[KEN CROCIE]

I think we invented the "dial a boost" back in '77. We had a customers car come in witha Fairbanks TH400 and a "dial a shift".This varied the amount of vacuum applied to the modulator to change shift "feel". We got the idea to apply this to the unused port in the (then new) Deltagate. Dial a boost was born. Were we first? I dont know , but there weren't a lot of CO's in the turbo biz back then.
Fuel pumps: We used the Holley "blue" with the Moroso "high pressure spring" which boosted the pressure to 20 psi, enableing boost pressures of 10-12 psi. At that time we retained the boost compensated mechanical pump which was much more reliable than the Holley elec. and came up with an elec.pump automatic bypass device so that the elec. pump would not have to run full time.

[CROCIE JR]

Moroso PN 65770. Says 19psi. Current item. Use a AN washer for back up on the spring for fine tunning of the PSI.
More stuff flooding in. Remember the black, plastic, 2 1/8", enclosed rectangular gauge cluster. Held 3 SW delux gauges. Had a Fuel pressure, bonnet pressure and manifold pressure. My job as a 7 year old was to watch all three gauges (usually taped to the windshield or in my lap) and report my tracking data to the Boss. Those cars hauled ass. 2.41 gears and a th400. Only way to go! First gear was fantastic. It just kept pulling to 60mph or something. My dad was always trying to find the limits. So 14-15 psi boost, 301e rayjay w/1.3 housing and 400-455 cubes. Very fun. And dont think there were not "Special" turbo cars at H-O. Pioneers for sure.

[Tom Vaught]

Originally Posted by KEN CROCIE

I think we invented the "dial a boost" back in '77. We had a customers car come in witha Fairbanks TH400 and a "dial a shift".This varied the amount of vacuum applied to the modulator to change shift "feel". We got the idea to apply this to the unused port in the (then new) Deltagate. Dial a boost was born. Were we first? I dont know , but there weren't a lot of CO's in the turbo biz back then.
Fuel pumps: We used the Holley "blue" with the Moroso "high pressure spring" which boosted the pressure to 20 psi, enableing boost pressures of 10-12 psi. At that time we retained the boost compensated mechanical pump which was much more reliable than the Holley elec. and came up with an elec.pump automatic bypass device so that the elec. pump would not have to run full time.

So when are you going to figure out how to post those pictures of the HO racing Flow Bench, Ken? (;>)

Tom Vaught

[CROCIE JR]

Hes got some small vac. lines running to the side of the computer tower right now. Might be cooling lines of some sort. There is a diaphram, and I see some Dorman brass. I will call him tonite to check on him. He has been barking a lot, and mumbling. But mostly barking. Its hard to hear over the Beethoven.

[Joe37]

Hi guys, work is progressing on the T/A, the brakes are being finalized so the car can be moved around to get the engine out. Our next step is going to be partial engine tear down for inspection then on to the test stand for a break-in run.

I have a question about waste gates and blow off valves. Being as turbo stupid as I am, can you explain what the each do and why you need them? I only work on diesels and we never have any turbo problems other then the Ford 6.0L, and those were just bad from the get go.

We would like to limit the boost on the T/A to about 6 or 7 till it gets some miles on it and we feel comfortable with how its running since the car hasn't been road worthy since the early '90s. We are sticking with the original Turboforce parts for now as this is what the budget allows. This is also a four speed car, with a 3.42 rear axle, and with that combination, there won't be much room for error between shifts.

Joe

[Craig Hendrickson]

H-O used both a wastegate and a blow-off valve on the TurboForce, but not at the same time and not always.

A wastegate is on the inlet side (between exhaust manifolds and turbo exhaust scroll). It bleeds off exhaust flow and pressure to control the boost indirectly. A wastegate lives in a hot environment being attached to an exhaust pipe somewhere. We usually ran them without an outlet pipe and muffler; you can definitely hear the "whoosh" when it opens up.

A blow-off valve is on the outlet side (between turbo outlet scroll and the pressure hat). It opens when the boost pressure exceeds its setting so it controls the boost directly. A blow-off valve lives in a more benign environment than a wastegate and is more effective on controlling the boost into the carburetor when you go from WOT to throttles closed quickly. However, a blow-off valve potentially lets the turbo overspeed and therefore operate further away from the sweet spot island on the turbo map.

Even though the wastegate is a little more expensive, that's what I would recommend. As a matter of fact, the earlier versions of the TurboForce pressure hat had a pad cast in the side which could be machined for mounting a blow-off valve. The final and best version of the pressure hat had eliminated that pad.

Craig

[Tom Vaught]

Originally Posted by Craig Hendrickson

Even though the wastegate is a little more expensive, that's what I would recommend. As a matter of fact, the earlier versions of the TurboForce pressure hat had a pad cast in the side which could be machined for mounting a blow-off valve. The final and best version of the pressure hat had eliminated that pad.

Craig

I remember that Pad.

Tom Vaught

[Craig Hendrickson]

Originally Posted by Tom Vaught

I remember that Pad.

Here ya go, Tom:



On my 1978 Turbo Macho T/A with 1972 455 engine (not the W72 engine), I had both a wastegate and a blow-off valve. I had the last generation pressure hat specially modified by Kern in order to fit the blow-off valve. It was on the other side of the hat than shown in the above picture. It was a belt & suspenders kind of solution to boost control.