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View Full Version : Carb mods for a turbo set up



disco_charger
12-16-2002, 08:31 PM
OK, so if the turbo usually doesn't spool up till about 3k on the tach, I got to think that you don't want to run the usual set up on the carb. I would think that you might want to run bigger jets in your secondaries.... Do you run power valves? If you're running a reasonably stock 454 where's a good starting point. I might get into this turbo thing here pretty quick, but have a lot to learn and need to figure out what to do to make my carb work. I saw that SuperDave was running an 850DP. Is that enough? Would a 950 be better? What am I doing? :( Perhaps I should sell my boat and buy a pair of roller blades...
As for the heads, is doing any blending and porting work worth it with a turbo? What changes with cam selection? This is probably what it feels like when Delbert buys his first Bayliner..."What does this button do?"
:rolleyes:
Disco

obnoxious001
12-16-2002, 09:28 PM
Disco
I sent you an email answering a few of your questions. I worked for Banks in the late 70's, and more recently have built quite a few large cubic inch turbocharged ski racing engines.
I would be happy to try and help any of you guys out with turbo questions, parts recommendations, or even supply parts or complete short blocks, long blocks, or complete engines.
Barry
http://free.***boat.net/gallery/Gearhead_Garage/Motors_and_Drives/001_engine.JPG
[ December 16, 2002, 09:32 PM: Message edited by: obnoxious001 ]

flat broke
12-16-2002, 09:46 PM
Brian,
I can give you my old 850 jetting recipe if you want. If anything it was little fat on the primaries, but I was happier with the safety margin than the small amount of HP to be gained by leaning out. I'd deffinitely take obnoxious001's offer on the help too. Let me know if Ty and I can be of any help to ya.
Chris

superdave013
12-16-2002, 10:11 PM
Disco, my carb was set up by Jones. I might be getting another set and if that happens this one will be offered to who ever gets the turbo system. If I end up keeping it and you get the turbos you can pop off the bowls and look at the jets and power valves.
These new carbs i'm after will go straight to Jones before I ever use them.

Infomaniac
12-17-2002, 05:20 AM
obnoxious001:
Disco
I sent you an email answering a few of your questions. I worked for Banks in the late 70's, and more recently have built quite a few large cubic inch turbocharged ski racing engines.
I would be happy to try and help any of you guys out with turbo questions, parts recommendations, or even supply parts or complete short blocks, long blocks, or complete engines.
Barry
http://free.***boat.net/gallery/Gearhead_Garage/Motors_and_Drives/001_engine.JPGShare the info with the rest of us please.

Hotcrusader76
12-17-2002, 10:55 AM
disco_charger:
OK, so if the turbo usually doesn't spool up till about 3k on the tach, I got to think that you don't want to run the usual set up on the carb. I would think that you might want to run bigger jets in your secondaries.... Do you run power valves? If you're running a reasonably stock 454 where's a good starting point. I might get into this turbo thing here pretty quick, but have a lot to learn and need to figure out what to do to make my carb work. I saw that SuperDave was running an 850DP. Is that enough? Would a 950 be better? What am I doing? :( Perhaps I should sell my boat and buy a pair of roller blades...
As for the heads, is doing any blending and porting work worth it with a turbo? What changes with cam selection? This is probably what it feels like when Delbert buys his first Bayliner..."What does this button do?"
:rolleyes:
DiscoYes you can run power-valves and it would be advised on a Turbo application.
An 850 or 950HP would be a great choice. I would opt for the 950HP, for the reason you can get the throttle response of a 750 with the increased upper-end response of an 850. When set-up with the Annular boosters or even the Modified cut boosters from Braswell, the extra boost won't effect the vacuum signal as much as it would with a stock booster.
Definitely look into having them gone through so you don't lean that motor out due to the increased vacuum signal and air-velocity.
~Ty
[ December 17, 2002, 10:55 AM: Message edited by: Hotcrusader76 ]