[arpad_m]

Originally Posted by Ericdared

I thought the bottom end was the same on the lt1 and lt4, just the heads,supercharger, and fueling are different?

That's a nope, unfortunately. Only the block and exhaust valves are physically the same, the LT4 has forged and stronger internals, titanium intake valves. The LT1 crank is also forged, but its LT4 counterpart is stronger. AFAIK the weakest link in the LT4 seems to be the AFM lifters.

[KingLT1]

Originally Posted by Ericdared

I thought the bottom end was the same on the lt1 and lt4, just the heads,supercharger, and fueling are different?

The heads, cam, pistons, rods, crank, compression and fuel system are different.

The biggest thing that limits the LT1 with boost is the tight piston ring gap. And it varies quite a bit from one engine to the next. I have seen reports of .007 to .011 gap which is very tight. Every heard of guys pulling an engine apart and gapping the rings for boost? If you did that on a LT1 it would go a lot further. Almost nobody does because if you are going that far you might as well do drop in pistons and rods.

That being said ethanol fuel is our savior. It's ability to pull heat out of the cylinders allows the LT1 to go a lot further on boost vs pump gas. 700-750whp on E60 is where I would draw the line vs 550whp on pump gas.

So, Yes, the LT4 is stronger, but you can still make good power on a SBE LT1 if you do things the right way. It starts with forgetting about running pump gas.

[VASTREETRACER]

Ted,
Thanks. I'll be giving you a call tomorrow to discuss fuel system upgrades for my upcoming project.

Mark

Originally Posted by JANNETTYRACING

Good Morning Mark,

We offer our Super Street Brawler package of which you already have some of the parts which makes 750 RWHP on E60.

This is where we draw the line for reliable power, then we strongly recommend forged internals of looking to go past 750 RWHP.

We developed this Package with the Old TVS2300 superchargers so the only difference is the superchargers that are available, any of the PDs Whipple, Magnuson, Edelbrock, except the LT4 without significant work and additional cooling, can handle this power level with ease.

The big difference between the 5th and 6th gen is Compression and fuel system.

With a 6th Gen we make this power at about 9 psi boost.

It would take 13-14 with a 5th gen.

The 6th gen fuel system has hard limits on fuel delivery, The stock LT1 fuel system is done about 570 RWHP.

So you are looking at minimum LT4 fuel system low side, high side, injectors and JMS fuel system voltage booster to support this.

There are many other options for fueling like LPE big bore, and +30% injectors that can extend the range a bit on how much E% you can run.

I stock both Maggie and Whipple 3.0 Plus every other performance parts, so I would be glad to have a conversation with you over the phone to answer all your questions and put you on the right path.

Also offer Custom remote tuning to bring this all together.

Ted

[adamjwilson]

Originally Posted by VASTREETRACER

Ted,
Thanks. I'll be giving you a call tomorrow to discuss fuel system upgrades for my upcoming project.

Mark

Can't go wrong with Ted. Also, I see you live in Bowling Green... there is a great speed shop in Fredericksburg as well (Mike and Landon) with Elite Speed and Performance. They did my set up, as they mostly do late model Camaros and Corvettes. Hope everything works out for you either way.... you are in good hands!

[JANNETTYRACING]

Originally Posted by VASTREETRACER

Ted,
Thanks. I'll be giving you a call tomorrow to discuss fuel system upgrades for my upcoming project.

Mark

I look forward to working with you on your project.