Re: Type 1 twin screw supercharger build / 9 yrs later I'm back at it

[Alexander_Monday]

Picked up an engine stand on marketplace cheap and modified it to fit the VW yoke.

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Also picked up a motorcycle lift cheap and cut out the bar in the middle and added bars towards the front and back to clear the sump drain.

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[Alexander_Monday]

I have now pegged the 1994 Cobra MAF at 5V at 7400rpm.
I ordered a 1993 Cobra SVT MAF and will install it after winter tear down.
The 94 MAF should theoretically top out at 270HP* and the 93 at 360HP*.
* Rule of thumb with a supercharger MAF g/s * 1.1 = flywheel HP with good tune.
* N/A and turbo MAF g/s * 1.25 = flywheel HP with good tune.
* Supercharger takes into account the power lost to drive it.
I also am at 80% duty cycle with 73% ethanol and 850cc injectors.
This calculates out to a BSFC of somewhere around .96.
Best I can tell it should be around .80 to 0.85.
This is also in line with the logged acceleration calculating out to 258HP vs 270HP MAF rule of thumb.
Unfortunately, Mike Jones has not received the cam blank needed yet to grind the new one.

I had to make 2 emergency stops due to head up their ass drivers pulling out in front of me.
Both times the front brakes locked up and the back did not seem to contribute much.
Since the front tires are so much smaller and the compound harder with the same size calipers this makes sense.
I could not find much about installing a proportioning valve in the front line since usually it is the back line.
I chatted with Wilwood and they confirmed that one can be installed in the front line to compensate.
The one they recommended is ordered.

With the weather turning it is almost time to tear down and check everything and see how much needs replaced.

[Piledriver]

FJCamper runs one on front of his ghias for same reason.

I went to a larger rear caliper, then switched compound with more bite on rear of my square.
(7" manholes front, 8" rear, polished,, fronts were 205/55s? rears 245-50s, cooper rs3 tires maybe just not enough grip)
Am running "965" rear rotors out back with 928 Brembo front calipers now stoptec sport pads on them, vs factory Pagids.
Front has Wilwood Superlites 1.25" 4 piston with PFC 14 pads on Wilwood 11.25" x 1.25" 8x7 rotors on steel hats.
(cut down stock rotors for hubs)
Front still (just) locks first, but rear contributes immensely now, combination now almost like catching a stump.

The rear calipers piston area is now IIRC larger than the fronts, so it's down to the grabbiness of the pad compound.
(or lacking tire compound)

Have some 8x18s and 12x18 flowone F2s for for square once new motor and 090 automatic is in.
(flaring fenders urquattro style)

[Alexander_Monday]

I'm just running the Varga TRW RCFD00706 Ghia 2 40mm piston calipers on all 4 with a Ghia master cylinder. Much better than the original brakes though. I might look for better pads for the back though, hadn't thought of that.

[Piledriver]

I went that route as it was all easily reversible, even the calipers/rotors...

[Piledriver]

Industrial clutch places can reline brake pads/shoes with a great choice of compounds... Ray and FJCamper suggested that to me a few times. There's even a place in Dallas that does it. I'm sure there are many places on the left coast that do it.

[Alexander_Monday]

I'm going to try the proportioning valve first.
I am a little worried about wearing out the rotors.
I cannot find where I got them or what part numbers it so many years ago and I had ARP press in studs fitted to them.
I did find the order for the studs, so I do have their part numbers as that was just a few years ago.

[Piledriver]

Do you have hubs and rotors? Usually 914 rear rotors. (hat part looks ~ 4" deep can measure one)
If you want internal parking brakes the early 911 ones can be made to fit, use 914/6 rear rotors.

If one piece with splines etc think everyone sells the same bits.
The one piece ones I have seen all appear dimensionally the same as the 914 hub/rotor combo, but you can get T3 hubs in CrMo.
You can get the hubs and 914 rotors pre drilled in many patterns, including blanks.
(same for the combined one piece setups)

When I originally set my square up I turned down the outer bit of the hub under the nut and added an aluminum centering ring.
(hubcentric) Made a noticeable difference, much smoother feel on the highway.

[Alexander_Monday]

They are one piece.
I got them local many years ago at a shop that specialized in VW and Audi stuff.

[Piledriver]

I can pop a tape measure on a 914 rotor if you want to know...

[Alexander_Monday]

That would be nice for reference, but at your convenience.

[Piledriver]

I need an excuse to clear a spot for the 914 in the shop anyway: it's next.

[Alexander_Monday]

And it begins

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[Alexander_Monday]

The gland nut was a bugger to get off.
Had to grind down a 38mm 3/4 drive socket to fit the back side of a torque multiplier.
Even then it took a cheater bar to get it loose.

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[Alexander_Monday]

The pressure plate has bent an arm or something.
That would explain the jerkiness engaging.

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