Which Supercharger? For 10:1 compression?
- Thread starter Pokageek
- Start date
S351R"Animal"
20+ Year Stangneter 
You have too much compression for a blower. You can run that much compression with a blower but, you have to have aftermarket electronics, built bottom end ( and be ready to go into it after each weekend), big injectors, and a larger fuel system.
+1
Or unless your wallet is pretty thick, you could probably run race gas, at somewhere in the neighborhood of $5 a gallon. It could probably be done on pump gas, but you'd be leaving some power on the table due to the very conservative tune you'd have to run.
Or unless your wallet is pretty thick, you could probably run race gas, at somewhere in the neighborhood of $5 a gallon. It could probably be done on pump gas, but you'd be leaving some power on the table due to the very conservative tune you'd have to run.
You could run a relatively low boost Eaton combo with that compression with little or no trouble at all so long as the tune was good. Looking to a centri blower for the low to mid range grunt you mentioned, is a step in the wrong direction IMO.
Discharge temps from an Eaton at 3 - 6 psi should be low enough that it won't cost you much in the way of timing (although it will cost some but they are VERY thermally efficient in these ranges). I would think that a setup like this would give you a huge change in throttle grunt. Just keep boost pressures low and don't try to overspin the blower.
Discharge temps from an Eaton at 3 - 6 psi should be low enough that it won't cost you much in the way of timing (although it will cost some but they are VERY thermally efficient in these ranges). I would think that a setup like this would give you a huge change in throttle grunt. Just keep boost pressures low and don't try to overspin the blower.
MattZ281LE
Founding Member
6psi tops on mild tune pump gas. LS1 Cars are 10.1 and thats what their kits are for, ATI with intercooler. Not worth the cost IMHO. Nitrous in your case would be better.
Ok. Thanks guys. Here is a few more questions then:
#1 What kind or rwhp I could get out of it safely then? I am at 290+rwhp now but the car doesn't habe the low end grunt I remember from my 5.7L.
#2 Is the retarded timing because of the compression be what kills the potential rwhp?
#3 Would it be smarter to go larger short block instead?
#4 If I went 9:1 compression instead of 10:1 on a new 347, how much HP am I losing n/a?
#5 If I slap my 306 trick flow heads on the 347, will it make good HP?
#1 What kind or rwhp I could get out of it safely then? I am at 290+rwhp now but the car doesn't habe the low end grunt I remember from my 5.7L.
#2 Is the retarded timing because of the compression be what kills the potential rwhp?
#3 Would it be smarter to go larger short block instead?
#4 If I went 9:1 compression instead of 10:1 on a new 347, how much HP am I losing n/a?
#5 If I slap my 306 trick flow heads on the 347, will it make good HP?
Pops Fun
10 Year Member
I agree here have a vortech and it is a great "top end" blower, doesn't make power til the upper rpm range. A roots style blower is a low end torque machine. I would lower the compression then go blower. Put a thicker gasket on it to lower compression.
reddy351
10 Year Member
"There is no replacement for displacement."
If you are used to 350 cid, then there is not a lot that can be done but go back to it (or better). You could put a 347 together for "resonable" money. Or you could just drop in a 351w roller motor. That's what Ford did in '95. Should be an almost direct swap. You'll need headers, oil pan/pickup and a distributor. Of course guys are taking their 351s out to about 100 cid more than that, too.
Good luck in you search for power!!!
If you are used to 350 cid, then there is not a lot that can be done but go back to it (or better). You could put a 347 together for "resonable" money. Or you could just drop in a 351w roller motor. That's what Ford did in '95. Should be an almost direct swap. You'll need headers, oil pan/pickup and a distributor. Of course guys are taking their 351s out to about 100 cid more than that, too.
Good luck in you search for power!!!
"There is no replacement for displacement."
If you are used to 350 cid, then there is not a lot that can be done but go back to it (or better). You could put a 347 together for "resonable" money. Or you could just drop in a 351w roller motor. That's what Ford did in '95. Should be an almost direct swap. You'll need headers, oil pan/pickup and a distributor. Of course guys are taking their 351s out to about 100 cid more than that, too.
God luck in you search for power!!!
I would like to do that but it would probably have me putting more $$ into the car than I want to. Being less experienced initially, I thought putting a H/C/I and getting a 5.0 beyond the power of my old LT1 would be enough. Truth is though that the 5.7 felt stronger due to a longer torque curve and more tq lower down. That's something you cant get withsmaller engines.
your first mistake sir was thinking that the horsepower bug wasnt going to bite you.....at 10:1 compression, the tune is crucial with any power adder. my recommendation would be nitrous over a blower though. it will give you the low end that you want that a centrifugal blower cant provide.
Yep. You are right man. So if I build a 347 at 9:1 compr, how much rwhp power am I leaving on the table n.a. vs 10:1? Also, if I want to go sprcharged or turbo down the road is 9:1 ok? Thanks guys.
I wouldn't put a power adder on a high compression motor. You can get away with it but why even risk it. I'm running 10:1 and I love it the way it is. I did the blower thing and its just way too finicky. I don't miss my Vortech at all. Like mentioned the tune is the only way a blower works correctly. Without a tune its a time bomb. Tick...tick...tick....BOOM! There goes the internals. Been there and its way too costly.
