Good day all, ive been stalking LS1tech for about 5 years off and on, and pretty constantly the past year since ive been itching to build a junk yard 5.3 LM7 drag only door car. As everyone else (mostly) im working around a budget. But my OT pays.for it so im able to work more to get more parts. So far pur plan is pretty straight forward (i think)
98-01 f body
LM7 5.3 junk yard engine
Summit racing 5.3L block to hot swap parts
Keep 862 heads for now
Full rebuild and gap rings 25 thousamdths
​​​​​​80+lbs injectors
Comp cam turbo cam
Twin CXracing 76mm turbos
Proglide 1.80 with transbrake

Thats the basic concept of the build, small engine, big turbos and shoot for some numbers. I know suspension and fuel system is required but haven't here's gotten there yet. We are building it for 1/8th mile with largest goal of mid-low 5 et. I doubt the 5.3 will get me there.

But here is where i get lost in the sauce.

We are trying to build a big potential engine that can slowly be pushed. Looking to get the above set up to est 500-600hp since the biggest hp ive driven was a 468hp car. Once we get the feel be able to bump it up to 700-800 then repeat. Am i going to be able to do that without hurting engine? I dont know enough about fuel injectors to know if running low psi will hurt me.

Same with rear end gearing. Do i gear the car for current HP raiting or do i gear it with gears needed for the end results? (That sounded off in my head) all the calculators say something like 4.58 gears for 5 sec 1/8th mile et. With a 3400 lbs car at 800hp. How will that effect me when low tuned to 500-600

I know adding 317 heads will drop cr to 8.5:1. But since i am a drag only car, is that ok? Im lookimg for better flowing heads and larger valves than 862s.

Suggestions are welcome
Thanks in advance

 

Lots of info in the boosted section. Just had a buddy push a 4.8 into the 20+ psi range before it finally let go. It was a bone stock engine.

 

several junkyard 4.8's on big single turbo's out there running single digits in the 1/4 so it should be possible to go 5's in the 1/8. usually big turbo builds don't go very deep on gear because the torque will easily overcome gearing then if you get a chance to run 1/4 you mays till have the gear to finish....

 

Ive researched big single vs twins and results are confusing. I want 1000hp with room for a little more. I know a 5.3 wont get me to a 1000 but its my first build so im ok with getting close and learning. Do i invest in a huge 80mm+ turbo or .....?

 

If its a race only deal, i'd put it on Q16 with 12.5-13:1 static, a good trans and converter behind it and it'll go fast.

 

Q16 at 12.5-13.1:1 compression? With boost? My brain just glitched thinking about that.....i was looking at E85 or E98

 

The engine that's in Ray's car (the car I work on) (5.3 Casting, ERL Superdeck)is in that range, and at 25ish psi of boost makes enough power to go 194mph in the 1/4. That's on gas also (Q16).