Cascade Crew

83Z28BlackBetty · Posted: Fri Feb 26, 2010 5:23 pm Post subject: TBI Swap

So its official, I'm done with my carb system. My current carb is shot, and being faced with the option of new carb or swap to EFI, It was a simple choice.

The next choice was TPI vs TBI, I elected the TBI option because of its simplicity and the ability of not actually needing to swap intake manifolds. Plus a buddy of mine down here has most of the stuff necessary.

I bought a wiring harness and ECM from a 91 Camaro from Bruce (THANKS!) and will be using a bored out TBI unit with 2in throttle blades. I'll be utilizing my edelbrock performer 4 barrel intake with an adapter plate. The plan is to mod the fuel pressure regulator to boost the fuel pressure a bit, and start the tuning adventure.

For now i'll be using the stock ECM, but may be looking to Flash EBL or MS in the future. More to come later.

~JAKE

Dewey316 · Posted: Fri Feb 26, 2010 7:48 pm Post subject:

Get the EBL, eat top-roman if you have to. It will make the tuning SOOOO much easier.

d00012 · Posted: Fri Feb 26, 2010 7:59 pm Post subject:

X2 on the EBL.

It's what I'm going to get for the Camaro and Firebird. The other tuning methods scare me...

Quasi-Traction · Posted: Sat Feb 27, 2010 12:01 pm Post subject:

you'll have to forgive me for asking jake, but wouldn't it be cheaper to just rebuild the carburator, or change to a carb a little more mileage-friendly, like say a q-jet?

Alphius · Posted: Sat Feb 27, 2010 2:33 pm Post subject:

83Z28BlackBetty · Posted: Sat Feb 27, 2010 9:02 pm Post subject:

That was my first route Chris, but since it is consistently a million degrees down here in the summer, the lack of carb experts down here, and i am starting to crave the drivability of EFI.

So i take it everyone loves the Fash EBL. lol

My first step in all of this comes tomorrow, I'll be fixing my flexplate and welding an O2 bung in my exhaust.

~JAKE

RSFreak · Posted: Sun Feb 28, 2010 8:25 pm Post subject:

What is EBL? Confused

Dewey316 · Posted: Sun Feb 28, 2010 8:26 pm Post subject:

RSFreak · Posted: Mon Mar 01, 2010 9:41 pm Post subject:

It doesn't seem to be compatible with the '730 or '165 ecm. Sad

Twilightoptics · Posted: Mon Mar 01, 2010 11:16 pm Post subject:

LOL those are MAF ecms.

EBL is TBI dude.....

RSFreak · Posted: Tue Mar 02, 2010 6:23 pm Post subject:

Red Bird · Posted: Wed Mar 03, 2010 2:14 am Post subject:

Wow! that is not very expensive for all that EBL offers. I never looked at the page with the price and assumed it would be much more expensive. time to start savin for one myself.

Al Hasse · Posted: Wed Mar 03, 2010 4:14 pm Post subject:

I thinkk I'm going to get one for myself here shortly. I'll pull the ECM and bring it to work and do the upgrade during break time. I've got some pretty awesome soldering equipment at work Cool

Makes it hard to save for the T56 when I have the funds to get other neat stuff now Laughing

83Z28BlackBetty · Posted: Fri Mar 26, 2010 7:38 pm Post subject:

Hey all, I've finally finished this project!!! WOO HOO! I took her for the first set of tuning runs/test drive yesterday. Wow this thing feels gooooood. I'm not sure if it is the fact that i haven't driven it in a month, or if it has increased performance at all... but either way this thing is great!

A few problems encountered along the way included VATS... (durrr i wonder why it wont start? HAHAHAHA) The original ecm chip frying the minute we tried to burn it. Not being able to find burnable original chips due to their smaller size (requiring modifying the socket to house a larger EEPROM chip) Heated O2 sensor wiring.

The last unsolved problem is finding a larger set of injectors. Apparently my lil 305 breaths a hell of a lot better than a stock car does because i'm leaning out like crazy at higher RPMs and i've just about maxed out the fueling. Anyone have a set of 350 injectors lying around?

~JAKE

Dewey316 · Posted: Fri Mar 26, 2010 8:54 pm Post subject:

Jake, here is the info on setting the BPW on the TBI computers.

;* Val = 1461.5 * (VOL/RATE)
;* VOL = Vol of 1 Cylinder in liters
;* RATE = Injector flow in gms/sec

So, if your car is a 355...

355ci * 16.39 = 5818.45cc

5.81845l / 8cyl = 0.7273 l/cyl

So, here is where it gets interesting. The stock 305 injectors are 40lbs/hr @ 13psi. If you bump the pressure up to 20psi, the rate is 50lbs/hr give or take. If you bump it to 25psi it is 55lbs/hr (the 350 caprice car injector size).

So, we do two more calcs here.

20psi--
49.6 lbs/hr: 49.6 / 3600 * 453.6 = 6.25 gm/sec

25psi--
55.5 lbs/hr: 55.5 / 3600 * 453.6 = 6.99 gm/sec

So, now we can plug those numbers into the BPW calculation, since we now have VOL and RATE calculated in the proper way.

20psi --
BPW = 1461.5 * ( 0.7273 / 6.25 ) = 170

25psi --
BPW = 1461.5 * ( 0.7273 / 6.99 ) = 152

You should be able to compare your values to those now. The tricky thing about the BPW is that it figured in engine size also. If you BPW is corrent now, it should be HIGHER than 170. If the BPW is lower than 170, then it isn't correct for you injector/motor size now.

Also, when you adjust the BPW, the VE tables should adjust with it, assuming it was correct before. but AE won't change, AE is will have to modified to get the car running how you want, given that the fuel going in is more. You should be able to start by taking out, say 10% on AE, and see how it goes from there.

Hope that helps,
John

DBL_TKE · Posted: Fri Mar 26, 2010 10:49 pm Post subject:

Eek, maybe I shouldn't be trying to read this at midnight after working a bell, it makes my head hurt.

83Z28BlackBetty · Posted: Sat Mar 27, 2010 8:49 pm Post subject:

Thanks for that Dew,

My question now is this. I drilled out the piece of solder in the pressure regulator so i could screw the "cup" farther in and bump the fuel pressure. I now have a consistent 14 PSI while the fuel pump is running, but it quickly bleeds off after the pump has shut off for few seconds. Is this a problem?

Also, i've maxed out the play in the pressure regulator. How can i get more pressure than 14? do i need a heavier spring?

~JAKE

Dewey316 · Posted: Sat Mar 27, 2010 8:52 pm Post subject:

You need a heavier spring, or you can try to put washers in there to shim it, and create more pressure.

83Z28BlackBetty · Posted: Sat Mar 27, 2010 9:09 pm Post subject:

I'll look into the heavier spring. what about the pressure bleeding off? is that a sign of a faulty regulator?

~JAKE

Dewey316 · Posted: Sat Mar 27, 2010 9:13 pm Post subject:

it means something is weak, and letting the fuel by.