Supercharger Addition to Built Motor

cnemac2

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Dec 19, 2020
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Hello. I am am thinking about adding boost to my Fox Body. My engine is already built with ported early 351 heads and a Crane Compucam 2031. It has a bit of a compression bump with forged rods and pistons. Intake is GT40 with 30 lb injectors. Exhaust is via Hedman equal length headers. It also has a 255 lph fuel pump and a performance chip. A mechanic I know who has a boosted Mustang says I could safely go to 6-8 lbs of boost. Engine built and balance by race builder. Recommendations and suggestions welcomed. It also is street driven and passes Cali smog...Thanks in advance......Mark
 
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Car makes 426hp to the rear tires, which is right at 500hp at the crank. With the stock pulley, 47lb injectors and a 340 lph fuel pump, there is more power potential there, but with the factory block they didn’t feel comfortable turning it up any more than that.
 
Hello. I am am thinking about adding boost to my Fox Body. My engine is already built with ported early 351 heads and a Crane Compucam 2031. It has a bit of a compression bump with forged rods and pistons. Intake is GT40 with 30 lb injectors. Exhaust is via Hedman equal length headers. It also has a 255 lph fuel pump and a performance chip. A mechanic I know who has a boosted Mustang says I could safely go to 6-8 lbs of boost. Engine built and balance by race builder. Recommendations and suggestions welcomed. It also is street driven and passes Cali smog...Thanks in advance......Mark

Meh,…your engine is far from “ built”.
You are wasting your time, and dramatically restricting the potential of ANY power adder with cast iron 351w heads ( early or not). Before you throw any money at your engine w/a turbo or supercharger, shelve that idea, and get yourself a set of aftermarket heads. Ive had numerous engines w/ c9 heads on them when they were all you could get. ( If you have been a ford guy for long , youll remember those days too). The last time I had a set of max ported 69 “4bbl heads” w/ replacement 2.02/1.6 valves added on a roller cammed N/A 351, simply replacing them with out of the box cast iron World heads, the engine picked up huge power.
 
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You don't mention your displacement, regardless, i'm with mike on this one.
Unfortunately, your current setup wasn't well thought out.
Change the heads, cam and intake and forget about the supercharger.
 
Lbs of boost is a measurement of restriction. With the current set up at 10 psi, you would find that with better cylinder heads you would be at 6-7 psi and make more power and have a wider tuning window.
It will run just fine with the current heads, you just won't know how much is left on the table until you put better heads on it.
 
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Which is the same as saying, your 3000 dollar investment in supercharger will run, it just won’t run as good as It could while working less harder to make equivalent power if you put better heads on it first.
You can certainly put a SC on the existing engine…….You’ll just never know what you’re missing.
I don’t know about you, but I’d think that if you spend the time and money to upgrade something trying to make more power and ultimately go faster, it usually isn’t in your best interest to drag an anchor along with you.
 
Maybe he wants a S/C on it because it will have a S/C when he pops the hood. Adding heads does not get as much attention. Who knows what the motivation is. He might already have spent enough money on the existing heads he just can't bring himself to yank them off and replace them. I have seen lots of stock engines with S/C's on them. It might just be a big deal to have a blower.
My idea of a engine build is certainly different than most people. Some would say I could have gone faster cheaper. The are probably right, but it did not stop me from doing it my way.
 
Maybe he wants a S/C on it because it will have a S/C when he pops the hood. Adding heads does not get as much attention. Who knows what the motivation is. He might already have spent enough money on the existing heads he just can't bring himself to yank them off and replace them. I have seen lots of stock engines with S/C's on them. It might just be a big deal to have a blower.
My idea of a engine build is certainly different than most people. Some would say I could have gone faster cheaper. The are probably right,
Well for one thing When I get on here and ask for recommendations and suggestions, I’m not asking for people to second guess why I’m askin. Why not just gut the thing and put a hollow polished shell on the engine if all he’s going for is a look. Why worry about 6-8 psi at all, if all he was going for a look.. Hell, since that might be the thing, Why don’t I just prop open my wastegate?
 
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