Prostcelica

Hey guys

Im looking for some direction on a 4.8 single turbo build im doing. The motor is going into a 100% street car (basically a weekend cruiser) so I want it to be super reliable and run on pump gas. I will run meth if I need to but would perfer not. Id like to make 450-500 rwhp. As for parts I dont want the best of the best but I dont want the worst of the worst either

My plan so far is (unless advised other wise) run the stock bottom end as is, ebay head studs, upgraded cam and springs, stock heads, stock truck intake, stock pcm coverted to speed density and dyno tuned, 4L60E (I know they are not great trannys but honestly it will only see boost once and a while. If it blows up I deal with it then because I already have it.)

What parts would you guys use to make this happen??
-Cam/springs?
-What turbo/what size? Id like to buy a kit like this http://www.cxracing.com/mm5/merchant...ory_Code=TRBDK so everything I need is there or is it better to piece it together? if so parts list?
-Converter? Id like to use the stock one but is this a bad idea?
-Fuel pump? I plan to use the stock truck tank and would like an in tank pump that wil work with stock tank that will support 500hp
-Injectors?
-Any input is greatly appreciated. if there is anything that I have not thought about here please advise. I know its alot of questions but Im fairly new to LS based stuff and FI

Thanks in advance

denmah

iTrader: (2)

call VSracing and get the denmah kit

you can do 500whp with stock camshaft and just pac1218 springs

gt45-68mm turbo will be a little laggy, ask him if you can get a smaller trim
the 72-76mm (on3 clone) style will certainly light off faster.

Bosch 044 external pump - 160 on amazon
GT500 60s or siemens deka 80s

check out my wiki for some good info and shopping items
https://sites.google.com/site/sloppywiki/

Prostcelica

Thank you for all the good info. How much boost would one have to run to achieve 500rwhp. ?
I don't know a lot about it (trying to learn) but it seems 10#'s on X turbo may not be the same as 10#'s on Y turbo. Not sure the reasoning on this. Maybe someone out there could clear it up.

krazy4

iTrader: (5)

Take a turbo with a 67mm wheel and a turbo with a 88mm wheel.
The turbo with the bigger wheel will move more air at the same PSI.

This is very basic but will give you the idea.

Prostcelica

Ok, so if you have those 2 turbo sizes on the Same motor the larger turbo will make more power at the same boost level cause its moving more air. That makes sense. I guess the larger turbo won't spool as fast and will make the power higher in the rpm range?

I've read that you don't want to run more than 10#'s of boost on stock internals on pump gas Is this correct? I guess what I'm wondering is what size turbo would be optimal to make the power I want, at an acceptable boost level for stock internals and pump gas and not be super laggy?

Tanus

Your 10psi turbo a vs 10 b question, the difference is because of restrictions in the intake flow, like if you do nthing but swap stock heads for some afrs yor boost will drop, once you up it back to 10 that 10 will add more hps than it did before.

Oh as for turbo recemmedations I would, actually I am, following the sloppymechanics parts list. Its by far the most proven setup.

And trust me you'll "only want 450-500hps" until you have that much, ha

Forcefed86

iTrader: (4)

IMO... Leave it alone!

For the power levels your looking for you wouldn't have to touch the motor. Don't touch the heads cam head bolts/studs etc... IMO most are more likely to mess something up taking the engine apart. As said, if anything do springs. Though for 450-500hp it's not needed.

I'd put the money and effort into the fuel system, trans, rearend, and turbo.

Look at the $450 10" PTC turbo converter. Nice converter will make or break the setup. save up your money for a decent cam/springs and you could rev the little 4.8 out to 7k. That will make the 10" converter work much better.

The walbro 400 intank pump would be much cheaper and easily make your desired power level.

For the small amount of effort and investment, always a good idea run a meth/water kit on pump gas setups. Pay attention to what the pump gas guys are doing with timing.


As seen here... 4.8 making much more power than you plan on. OE long block, never opened...even OE valve springs.

https://ls1tech.com/forums/forced-in...float-now.html

Prostcelica

Ahh, ok. I'd rather upgrade the motor. ie camshaft, heads, intake to achieve better flow and be able to run a lower boost level to achieve my goals.

Am I thinking about this the right way??.... The lower the boost level the easier it is on the motor? I dont want to be having to mess with this thing to much once its built. I already have a car that requires constant attention lol.

Forcefed86

iTrader: (4)

No offense... but at the power levels you want, that makes NO sense! You turbo charge something to have the turbo do the work. Turbos and piping are cheap. Aftermarket heads/cam/intake are not. To me, it makes more sense to get to your targeted HP goal as cheaply as possible. Why do it the hard way? OE parts are more than capable of your goal.

Tanus

Like forcefed said your thinking is incorrect in trms of your goals, but the logic is right , its better to be at lower levels but when your talking 20psi on stock 500 dollar motor making x amount of hp vs a 5000 motor makeing same power but with 5, or whatevr less psi both can be very reliable setups, so save the 4500 for spinner hubcaps.

Prostcelica

None taken. I appreciate the Info. I know it is probably hard to say but how much boost would a guy have to run on a 100% stock 4.8 to achieve the 500rwhp goal?

Prostcelica

Lol. I do like spinners.

wutsaiu

I got 500whp from a stock 2008 4.8 with 15psi.
I'm sure someone with a proper setup and better tune could do better.
I hope you're going to use the newer 4.8 though.

Forcefed86

iTrader: (4)

Not hard to make a guess… The 4.8’s were rated at 270 crank hp. (Some rated higher)

With a properly sized turbo in a perfect world at 14.7PSI you would double that number. So 540 crank hp or 18ish hp per lb of boost. Since it’s not a perfect world and turbos aren’t 100% efficient you’ll make less power per lb of boost. How much less will differ greatly depending on many things. Altitude, intercooling, air temps etc…

Pretty safe to assume if you had a well designed turbo setup you could reach 500+ crank hp at 15psi or so.

Prostcelica

Them motor I have is an 01. I think I read that the rods aren't as good in the older one or maybe the pin used to attach the piston to the rod was an issue....or maybe both. Re the older ones no good for boost?

Forcefed86

iTrader: (4)

Its fine for your goals. Run it.

wutsaiu

As far as I know the older heads don't flow as well. Just makes it a bit harder to reach your goal.

Prostcelica

In your opinion what size turbo would be ideal for what I want to do?
I also can't help thinking a camshaft would not be a horrible idea. Any thoughts on that. ? What cam? I know you guys are thinking for what I want to do just leave it alone but the motor I have has been sitting for a year or so. Ill probably pull the heads to have a look anyway. I was thinking camshaft, springs an maybe some clean up on the heads. Any idea how those heads respond to a little porting? Is the juice worth the squeeze there?

Forcefed86

iTrader: (4)

I'd look into something like this if you want cheap.

http://www.ebay.com/itm/GT42-turbocharger-1-05AR-turbo-charger-MONSTER-t4-flange-twin-scroll-1000HP-/330952287067?pt=Motors_Car_Truck_Parts_Accessories&hash=item4d0e4b235b&vxp=mtr
If you want to buy brand name turbos I like BW/Airwerks units if you have the space. Forcedinductions.com sells them reasonably. S475 with the smaller t4 housing and wheel would work great on a 4.8.

Haven't met a person yet that wasn't happy with the isky tripple 12 cam on a 4.8/5.3. Pm Stock48 if you want one. They are about $370.

Look up LS head porting on youtube. There are a couple good tutorials on what to port and what not to. Easy to do more damage than good...wouldn't' bother for 500hp.

dezlfrek

iTrader: (1)

I have a ptc 10" converter with the upgraded 21 blade stator and low miles for 300..
I would go with a bw 471/83 for you goals with this converter would be low lag for sure..