Supercharged 308GTB almost ready to go

Thank you, Thank you. No, I have access to CNC but my own machines, which I did the work with, are hand operated with the aid of DRO (digital read-out) set-ups which save time and effort. Staying accurate is a lot easier too.

 

Steve,

Thank you for the compliment.

To answer your first question: I've been driving the car on the street and on the track and have taken it to various shows. Unfortunately it's getting a little sand blasted in the front for shows now but I had a great time getting it in that condition.

I have a Meziere constant speed electric coolant pump mounted in the front of the car. The original pump, which is marginal to begin with, probably would have had trouble moving enough coolant to keep the more powerful engine happy but the main reason I removed it was because it was in the way of my super-charger installation. I removed the actual water pump and also the back housing and made up all new coolant plumbing in the engine compartment. There is a photo in post #52 on page 3 of this thread showing the engine sitting on a bench. On the "front" face of the engine, next to the rear cam-cover is the in-let port for coolant from the water pump.

If you eliminate the entire water-pump housing you will need to make up a hose fitting to mount to the inlet port for coolant returning from the radiator.

If all you want to do is eliminate the belt driven water pump part of the assembly you should be able to make and install a block-off plate in the shape of the water-pump mounting gasket. The electric pump will move the coolant right through the rear housing of the old belt driven pump without the restriction of the old impeller.

I tried running the system without a thermostat and had the electric pump controlled by the ECU that controls FI and ignition but it was unable to react quickly enough, oddly enough. I now run a thermostat with two 1/8" (3mm) holes drilled in the outer ring so the pump can at least make some flow when the thermostat is closed. The electric pump now runs full time and has been very reliable. Since I eliminated the entire old water pump housing I lost the thermostat housing also. This was solved by purchasing two billet aluminum Chevy V8 thermostat housings (cheap), bolting them together, back to back, and splicing them into the coolant hose running towards the radiator.

I also installed a water cooled oil cooler, an aluminum radiator and a big Spal type electric fan. The whole system works very well.

The included photo should help with water flow questions. If you have more questions I'll be happy to try and answer them.

Wil
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Hi Charles,

The rotors and Brembo calipers are from a Porsche 966 Turbo. I bought them used from ladismantler.com. I read once that half of Porsche's world production was sold in the Los Angeles area. I don't know if that is still true today but you can still get lots of good used Porsche parts in LA at good prices.

All 4 rotors are 966 FRONT rotors. The rears from that car are not removable from the hats. The front calipers are radial mount. The rear calipers were old style ear mount but I converted them to radial mount.

I machined the hats from 6061 aluminum bar stock.

I've tracked the car numerous times with this brake set-up and it works well.

An alternative is to go on-line to Wilwood. You can find many sizes of rotors and aluminum hats. I bought some nice front rotors for my Mazzer and a pair of aluminum hats at very good prices. I had to modify the rotors to fit the particular hats I needed and modified the hats to fit the Maserati hubs but that wasn't too bad.

Good luck.

Wil

 

I received a PM from Brian asking about a manifold for an 82 308GTSI to adapt a Lysholm type supercharger like mine and decided to answer him here.

Brian,

I don't have an extra manifold like I made for my formerly carbureted 78 308 and my manifold was machined from billet (expensive). An 82 308 has a nice plenum sitting on top of the engine just about ready-made for a supercharger to blow into. I would mount a Vortech or similar centrifugal supercharger at the right rear corner of the engine bay and run some plumbing up to the existing plenum. Vortech makes a nice in-line air-to-water intercooler with the intake and outlet all set up for hose connections. It couldn't be easier than that! With EFI you should have no trouble making 400 HP with that car.

Wil

 

Charles,

Thanks for the compliments.

Those aluminum rotor hats were machined without the aid of CNC. They would be very expensive.

Your best bet is to select a pair of Wilwood rotors (my Porsche 966 rotors are 12" diameter) to fit your calipers (in width and diameter), figure out how you're going to mount your calipers and see if Wilwood has a pair of hats to fit between the rotors and your hubs. The bolt circle doesn't have to match. If you buy hats with a five hole circle you can have a machine shop drill new holes of the needed circle diameter between the factory holes. It's going to take a lot of measuring and looking through web catalog pages to find a combination that will work for you.

Girodisk makes larger rotors to fit 308 front hubs and they're nicely made but I don't remember what diameter or thickness they are.

Wil

 

Last Sunday we attended a Ferrari club event, about 2 hours away, with the 308. Shortly before arriving at our destination the air conditioning quit making cold air. Not fun on a hot day but oh well, roll the windows down and soldier on. On the way home after the event the engine had good oil pressure, good coolant temperature, good boost from the supercharger, no alarming noises and everything except for the AC seemed good.

Getting close to home we saw and smelled smoke when we stopped at a toll booth and shortly there after the engine suddenly lost boost and quit. I knew the serpentine belt, which powers the super charger, GM alternator and GM AC compressor had broken and opening the engine hatch confirmed it. We trailered the car home and on Monday we took the back of the car apart. It looks like the AC compressor clutch bearing failed, got hot and fried the compressor clutch or the clutch got hot and caused the bearing to fail. In any case, that was the cause of the belt breaking. What else is interesting is that the alternator is cracked at at it's mounting boss. Not sure what caused that and the AC compressor failure but I wonder if it's from the stress put on them by the engine turning the supercharger with the serpentine belt and the alternator and AC compressor acting as idler pulleys. It's still not bad after several years of hard driving including track events.
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There are more than a few too-bads crammed in there but that's the way it is. You're exactly right about the serpentine belt but one thing it does do is to allow a lot of accessories to be stuffed into a tight space (and tight it is).

I may be misunderstanding your point but the AC compressor only turns on demand with an electromagnetic clutch. If the AC system isn't switched on, the pulley just idles. If I had built a pure track car I certainly would have eliminated the complexity and extra weight but this is my only Ferrari so it has to be reasonably comfortable for the road also. It's the old story. The more complicated you make any kind of system, the more likely it is something fails. I should rip out the stereo though, since I never listen to it

 

Hello Martin,

Thank you for your input on my car's alternator failure. I've read your posts on F-chat in the past but I'm not sure we've ever "spoken".

My 1978 308 (built for the German market by the way) is modified and has 3 electric fans (one large fan for the radiator and two smaller for the inter-coolers), an electric water pump for the engine cooling and another electric pump for the inter-cooler plus a big electric fuel injection pump, high energy ignition, an ECU (computer) and it still has all the other electrical equipment the car came with from the factory. I don't remember exactly but I believe the original Bosch alternator only produced about 60 amperes which is not enough to keep the battery charged under that electrical load. The GM alternator puts out 120 amps.

To deal with all the extra power the engine makes I've actually removed one "silent block" rubber bushing from the dog-bone torque strut. With all the pull on the belt from the supercharger It's probably not a good idea to have too much flex at the alternator mounting. If the new alternator lasts another 3-4 years before it cracks, like the first one, I'm OK with that. Nothing is free.

Wil

 

Hi Sean, You can find a separate thread on the Brembo (Porsche) brake up-grade here: http://www.ferrarichat.com/forum/showthread.php?t=45920 I haven't looked at it for a while but it may help answer your question.

 

Thanks Garnet. Funny post!

 

Thank you Taz.

There have been other failures but mostly on the race track. An ignition coil pack and a spark plug cable failed from excessive heat at the Monticello track (better insulation kept that from repeating). The actuating arm came loose from the supercharger by-pass valve at the Watkins Glen race track and I lost 3 pounds of boost (out of 8). A header gasket blew out at New Jersey Motorsport Park and the following year, at the same track, I was turning hard right and, while coming out of the turn, I was supposed to shift from 4th gear to 5th but the G-force on my body helped me to stupidly pull the shifter into third instead and the supercharger belt broke instantly. I was able to change the belt in the paddock garage and return to the track but it was no fun without a lift and rudimentary tools. This was the first time since initial test runs that the car had a failure on the road.

The engine puts out about 400 HP.

 

I have lots of ideas: Port the heads, change the pistons and raise the boost, install vernier cam pulleys to dial out the remaining valve overlap, carbon-fiber engine cover (the steel cover weighs a ton!), a radiator exhaust duct in the front lid, stronger rear stub-axles so I can run slicks, racing seats, a roll bar......