[ShizzySupra]

Just do the Cunningham drop-in rods and pistons. The extra labor is negligible when doing a cam since almost everything is removed at that point. Good insurance for those wanting to push more. I would comfortably push the stock internals to 700-750+whp through an auto but I am a little riskier than most. I know I would want more since these cars are so heavy, so I am opting for the drop in rods/pistons to have 1000+whp worry free.

[toohighpsi]

Originally Posted by PinHead

Don't you also modify the timing curve when changing the tune to address knock?

I run as much timing as the combination of IAT and Octane will allow up to the point of MBT (max brake torque) timing. If I get close to MBT timing before knock - I add more boost

[jessrayo]

Originally Posted by EDFHOBBIES

Are you running meth and cam w a different fuel lobe profile?

I have had meth injection since the turbos were added. Have been running the stock cam to this point but now that the motor is coming out I'm going to definitely change the cam for both fuel lobe and probably try to get more flow than stock.

[jessrayo]

Originally Posted by ShizzySupra

Just do the Cunningham drop-in rods and pistons. The extra labor is negligible when doing a cam since almost everything is removed at that point. Good insurance for those wanting to push more. I would comfortably push the stock internals to 700-750+whp through an auto but I am a little riskier than most. I know I would want more since these cars are so heavy, so I am opting for the drop in rods/pistons to have 1000+whp worry free.

All of the drop in pistons I have seen maintain the stock compression ratio of 11.5 to 1. This is too much compression to run significant boost on pump gas. The stock compression ratio is only going to allow about 650 whp unless you run alcohol or high octane race gas. I'm going to drop to at least 10 to 1 compression ratio so I can push more boost off of pump gas.....it is really easy with turbos, just adjust the wastegate spring/settings.

*edit* I went to the Cunningham page.. http://www.cunningham-motorsports.co...bbcfecd6d8a275 and saw that these are 10.5 to 1 pistons. That is better but I have a lot more boost potential than most superchargers so I'm going to drop it even more while it is out. The other thing is my engine failed so it needs a complete disassembly and inspection, may have piston or ring fragments in the bottom so I need all new bearings and seals.

[ShizzySupra]

You can achieve 850whp through an auto on pump gas if you have meth and are dead on the tune. Dropping the compression just lowers the total power output per psi. For these motors I wouldn't take it lower than 10.5:1.

The hard truth is people always want to push as much power as they can on pump gas and it's just not feasible to do safely most of the time. Why spend all that money on a forged motor just to risk it on a bad batch at the pump or bad air, etc etc.

Also your turbos are quite small on a motor of our displacement. My guess is they will run out of breath around 16-18psi depending on cam combo.

Originally Posted by jessrayo

All of the drop in pistons I have seen maintain the stock compression ratio of 11.5 to 1. This is too much compression to run significant boost on pump gas. The stock compression ratio is only going to allow about 650 whp unless you run alcohol or high octane race gas. I'm going to drop to at least 10 to 1 compression ratio so I can push more boost off of pump gas.....it is really easy with turbos, just adjust the wastegate spring/settings.

*edit* I went to the Cunningham page.. http://www.cunningham-motorsports.co...bbcfecd6d8a275 and saw that these are 10.5 to 1 pistons. That is better but I have a lot more boost potential than most superchargers so I'm going to drop it even more while it is out. The other thing is my engine failed so it needs a complete disassembly and inspection, may have piston or ring fragments in the bottom so I need all new bearings and seals.

[04lss]

Sorry to bring up an ancient thread, but reading through this it sounds like the standard power improvements from the superchargers on the market (600whp) is about the limit of what is safe without needing to baby the engine. (IE, i can track it, drag race it, stand on the throttle) is that accurate?

[KingLT1]

No that is not accurate...lot's of variables come into play. On 93 octane with SBE yes that is probably a safe limit. If you install a cam to bleed off some dynamic compression you can go a bit higher on 93. Spend the money on a fuel system so you can run E50+ fuel, you can likely go 700-750whp. The key is keeping cylinder temps in check so the rings do not butt and/or crack a piston.

High compression, boost, and 93 octane is a very limited combination with pistons that were designed for NA. Hell it's even limited(octane wall) if the rings were gapped for boost. E85 loves compression and has been a game changer for years. The old LS1 was similar to the LT1 in regards to power limit with boost. They would only tolerate about 600whp on 93 with the stock long block. Then when E85 started getting popular you started seeing SBE LS1's handling 7-750whp without failure. Same scenario here other then the fuel systems are a lot more complex and expensive to upgrade. So band-aid methods have been commonly used to supplement fuel and many LT1's have failed as a result.

[wnta1ss]

Originally Posted by 04lss

Sorry to bring up an ancient thread, but reading through this it sounds like the standard power improvements from the superchargers on the market (600whp) is about the limit of what is safe without needing to baby the engine. (IE, i can track it, drag race it, stand on the throttle) is that accurate?

Actually there is not truly an arbitrary safe number. The big issue with the stock LT1 engine is that some have crazy tight ring gaps from the factory, making them more susceptible to heat-related problems. So you can get away with more on some engines than others, problem is that you don't know what you got unless you take it apart. Cooling things down with methanol and E85 helps with heat, but still no arbitrary number that is guaranteed to work in every example of the LT1, or every situation. Drag race is one thing, 20 minute HPDE sessions will build more heat and therefore more of a concern.

For your M6 car I would actually suggest nitrous oxide as your power adder for drag racing instead of a supercharger. Stuff works awesome with a stick. I have seen an M6 SS on drag radials that ran 11.5@119 off the bottle, then spraying what he said was a 150 shot, he went 10.8@128. I have seen some M6 Camaros with blowers here and they were not as quick as that nitrous car, and yes with MTs on all of them. Plus if you want to do HPDE (assuming that's what you meant for track it), just remove the bottle and it will not be a problem. Adding a supercharger of course would make it run hotter during HPDE driving. FYI I had a supercharger on my SS before, so not against superchargers in the right situation, just pointing out some things that I've noticed over the years.

[04lss]

Will the LT4 system let me run e50 at close to 700 whp?

My plan is basically to get a supercharger, run what i can on the stock fuel system on 93. Then upgrade the fuel system to the lt4 and get whatever i can out of that with my aim being 700rwhp.

I want to be in the 10s but I want to do it safely.

[04lss]

WNTA1ss,

Tracking and drag racing are great, and i want to be able to do that. But my primary desire is every day driving. Nitrous wont do that, since at least in my state i think its illegal to use off the race track. Id rather run 600whp on an e30 blend to keep the engine cooler at hpde.

[KingLT1]

Power Adder: Whipple 2.9 with 3.375 pulley. Produces 9psi peak in 70+ degree weather @ 2k da.

Fuel system: LT4 injectors, LPE DI pump, LT4 tank pump with JMS booster.

Other mods: Ported LT5 Throttle body, Rotofab big gulp, Flex sensor, CA cat delete pipes, Borla 60608 x pipe into Corsa NPP.

Dragy Performance time: Street pull, second gear launch(A8), the car ran 1.75 60ft, 3.0 0-60, 6.17 0-100, 6.9 @ 107 1/8 mile 10.5 @ 135 1/4mi full weight on 20's with a 305/35/20 Nitto 555r2 drag radial.

Log Data: Running E55, My High side pressure holds 27-2900psi, Low side pressure holds 70psi, Injectors 5.6-5.7ms in 70 degree weather. So the fuel system is holding fine.

Longevity: In 3yrs I have logged 8k miles of drive time and easily a 100+ 0-60, 0-100, 1/8, 1/4 and wot pulls from a roll...no issues so far knock on wood. Lol

[04lss]

Awesome! I was a little bummed actually thinking i was stuck at 600. Is the whipple still available, I see it on the Jannety site, but whipples site doesnt seem to offer it.

[KingLT1]

No they are suppose to be replacing it with the Whipple 3.0. The Magnuson 2650 will do everything the Whipple 2.9 can and some. Unlike many, I am not biased to parts I buy, So I wouldn't hesitate to get one of those. I bought the Whipple because I got it for a steal. I paid 5500.00 for the entire kit BNIB and that included Hptuners, 2 sets of plugs, 2 gallons of coolant, 2 sets of NGK LTR7ix plugs, lift pucks, and some tools like flywheel wrench and crank pulley puller. I sold what I didnt need and ended up around 5k for the setup. Then put the savings towards the fuel system upgrade. Not mentioning this to brag, just informing that if you keep a eye out you can likely score some deals on stuff. A lot of guys buy parts for cars, never install them, then take a loss. Just depends on how patient of a guy you are. lol

[04lss]

The big question i have to ask myself is do i want to go roots, or turbo. If i go turbo I think i can run the MSD intake along with port fuel injection, which i imagine would resolve all of my fueling concerns.