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Boost Pressures
Posted by: kaminski45 ()
Date: June 24, 2020 04:50PM

Does anyone know what the maximum boost you can achieve out of the all the Corvair turbo possibilities? I'm talking about a b-flow, f-flow, e-flow, b/f hybrid, e/b hybrid, or e/f hybrid. I know that the type of carburetor is the major limiting factor of the turbo, but I am wondering what could be achieved out of these combos.

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Re: Boost Pressures
Posted by: v8vair ()
Date: June 24, 2020 05:09PM

My 64 Spyder has a 180 carb and cold side,150 exhaust, exhaust and turbine housing wrapped. Stock points and condenser,MSD blaster coil.Seths Plug wires,Bosch W8A plugs. 3:08 gear.I bring the mechanical advance in a little earlier than stock.
Will get the boost gauge 1/2 way in first and second and might peg the gauge in 3rd and fourth Hot but I don't want to blow up so I don't do it often with a stock motor. And it seems fine with 93 octane A Blast to drive, wish 362 was as strong as my street car !

1965 Crown V8 Racer
1964 Bill Thomas Monza Replica Racer
1964 Spyder Street Car
1979 Mazda RX7

Mike Levine



Edited 1 time(s). Last edit at 06/24/2020 05:10PM by v8vair.

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Re: Boost Pressures
Posted by: MattNall ()
Date: June 24, 2020 06:23PM

Well over 20 psi... the Rajay is way too large for the Corvair engine!

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: Boost Pressures
Posted by: 63turbo ()
Date: June 24, 2020 07:52PM

Its easy to get over 20 psi with a F compressor and B exhaust... I have had mine up to 22psi in second gear. Yes, it REALLY screams with that kind of boost!! Friends of mine have reported 25-30psi with a E-flow compressor, but when doing that, they said that the standard F-flow exhaust turbine was a much better match for the E-flow compressor than the B-flow, and actually, for higher rpm power, the F-flow turbine coupled with a .8 A/R exhaust housing is even better.

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car






Edited 1 time(s). Last edit at 06/24/2020 07:54PM by 63turbo.

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Re: Boost Pressures
Posted by: Chet Jr ()
Date: June 24, 2020 08:58PM

Many years ago I purchased a fully modified Corsa Turbo from Bill Austin (CT?. The car had most if not all of the potential turbo modifications done that were possible for a street car at the time, including a 2” SU carb, and the Crown water injection.

The car was an absolute beast whose performance definitely shocked a lot of people. I believe the aftermarket gauge showed 30+ psi on a fairly regular basis. The one big drawback however was that the mileage dropped to about 6.5 mpg.

The stock carb is definitely a severe restriction.

Chet



Edited 1 time(s). Last edit at 06/24/2020 09:07PM by Chet Jr.

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Re: Boost Pressures
Posted by: joelsplace ()
Date: June 24, 2020 10:24PM

If I could run 30psi I wouldn't mind 6.5 mpg. I don't think any Corvair engine is going to stay together at that level.

Joel
Northlake, TX
5 Ultravans, 114 Corvairs and counting...

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Re: Boost Pressures
Posted by: MattNall ()
Date: June 24, 2020 10:27PM

David Clemens reported 28 psi with 2bbl Weber and Wastegate along with bent rods quite regularly.

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: Boost Pressures
Posted by: joelsplace ()
Date: June 24, 2020 10:49PM

Bent rods are bad.

Joel
Northlake, TX
5 Ultravans, 114 Corvairs and counting...

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Re: Boost Pressures
Posted by: American Mel ()
Date: June 25, 2020 01:15AM

joelsplace Wrote:
-------------------------------------------------------
> Bent rods are bad.


grinning smiley hot smiley grinning smiley hot smiley grinning smiley hot smiley grinning smiley
LOL, thank-you Mr. Understatement!

-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
WA. state, 1 mile south of the Canadian border,
I am not at the end of the world, but you can see it from here.
Have; '66 Monza Coupe - 140, 4-spd. Daily driver beater
'67 Monza Vert. - 140, 4-spd. Daily driver beater
'67 A/C Moredoor Monza
Have had; '61 Monza coupe, 80hp, PG
'62 Monza Wagon, 4spd.
'63 Spyder,
'65 Corsa
.
non-vair
'04 Dodge Cummins Quad Dually, approaching 400K
'03 Honda Del Sol
17'Terry

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Re: Boost Pressures
Posted by: dryenko ()
Date: June 25, 2020 05:23AM

My 1969 coupe with a "built" 180 HP engine would produce about 28inches of boost which is about 14 PSI.
The engine was balanced and had polished rods, 0.030 overbore forged pistons and 180 open chamber heads with most of the step removed [ about .080" ]
The main change from the stock configuration was exhaust porting with 140 exhaust tubes and manifolds.
The turbo was clearance checked and made as comfortably close on the impeller and exhaust turbine as practical.
Stock 180 carb and muffler.
Mildly modified advance curve in the turbo distributor and water / methanol injection staring at 3-5 psi.
My estimate was 250 WHP based on acceleration contests with SBC 350 Camaro at the time.
I am sure more was possible but my desire was to make it live.If I were to do it again, I would use 95 or modified 1964 deck style 150 HP turbo heads with the same exhaust.
For better burn due to mixture swirl. And for less detonation potential.

Bob C aka Dryenko
Dobson, NC 27017

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Re: Boost Pressures
Posted by: v8vair ()
Date: June 25, 2020 07:06AM

If I ever rebuild the motor in the 64 with the smaller od cylinders I might use the 63 turbo heads,suggested by Ray Sedman with the better chamber plus they all ready have the drain back.

1965 Crown V8 Racer
1964 Bill Thomas Monza Replica Racer
1964 Spyder Street Car
1979 Mazda RX7

Mike Levine

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Re: Boost Pressures
Posted by: dryenko ()
Date: June 25, 2020 08:27AM

Mike, because of the boost pressures, I would say use the larger top diameter 64-69 cylinders.
The heads can be easily bored out.
It is my understanding that was why it was done.
You may have very high CR with those heads.
On a 164 CI engine.
BC

Bob C aka Dryenko
Dobson, NC 27017

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Re: Boost Pressures
Posted by: kmart356 ()
Date: June 25, 2020 12:52PM

This graph is an attempt to demonstrate how the carburetor venturi flow compares to the different turbo intake sizes. Comparison is at WOT.

The Carter YH flows just under 150cfm vs the F-flow turbo intake at approx. 430cfm. The classic Stromberg WW 2bbl upgrade provided nearly 320cfm flow for a nice increase in boost. Dick Griffin is credited with developing the Stromberg WW kit to increase boost (5psi) & power (34 HP @ 4000rpm) when compared to the (factory) restricted YH carb set up. I was getting 10-12psi when the Stromberg was bolted up.

Those guys using Weber 40DCOE (400cfm) were pretty nicely matched to the F-Flow 430cfm for increased boost & performance. Take a look at the E-Flow 650-720cfm calculation and notice the Q-Jet at the top of the curve flowing a beastly 750cfm. eye popping smiley

The current setup for my Spyder is F/B turbo with Mikuni HSR45 flat slide producing 14-15psi (wastegate setting) + Methanol-Water Injection starts at 4.4psi



Ken
'62 Spyder Coupe
Florida


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Re: Boost Pressures
Posted by: playerpage ()
Date: June 25, 2020 01:59PM

In comparison, my contribution is going to be a little boring:

My setup is stock 1966 YH Carb and the 3856709 exhaust vent (if I'm saying it right). I have an after-market boost gauge I installed to replace my broken one (on the cheap; whole gauge cost $14 and I just disassembled the housing so it would fit in the dash). I am not sure how to read it though--that is, how its readout compares to the stock. Photo attached. I get vacuum down to -.3/-.4 on the gauge when I am idling (no problems idling) and when I slam the gas to head into 80-90mph territory (my record in the car is 102mph) the boost ticks barely above the zero to +.1 or +.15 I guess that means I AM getting boost but I have no idea how much because I'm not sure how to read it.

____________________________________________

Eric C. Player, Porterville, CA, USA (Seriously! It's the USA out here!)
MEMBER: CORSA National, Central Coast CORSA, South Coast CORSA, Vintage CORSA, Sfba CORSA, and the San Joaquin Valley Corvair Club.
THEN:
1965 Monza 110, Canary Yellow
1965 Corsa 180 Turbo, Red
1966 Monza 110, Purple
1967 Monza 140, Red
1966 500 110, Black; nicknamed "Shadow"
1965 Monza 110, Camaro Yellow; nicknamed "Silver"
NOW:
1966 Corsa 180 Turbo, Blue; nicknamed "Bluvair"

"He cautioned me not to take notes. It would not have helped if I had, as he would start a paragraph with, 'It is therefore obvious. . .'
and go on from there to matters which may have been obvious to him and God but to no one else."
-- Robert A. Heinlein, character of Daniel B. Davis, 'The Door Into Summer.'

Attachments:
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Re: Boost Pressures
Posted by: thewolfe ()
Date: June 25, 2020 03:12PM

I'm guessing you either have low boost or a piece of crap gauge. Maybe both. Also guessing the boost scale is bar. 1 bar = 14.5psi so that reads up to 29 psi. .15 bar would be a measely 2.2psi. Something isn't right.

Nate Wolfe
Portland OR
65 Corsa 180




Edited 1 time(s). Last edit at 06/25/2020 03:20PM by thewolfe.

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Re: Boost Pressures
Posted by: joelsplace ()
Date: June 25, 2020 03:15PM

You won't bend any rods.

Joel
Northlake, TX
5 Ultravans, 114 Corvairs and counting...

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Re: Boost Pressures
Posted by: playerpage ()
Date: June 25, 2020 03:23PM

Not beyond the realm of possibility that my gauge is a piece, Nate. I know my vacuum tube is okay because I replaced it when I installed the new gauge.

I pretty much installed the gauge as a stop-gap because I wanted to know if ANYTHING was happening.

So the original gauge markings are in psi, if I understand you?

Would the low boost mean my turbo fan isn't turning, or are there simpler things I can check?

Yeah, Joel, I guess not. I do feel like something is happening when I drive it, so if the pressure is supposed to be a lot higher then I wonder how much better it will be if I can adjust it.

____________________________________________

Eric C. Player, Porterville, CA, USA (Seriously! It's the USA out here!)
MEMBER: CORSA National, Central Coast CORSA, South Coast CORSA, Vintage CORSA, Sfba CORSA, and the San Joaquin Valley Corvair Club.
THEN:
1965 Monza 110, Canary Yellow
1965 Corsa 180 Turbo, Red
1966 Monza 110, Purple
1967 Monza 140, Red
1966 500 110, Black; nicknamed "Shadow"
1965 Monza 110, Camaro Yellow; nicknamed "Silver"
NOW:
1966 Corsa 180 Turbo, Blue; nicknamed "Bluvair"

"He cautioned me not to take notes. It would not have helped if I had, as he would start a paragraph with, 'It is therefore obvious. . .'
and go on from there to matters which may have been obvious to him and God but to no one else."
-- Robert A. Heinlein, character of Daniel B. Davis, 'The Door Into Summer.'



Edited 3 time(s). Last edit at 06/25/2020 03:28PM by playerpage.

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Re: Boost Pressures
Posted by: joelsplace ()
Date: June 25, 2020 03:34PM

The stock gauge is in inches not psi. Yours is way off. It may have exhaust leaks, timing issues, bad turbo.

Joel
Northlake, TX
5 Ultravans, 114 Corvairs and counting...

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Re: Boost Pressures
Posted by: MattNall ()
Date: June 25, 2020 03:53PM

ERIC...you say you feel something happening? Does the NEEDLE ever go to the RIGHT SIDE of the ZERO mark? EVEN 1/8"??

ZERO or to the LEFT is VACUUM not pressure / boost.

Here's a demo... listen to the engine!

[youtu.be]

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo




Edited 1 time(s). Last edit at 06/25/2020 10:35PM by MattNall.

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Re: Boost Pressures
Posted by: joelsplace ()
Date: June 25, 2020 04:09PM

-1 is minimum on his gauge and 2 is maximum. He said it goes .15 positive so no boost all to speak of. Just barely enough to know the turbo isn't locked up.

Joel
Northlake, TX
5 Ultravans, 114 Corvairs and counting...

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