bluehawk2

iTrader: (74)

I guess what I am asking............... is it the boost pressure that everyone has probs with breaking ringlands or is it a power limit

rufretic

iTrader: (37)

The F14 is not going bleed off much boost if any even on 112lsa. Thats the exact cam I had and it made more boost and more power than simular set-ups with different cams. My set-up consisted of stock 346, D1, dual inline fuel pumps with 60lb injectors, ebay fmic, F-14 112lsa, fast 90mm intake, nw 90 throttle body, qtp 1 3/4 long tubes, true duals, stock 317 heads and had a 4.25 pulley on the D1. The pulley on the crank was whatever size comes with the 8-rib set-up. It made 14psi and made 682rwhp. Ran low tens and had mph for 9s. It also blew the stock 346 to pieces so be careful what you ask for. I would take it easy on the stock 346 until your ready for a rebuild or just build it stronger before you add boost.

bluehawk2

iTrader: (74)

You must have had a smaller crank than I have. I think mine is the 7.65. Mine with a 4.00 pulley with ported ls6 heads and a cam like the f-14 will prob only make 8-9 pounds of boost. I will also only make around 500 on a mustang dyno coonverter unlocked with the 12-bolt Just wondering how safe i will be with the 4.00 pulley


Bob at Exotic told me that my cam may not be ideal for the procharger, but It would not make a significant difference to swap to the blower cam right now.

Jake@EPP

If you own the cam, then no need to go changing it up, just another hassle and expense.

The whole "bleeding" boost is far over rated, you want to make the most hp at the lowest boost, its called efficiency! It doesn't take boost away, the overlap will cause the airflow to somewhat clear the cylinder, resulting in more room for fresh air and fuel.

A large NA cam likes to make power in midrange and up top right...

A centri blower makes its power up top as well, so pick a cam that does a good midrange to a extent.

I would base your end results off a impeller speed, and also a end hp. No need to go chasing boost numbers (damn ricers!), go for the end hp and call it a day.

Most stock kits ship with a 4.50 or 4.75 pulley depending on mods FYI.

bluehawk2

iTrader: (74)

I have since determined that I have a prob with a boost leak or a bad bypass valve. I put the 4.00 pulley on and it went to 6 pounds.............deff not correct for that pulley. Looking at my graph I can see that it gets to a point and the boost flat lines.



Jake you are correct about the cam...........When I get my problem fixed I should be able to make 7-8 pounds with the 4.25 pulley. That is not a very big loss of boost for having a 600 lift cam and ported ls6 heads. Deff wouldn't be worth the expense and hassle of changing my cam right now

SHINER

iTrader: (18)

How much power you making, and whats the grind specs on your cam?

bluehawk2

iTrader: (74)

With it only making 5.5 lbs with the 4.25 pulley it made 440 hp and 400 tq.
That is on a mustang dyno, converter unlocked, through a 12 bolt. I will see another 1.5-2 lbs of boost when I get the problem fixed


My cam is a 232/236 595/601 112 +2 XER

BlackNiteWS6

iTrader: (2)

You are deinately the pro on this subject...but i think using a smaller cam
with less overlap or an lsa of 114 to 116 will trap or bleed less boost off
so you can create more cylinder pressure at low, mid , and top end.
That would be what i think is more efficient. And i agree boost is only
a number it's about your power goals.

Inspector12

iTrader: (29)

Yeah most agree with what you are saying, but it will not be a big deal with the stock bottom end as he is limited by the stock internals already so it would be a wasted expense in that way.