher efficiency due to the heat capacitance of H20 compared to air. Radiator up front of bumper. Use a 5 gal fuel cell with breather and cobra pump. -
Oil Cooler upgrade – $400, estimated high.
Don’t like all the expensive Porsche options, will fabricate my own. Oil coolers are cheap with a fan and should work just fine. Located in wheel well, maybe double in both wheel wells.
Twin plug direct fire ignition - $200 + $450 for machining
Ford EDIS system works great with twin plug, 6 pack, VR crank sensor 36-1, timing controlled with computer with serpentine crank, fan and S/C pulley. I was thinking of going with the XDi2 set up from Clewett but this way is cheaper and should work just as well. Also, making the XDi talk with my computer would require just a little more effort so EDIS is a little easier. Twin plug machining ($450).
Carrera Intake with throttle body - $600.00
No porting head necessary because I have the larger ports already. Many sources and bids. Add TPS – ’86-94 throttle body has this.
Computer – $500.00
I would have went with tbitz racing full set up but he doesn’t have the computer I need to work with a supercharger, so I will use everything he has but the computer. Our fuel pump is rated at about 70psi and 54 gph from what I remember so fuel is not an issue. I will be using 45# injector which are good for up to 400 hp. I need the MS2 chip to control boost and tbitz uses the older chip. I will also be using the wide band hot 02 sensor to make tuning and cold starts better. Boost control and ignition controlled by comp. I will also set my rev limiter at 6000 or 6250 because the rods are not forged and the rod bolts stretch at about 6700 rmp.
Fueling - $1000
TBitz Racing, everything but the comp.
1-3/4” Exhaust – 2k
Ceramic coated headers that stop after the collector. I should be able to get this for about 500-700 dollars. I want them to stop at the collector so I can throw on cats if I need to. Custom muffler with a GT3 style double tips coming out the center of the bumper ($900).
Custom bracketry and Supports - $TBD
Will be mimicking the setup of the 993/964 kit from TPC. Need to make tensioner plate, buy tensioner, coil bracket, fan bracket, left bracket, right bracket, inlet manifold, discharge manifold, discharge elbow and bypass air duct.
Pistons – 0.00
8.5/1 compression ratio is fine. Rings may have blow by but a breather tube from the case to the SC will lower the positive case pressure.
Rods – 0.00
Stock rods will work fine for now.
Hardware – 0.00
Limiting factor for strength of motor. Check head studs for bad dalivar studs and keep boost low for now (.7 bar). RPMs need to stay below 6700 for rod bolts. Engine cooling is important too.


Upgrade Plan (stage 2)
Larger pistons/cylinders, probably 3.2 to 3.4 – $4300
ceramic coated JE pistons, hastings piston rings or niresist LeMans rings ($450 plus head machining work).
Crank – $750
Mag crank, cross-drill, R&I oil plugs, micropolish, balance
Hardware –
head studs and other fasteners ($675), rod bolts ($285), rocker locks ($360/set) + motorsport seals ($96), turbo exhaust valves ($450/set), valve springs ($550) or ($750) with Ti retainers, motorsport timing chans and guides ($350)
Case mods –
3.0L case, boat tail ($300) dowel pinning case halves ($500), upgrade oil squirters ($300), 3.6L oil pump ($900) maybe a 993 super sport camshaft, high performance valve springs, gaskets ($95),
G50 Tranny – 5-15k
87-89 tranny with a 240mm clutch with hydraulic actuation, newer syncros, lightweight flywheel and limited slip differential.


References:
Hargett engineering, TurboKraft, Supercharging of Knoxville, TPC, Wayne Dempsey’s books, and a whole lot more that I’m not putting up here.

I am done with my planning stage and am now collecting components. I can't wait to take this puppy to the track looking relatively stock (except for bumpers) and killing those C5/C6 corvettes and beemers. HA!

-Patrick

[totle]

Sounds like i nice and well thought build.
Will be fun to follow

[MarKoBrow]

This is a great project that you are embarking on good luck. I have a few thoughts. The first, if you can get you hands on the M90 blower from the Ford T-bird you will be starting with a better blower that has the coated rotors. and it is far more efficient. Second, if you look at TPC's manifold it provides a platform for the supercharger to mount to. This is a pretty big challange when putting together a superchearged car. The third and most important point is stick to it, you will get it done!! Good luck

I am placing a picture from TPC's website

[Packy]

I did see TPC's kit and it is out of my price range. Not only that but they don't seem to take kindly to SC folks over there. They also are not too willing to sell manifold parts separately without the rest of the kit. I did get their install instructions and am planning on mimicking their bracketry with a 3.2 carrera intake manifold.

[Packy]

I was thinking of getting an m90. I wonder if the manifolds for the m90 and m62 are the same? I have seen build with both and went with the m62 because my friend already had one, soooo.......


But thanks for the good luck guys. I'll need it.

[MarKoBrow]

In looking at their manifold I can't help comparing it to a turbo manifold. I started my career designing patterns and cores for a foundry that specialized in aerospace design and I can't help noticing how simple that pattern would be for the home foundry type of person.... check out the home foundry websites , just a thought

[Packy]

Interesting Marko, I'll keep that in mind when I start my bracketry. I never thought about casting my own parts. I am an engineer by trade so I was thinking of machining some of these. I could maybe cast them if my green sand mold doesn't fall apart. When I do design these parts I am thinking of making a few of them so other people can have the opportunity to do the same install. But, that will not be for awhile.

[rennch]

Just following up on this...any updates?

[Packy]

Not on this car. My street porsche (another 1979 SC) broke a valve spring and spring retainer so I'm putting the motor that was going into the race car into my street car now. I give it another 2 or 3 weeks until I'm done with that. I still need to clean the engine bay, rebuild the CVs and replace the front wheel bearings on the street car, THEN I can jump back on the race car. I'm getting pretty antsy to jump back on the project though. It may be awhile until I supercharge because I need to replace ALL of the valve springs, rebuild the transmission fork which is sticking, and look over the entire motor for other bad parts before I start upgrading. If I need a top end rebuild then I have some thinking to do.

[Tippy]

Read what I posted on the "winter project......." thread.

[Facey]

Originally Posted by MarKoBrow

I am placing a picture from TPC's website

Do they have this for sale? i looked around their website an cannot find this!

[Packy]

The kit is for a 964 and is here:
Porsche 964 and 993 Supercharger Kit - TPC Racing

Tpcracing doesn't have a kit for 911SCs.

I want the brackets though.

[27Carrera]

We dont part our kits because it is designed to be a... kit. Fully inclusive from front to back. We are about to announce a sale as we just joined rennlist... Sorry if you thought we didnt treat you fairly, however, we dont sell pieces of our systems.

Email me if anyone needs assistance. cparkin@tpcracing.net

[sjf911]

Originally Posted by 27Carrera

We dont part our kits because it is designed to be a... kit. Fully inclusive from front to back. We are about to announce a sale as we just joined rennlist... Sorry if you thought we didnt treat you fairly, however, we dont sell pieces of our systems.

Email me if anyone needs assistance. cparkin@tpcracing.net

What an elegant setup, very short airflow path, very nice. Out of curiosity, considering the HP levels and the amount of thought that appears to have gone into this, is that the stock MAF or are you using an extender or alternative MAF to "extend" the sensor range? Also, compared to what you see from all of the aftermarket OEM cold air intake replacements advertised, that air filter looks relatively undersized (I assume the aftermarket sellers are appealing to the bigger is better mentality), what size air filter is that and what size intake piping are you using and do you have recommendations on how to size for HP?

[Packy]

Originally Posted by 27Carrera

We dont part our kits because it is designed to be a... kit. Fully inclusive from front to back. We are about to announce a sale as we just joined rennlist... Sorry if you thought we didnt treat you fairly, however, we dont sell pieces of our systems.

Email me if anyone needs assistance. cparkin@tpcracing.net

Why can't you sell the brackets separately?

I understand that it is a kit, but I have a 911 SC (actually 2), so sadly you don't sell a kit for my car. Hence, my desire to buy the parts that work for my car. I wish you guys would reconsider selling some of the parts alone. It is a well engineered kit, for the 964. I guess you don't like money

[John at J&S]

Companies are in business to make a profit, which is not a four letter word.

TPC paid engineers to design those parts, then a foundry to cast them, then clean up, machining, anodizing, etc, all with an eye toward going into a $4000 kit.

They didn't invest that time and money to be a "good guy" so they could sell you DIY pieces at materials cost plus 50% markup.

Sometimes a piece of inventory is worth way more than its cost, because it represents a complete kit that could have been sold.

For example, I make ignition controllers. The end plates are just a few dollars, but if I am out of them I can't ship a $600 order.

[Packy]

Originally Posted by John at J&S

Companies are in business to make a profit, which is not a four letter word.

TPC paid engineers to design those parts, then a foundry to cast them, then clean up, machining, anodizing, etc, all with an eye toward going into a $4000 kit.

They didn't invest that time and money to be a "good guy" so they could sell you DIY pieces at materials cost plus 50% markup.

Well, obviously. I'm not asking for a handout here.
What is this? Lecture time? Geeze!

Originally Posted by John at J&S

Sometimes a piece of inventory is worth way more than its cost, because it represents a complete kit that could have been sold.

For example, I make ignition controllers. The end plates are just a few dollars, but if I am out of them I can't ship a $600 order.

I am asking if he had extras or the means to make more or the many other numerous options to supply.

Where there is a will there is a way. I'm an engineer and I'm planning on making my own. There are ways. I have a welder. I can cast metal. I can machine metal. I'll probably make extras to help supply those who want them.

[Tippy]

Your car is going to be a beast off the line with that Eaton! I had a Ford Lightning once with one.

Once I went to 16 lbs of boost level (doubling stock boost), the blower would whine like crazy just by a slight throttle movement.

[patkeefe]

My guess is that "inexpensive" will be about $12k, when it is all said and done, not counting your labor. Many reasons for this, which are expensive lessons to learn.
Good luck!
Pat

[Packy]

Originally Posted by patkeefe

My guess is that "inexpensive" will be about $12k, when it is all said and done, not counting your labor. Many reasons for this, which are expensive lessons to learn.
Good luck!
Pat

???????

Don't let me stop you from sharing.

Please elaborate.