is there anyone running 20-23psi on a blow through sbe setup.Was on another forum and this conversation came up.I currently run a sbe ls with a csu e85 blow through and want to hit 20-23 and hopefully the engine lives for a bit.Im still in the beginning stages of the tuning and for the hp I want to hit need to be in the 20-23psi range.Would love to hear the success stories of running a blow at high boost.

 

There is no reason you can't. You will need good timing control, and enough fuel pump beyond that it should be just about the same demands as running EFI.

 

thats kind of what I was thinking but had a few totally against it

 

Quit listening to the few lol.

I'm in a couple of groups that talk about SBE builds bending rods and breaking pistons at 15-18psi. That's BS - it's the tune that keeps it together.

I've been 22-23psi accidentally, and then later on purpose, and it still runs. Good fuel helps A TON. I wouldn't try it without E or C16, but don't let some chucklehead tell you it can't be done. I'm looking to put my SBE 4.8 and 5.3 to run 25-28psi. It'll be spring before I figure out if 28 is too much, but it'll be fun finding out

 

The tune is a large part of it, but building it right from the start is important as well. If you want high boost on a sbe, you need rpm, or good boost/timing control. You need to keep it above peak tq throughout the pass on high boost unless you want to try and limit power. I don't see the carb as an issue as long as its capable of flowing the required fuel.

 

I was planning on shifting at 6500-6700 on the 5.3.Im only trying to hit 750-800 wheel.I figured it would take 22-23psi to get that with a basically stock ls other than camshaft.I have been seeing where alot of people are having timing at say 4000-4500 somewere around 14-15 degrees and then ramping it up after that to 7k.Im still collecting a ton of info from all you guys on the site so hoping to have alitter better grasp on it by spring.I run a magnafuel 500 pump with the big boost referenced regulator.Have a csu 750 on e85 with dual needle and seats..

 

I run e85 in my current ride.To get the 750-800 wheel I think I need to be around 22-23 psi so really paying attention to what all the guys who do it are saying.25-28 your trying for should make some real good power.

 

Is it a gen 3 or 4? Gen 3s are pretty easy to wreck, and there are a few here that have bent gen 4's pushing too hard too near peak tq.

 

It started out as a gen 3 but I put the gen 4 flat tops and rods in it

 

I see a lot of knowledgeable people saying to rev your LS and get it above peak torque on the shifts. What rpm are we talking about here, and on a stock bottom end Gen 3 or 4 what are some rpm limits or concerns?

 

6700-7200

 

There are guys taking the 4.8's to 8000ish. Peak torque depends on a few things, but ball park would be no lower than 5000 after the shift with a mild cam. The drop will depend on your converter, and transmission gearing.