Supercharged 308GTB almost ready to go

Russ,

Have you tried looking in the aerospace industry?

Burns Stainless sells oval stainless exhaust tubing and bends. They sell round aluminum tubing and bends and maybe have a source for oval aluminum tubing? You should check with Aircraft Spruce too. You could maybe run rigid tubing with silicone hose connections.

Wil

 

Thanks. Yeah, they'll be repainted before the car hits the road. I bought them used from a Porsche recycling yard in Los Angeles. They're the same calipers as on an F355 but much cheaper when they don't have the Ferrari sticker on them.

Wil

 

Steve,

I just took some pictures.

#1 Side view. You can see the 308 pedal box with a 1/4" aluminum plate sanwiched under it holding the Tilton tandem remote master cylinders. The top plate acts as a cover for the pedal box inspection hole and also as a brace for the master cylinder mount. I'm in the middle of machining an aluminum spacer block to fill in the gap. All the aluminum is 6061 T6. The hole in the side of the pedal box is where the power brake booster was removed. That will get an aluminum cover.

#2 Top view. The connecting link between the pedal and the Tilton piece, machined from 3/4" steel hex rod, is visible here. It should be aligned better but with no clutch pedal in place right now, the brake pedal slides back and forth on its fulcrum shaft. The rod connecting the two master cylinder push rods is threaded. Turning the rod moves a bearing side to side to change mechanical advantage left to right (front to rear master cylinders) to vary the brake bias. This is a typical race car bias mechanism and works very well.

#3 Bottom view. Plate is unfinished. Link with 1/2"-20 LH rod-end bearing and extension welded onto pedal visible here.

#4 Tilton remote brake bias control cable kit.

#5 Brake fluid reservoirs. Each master cylinder comes with the choice of a large and a small reservoir and whichever reservoir you choose can be mounted directly on the master cylinder or remotely on a special bracket which is included as is the hose and a choice of master cylinder out-put fittings for rigid brake line or AN braided hose.
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Thanks Mark,

So far, stock flywheel and pressure plate with Kevlar pumpkin tooth lining on the disk. I'll see what happens. The clutch is easy to change. The problem with a lot of multiple disk clutch set-ups is that they don't hold up well in traffic. I want to track the car but I want to use it on the street too. It's all a big experiment as you well know.

Wil

 

Hello Clyde,

The next EXOTICARSHOW is on September 24 so yeah, I certainly hope I won't be pushing it then. We only just got the date a few days ago and haven't started advertizing it yet. Last August 14 was too hot. We nearly had a riot on our hands with people saying " just give me my damned trophy to I can find a place with AC!" I look forward to seeing you there!

Wil

 

Hello Paul,

Yeah, the Electromotive ECU and all the sensors are in the car. We just need to wire it all up and do the mapping. Once we have the system basically set up I'd love to compare notes. We just installed the same system in a Diablo and a Countach but that data won't do me much good.

I can't remember what size injectors I put in there. I'll check.

According to the pulley sizes I should wind up with about 10 PSI. I probably will try raising the boost but I wanted to see what I could do with totally stock engine internals. I think any increase in boost will require better pistons. This is a Koenig 308 but when I took the engine appart I didn't find any parts you wouldn't expect to find in a 77 Euro 308 engine.

Did you see the photos of my master cylinder set-up? Looks familiar doesn't it?

Wil

 

Paul,

No, I'm pretty sure I have cast pistons. I wanted to see what I could do with totally stock engine internals. Forged pistons are on the list for the next upgrade, possibly with an even lower compression ratio.

The Electromotive ECU is mounted behind the driver seat along with the fuse box.

I do have other components in the trunk, such as the fuel filter, the intercooler expansion tank and the coolant recovery tank, which shouldn't get too hot so I hole-sawed a long row of 1" holes along the botom of the rear trunk bulk-head, hiding behind the rear bumper and I have a fresh air duct into the trunk from a scoop under the car. The stailess steel exhaust system will throw off less heat into the trunk than the OEM system did and the low restriction "mufflers" will help in reducing heat build-up too.

I also feel that removing the (oil to air) oil cooler will help a lot too. As far as I'm concerned, that thing just blew hot air back into the engine compartment, straight at the dry-sump tank and trunk front bulk-head.

I have the biggest (oil to water) Setrab oil cooler I could get, mounted on the engine compartment front bulk-head. This will bring my oil temp up quicker and will hopefully keep the oil temp the same as the coolant temp. The more efficient aluminum radiator should be able to handle the extra heat.

Good luck with your engine assembly.

Wil

 

Thank you, I'll do my best.

Thank you and everyone else who responded for the interest.

Wil

 

Mark,

Thanks for the feed-back on the clutch. It's much appreciated.

Like I related to someone else on this forum: I bought the calipers, and rotors too, off of a low miles wrecked Porsche at a recycler in Los Angeles.
I originally contacted Wilwood but they had such an uncooperative sh*t attitude that I gave up on them. I also didn't find what I wanted on E-bay.

the brakes I have now should work just fine. The 308 is such a little car compared to a lot of the newer stuff, a reasonable amount of performance from the engine, brakes, suspension, tires, etc should go a long way to making this a real fun car to drive.

Wil

 

Paul,

Thanks,

This whole thing is an experiment. I wanted to see what could be done retaining stock internals, mostly, but I'll probably be experimenting with some more radical components later. Unfortunately, what works on the track is not always suited to the street. What I like about supercharging is that at low speed the engine is still very docile and driveable. A lighter flywheel will probably effect that negatively. I appreciate the input though.

Wil

 

Paul,

It's pretty well impossible to see the holes in the trunk. If you slide your hand down the inside of the rear bulk-head/tail-light panel you should find a step before the trunk floor (The later cars hve a different trunk interior so that step may not be there in your case - I can't remeber). I cut the holes in the vertical surface of that step from the outside with the buper off the car. I re-carpeted the rear bulk-head so that the holes would be hidden but not covered when looking into the trunk. I also riveted a sheet aluminum baffle behind the holes, spaced out about 1", to prevent flooding the trunk if I hit the bumper with a spray of water while washing the car. The holes are pretty well invisible but it's just a 30" row of maybe 12 holes in the verical metal at the back of the trunk that come out behind the bumper.

You can see the 3" diameter aluminum inlet pipe in the bottom photo of the first series of pictures I put up. It's above and left of the right rear upper control arm. You can also see a sliver of it in the bottom right of the first picture. I have 3" silicone brake duct hose that will go to a scoop in the area under the right fuel tank. Those pieces are still on the bench. The scoop and hose came from Pegasus Racing but I can show a picture of those pieces.

You're very welcome to come and look.

If you want kevlar lining on your clutch disk, send it to me and I'll take care of it.

Wil