TURBO GUYS! Is there a formula for..
#452566
08/28/09 04:07 PM
08/28/09 04:07 PM
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Joined: Jan 2003
Posts: 408 Tampa, Fl
valiantboy
OP
super gas
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OP
super gas
Joined: Jan 2003
Posts: 408
Tampa, Fl
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for choosing a carb for a turbo app? i know there is math for finding the right turbo. how do you choose the right carb for the app? ill be sticking a turbo in a 318 powered a100 van. not alott. maybe a 70-78mm unit, air-to-water cooler. 18psi max probly. i was thinking maybe 750 - 820cfm. am i off?
I'm WAY too baked to drive to the devil's house.
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Re: TURBO GUYS! Is there a formula for..
[Re: valiantboy]
#452567
08/28/09 05:35 PM
08/28/09 05:35 PM
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Joined: Jan 2003
Posts: 28,071 Irving, TX
feets
Senior Management
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Senior Management
Joined: Jan 2003
Posts: 28,071
Irving, TX
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That's not a bad choice. For years the common word has been to use the same size carb as a N/A engine. I disagree. I felt a HUGE difference between a boost prepped 650 and standard 750 carb. Go a step or two above your typical carb for that motor and you'll make a bit more power. Drivability may be down a wee bit. That's your call to make based on the type of use the vehicle will see.
We are brothers and sisters doing time on the planet for better or worse. I'll take the better, if you don't mind. - Stu Harmon
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Re: TURBO GUYS! Is there a formula for..
[Re: RoyceFlo73]
#452577
08/31/09 12:15 AM
08/31/09 12:15 AM
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Joined: Sep 2007
Posts: 576 Escondido, CA
kick_the_reverb
mopar
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mopar
Joined: Sep 2007
Posts: 576
Escondido, CA
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It's certainly going to be interesting to see how you plan to package everything in the cramped space of an A-100 Good luck! Ran
"Hey mister, something's wrong with your car, it idles roughly" - number one comment I got in Israel when daily driving a 70 Barracuda with a lopey cam.
Currently working on - 1966 Dodge A100 van 318/auto Finally - disc brakes on the front. In the plans - rear disc brakes, B&M 250 blower
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Re: TURBO GUYS! Is there a formula for..
[Re: RoyceFlo73]
#452578
08/31/09 01:47 AM
08/31/09 01:47 AM
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Joined: Jan 2003
Posts: 8,182 Detroit, MI
CokeBottleKid
master
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master
Joined: Jan 2003
Posts: 8,182
Detroit, MI
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Quote:
HPbooks "Turbochargers" by Hugh McInnes for me was one of the hands down best book for turbocharger theory.
It explains everything very very well, and is sectioned off well as to give basic theory and specific applications.
As for a twin-turbo setup, I ran a twin turbo for my 318 because i was able to build boost at very low rpm and I have zero turbo lag. By using two small (garrett T04B's(cant remember if theyre Bs or Es)). Either way, like i stated before, their efficiency drops so low past 6k rpm because they can't handle that volume of air that they start to drop the psi.
Also, for the 318 C.I. at 3800 Rpm, the volume of air being put out is right in the sweet spot of my turbos and they're running at a high 88% efficiency (according to the maps). Which is nice for my big car that just roams the streets and it doesnt make sense to have a Ve (volumetric efficiency) achieved at a higher RPM.
Large turbos are not used to make "more boost". You have to consider where most of your driving will be, and where you want the boost. If you are going to be drag racing it, then a big single turbo that has high Ve at High RPMs makes sense.
Too small a turbo may dump efficiency above a certain volume of air being put out of the engine and although you may spool quickly; it means nothing because you swamped the turbo and it won't be able to deal with it.
I know that even a single garret T04B is a good turbo for the 318s...single or twin setup. It really just depends on exactly what you plan to do with it, and where you want the pressure.
It's air consumed not put out...
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Re: TURBO GUYS! Is there a formula for..
[Re: valiantboy]
#452581
08/31/09 01:14 PM
08/31/09 01:14 PM
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Joined: Sep 2007
Posts: 576 Escondido, CA
kick_the_reverb
mopar
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mopar
Joined: Sep 2007
Posts: 576
Escondido, CA
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Fitment wise, I would say you will need to extend the doghouse in the available directions. Just trying to fit the whole thing in a stock doghouse is asking for trouble. Also, you might need some heat extraction blowers to get the trapped hot air out of the doghouse.
Ran
"Hey mister, something's wrong with your car, it idles roughly" - number one comment I got in Israel when daily driving a 70 Barracuda with a lopey cam.
Currently working on - 1966 Dodge A100 van 318/auto Finally - disc brakes on the front. In the plans - rear disc brakes, B&M 250 blower
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Re: TURBO GUYS! Is there a formula for..
[Re: valiantboy]
#452583
09/01/09 01:32 AM
09/01/09 01:32 AM
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Joined: Sep 2007
Posts: 576 Escondido, CA
kick_the_reverb
mopar
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mopar
Joined: Sep 2007
Posts: 576
Escondido, CA
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I suggest you keep the MSD stuff inside the van and not inside the doghouse. I installed my Mallory unit and the coil on the back of the doghouse (inside the van), but some people like to hide them on the floor beneath the seat. The doghouse is very cramped and gets very hot. About traction, I wish I could tell you, I am no where near that stage yet. One thing about Cal Tracks, you have to remember that the springs are over the axle in the van, but i think they make a version for that kind of setup. What's you brake situation?
Ran
"Hey mister, something's wrong with your car, it idles roughly" - number one comment I got in Israel when daily driving a 70 Barracuda with a lopey cam.
Currently working on - 1966 Dodge A100 van 318/auto Finally - disc brakes on the front. In the plans - rear disc brakes, B&M 250 blower
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Re: TURBO GUYS! Is there a formula for..
[Re: valiantboy]
#452584
09/01/09 02:32 AM
09/01/09 02:32 AM
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Joined: Jan 2009
Posts: 374 CONNECTICUT
RoyceFlo73
enthusiast
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enthusiast
Joined: Jan 2009
Posts: 374
CONNECTICUT
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Quote:
i will probly max out around 15 psi so they wont be too stressed. that should put theyr efficiency in the 70 - 75% range id hope. also have a low single plane intake thatll hold the carb. dont think runner length will have much say in this setup?
I have no idea about fitting it into an an a100. I have never worked on one at all.
However, you can google most turbo maps or call the manufacturer and request one. This will tell you exactly the efficiency that a given turbo will run while displacing a given amount of boost. All you have to do is figure out the CFM or lbs/min of air that the engine will be using. This is derived by displacement, given RPM / 2 that you want your peak boost at.
Turbos will be listed with a trim and A/R. The A/R doesn't really change the Ve strictly speaking. However, it will change the velocity of the incoming charge and does have an effect on overall boost. It play's a big roll in tuning lag.
The book i listed early, as well as garrett's website can give you a lot of good insight on designing and choosing your turbo system.
That book I know has some interesting ideas that will help you alot with the a100. There is a section on under-chassis mounted turbos. There is some things to consider when doing so due to the amount of volume of air that would be present in the plumbing between the turbo and intake.
However, it really does give ALOT of information and takes many applications into consideration. It's a fairly technical book, I am a physics/math major (5th year senior and going back for mechanical engineering) and a lot of the information i felt was laid out in a very clear scientific and theoretical way, then more specifically.
It gave a good understanding as to how turbos work, not just another stupid book that tells ya to "connect A to B to C and there you have it"
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