longrange4u

iTrader: (2)

I am looking at what options I want for my forged motor. It will be with a STS FI setup so there is allot of value in a motor that get climb safely in the RPM's.

What do you guys think is required to build a high spining motor? Do you think a 402/8 would be better than a 347/70?

With an STS I truly am not in boost untill 3200RPMs... I dont want to run out of room too fast.

Thanks guy's!!!

Jared

Ragtop 99

iTrader: (7)

You can build a nice 346 boost motor and spin to 7000. If you are looking at mega boost, an iron 402 has some advantages.

GTObsessor

iTrader: (2)

What he said... if I was going FI, I'd build a 346 and just dump the boost in... our motors have pleanty of low-end but if you wanna go completely nuts, 408's can be just plain mean... hope you're running slicks...

longrange4u

iTrader: (2)

Yea I was thinking of an Iron 370 or 402.... what do I need to do to insure safe spin at or above 7k?

BlackHawk T/A

iTrader: (3)

Lightweight forged internals and a shorter stroke, which means you should probably stick to stock cubes.

rollinna65

iTrader: (18)

A dry sump setup.

LOnSLO

iTrader: (15)

A 4" crank will spin fine up to about 8000 before you need to worry about a dry sump.

longrange4u

iTrader: (2)

Now I have heard that the 370 (LQ9 Iron Block) with the smaller rotating assembly is the best of both worlds... Smaller rotating mass, and bigger cube then the 346. So where in my powerband should I be setting my shift points if I have a 7k RPM curve? Just before my HP/TQ begin to go back down?

Steel Chicken

iTrader: (3)

depends on the curve. you want the most "area" underneath the curve. if your making increasing power all the way to redline, shift at redline. if your power curve drops off significantly as it approaches redline (like some LS1's) then you want to shift a little earlier.