[White16ss]

Okay guys- so I’m New the forum and about a year into ownership. I have a 2016 1SS with a few mods (wheels / intake / exhaust / tune / flexfuel... etc) but I have my eyes fixed on a hellion twin turbo kit. A buddy of mine with the ‘17 SS claims the LT1 will not like boost one bit, but I’m convinced with new lifters and valve springs she should handle 5-8lbs and 600-700 horsepower pretty darn well. Do you guys have any experience / recommendation / tips regarding the boost capacity of the LT1 or my build? I have heard horror stories of damage to the block and rods flying places they shouldn’t but i’d like to hear it from y’all. Thanks!

[Puddin]

It's not the lifters and springs you should worry about its addressing fuel supply then the pistons. If you plan on being at 700 to the wheel upgrading the fuel system is is a must. Most supercharger/turbo kits for our car land you at right around 550 to 580 with no other modifications. After that prepare to spend some decent coin depending on how you plan to get the fuel needed for more boost.

[crosive]

you'll hear different numbers from different people. the general consensus is 600-650 hp is about the limit of the stock lt1 fuel system, and is getting to the limit of the stock piston ring lands.

if you plan on more than that, you will need more fueling, and it would be wise to upgrade the pistons (and rods while you're in there).

[laynlo15]

I started out at about 7 lbs of boost on my Magnuson Heartbeat and that was about 550 rwhp on 93 octane, that put me in the 10.80s@129 with my Hoosier and Race Star Drag Pack. I started changing pulleys adding more timing, running some meth/water on 93 and making about 10 lbs of boost running 10.50s. Decided to run a little faster so changed pulleys, more timing and VP 109 race fuel and 12 lbs of boost running 10.30's and couldn't help myself and wanted to run 10.00's or break into the 9's. Then I had to up the boost to about 14 lbs (700 rwhp) and went 10.03@138. Well couldn't resist went to 70mm pulley and then pushed the front seal out, fixed that and at the Camaro Fest pushed the rear seal out and that was on 16 lbs of boost. So guess I should have stayed in that 12 to 13 lbs of boost and I probably would still be running the stock motor. So there ya go, that's about what it will take to break a couple ring lands and build a new forged motor.

[7LitreC5]

Were you running 10psi+ on the stock bottom end or was it built by that time?

Originally Posted by laynlo15

I started out at about 7 lbs of boost on my Magnuson Heartbeat and that was about 550 rwhp on 93 octane, that put me in the 10.80s@129 with my Hoosier and Race Star Drag Pack. I started changing pulleys adding more timing, running some meth/water on 93 and making about 10 lbs of boost running 10.50s. Decided to run a little faster so changed pulleys, more timing and VP 109 race fuel and 12 lbs of boost running 10.30's and couldn't help myself and wanted to run 10.00's or break into the 9's. Then I had to up the boost to about 14 lbs (700 rwhp) and went 10.03@138. Well couldn't resist went to 70mm pulley and then pushed the front seal out, fixed that and at the Camaro Fest pushed the rear seal out and that was on 16 lbs of boost. So guess I should have stayed in that 12 to 13 lbs of boost and I probably would still be running the stock motor. So there ya go, that's about what it will take to break a couple ring lands and build a new forged motor.

[laynlo15]

I ran 16 lbs on stock bottom end, so yes on 10 lbs.

[Juiced1]

10 lbs is usually max but your tune and fuel systems needs to be up the task. We have plenty of options.

[KingLT1]

Most stock LT1's fail from pushing the stock fuel system on 91-93 octane. Spend the money on a fuel system upgrade and get it tuned correctly and it will live. I have seen SBE LT1's up over 800whp. A gal on FB has a SBE LT1 with a F1A making 850whp...engine had over 24k miles at that power. I am not advocating you attempt the same but I wouldn't be worried about running it around 10psi with a good tune and fuel system.

I chose to keep mine on E85 because ethanol is extremely effective at pulling heat out of the cylinders on combustion. That will help keep the stock piston rings happy. The caveat is E85 require alot more fuel volume. The stock fuel system won't support E85 with boost, so you will need LT4 injectors, LPE DI pump, ZL1 intank and a JMS booster. With this setup my low side holds 70+ psi, high side 2500psi on 8psi with E.

[7LitreC5]

Thanks for the info laynlo15, Juiced1, and KingLT1. I have a stage 2 E-Force on my Stingray at about 8.5psi now. I've been thinking about adding LT4 pump/injectors, upping the boost, and running E85. Sounds like a couple more psi would be fine. I live at high altitude (7350 feet) so I have lower cylinder pressure vs. sea level which will help.

[White16ss]

This is all awesome info, thank you guys. So you guys think the hellion twin kit (6-8 lbs) would be safe without supporting modifications? If not do you have a list of necessary supporting mods? I’d be happy with 550-600 wheel but if a fuel system and forged internals are necessary, I’ll absolutely wait the extra time and save money to do everything right. (By the way, this is for road course / street monster and not for drag racing.)

[SC88]

Like everyone has already said forged pistons are not necessary but I would do the LT4 injectors ($550) ZL1 Tank pump ($280) LT4 HP Pump ($8xx) during your build so when you decide you want more (and you will lol) you will already have your fuel set.

10 psi here with stock pistons and rods.

[wnta1ss]

The biggest problem with boosting a stock LT1 is the piston rings. The factory does a very crappy job with them, and shops have seen top ring gaps as tight as .007" or .009"! That is terrible for adding boost. Roll of the dice really, whether yours is really tight or just tight. The dude from Procharger posted that he's seen enough of them break if they are run hard for over a 1/4 mile. Longer runs or higher boost seem to break the pistons (rings butt up when it heats up) more often than short runs do. If you want to really use your car hard, then be aware that most of the claims on the internet of stock LT1 pistons being fine for boost, are from people who either screw around on the street, or make short runs like 1/8 mile or 1/4 mile. They might get away with a level of boost that, in your situation, could break it. Since you want to do road courses, I think that you should consider that a 'longer run', and we did have a member doing exactly that with a turbo setup, and yes indeed it broke pistons on a road course.

[MR 45TH]

You will find a lot of different opinions on this subject but at the end of the day it truly comes down to how much risk you are willing to take. Adding boost at any level could do damage if not tuned properly. That being said sitting in the 6-8 range is very safe with no other mods. I’m currently running 10 with stock fuel system. It’s next on the list

[Gunkk]

Originally Posted by wnta1ss

The biggest problem with boosting a stock LT1 is the piston rings. The factory does a very crappy job with them, and shops have seen top ring gaps as tight as .007" or .009"! That is terrible for adding boost. Roll of the dice really, whether yours is really tight or just tight. The dude from Procharger posted that he's seen enough of them break if they are run hard for over a 1/4 mile. Longer runs or higher boost seem to break the pistons (rings butt up when it heats up) more often than short runs do. If you want to really use your car hard, then be aware that most of the claims on the internet of stock LT1 pistons being fine for boost, are from people who either screw around on the street, or make short runs like 1/8 mile or 1/4 mile. They might get away with a level of boost that, in your situation, could break it. Since you want to do road courses, I think that you should consider that a 'longer run', and we did have a member doing exactly that with a turbo setup, and yes indeed it broke pistons on a road course.

+1 this.

If you're going over 650hp and/or plan on 1/2 miling the car, upgrade the internals.