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#1
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Twin Turbo 535 RA-V Build
Making some progress on the heads!
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#2
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Looking good ED. Waiting to here some thunder
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#3
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VERY IMPRESSIVE
Looking forward to watching a dyno test at some point. Tom Vaught
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"Engineers do stuff for reasons" Tom Vaught Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward. |
#4
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Thats going to be a great combo!
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DOC'S TA Turbo 535, CV 1 heads. Built by Cerralli Competition Engines Tenth Anniversary (Van Nuys) restored. Tenth Anniversary Barn Find (Norwood) Both 4 speeds! |
#5
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Very good Mr.Ed!
A great build takes time.
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Carburetor building & modification services Servicing the Pontiac community over 25 years |
#6
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Very Cool! Best of luck with it.
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#7
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Are you planning on leaving the deck wet or plug the holes? Have you looked at the possiblity of adding the extra bolt holes in that head? Just curious if the layout allows it?
What size turbo's? |
#8
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We did the newly designed header flanges yesterday and put them on the heads. Now we can do the exhaust. These heads have the alternate valve spacing for the 4.350 bore. This head will have 2.30 intake valve.
This will be our standard CNC program for the stock head castings.
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Lynn McCarty dba/McCarty Racing www.RamAirV.com lmc3470@aol.com www.ChemicalManagementIndiana.com 317-260-3486 |
#9
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We’re going with Turbonetics 88mm turbos.
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#10
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Plan ahead for back pressure issues -
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#11
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Anything specific we should watch out for?
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#12
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On my 525 - it starts to get into back pressure "issues" at about 22 to 24 psi - we had the tubine housings modified and it helpped but is still there - I have been told the only way to fix it is 91s or 94s -- and those things are huge -
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#13
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cg did you dyno this engine? Normally aspirated and then with boost?
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Lynn McCarty dba/McCarty Racing www.RamAirV.com lmc3470@aol.com www.ChemicalManagementIndiana.com 317-260-3486 |
#14
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Quote:
Tom Vaught
__________________
"Engineers do stuff for reasons" Tom Vaught Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward. |
#15
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OK CG you got the ears of the "big dog" boostman listening. I have the explanation from my engineering student son, but students are silent when the professor is ready to chime.
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Lynn McCarty dba/McCarty Racing www.RamAirV.com lmc3470@aol.com www.ChemicalManagementIndiana.com 317-260-3486 |
#16
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Did they go into specifics on why those would fix the problem? Better/bigger turbine housings than the 88s? just curious
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Panos Little Miss G Racing |
#17
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I have never run the car on the dyno with no booste - but I know it will run mid to high 9s with out the turbos working - dont ask how I know - the back pressure starts to creap up into the 2 to 1 range when it goes over 24- to 25 psi - and yes - the bigger turbos seam to have a better - more efficient turbine housing - but the whole turbo is so big it would take a major rework to make them fit -
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#18
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Couldn't you bypass some of that backpressure through the wastegates? Back in the day,turbo drag racers used to use small turbine housings for quick boost response and then run a lot of the exhaust gases through the 'gates.
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#19
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Quote:
So how are you reading that pressure? A 3 BAR sensor can only read accurately to 43.5 PSI (1 bar is atmosphere - 2 additional BAR would be 43.5 psi. So how is that 2 to 1? Last time I looked 24-25 psi at 2 to 1 was 48-50 psi of pressure. Need a lot more actual info/ data. How you read the numbers, what instrumentation, etc. Quote:
A Guy named Danny Jones, who was the Indy Car Turbo Guy for Ford many years ago, told me you would like to be close on the intake and exhaust pressures at max boost with the waste gates open. You confirm this with pressure taps/ gages on the compressor and turbine flow paths. Tom Vaught
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"Engineers do stuff for reasons" Tom Vaught Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward. |
#20
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Tom - Im reading the back presure with a unit that racepak makes to tie into the data recorder - and yes - I have seen over 70lb of backpressure at 30lb of boost ( by mistake) I just checked - its a 0-75 pressure sensor -
Last edited by cgeise; 06-20-2011 at 01:40 PM. Reason: addition |
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