I'm building a 72 Cutlass with a 455 Olds and I was directed to come here for advice. I would really love to run TBI and I'm assuming its quite possible. I want the consistency and reliablity of FI without the startup costs of a 1k+ aftermarket unit. I'd also love to keep it GM I've looked through the stickie's before posting and I want to make sure I have all the things in order while I work on this over the winter. The motor is bored .030 with low compression (8:4:1) pistons, mild cam, and edelbrock RPM intake.

1. Will the 454 TB work on the 455 with aftermarket carb intake with an adapter plate?
2. What size injectors would I need? I have acces to a 454 TB with 80lb injectors installed, are they too large?
3. Besides the PCM and harness, is there anything else needed to get this off the ground?

4. From what I read it would be best to get a custom program of the PCM to make this most efficient(ie TBI Chips). Is there a particular yr/mdl PCM that is best for this install? I would love to pair this with a 4l80e and I assuming this would work? Asking now because this would effect my trans choice before the final setup.

I know those are a lot of questions, but any direction that could be offered would be great.

 

Not sure what mods your electrical harnes will require, though tbi harnes is easy to find.

Here are some helful calculators http://www.wallaceracing.com/intakecfm.php not sure but stock 454 tb should be around 700cfm.

Ported TB's are also available http://cgi.ebay.com/ebaymotors/54mm-...Q5fAccessories

80 #/hr injectors should need 35 fuel pressure psi to support 500hp.

For the tuning http://dynamicefi.com/ best and easiest.

 

1) Stock 454 TB can support 230 to 255 HP (that's what 454SS trucks where rated at). As suggested by thomas you can increase fuel pressure to increase amount of fuel that a pair of 80 lb-hr injectors (rated at 13 pSI) can deliver. The problem with increased fuel pressure is that engine will have too much fuel at idle. 80 lb-Hr injectors have a minimum 1 mSec open duration period - in other words you can not shorten injector pulse less than 1 mSec. At idle, 1 mSec injector pulses will deliver more fuel than required for normal engine operation (assuming 35 pSi Fuel pressure). To get around this - VRFPR should be used. At idle fuel pressure is reduced and injector is not dumping more fuel than required to satisfy engine idle requirements.

2) A pair of 80 lb-Hr at 22 pSi can support 350 to 375 HP with VRFPR. BBC TB can flow around 640 CFM - as long as you are not planning to spin that 455 olds past 5k RPM stock BBC should provide enough air flow (for normal street operation). IIRC OLDS 455 Output ranged from 275 to 400 hp in factory trim. Also, avoid long duration cams in your low compression engine as this play havoc with MAP sensor! Make sure that your engine can idle nice and steady with about 16 to 18 in-Hg between 600 and 800 RPM. This make idle tuning easier for you.

3) To control 4L80E look for 16197427 PCM - these were used 94-95 C/K and burbans. Look for '7427 PCM with the following BCC codes BYYC, BYYD, CAJP, CAJR, CAJS, CAJT (454 with 4L80E) and possibly other. These were the last BCC releases before OBD-II. The above BCC codes are $0D masks for which there is TunerPro support.

4) This is a loaded question. Mail order tunes are approximations at best. You will be going back and forth - with a long delay in between. You'll be better off to learn how to do your own tuning. Yes, there is a learning curve and equipment to buy, but in the end you'll be better off.
Tuning PCM maybe a bit too much for a novice. You might be better off with 1227747 ECM and EBL. However this combination will preclude 4L80E unless external (expensive ) TCM is used. A properly built THM400 will do just fine behind 455 OLDS, but no overdrive.

//RF

 

Thanks for the feedback guys. After using the CFM calculator, seems I would need 770-960 CFM to support that motor. I'm assuming a larger CFM tb would work with smaller injectors?

The motor I have was the stock 372hp model from a 68 Toronado. The machine work to the block was done out of necessity moving the ci to 461. I'm assuming I'll be at least 400hp now. I have no plans on running high RPMs on this motor as the Olds torque range is usually best up to 5500. This will be a street car. I haven't chosen a cam yet, but could do a custom grind based on the application.

As far as tuning goes, I would have no problem learning myself. I have a some friends that are very knowledgable with fuel/air ratios and would be willing to help.

 

Have you over-estimated your VE and CFM requirement? Is that a realistic engine operational RPM? See here for large TB's if so http://www.rvmorsemachine.com/

What I would use is the early BB TBI with 17084303/17112560 75pph injectors.
Not a GM supplied configuration.
Avoid the 5235231/17111784 80pph. injectors, they won't like the pressure necessary to supply 400+ hp.

Besides the harness & computer (used) of course the EBL (must have) to run it, and you will need a wide-band o2 setup,
aftermarket fuel pump, VRFPR, electronic pressure monitoring & fuel lines can get pricey...
so spending 1k for a complete, tunable EFI that supports 400+ HP is realistic, I know.

There are very few of us actually running GM's TBI over 450hp on big cube engines so advice backed by experience is very sparse.
If you look through TBIChips site he has no BB experience & no real success with ANY performance build, see his dyno results.

Anyway, pushing the GM TBI to this level has been a fun & rewarding experience for me & I hope it's the same for you!

 

You will need a HEI EFI electronic distributor as well....

 

He can use CCC distributor from 1980 to 1988 Olds. 80's HEI distributors used 7 pin ICM module and compatible with C3 ECM 4-wire interface.

//RF

 

RF: are ICM modules same for all V8 CID? 305-350-454 ...

 

Yes, GM HEI 7-Pin distributor Module - Original Delco D1961A or GM 16139869.

 

Technically, he can put that 7 pin module in any Olds HEI distributor from 1975 on, just remove the vacuum advance. I have had to do it for Buick engines that didn't come with that big cap 7 pin distributor. Its no problem.

I would be willing to bet that your 455 with a stock cam would run pretty decent with the 454 TBI and ECM. A custom tune is always best, and you can learn everything you need to know off of this forum. These guys have the best tech I have ever seen online.

Also, when I do TBI swaps I always do at least two things; 1. I use the Vortec fuel pump for a 97 GMC Suburban (also used in the 89 TTA and the GMC Syclone/Typhoon trucks) which puts plenty of fuel at your disposal. 2. I use an aftermarket (from eBay) fuel pressure regulator for the TBI unit with an adapter to allow you to hook your pressure gauge (like a shrader valve, also bought on eBay) to it to fine tune the mechanics of the setup.

The fine tunings of the electrical cannot be stressed enough. Getting that right will make it all really nice.

And hey, why not pick up a junker 80's Camaro and put it in? I'm just saying... You could always pull the engine later and put it in your Cutlass...

Have fun!!

 

Stumbled on the somewhat stale thread, but thought if you have not made any commitment, you need to know that early GM ECM will not run a 455. This has been tried by several GMC motorhome guys and it is impossible to get it to run right. There was a large group of them, 10 to be exact. They have all switched to EBL and are now running fine. You could also run a 7427, as it has enough adjustment to get it to run.

 

Well, as stated above, we know that you need to custom tune your chip yourself to make it perfect. Its not as good as the EBL, for sure.

But there are guys here running GM ECMs from small block chevy engines on their inline 6 Japanese cars.

Its all about the chip tuning.

 

No such thing as an RPM intake for BBO. Sure that isn't a Performer (non-RPM)? The original Toronado intake manifold probably had larger runners and better flow. (but at ~60 pounds bare, they're monsterous!)

That engine was rated for GROSS horsepower.

Modern engines are rated for NET horsepower.

An ~8.5-1 compression Olds without aftermarket heads or major porting has nowhere near 400 "real" horsepower. (Not unless there's nitrous or a supercharger, anyway.) More like 200--250.

First Guess: You could drop on the 454 throttle body, sensors, and computer and the fuel injection would hardly know the difference between the Olds and the Chevy engine. (Depending, of course, on the camshaft chosen.)

 

I should make one other note. The GMC motorhome guys have a new aluminum manifold for that. The reason why you might care is that it has bungs cast into the casting for multi-port injection. They would need to be drilled, but the bung is there.