SonofaBish

iTrader: (5)

Okay guys. I've been doing some looking around, and i have a few questions for the build that i'm going to start. It'll be small twin turbos, looking for 600-700 rwhp

I have two options. (either way i'm sticking with the stock crank). Rebuild my stock ls1 with forged pistons/rods, or part out my current motor and buy a 6.0 to build with the afformentioned forged parts. Now, i know that the iron block will hold up better, but being that i only plan to make ~650 rwhp, do you still suggest going this route, or sticking with the aluminum 346?

Also, i'd like to do this on a budget, so my plans were to use the 6.0 litre truck heads - however, if you suggest using the aluminum block, can you slap the truck heads on the smaller 5.7 bore?

As for cams, is it suggested that you get as much negative overlap as possible, or shall i just make sure there is 0 valve overlap. Basically, shall i go with the largest cam i can get with 0 overlap, or not? any suggestions? I like lope, but understand this may not be real possible with the TT setup. If so, that'd be sweet as hell.

I already have a moser 12-bolt in the rear, however, with 4:10s. Good idea to change to a higher gear (lower #)? what gear ratio?

Finally, what # fuel injectors am i looking at needing? 60 or 75?

That's all i can think of for now, but will update if i think of anything else. Thanks in advance

smokinHawk

iTrader: (48)

the stock block should take the power, its up to you if you want the weight (if you go with iron) or the extra cost as you dont really need it.

I am using 6.0 heads on my 347 alumium block so yes.

cams thats up to you

yes youll probably do better if you get a lower gear ratio

60's should work out ok, but if you want more later then 75's

FastKat

iTrader: (10)

The aluminum block will be absolutely fine for what you are trying to do.. it will be cheaper, easier, lighter and plenty strong.

The 317 casting truck heads will work on your 5.7L block, however I am not sure which head gasket to use... the 6.0L or the 5.7L.

The stock F-body cam is a very good turbo cam, however there is ALWAYS debate over cam selection... there's no perfect cam for everyone. The cam is worth putting some time in with the Search feature and learning more about.

It seems like turbo setups generally benefit from a taller (shallower) gear but I think it really depends on what you want to use the car for.

60's should be fine. Get a quality brand. If an injector takes a sh$t at the wrong time it could cost you big.

Where are you at in Pittsburgh? I am from Pittsburgh myself!

-Dave

SonofaBish

iTrader: (5)

Thanks guys!!

Its good to hear that i can just use the aluminum block with no worries. That will save me a couple hundred bucks. As far as a cam goes, i'm not really sure what to do. I have never heard a turbo car with some lope, but i think it'd be badass... I'm not sure if i should go with something wht 0 over lap (e.g. 238/230 117 lsa would have 0 overlap and be a decent size cam) or something smaller with less lobe seperation. Not quite sure what kinda of changes in power the different cams will make, especially being that there is going to be so much poer in the first place. Do i want reverse split, or traditional split? A big difference b/w durations, or should they be somewhat close together? Just trying to get an idea of what is best. I hate it when there are so many options haha

I live on Neville Island in Pittsburgh. How bout u?

smokinHawk

iTrader: (48)

use a 4" bore head gasket, when i used the 3.9" gasket it leaked, you could tell the edges were exposed in the combustion chamber and were damaged then causing a leak.
i havent had any problems since i go the 4" bore gaskets
so use the gasket to match the head

SonofaBish

iTrader: (5)

cool, thank you...

any more thoughts on the cam?

FastKat

iTrader: (10)

The late LS6 cam has been used with success as well... probably a bump up from the early stock F-body cam.

I am from the McKeesport/Elizabeth area southeast of the city... pretty much the other end of Pittsburgh I think.

SonofaBish

iTrader: (5)

cool man... i'm sure an ls6 cam would be quite cheap. However, i wanna make sure i make the right choice. I'd love to get a big cam, but i'm just not sure it would be worth it. Hopefully someone else can chime in on whether i should get as much duration as possible on like a 115 or 116 lsa or if its really not worth it and just go with a LS6 cam.

another quick question. I'm assuming its best to build the motor, then do a complete warm-up or two before i go put the turbo kit on it and boost it. Is this the case? or what is the suggested break-in procedure for a new TT kit?

ninetres

iTrader: (35)

My cam lopes pretty good, see my sig for numbers

228/232 588-595 on a 114

It is an AFR grind cam that I was going to use for an NA/nitrous build, but plans changed and it seemed there was no SURE answer to turbo cams. I was also out of money. WORKS for me!

Pro Stock John

iTrader: (34)

I'm running a 2001 LS6 block that is 3.910. My 234 single pattern cam has some lope to it. I'd focus more on the cam duration than the lsa.

SonofaBish

iTrader: (5)

Okay... so am i looking for more intake than exhaust duration (or the other way around)? Am i wanting to get as much duration as possible without having overlap? Remember, i'm building this as a street monster that will rarely ever see the track, so a wide, early powerband i think would be best. I'm not sure how much the cam affects this with FI

NassyVette

iTrader: (22)

Subscribed

BTW The GM 6.0L MLS gaskets are what your looking for. Always match the gasket to the largest part of the bore...in this case its the head.

SonofaBish

iTrader: (5)

what about the cam i currently have (see sig) or would it bleed off too much boost?

Pro Stock John

iTrader: (34)

I think a single pattern in the 22_'s is what I would run for a <700hp setup. I'd run more cam like a 23_ single pattern for high hp levels. I'm running a single pattern 234 cam on a 114.

Bird-Of-Prey

iTrader: (23)

I'm not sure how this would relate to a twin setup but for a single you would only want a reverse split if your exhaust was restrictive. You want as little back pressure as possible on a turbo setup. If you have a stock intake setup or even something like a FAST 90 I think a straight up cam on a 114-116 LSA should be fine. Something in the mid 220 range. You say this is for a street car in the 650-700rwhp range. Don't think like the car is NA when it comes to cams. You don't need half the cam in an FI car to make the power you would in a NA car. LS6 cams are quite capable of putting down 700rwhp as many have done so. There are definatley better ones out there but there is no perfect cam. Definatley loose the 4.10's and go with something like 3.42's or even a little lower.

SonofaBish

iTrader: (5)

Welp, i've got the turbos, and that's pretty much all the money i'm going to spend on the turbo part of the project for now. First, i'm going to need to build the bottom end....

I have heard recently that i am going to be needing different fuel lines and a different tank (one with a return or something like that) if i'm doing this project.... can anyone shed anymore light on this, or tell me something about this?

Also, i completely understand what you guys are saying with cams... however, my builder has been thinkin he wants to do custom stainless manifolds (if i can afford)... so does that change my cam selection at all? by this i mean, am i not going to want a straight up 22x or 23x cam, and want a split duration of some sort?

thanks in advance! i'm sure there will be plenty more questions as this project gets off teh ground!

smokinHawk

iTrader: (48)

if your budget is tight, just do the truck manafolds, no reason for stainless as these have seen low 8's, your builder is probably just trying to squeeze you for more money. plus stainless is more likely to crack (if not slip fitted and junk)

SonofaBish

iTrader: (5)

One more thought i've had recently.... i have a set of Ported and polished 5.3 heads with the 5.7 valves and the whole deal.... i was thinking recently, well, why don't i just use the heads i have, and get a larger dish piston to make up for the difference in combustion chamber... but i was told i'd "float" the heads (i actually don't even know what that means - i have a guess, but not fully sure).... is this true? or is my assumption correct that i can just get a larger dish piston to compensate for the smaller cc and bring the CR down into the proper 8.5-9.0 range?

CHRISPY

Are you sure he didnt mean "lift" the heads? If they were milled a lot you'll lose deck thickness and may be more prone to lifting under boost.

As for cam I would go with something smaller unless you are planning a radical strip setup. An Ls6 cam will spool small twins very quickly and likely give you great area under the curve.

What turbos did you buy?

Cheers,
Chris

SonofaBish

iTrader: (5)

No, he said specifically that i would float the heads.... my guess was that he meant the same thing as what you are describing as lifting. And no, the heads have not been milled at all - thats why i was hoping i could save a few bucks, just use the 5.3 heads, which i've already had ported and polished, and go with a bigger dish piston - good idea?

As far as a cam, my reason for going with something larger was b/c i sorta wanted a nice lopey sound when idling - I have never heard a turbo car loping around, and figured it'd be the best of both worlds for myself. thus the reason i was looking at going with sometihgn with a 112 lsa - still a little less lopey than my current cam.

the turbos are Precision T44's, with 76mm wheels i believe... engraved on the compressor housing is "4476E" so thats why i'm guessing 76mm wheel. Currently the one is my new kitchen-table centerpiece