I thought boost was less sensitive to porting than NA.

 

Yes and no. Its a loaded question, but thats not my point. Boost loves very big intake and especially exhuast ports. NA isn't the same. You can easily go too big on the exhaust side, unlike boost. All generally speaking- i'm sure someone will step in and tell me about a set of heads that went on their supercharged car with basketball sized ports.

 

But with a turbo you want the exhaust ports to be smaller to keep the velocity up to spool faster. Hence the reason for using reverse split cams.

 

Isn't this the same guy that said stock brakes were better than anything else?

I really don't see a problem with good quench, good heads and a 9.3-9.5 compression ratio. With good gas, 15 psi shouldn't be a big deal. Keep your current cam for the 402-408 NA and get a turbo cam for the turbo setup.

 

By the way, I'm not saying you wont be happy with it. Its just not my style; Id rather save up for a few more months and have a nice setup for boost.

I've been personally looking into a +10:1 compression motor + boost for the street. I think it would be sweet on the street. Make good power without boost for good throttle response and add a turbo. It would take a good amount of time to tune it, positive pressures would have to cut the spark timing down. I'm not sure how much boost it would take on 93 but I wouldn't be opposed to water or methanol injection under boost either. With the higher compression, it really shouldn't dip too hard into the boost unless you want to. With an extra windshield washer tank (or two!) it should go last a while. but then I look at my upcoming law school tuition and get back to looking in the couch for spare change

 

this is the guy that told you ceramic pads and holes in your rotors wont help.

 

Turbos dont really have any definative rule. They are weird because your exhuast defines your intake.... which defines your exhuast and... which came first? the chicken or the egg? Depends on your setup, turbo, etc I forgot you were looking at turbo; i was looking at your sig.

 

Dude Trey give it up.

He is willing to give up N/A performance now for it being a good setup for a turbo later on. Who gives a **** whether it is your style or not.

Thunder, give me another month(I got everything except injectors) to get my **** up and running. It will be running 9.4CR with stock 317s and a really non-mainstream cam for a turbo app. I will tell you this, with the old setup 10.8CR with DARTs and a 237/242 112 cam had more tq then any of the radix trucks I have been in and I still got 13.2mpg from AL to TX with about 3000#s of cargo, no tc lockup in 4th and a rich tune so IMO that aint too bad considering the circumstances.

17 on the highway isnt too far out of reach with a good tune and semi-decently sized cam. You are going to be doing good to hit 450rwhp with the truck intake, with oyur radix I would bet you will hit mid 500s but with that many cubes under it, it is going to be one hell of a heat pump that is if you use the radix at all.

Go for a shortblock if you can find one for a decent price. Assembling your own shortblock isnt bad but it requires a whole day to put it together and about 600bucks worth of tools to do right. Also shoot for a piston that has greater then a 1" compression height, this will add alot of strength and for god sakes go with a 4" stroke NOT a 4.100. I learned after the fact that if I would have went with a 4.200 rod my clearances problems wouldnt have happened but I didnt know about all that back then.

You can find a nice Lunati rotating assembly for about 3K with rings and bearings. Icant remember where I saw a iron 6L block with a Lunati rotating assembly for about 4K but it was a while back anyway. Do some searching on tech in the LS1 internal section. LS2 402s seem to be pretty common over there and not too expensive considering everything.

Another thing you may consider is going the 370 route, would save you about a grand. I would use the stock 317 heads, good heads arent nearly as pertenant as in N/A setups, it has been proven time and again. You are correct about smalller exhaust ports and intake biased cam to keep exhaust velocities up. The hogged out exhaust ports only really come into play in the 8-9 sec players. With the relatively low boost numbers you are going to be running stock heads should be fine when used with ARP heads studs over tq'ed by 10-15 ft#s.

Hope this helps you alot, and hopefully I have saved you the hours of reading I have done over on tech.

 

On the Wood Haulers setup I built:
Eagle Crank (4.00")
Mahle -12 cc dished pistons (10:1 compression)
Scat H-beams (complete w/ ARP hardware)
ARP main studs
ARP head bolts
TSP 233 239 cam....great power from 3000 up to 6500 or so ( it you have the supporting intake)
Stock intake, TB.......KILLED the power past 5600 or so.
Stock IRON 6.0l heads..........good for anchors, thats about it.

This setup had great torque but WOULD NOT breathe past 5600 and therfore left a lot of power on the table.

The Wood Haulers new setup will be:

Same shortblock and cam
Worked over 317s (milled at least)
Victor JR. and 4bbl TB
11:1 compression

Strokers are great for all around power and his has proven to be very reliable and durable.......his milage with a 4000 stall sucks though, but other than that I'd say go for it. With the right induction, you can run much more cam than I put in his, but I was trying to make his work with the truck manifold (which it definelty doesn't).

I'd shoot for 11:1, 402-408, good heads, LS6 Intake at minimum though I'd prefer the Victor, and your cam of choice.

 

Great info, thanks guys

Cody - what kind of tools are you talking about?

And no, I won't be using the Radix on the 408......it barely keeps up with the stock LQ9. Can't wait to ditch the 160* IAT's!!

If stock 317 heads would work that would be good, save me lots of $$ of new heads.