Charlo

The largest injectors for TBI are currently 90lbs injectors correct?
Could these injectors support 400hp with a LOT more pressure?
I have read(I think) of people on the board runing their injectors at 30lbs+ with out any problems.

Plans are for a 496 roller cam with 8.75:1 and about 6lbs boost.
Will throttle body flow not be a problem up to 5000rpm with the forced induction?

Charlo

BMmonteSS

Gm injectos are very tolerant of high fp. I wouldn't be afraid to run 25-30 psi on them As long as the gaskets around the injectors hold up you should be fine. 90 pph with 30 psi should support 400 hp pretty eaisily.

But..... If your only getting 400 hp from a 496 with 6psi of boost I would be disapointed. In fact 400 hp from a 496 should be really easy with a small cam natureally aspirated. 6psi on a 350 should get ya over 400hp pretty easily.

I hate to say it but if your playing with boost on anything other than a mild 350 or 305 you are probably going to have to look into other forms of induction.

Grumpy

Hunt around for info on the 454SS's.
They're running some really high PSI on the fuel systems. Couple code changes, and vacuum referenced fuel pressure regulator.

Charlo

400 hp is not so bad.........at 2000 rpm

I gotta stay with TBI for smog. The blower will be a whipple and be smog legal also. I thought with a blower I could run a smaller(more smog friendly) cam to get the power I want. I figured it would also eliminate any airflow problems I will have through the restrictive throttle body.

If I can get 600 or more ft/lbs from a NA 496 and still pass smog I will go that route. Thanks for the info so far.


Charlo

BMmonteSS

I see what your doin. The lower the rpm you make your power the better off you'll be. Like grumpy said the 454ss guys have had alot of experience with torque monsters. The blower will solve alot of your problems. Hope it all works out.

Charlo

Well I am glad you dont think I am crazy. I am starting to think so. I know it will be a whole mess of work but you think it is reasonably doable right? I hope so because i just left a deposit on the rotating assembly. Also what size headers would you run?


Charlo

BMmonteSS

No I wouldnt' call you crazy....just ambitious. This is a huge project your jumping into. Your really going to have a tuff time getting this thing to pass smog. If you just have a visual then you might be ok. If they are smog ****'s then just changing the air filter will fail you. It all depends. Also I hope you understand this thing won't even run without chip tuning. This is a pretty big project to be learning how to tune your ecm. Let alone trying to tune it to pass emisions testing. ......but in all sierousness you need to stop building and do alot of reading before you go any further. See what problems the 454ss guys are having and see what problems the newbe chip tuners on this board are having. If your not new to chip tuning then you'll already have a feel for how big of a project this is.

As for headers, man i dunno i'm used to motors half that size... I would stick to the lower end of the spectrum of big block headers to help with bottom end torque. Also you going to be in for a trip with tht much torque down low. You won't be able to hook in on anything less than slicks and a ton of suspension upgrades.

BMmonteSS

I just realized your from cali. I'm going out on a limb and saying that there is no way your going to be passing a sniffer test. That motor is just going to be moving way too much air to pass thier stringent emisions laws. You need to talk to some guys that have delt with this before... I coulnd't begin to tell you where to start.

Charlo

Well thanks for the input. That is kinda the response I was originally expecting. This is going in a full size blazer and traction wont be a problem at all. As for the inspection, the blower comes with an exemption and the big block is legit and has been approved by the referee. They dont check internals with the exception of timing either. So the visual end is covered. All that leaves is the sniffer. If she dont pass shell be a trailer queen.

I realize the sniffer will be the biggest problem and there will be never ending hours of programming involved. I also realize it may simply be not possible. If I have to register it non op I will. The only hope's I have are that they do everything by percent. Yeah it puts out a crap load of HC and NOX and CO but hopefully all within the correct %. But yes I am crazy.


Charlo

BMmonteSS

Ohh ok thats the kind of response I was hoping for. You sound like you have a pretty good handle on the situation then. Yeah since it's a truck they came with bbc. I know for camaro with a 305 you have to pass the limits for a 305 so that would have been near impossible. You may be able to get this thing to pass. If your run a small enough cam and spend enough time on the chip tune it could happen. Just don't give up the first time you fail. It would be nice if you had a shop that would work with you on the tuning end. It would really help if they would let you do back to back testing while you play with the ve and stuff, then go for the real test some where else that doesn't know what your trying to do. Good luck, and stay crazy it's so much more fun!!!!!!:lala: :lala: :lala:

Charlo

So far the referee I have been working with is very cool. He has already said he would do a "pre test" on the dyno to see what the sniffer is picking up and not report anything till I ask. Free of charge to. I am sure that wont last to long though.


:lala: :lala: Charlo :lala: :lala: