I have only messed with a turbo once, so I am by no means an expert. I was looking on ebay and saw a setup for a BB Dodge (Ooo, bad word) Anyway, it had an adapter that went under the carb for the turbo. How well would this work? It seams to me it would be like roots type blower. Would this draw through setup be efficient enough to warrant the cost?

Thanks,


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Joshua Johnston
1991 Z-28


350, T-5, K&N, Ported Vortec heads, Edelbrock RPM, Holley 750 D.P., HEI, 11.07:1 CR, Comp Cams Roller-.510"/.520"-282*/288* dur., Shorty Headers, Dual 2.5 Exhaust,Dynomax Bullet Mufflers, T&R Motorsports custom air intake

 

Drawthroughs are a great way to do it..been done many times...but they have 2 major problem. For one..you can't run an intercooler...altho for low street levels of boost you don't really need one.

for two..the turbo has to be very close to the carb..like sitting right over the valve cover. If you can make it fit there...you're good to go.

 

Jester, I don't mean to question you, I'm just unclear on some things. Why cant you run an intercooler? And why would the turbo have to be close to the carb?

Thanks,


------------------
Joshua Johnston
1991 Z-28


350, T-5, K&N, Ported Vortec heads, Edelbrock RPM, Holley 750 D.P., HEI, 11.07:1 CR, Comp Cams Roller-.510"/.520"-282*/288* dur., Shorty Headers, Dual 2.5 Exhaust,Dynomax Bullet Mufflers, T&R Motorsports custom air intake

 

Well..think about it. If the turbo is after the carb...that means there is gas there. You can't run it through an inter cooler..all the gass will just pool in the bottom of it.

Same reason you have to have the turbo close. If you have the carb 5' of piping away from the motor, it ain't gonna run right.

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"American made baby. 100% American iron. The muscle among the masses. My hero. Yep, you can take your ergonomically designed, space age, computer controlled, 4 door, cup holding map lighted split double wishbone split fold down retractable cargo covered moon roof piece of transportation and keep it. For I have felt the thunder. And I know the difference!"
JSP Motorsports
ICON Motorsports

 

the 2nd gen turbo T/As had the draw through set up. I think they had 4-5 psi, but then they were for the 301 engine....

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85 Firebird. $150.00
2.8 Auto.
Blown Head Gasket.
turbo has arrived,

 

Okay, I call me stupid, but I still don't understand what you are saying Jester. This is what I understand from the turboford site I use to be at when I had my Turbo Coupe. The comp. sucks air in, pushes it through piping to the TB, or carb. When an intercooler is present, it is between the turbo and the TB, or carb. This is how the air gets cooled before it hits the intake. No fuel is present until it gets to the intake, or heads if you have TPI. And the piping, and intercooler only reduce boost by about .5-1.25 psi. This of course can be overcome by upping the boost. With the setup I asked about, this air is sent to a plate under the carb. I was curious if it would work b/c once the pressure is under the carb, I though it might want to blow through the top of the carb instead of into the enigne.



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Joshua Johnston
1991 Z-28


350, T-5, K&N, Ported Vortec heads, Edelbrock RPM, Holley 750 D.P., HEI, 11.07:1 CR, Comp Cams Roller-.510"/.520"-282*/288* dur., Shorty Headers, Dual 2.5 Exhaust,Dynomax Bullet Mufflers, T&R Motorsports custom air intake

 

Ahhh ok I see where you're getting screwed up.

Those adapters you see under turboed carbs have a divided plenum..upper and lower. The upper half (where the carb is) has a hose going to the turbo inlet, the turbo outlet goes back to the lower portion, which faces the manifold. It's called a draw though system.

If you want the flow through the turbo system to be dry you have to put the carb after everything else...blowing through the top. Called a blowthrough system.

 

I see now. Thanks Jester. If I was to use a turbo, I'll keep it blow through. And probably use FI.

Thanks again,


------------------
Joshua Johnston
1991 Z-28


350, T-5, K&N, Ported Vortec heads, Edelbrock RPM, Holley 750 D.P., HEI, 11.07:1 CR, Comp Cams Roller-.510"/.520"-282*/288* dur., Shorty Headers, Dual 2.5 Exhaust,Dynomax Bullet Mufflers, T&R Motorsports custom air intake