ALPz28

iTrader: (8)

I have a build that consists of an LS3 stroked to a 427 at about 11.5:1 comp ratio. Fully forged bottom (dragonslayer crank, compstar rods, wiseco -14cc, ARP everything, etc). Top end consisting of Mamo 235 with NFI and hand touched 59cc, Mamofied Fast 102/NW 102, Yella Terra 10mm rockers, Johnson lifters w/AOL, cam specs 245/252 113+1, and 1 7/8 Kooks. 120lb injectors and dual 450 pumps to provide fuel supply. G Force T56 and RXT clutch. Fabbed 9". No cut corners with the exception of using a new LS3 block and not a LSX iron block

Anyhow, I'm trying to decide on spraying like originally planned or boosting the car. It's a street/strip car with goals of 750+ to the pavement. I know the flack about high compression and slapping a bottle a bottle to call it good would be most of your answers but hopefully I can get a fair opinion from both sides. Any and all input is appreciated.

SLOW SEDAN

iTrader: (13)

With a goal of 750whp sounds like you would only need a small shot to get your goal as you should be north of 650whp on engine alone. I would see what the setup runs as is, then slap a kit on it and run to your hearts content. Then maybe over the winter fab a turbo setup and swing for the fences. For current goal the added weight and complexity of turbo isn't really even worth it. But that said I wouldn't flinch at the compression with boost on corn if you decided to aim a lot higher in the future.

ALPz28

iTrader: (8)

Very fair input. I plan on running it N/A and see what I'm working with. My main concern is the aluminum block honestly. Otherwise I'd be pretty certain about boosting it.

Thank you

SLOW SEDAN

iTrader: (13)

The nice thing about your efficient NA engine is it wont need a ton of boost to make big power. Its not like you have a 5.3L that needs 30PSI to have fun, your engine with 10-15PSI from a turbo with a hotside big enough to not choke flow (or twins) would have that thing hauling ***.

1bdbrd

iTrader: (12)

Depending on how high the + is in your horsepower goal you don't need to worry about the block. But why build an engine like that for boost and then make such a low goal? You could sell it and completely fund a boosted setup and suspension and still have great parts.

ALPz28

iTrader: (8)

Ya I had the same thoughts.

ALPz28

iTrader: (8)

Was trying to be realistic/modest on the low end. My goal is 750 with 1000 in mind with the switch of a map using the Holley dominator system. Know what I mean? I've thought about selling it eventually and building my other F body with an lsx block for the future. I'm shooting for max potential of course with my current build for now.

Detoxx03

iTrader: (14)

Blower will get that done easily.

ALPz28

iTrader: (8)

Lol I'm sure it will. I actually had one but sold it so I wouldn't have to cut into my car (ZL1/LSA blower). Since then I decided to use a turbo or procharger set-up if I ever boosted it.

Detoxx03

iTrader: (14)

D1SC or D1X is the ticket if you don't go turbo

a05c

With that low of compression, I'd put a D1 on it and enjoy it.

ALPz28

iTrader: (8)

Lol @ "low compression". Meth and corn sound like what's in store for the car and I'll look into finding a D1.

Thanks everyone for the great input thus far!!

a05c

11:1 isn't high compression. high to me, is over 12.5:1.

Especially if on E85 and adding Meth on top of that.

ALPz28

iTrader: (8)

Now I see your point.

AnotherWs6

iTrader: (17)

yup

Forcefed86

iTrader: (4)

As has been mentioned before in similar threads… Why spend the money on a super nice engine like that and run janky fuel?

Pump E85 base fuel is typically garbage and the ethanol % varies a ton year round. Which can make tuning very inconsistent. If I had an engine like the one you are describing I’d use a quality ethanol or race fuel for the consistency and reliability. I can see using pump E85 on JY or budget builds. But it’s a pretty crappy fuel all around if you are looking for reliability and consistency in a high compression boosted build.

You can mix your own blend with some quality ethanol free 93-91 octane pump fuel and you will at least have a known consistent blend. If you are trying to save money you can buy a drum of E98 or another ethanol blend (Ignite 112 is popular). Then blend in your own premium fuel to save a little money. One of our local blender stations will pump straight E98 for us if you go in and ask them to change the pump. That might be another option depending on your location.

The higher you go compression wise with boost, the less room there is for error in the tune. So having a consistent fuel is pretty important IMO.

ALPz28

iTrader: (8)

VERY solid advice. Going to have to inquire about that with my local pumps or at the very least run a stand alone and race fuel.

SLOW SEDAN

iTrader: (13)

Why on earth would you guys run a D1 on a nice 427? I've seen them struggle to crack 800whp on a 416. If the guy is seeking an honest 1000whp a D1 is not the path to success.



I guess we are lucky that our content % doesn't seem to vary much around here. But I assume one would use a content sensor if planning to run year round fuel despite what ECM is used. Very easy to dial back timing or boost if the content drops below what's deemed acceptable, but honestly even in the winter we see E70 and anything over 50 is fine by me.

11.1 is barely higher then a stock LS3 at 10.7:1 so I wouldn't call it high compression at all, especially running on anything higher then E50. People boost LS3's all the time without worrying about analyzing fuel every fillup. I've thrown 17PSI at an LS3 on straight pump gas without issue, its still running fine.

ALPz28

iTrader: (8)

Bad ***. The c/r is actually 11.5:1 but somehow it got reduced in the thread. I was looking at the D1X and maybe even the Fs but for now just researching, getting input, talking to vendors, and tuners before I make my purchase. If you don't mind me asking, What kinda power are you putting down?

Again, thanks everyone for their input.

93camaro_zzz

iTrader: (13)

To kind of hinge off of this point, I would also say that if I had an engine this nice, I would also not be on a factory ECU. So whether you go with MS or Holley setup, or others, you could easily incorporate an ethanol content sensor, and with WOT closed loop operation would be certainly fine to run that good ole janky e85 fuel.