I haven't been on here much, just had a nasty devorice. Well I managed to keep the firebird so its on!

What I have going on, motor .040 over 350, 190cc aluminum heads 9.5:1 compression, torker II intake odd ball tbi of a big 454 powered cargo truck with the holley yellow injectors in it, Edelbrock headers( not the best but I got them dirt cheap) exhaut cutout, 3inch carsound cat and 3 inch flowmaster cat bac, no A.I.R. or egr, and 255 fuel pump and a t-56 six speed with 4.10 gears in the axle housing.

Do you think I have over stepped the tbi bounds? Will the injectors keep up the fueling needs ( the tbi is ajustable to 70 psi in stock form, I wish the injectors where good just rusted junk now). I just fired it up tonight with my first chip. Oh man do I have ways to go.

Any tip or thing I am missing or just ideas.

 

With the hotcam, yes, you need more fuel.
Sounds like fun, wish I had a T56, every time I look the price just keeps climbing.

 

I haven't looked in a long time! The price is really rising on them? That really sucks, was hoping I could find one cheaper than they were a year ago or so, in case i want to swap out the T5 someday

 

Yeah they are getting high on price, I got mine back in 98 for 1400. It came with the bellhousing flywheel clutch shift fork hydrolic system drive shaft shifter and pedles. I Don't know how to drive and I'm very hard on transmissions. I got tired of replacing t-5's.

 

Think the holley injectors for a big block will work?

 

It depends on if they're the old style or new delphi style? Delphi style injectors can handle a lot of fuel pressure, upwards of 50+psi, similar to the OEM injectors. The old style holley injectors were mopar crap that never sprayed a nice code and couldn't handle 20+ psi without straining the injector drivers into erratic behavior. You can tell the difference just by looking at the connector. If it's a small black clip it's the good kind, if it's a big dome it's the bad kind.
I wish delphi would make 100# injectors so when I put together my new motor I'd be able to retain the 2 barrel .

 

Figure out how to modify the tip Jon.... you can do it.

 

I guess I need to dig up my old pod and get some 80pph injectors, that a shame too this pod has great ajustablity

 

It didn't look too hard did it. Only trouble would be getting a matched pair.

 

we have faith in u... lol, never failed us before... snuf and jon should collaborate on a TBI... gm would pop a boner...

 

BAH!... I'm a has-been Jon's got all the skills needed...

 

Ummm busting the 3 spot weilds (there are 2 spring under there) would give access to the 5 () shaped ports. Would opening up the ports flow more fuel or is there more to it than that? Any ideas on on how and what to use to open then and by how much?

 

Skills... maybe, but time, no! I hate to say it but if I can figure how to fire MPFI with this ecm AND Holley releases the vortec stealthram... well you know where I'm going with this.
As for the TBI injectors, aren't they just punched stuck? I don't recall them being welded. Then they thread out, I don't have pictures, Snuf, could you upload them or send them to me in an e-mail to jonprevost@gmail.com ? I've got a couple injectors I'm going to take apart here with a dremel but they're the 4.3L size to compare the differences.

 

Not sure about the holley one but here is on off a 4.3 THey have 3 spot wields

 

I would be willing to try and mod some. How about this, there is the 5 () shaped holes arong the post in the injector. Kinda think of it like a 5 spoke star rim how about removing 2 parts of the star and rounding some of the other peices in side the injector ( kinda like a intake or exhaust valve) or also enlarging the fuel entry ports if you think it will help.

Any one got a way to test them? I make sure they seal and spray, was thinking some one could swap them in real fast and do a data log and see how much more fuel they dump comared to the holley ones(delphi)

 

... suuuure... me and bruce both have been thankful of your services, youre the local F-Body guy in my phonebook...

 

the tips are punched to keep them from unthreading...

I think if you shrank the pintle in the center a TINY bit or changed the dia of the hole surounding, it would flow more. The smallest link in the chain is the tip, not the holes inside.

 

My holley ones a puched the GM ones are spot wieled. THink I can get way using Holley p/n 522-43 injectors at 50 psi?

 

I don't know if those are the old style or new. I think they're the old, call and ask. Tell them the year you bought the TBI, I think it started 3 years ago for all of the 502-6 TBI's to got the delphi injectors.
As for the fuel delivery issue. Just think about it for a second and look at the facts. 450hp MPFI engine needs 28# injectors at least, so what's that equate to in TBI injectors. Well they have 8 28#, we have 2, that means we need 112#. But here's where TBI falls short AGAIN and why we need MORE than that for that horsepower level... double fire. Our injectors close and open twice as often as the batch fire MPFI. This means we aren't flowing as much fuel because an injector doesn't actually flow much fuel when it's transitioning to a closed and back to open state. In other words firing 1 injector for 8ms WILL flow more fuel than firing that same injector twice at 4ms. So we need like 120# to get to 450hp.
Now for some fancy thought; get a nitrous carb setup and open just the fuel solinoid, you get a mist of fuel and if you time the transitioning correctly you'll have plenty of fuel for a n/a engine. Of course when you turn on the fogger you would want to cut back the injector pulse width... just brain storming some ideas I might try.

 

THe 522-43's are the new ones 60pph at 12psi and 86pph at 28psi, what I have now is the same p/n injectors as you do or an unknown set of GM 7699 brown ones.

 

What about the whole intake charge cooling effect that wet flow creates? maybe not 120# for 450?

The need exists for 4bbl tbi setups - no questions there.