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View Full Version : Which EFI system. TB , TPI . S ram, St ram



LowBuckX
08-09-2005, 11:48 PM
Ok I know Im not getting off cheap on EFI Ive tryed to find a Bulletproof way but no luck. I just dont want a pieced together system that may work one day and not the next.

So I have a few questions
Keep 380-390 HP Small block in mind
1) Is a system with a WideBand O2s worth the extra cash?
2) Is a throttle body set up worth looking into? Holley
3) What system type is the best for performance and economy
A) 4 BARREL tb WITH sfi on a single plane intake --Pro flo look
B) Ram type AKA Stealth Ram Super ram
4) What would be a good Upgradeable system


Thanks for your time

Fuelie Fan
08-10-2005, 07:53 AM
THese types of questions have been asked many times, so i'd like to see a FAQ created. I have a word document going. It's already 4 pages long. Should I post it here first, let people add suggestions? Or email it to a moderator?

LowBuckX
08-10-2005, 09:17 AM
I have read through this hole EFi forum and it made me more confused than ever. That is why i asked with specific questions pertaining to me.

inSANe DIEGO
08-10-2005, 11:19 AM
try going here: http://www.customefis.com/ if you haven't already. Be sure to check his links to other sites too. According to what I've read sequential injection is not worth the extra cost for the gain (if any.) I myself like the idea of a multiport with throttle body on a modded intake, but that takes a bit of fab. I would only worry about wide band O2 if you are going to force feed. N/A is fine with narrow band unless you're wanting to get really anal about your tuning. This is what I've gathered as I try to read up for my turbo motor build when my money tree starts bearing fruit. I haven't heard any horror stories about Megasquirt and the best thing about it is if you decide to change the style of F.I. later, you can still use the same computer. = less $$$ spent. So far that is the route I'll be taking.

Ralph LoGrasso
08-10-2005, 11:32 AM
THese types of questions have been asked many times, so i'd like to see a FAQ created. I have a word document going. It's already 4 pages long. Should I post it here first, let people add suggestions? Or email it to a moderator?

If you'd like to compile and FAQ, that would be great. Feel free to post it here and get suggestions, additions, and then when it's done, just post it in a new thread, and I'll stick it to the top of the forum and label it as an FAQ. Perhaps we can even work it into more of an article format, and post it in our new tech section as well(once the new home page is completed).

Thanks,

Hocky
08-10-2005, 11:55 AM
I will go for a intake with individual throttle bodies and a sequential Autronic or Nira ECU with a lot of extra functionalities. Wasted spark with 8 ignition coils and no distributor. Innovative motorsports broad band lambda.

I did go with the Autronic on my Volvo 4-banger turbo and I have been very pleased. Will probably try the Swedish built Nira on my 547".

Fuelie Fan
08-10-2005, 07:25 PM
Ok, here's the short version:
1-4) depends!

Seriously, you haven't found a cut-and-dry answer becuase there isn't one. That's why my document is growing by the minute. There are so many routes you can go, depending on what you want. Do you want your car to have the look of a carb? The TBI may be a very good option. Simple and reliable. However, around 400 hp on a small block, it does begin to get a little difficult to get good idle quality due to pulsewidth limitations. Not impossible at all, just more difficult.
Any dry-flow intake (stealth ram, ram jet) imo is a better solution than converting a wet flow (your typical 4bbl) to MPFI, but it will certainly not have the retro look. How do you select which intake? Good question! The one you select, just as with choosing any intake, depends on what you want from your engine. High rpm? Short runner. Torque monster? Consider a long tube runner. Generalizations, but you get the point. The key concept here is that EFI matches fuel to air, but airflow is what shapes your torque curve, and airflow will be decided by heads, cam, intake, and exhaust.
Is a wideband worth it? Depends! If you take a traditional approach of calibrating the majority of the table to 14.7 and using a power enrichment scheme for WOT, a wideband would be helpful for tuning but pretty overkill otherwise. And, if you have someone else calibrate your car for you, it'd be even more useless (assuming the calibrator owns one, which he should). If you're trying to calbrate yourself, without any dyno, and do not plan on running at 14.7 even during part throttle, a wideband would be very helpful. With forced induction, it's almost mandatory. Why would you want/not want to run at 14.7? Good question!

Could you maybe see how FAQ could be beneficial? One question spawns another, spawns another, spawns another. Hopefully we could at least answer some of these intro questions.

Ralph, I'll be happy to help out with any tech article.

Fuelie Fan
08-10-2005, 07:28 PM
Sorry if that sounded rude,

If you post more info about your combination, and how you plan to use it, we can tailor some these responses to your needs.

Andy

LowBuckX
08-10-2005, 11:32 PM
FF It started off sounding rude but contained alot of info that actually cleared some stuff up for me.

My combo as of now. 355 sbc trickflow twisted wedge heads
Lunati 224 @.050 .465 lift abd 1.6 rockers (.490 lift with 1.6)
10.3;1 compression. .. And a well built and tunned q-jet and holley contender intake

I will Be using it in a "spirited" street driving manor
But will eventualy build a 383 with 450 HP and want to be able to swap the EFI to my new motor.

Fuelie Fan
08-11-2005, 06:28 AM
To me, spirited street driving means you plan to stretch its legs prenty frequently, but probably won't be really "winding it out" to 6500ish rpm or anything like that. Am I correct? Both your current engine and the 383 sound healthy, but not at all wild or unruly, which also makes things easier. What kind of EFI experience do you have? Will you be calibrating it yourself, or will somebody else do the duty?

If yourself, are you generally comfortable with computers? Do you use any spreadsheet-style programs like excel? Or, in general, if presented with a new computer program, can you usually "figure out" enough to get going, or are you fond of manuals?
Why I ask: Your engine plans are mild enough that, in keeping with your low-buck theme, you could go with a GM ECU and harness and some sort of MPFI intake. Some people see this as "unreliable", but on contrary GM ecus have more engineering time in them than any aftermarket ECU, and if you can read a wiring diagram and know how to solder, you can create a very reliable system. But, even the more developed programs like TunerPro (which I like and recommended on a previous thread) won't have the pretty manual and 1-800 tech support. So, if terms like "ram location" sound foreign, or you don't know the difference between a bit and byte (and there's no shame in that, it's not exactly common knowledge), you may not want to go that route. But, if your the type that generally figures computer stuff out even though you may not know the details, it might be fun to try, and a good learning experience.
Neither combination requires sequential injection.
If that doesn't sound like your cup of tea, Holley does offer a TBI package with 4 65lb injectors that would work very well on your 383, and probably pretty decent on your 355. I would certainly debate that their system works well on anything from 250-450 hp, no way i would install 4 65's on a 250hp engine, but that's off-topic. Anyways, Holley's systems are also generally regarded as pretty user-friendly. And, i think they'd match your square bore intake. But, the 383 will be pretty much at the top end of those injectors. Next up would be 4 75's, which should be ok on the 383 but really pushing your luck with the 355.
Becuase of the "nature of the beast", MPFI isn't AS sensitive (though still important) as TBI is with injector sizing. You could run 8 30's on either combo with pretty much no problem. You could even maybe run 8 36's and allow yourself more room to grow on your 383 should you ever desire to do so.
If you go MPFI, as mentioned before, you do need to make a decision about the look and feel you want for your system. A stealth ram would probably work well for you, since it's got decent length runners. It may be a little soft below 3000 rpm (it is a tunnel ram lower, after all) compared to a good dual plane, or TPI, but you'd have to invest a lot of cash into the TPI (new lower, new runners, new injectors) in order for it to keep up with your 383 that i wouldn't really recommend it. If you were in california, owned a 3rd gen, and needed to keep the TPI, "where there's a will, there's a way", but it wouldn't be easy. I've never run an HSR and a 4bbl back to back, so if someone else has, please chime in. There's a ton of info on www.thirdgen.org about HSRs as well. Plus, there is still a question of whether the look of the standard 14" air cleaner is important to you. If it is, a holley commander 950 MPFI with 30 lb/hr injectors may be the best bang for the buck. Although, i think that kit is based on single plane with larger runners, so in actuallity it's torque curve would probably be in between a dual plane and the stealth ram.

As point of clarification, though i keep referring to single and dual plane, the size and length of the runners are just as important (if not moreso) as whether the plenum has a divider. But, in general, dual planes have shorter, longer runners, while single planes have larger, shorter runners. It is possible that Holley's MPFI intake combines a single plane plenum with smaller runners, but from the picture on their website, this doesn't look to be the case.

blown69nova
08-11-2005, 12:43 PM
If you do not want to piece together a system, go with one of the plug and play setups frm Holley, accel, Electromotive etc. Any of these systems can be upgraded to wideband or sequential I believe. The three I mentioned all come with single plane manifolds and "4-barrel" throttle bodies. The Holley or Accel can be had with the TPI/ram style intakes. Any of those intakes would work fine for your application. As for tuning, no system is going to tune itself! Using a wideband to tune is going to help, period- more so with forced induction.
Good luck with your decision, Steve

Ralph LoGrasso
08-11-2005, 01:38 PM
Ok, here's the short version:
1-4) depends!

Seriously, you haven't found a cut-and-dry answer becuase there isn't one. That's why my document is growing by the minute. There are so many routes you can go, depending on what you want. Do you want your car to have the look of a carb? The TBI may be a very good option. Simple and reliable. However, around 400 hp on a small block, it does begin to get a little difficult to get good idle quality due to pulsewidth limitations. Not impossible at all, just more difficult.
Any dry-flow intake (stealth ram, ram jet) imo is a better solution than converting a wet flow (your typical 4bbl) to MPFI, but it will certainly not have the retro look. How do you select which intake? Good question! The one you select, just as with choosing any intake, depends on what you want from your engine. High rpm? Short runner. Torque monster? Consider a long tube runner. Generalizations, but you get the point. The key concept here is that EFI matches fuel to air, but airflow is what shapes your torque curve, and airflow will be decided by heads, cam, intake, and exhaust.
Is a wideband worth it? Depends! If you take a traditional approach of calibrating the majority of the table to 14.7 and using a power enrichment scheme for WOT, a wideband would be helpful for tuning but pretty overkill otherwise. And, if you have someone else calibrate your car for you, it'd be even more useless (assuming the calibrator owns one, which he should). If you're trying to calbrate yourself, without any dyno, and do not plan on running at 14.7 even during part throttle, a wideband would be very helpful. With forced induction, it's almost mandatory. Why would you want/not want to run at 14.7? Good question!

Could you maybe see how FAQ could be beneficial? One question spawns another, spawns another, spawns another. Hopefully we could at least answer some of these intro questions.

Ralph, I'll be happy to help out with any tech article.

An FAQ would definitely be beneficial. I'd like to read one myself. What you have above looks like a solid start. The only thing I would maybe change is the format a little bit. Perhaps more of a straight forward Q & A format, just so it's easier for the newbs to navigate?

Thanks,