Super rough rule of thumb because it makes tons of assumptions. Rough as in "a rough guess" or "a ballpark figure", super as in exceedingly so, or a large amount.

But yes, you did the math right.

 

HAHA! I was pretty rough for me to figure out the math last night
seems to be fairly close tho. kinda like 1/8th mile time X 1.55= 1/4 mile time
and sounds like I need about 15 lbs

 

Run it with a 5psi spring and you'll be fine. If the wastegate is positioned to where it actually bleeds both banks of boost then it should not spike or creep. It should work especially well considering your running allot of cubes thru a small turbine. That means when the wastegate opens the turbine pressure will be more than happy to escape out of the wastegate. You'll be over 400whp with 5psi. It'll make it way more fun to drive.

 

If you cant afford the rebuild, don't put a turbo on it. Jus sayin.....

 

There is wisdom in this post.

 

thanks for all the posts guys. Seems that I can easily stay under 500whp with my combo according to you posts.

I cannot afford a rebuild. I just got done building it, the engine only has 700miles now.

so If I am at 350whp and I add about 6psi I would be around 420whp. That would put me at a pretty safe power level wouldnt you guys think?

then possible a 50shot when things get crazy at the track.

 

Yeah, adding nitrous to this is definitely a good idea if you're worried about splitting the block on boost alone. Fuck it. I'd go with at least a 150 shot.

 

this would mean around 11.5hp per lb of boost.

does that seem right?

 

Without knowing the exact turbo, or wastegate placement, what are the chances a 38mm will not creep at 5-6 psi on his setup?

 

here is a pic i found to show placement.

The wastgate is on the downpipe in between the shocktower and the valve cover.

This is a PTK kit 38mm tial WG

#ad

 

I'd run a fogger myself...don't want to take any chances of it surviving to the end of the track.

 

Why build a 347 and keep it under 500?

10 psi and you are beyond that number easily!

:homos:

 

its quite evident in your sig bumblebee. You had a mild 302 break 500whp with that boost.

 

Just keep the rpm's low and make sure that you have a GOOD tune, and you should be just fine at 8-10 lbs

 

I think so to!!

I run 15 psi with my stock short block and it's still in one piece

Good tune and not crazy on the revs seems to be the way to go with this stock production blocks!