Chevy 350 turbo idea.

[pokertramp]

I almost did it with a inline 6 Mustang and then I got cancer and the car had to go.

Now I have my 1982 Regal with a 1975 Chevy 350 4 bolt main. I am in the planning stages of a turbo setup. I have most of the basics figured out, fuel pump, bypass regulator, blow off valve, boost controller, pretty much all the basics I have worked out.

There are 2 things that got me scratching my head, Should I go with one big turbo from both banks or should I do 2 small turbo's one for each side?

Second question, when it comes to the ignition timing I am LOST. I don't understand what I need to do. I hear about changing the curve, welding the distributor and all different other things. Anyone have any insight on this?


I plan on doing a inexpensive build and I am not going crazy on parts. Everything will mostly be junkyard parts except for the fuel pump, regulator, blow off valves and whatever else can't be found at the junk yard. I will probably make sure I got the right pistons in my engine before I even attempt it. If I don't then I will just put a 150 shot of NOS on my engine and see what happens Maby have to rebuild the engine :wink:

 

[XbeasleyX]

I would 100% urge you to go TPI with the turbo, will make it much easier. As far as 1 or 2 goes, I'm a fan of the one big turbo plan.

 

[gs dewd]

As far as the dist. goes you need a way of retarding the timing under boost. 1 big turbo will be easier to setup but you will have lots of lag. 2 smaller ones are a tad harder to setup not by much but if you pick the right size you will have the same power with next to no lag.

 

[85 Cutlass Brougham]

Here is my ghetto-fab way to go about this, in theory at least. First off, I would go with two smaller turbos if it is a street car. They will spool faster, and you could theoretically run them off of upside down and reversed log style exhaust manifolds with homemade adapters. This also lets you use smaller parts intended for smaller engines instead of parts for rarer, larger turbo engines. I am thinking of the BOV in this case. Next, yes. TPI will work best. Run it off a Megasquirt EMS that you can build yourself, and upgrade the injectors. The stock runner sizes will work fine due to the greater than atmospheric pressure you are pushing. You will also need a fuel pump capable of pressurizing the rails at a pressure equal to what is needed in an N/A setup plus the boost pressure in the intake in order to counteract the force of the boost trying to shove the fuel back into the rail. This can be done with a rising rate pressure regulator (FMU) so long as you have a pump and lines capable of keeping up with the demand. Demand is calculated off the gross horsepower of the engine, but must also take into account the internal power losses of the engine of about 20%. This figure is higher on a larger engine than a small one of the same horsepower due to the extra rotational mass. Is there more? Of course there is! I suggest reading up on tons of theory before you buy anything.

 

[vladj]

why not just buy a kit:

http://cgi.ebay.ca/CHEVY-SB-283-400-CAM ... 1|240:1318

 

[85 Cutlass Brougham]

Ebay kits can be a nightmare with crappy Chinese turbos, etc. Buyer beware as the lower priced ones tend to be cheap for a reason.

 

[dan2286]

Ebay kits can be a nightmare with crappy Chinese turbos, etc. Buyer beware as the lower priced ones tend to be cheap for a reason.

To the point that the turbo will probably self destruct and send shrapnel into your engine.

 

[pokertramp]

I heard good and bad stories of the Ebay turbos when I was going to do the Ford setup. It is a matter of luck I guess.

I planned on doing a blow threw carb setup, trying to keep it simple. Great ideas though. I don't plan on buying anything soon. I will not even attempt it until I am 100% sure I can do it.