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Help with Grand National Turbo Install? Getting it together.
https://slantsix.org/forum/viewtopic.php?t=55686		 Page 1 of 1
Author:  BigCarl [ Thu Jun 26, 2014 8:57 am ]
Post subject:  Help with Grand National Turbo Install? Getting it together.
Well, I am coming to the end of my '72 Blazer Project and know that I am going to need to start on something else or I will lose my mind.

This winter I am planning on getting the front seat fabric replaced and getting a nice paint job on my '65 4-door Plymouth Fury II.

In addition to these plans, I am intending on putting a GN turbo setup on the old girl.

Engine is stock and tired, I just figure I want to get this setup running before putting new components into it and blow them up.

So, you guys with the GN draw-thru setup, I have the turbo with carb manifold coming in, so I haven't received it yet, what did you do to adapt the 3-bolt turbo outlet to the 2-bolt, 1-bbl, slant-6 intake?

Did you have an adapter made that bolts to the /6 intake and bolts to the turbo or did you just drill and tap new holes into the stock /6 intake and bolt the turbo directly to it?

Also, what modifications need to be done to a stock Quadrajet to make it work as a draw-thru for a turbo? - I have read that I need to boost-reference the carb, which I am currently trying to research for a quadrajet. Any insight on doing that would be great.

Will the stock fuel pump work for the turbo setup? The GN setup is stock, no upgrades or modifications. If the stock /6 fuel pump isn't enough, I have an electric pump that is currently on my Blazer. Its going to a QuadraJet on a 454, but I am switching the 454 back to a mechanical pump. So, I can use the electric pump from there, but I would like to keep this as simple (mechanical and stock) as possible.

I am new to turbos and this is my first project with FI on any of my vehicles.

Any help is appreciated.
Author:  Junior [ Sun Jun 29, 2014 7:37 pm ]
Post subject:  Re: Help with Grand National Turbo Install? Getting it toget
check out this thread for how to get the exhaust into the turbo, http://www.slantsix.org/forum/viewtopic.php?t=51304

shouldnt have to do anything to the carb for a draw through because its still running on vacuum like it would if it were just on top of an engine. stock fuel pump should be able to keep up.
Author:  Charrlie_S [ Mon Jun 30, 2014 3:58 am ]
Post subject: 
The factory Q-jet, was set up for the turbo use. I have a setup on the shelf with the correct carb. I could give you the number off the carb, if you think it would help. I don't know what was different with the turbo Q-jets.
Quote:
shouldnt have to do anything to the carb for a draw through because its still running on vacuum like it would if it were just on top of an engine.
Not entirely true. If the carb is not large enough (Q-jet should be) the carb can become a restriction, and have vacuum at the base of the carb, while the intake manifold has boost. On my draw thru turbo setup, I had a pressure/vacuum line from the intake manifold to the power valve on the 500 cfm Holley 2 bbl carb.
Author:  emsvitil [ Mon Jun 30, 2014 2:41 pm ]
Post subject: 
Quote:
The factory Q-jet, was set up for the turbo use. I have a setup on the shelf with the correct carb. I could give you the number off the carb, if you think it would help. I don't know what was different with the turbo Q-jets.

Probably run richer when the needles are pulled out of the jets.
Author:  BigCarl [ Tue Jul 01, 2014 6:42 am ]
Post subject: 
Charlie, if you can give me the carb number, that would be excellent. I did a search and there are rebuild kits for GN carbs. I am wondering if a GN carb is different physically that an average Q-Jet. -Any extra outlets or vacuum ports. The Q-Jets that I have have all come off stock 67-80 GM V8s, so a rejet may be necessary regardless.

I have tried comparing pictures of GN carbs/setups to my Q-Jets that I have here and have mainly only saw vacuum hoses attached to the Q-Jet manifold on the GN.

I looked at your link and think I have a plan for a simple steel adapter. I am just going to get a pair of flanges, one to fit the 1bbl intake and one to fit the turbo flange then just weld a short piece of pipe between them, keeping it as low as possible so I, hopefully, don't have to cut into the hood. -Much like your setup, just with flanges instead of the rubber tube. I am going to use a J-Pipe from the exhaust manifold to the exhaust side of the turbo and then run a down-pipe and continue it straight out the drivers side of the car.

What is your recommendation for exhaust pipe size? I am thinking 3 inch.

To initially get your setup running, although you have a 170 and I have a 225, what did you do in regards to jetting. When you bolted everything on and started the engine, how did she run? How did you get the carb tuned for a general tune?
Author:  BigCarl [ Tue Jul 01, 2014 6:45 am ]
Post subject: 
Emsvitil - Some of the Jets were removed from the GN's carb?
Author:  Junior [ Tue Jul 01, 2014 12:16 pm ]
Post subject: 
invest in a good wideaband o2 sensor for tuning. i went with a AEM uego. pretty much plug and play.
Author:  Charrlie_S [ Tue Jul 01, 2014 3:29 pm ]
Post subject: 
Just pulled the turbo setup off the shelf. Sorry, my mistake, it is not a GN. It is for a 1980 Pontiac Firebird 301. I looked for the numbers on the carb, but I can't find any, though I thought I had used those to verify what it was when I got it..
Quote:
The M4ME (E4ME for 1981) 800 cfm Rochester Quadrajet, unique to the 301 Turbo, had super rich "DX" secondary metering rods and a remote vacuum source for the primary metering rod enrichment circuit; the "PEVR" or Power Enrichment Valve Regulator. Boost was wastegate limited to 9 psi (+/- 1 psi) although factory settings ranged from 7 on low to 10 psi on high.
Author:  emsvitil [ Tue Jul 01, 2014 4:57 pm ]
Post subject: 
Quote:
Emsvitil - Some of the Jets were removed from the GN's carb?

No idea.

The quadrajet meters fuel like a BBD or BBS and the edelbrocks, needle in a jet.

With a NA engine you want WOT to be 12.5 - 13.2 or so.

With boost, WOT is richer. So I just figured that different needle/jet combos are used so that at WOT the mixture is richer (keeping cruise mixture the same)
Author:  kesteb [ Tue Jul 01, 2014 10:42 pm ]
Post subject: 
The Q-jets for the Buick turbos have an external vacuum reference for the step up pistons. Your best bet is to view the "Before Black" sections on the Buick turbo boards. They are some very knowledgeable people there.
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