Whats the pros and cons of each system? I'm still in the planning phase of my build and already have a tbi setup capable of 400 plus hp but its seems like tpi supports more power from what I've heard and makes more tq and hp because of the better atomization and intake design.

I'll be posting this in the tpi thread too to get both sides of the story.


I just thought about it last night... why put all this money into a tbi system when a tpi system can do it better and handle more power? Or can it? I don't know much about the tpi setup... Thats why I'm posting this.

I'll probably end up starving my motor if I stay with tbi... my old plan was hyd flat tappet lifters and afr's older street heads but I'm planning on a 383 with afr eliminator 195 street heads(has to stay CA smog legal), roller rockers, and mechanical flat tappet lifter so I'll be somewhere around 450-475 hp and 520 or so ft lbs N/A at least thats what desktop dyno says.

I think tpi would be the only option for that but then again you guys know your shiznat when it comes to tbi...

School me.

 

You will need an aftermarket intake for TPI to make the power you want. TPI starts to choke a STOCK L98 around 4,200 RPM or so.

 

how about the throttle body? is 475 ish(being generous) hp doable for tpi?

 

Not really. What are you considering TPI? TPI as you know it with the long tube runners, stock lower intake, stock type plenum will be luck to hit 280 RWHP in most cases.

 

I wouldn't spend all that money and control it with either system...

 

I would however recomeend the EBL to run either setup.

 

Blazin, a TBI setup will work with what you are planning. As for staying Cali smog compliant, an EGR is the catch. A decent single plane manifold with EGR is a good choice. A BBC TBI unit with 81 lb/hr injectors at 30 psi will support 475 HP on a 383.

Part of that statement is because a 383 will make that HP at low RPMs, such as 5,800 RPM. So injector DC% can be pushed a little (there is more to injector open/close time then DC%). Run an external fuel pressure regulator vacuum referenced and it will be a great running setup.

I too am in the process of building a 383. It will be TBI. Which I wouldn't even attempt without an EBL setup (If you know of a good source for the AFR heads {1038's}, please PM me).

RBob.

 

Bob.............you need a test mule?

I need a CI boost!

 

Thats what I was hoping to hear and yes the ebl will be a major priority in my build... compliments to you rrob that is some cool shiznat.

But I have a holley 670 with 85 pph injectors... is 30 psi still ok?

 

My understanding is that the new(er) units with the Delphi injectors (right angle connector) will take that kind of pressure. I was working with someone that was using that unit and we had no problems with 30 psi. Others have said the same about the Delphi's, they can take a lot of pressure.

RBob.