I'm looking at switching my carbed setup to fuel injection the easiest way possible and it looks like that will be going with a TBI setup of some sort since I'll be going with a roots blower soon. Problem I'm running into is that none of the TBI setups will support 600hp and forced induction. I'm thinking by piecing together a system I'll be able to get what I want out of it: 2-bar map (not sure how to boost reference it on a roots blower, any ideas?), 4-bbl ez-efi TB, gm sensors and EBL Flash upgraded to 4-injector capable. Will have to get with F.A.S.T. to see if I can fit GM injectors in the unit. I'm thinking 4 BBC injectors with a bit of extra fuel pressure should do the trick. Good idea, bad idea, suggestions?

Blower is a magnuson MP122 gen-1 if it matters.

 

The 2-bar MAP will be connected to the intake manifold pressure. This is after the blower.

For a TBI unit, can run dual 2-bbl GM units. Or a Holley or Accel 4-bbl unit. Note that the Accel unit uses port style PnH injectors and the 4-injector upgrade is not required. While the dual 2-bbl and Holley 4-bbl will require the 4-injector upgrade.

From the pictures of the Ez system it also appears to use port style PnH injectors.

RBob.

 

Have you considered port fueling as an alternative? I would presume less cost and more potential and less headaches?

 

Would either the accel or holley units provide enough fueling out of the box? I'd like to go with a single TB rather than dual setup.

Is the EBL capable of running WB only since I've already got one installed and don't have a second O2 bung?

I'll consider anything that works, can you show me a system that would be cheaper than running TBI?

 

Four TBI style 85 #/hr injectors with a fuel pressure bump will get the job done. Using 90#/hr port style PnH injectors in the Accel TBI will also get the job done.

The EBL will do VE Learns from a WB O2 set up. But won't run closed loop from one. Although many WB controllers have a simulated NB output that can be used for closed loop mode with the EBL Flash system.

Closed loop WOT fueling via a WB is just too scary. Since I decided years ago to not go in this direction I have seen engines melted from doing this. In one case the WB O2 was reporting incorrectly. In another case the "AFR correction system" wasn't set up properly.

RBob.

 

No doubt TBI is cheaper. Pro Products port manifold is $266. Throttle body is another $400. Fuel rails $92. Injectors $250. $1,000 right there. EZ-EFI is $1,750 with puter. Can it be purchased w/o puter? Summit does not list that option. EZ-EFI it appears does not support boost. Which goes back to Q will they sell just the TB unit to allow use of aftermarket puter(EBL)?

 

That's about what I was thinking as far as the injectors go. Unless the LC-1 kit does narrow band sim, I'm thinking I'll need to install a second bung. Would it matter which one stays closer to the engine?

I don't think I can run port since I'm going to be using the roots blower. I wouldn't mind going with magnuson's MP112 injection kit but haven't found any reviews on how well their own brand EFI controller is and the kit is an extra $3300 over the carbed version. I'm thinking I could run a TBI setup for half that cost. The EZ-EFI does sell the TB separately as both fueled (85# injectors and rails) and dry (sensors only).

 

Hi Guys,

New here but hopefully I can help. Bunch of misinformation here.

The ECM alone doesn't necessarily dictate the amount of horsepower it will handle. The injector size and being able to control it does.

No, it's best not to run port EFI with a Rootes style blower. They'll live longer when wet.
Any TBI doesn't work that well when you have big injectors, fuel sprays everywhere at low rpms. Remember Holley injectors only run at about 20psi, all others twice that.
The Accel has a staged injector cycle that will run 2 then all four, this helps.

The EZ-EFI doesn't do spark either, how important is regulating that on a blown application? IMO very.

When running in closed loop, if you're already at the limit of correction, guess what, if you go further lean then you're done. Calibratiing it correctly negates this potential problem. All these self learning EFI's have that and additional problems, they have no floor or ceiling. What I mean is it'll keep richening or leaning no matter what, not a good thing.

I'm an Accel dealer, became one AFTER I installed my system. I'm on their website as well, did their How-To video.

For a blown application I highly recommend the Accel. More transient fueling tables than anything in it's price class, period. Boost control, scaleable maps and their Wideband has a lean alarm feature. Program it to an acceptable air/fuel and if it goes leaner it'll shut the motor off, Neat huh?

Mark

 

Never said it was the ECM that limited HP, was more worried about whether or not I could get injectors big enough and if the ECM would reference boost. What size injectors are the ones on the TBI kit? Are they different on each kit, 1000cfm vs the 750cfm?

 

Kit comes standard with 30's but you can put just about any size injector in it that you want. It can just get a little sloppy at idle depending on the setup. I've done 72's myself. The ECM will reference up to 41psi of boost with the correct MAP sensor.

 

Was thinking about the puddling issue with large injectors, I'm not sure this would be a problem since it would be going through the blower. Is my thinking accurate or am I just more jet lagged than I thought??

 

The Blower will help "homogenize" things so to speak. But you may have an issue or two in off boost running.

 

Seems like the staged injecting would help that part, or am I understanding that wrong?

 

Yes it will no question.

 

But also does running a VRFPR on a TBI setup. And it does away with the transitional issues with staged injection. Misinformation on your part?

I too have run EBL setups (plural) well before they became available to the public.

RBob.

 

I'm guessing the variable regulators adjust in both directions via just one reference port correct? I mean I won't only be getting an extra 1psi per pound of boost right? Assuming it goes both ways that would give me a comfortable ~20 psi spread I think. I forget, does the EBL have a built in adjustment table just for the purpose of compensating for a regulator or do you have to tune around it? Seems like tuning would get a lot more complicated if it didn't.

 

You will not have any transitional issues with a good controller. It's no different than the progressive linkage that's on any throttle body today.

Most ECM's will compensate for those pressure changes. I know on the Accel there a lot of tables/calibrations going on in the backround that are never seen.

 

By referencing the VRFPR to the intake manifold the fuel pressure will be lowered under lighter loads. As boost builds the fuel pressure will be increased. The FPR should make a 1:1 change in fuel pressure vs. intake manifold pressure.

The EBL Flash has the proper tables to compensate for this. No need to tune around it. It is also supplied with a utility program to calculate the table values. Then just copy & paste into the calibration.

This change in fuel pressure vs. manifold vacuum/boost is helpful. It allows larger injectors to be used while changing the flow rate dynamically with the engine load. This makes the engine easier to tune and provides better driveability. This technique is also usable with a non-boosted engine.

RBob.

 

This is one that I use. I am not currently running boost.

Aeromotive
13301 - Universal Bypass Regulator On product category Regulators>>Carbureted Regulators

A dual purpose, universal regulator for EFI or Carbureted and street or strip applications. Base pressure adjustable from 3 to 20 PSI with standard spring, (installed) or from 20 to 60 PSI with high pressure spring (included). Offers the full flow and rock steady fuel pressure that only a dynamic, Aeromotive bypass regulator provides.

• Capable of regulating any fuel pump between 100 and 250 GPH.
• Fuel pressure rises on a 1:1 ratio when referencing boost.
• All ports are 3/8” NPT, with one inlet and three outlets on the main body and one return port on the bottom.
• Bypass design provides the ultimate, dynamic fuel pressure control.
Note: (Requires a return line to be installed from the bottom of the regulator to the top of the tank.)

Download Installation Instructions

 

That's a relief, seems like I just avoided a lot of headache there.

So I've seen a few debates go back and forth on whether or not it's best to have the injectors spray above or below the throttle blades, what are your thoughts on this and will it even matter once I get the blower on there?

If that doesn't matter it puts all the TB's on the board and at that point I should probably just look for the shortest one to help maintain hood clearance (trying to fit it all under the stock hood). So does anyone know if there are any TB's that are shorter than a 4150 style carb?


-Now that I'm thinking about it I probably should have put this whole thread under the TBI section rather than ECM, mods feel free to move it if you want.

 

I've seen Aeromotive and other brands of regulators that weren't rock steady.

 

What would be a better option?

 

My GM 7.4L TBI is 4.5 inch tall including inj pod. I then added an alum spacer 1.0 inch to allow my 2.00 inch bonnet to clear the pod. Overall height with bonnet is 5.5 inch from manifold pad to top of bonnet.

Bonnet would work nicely with a gear drive centrifugal blower(hint..hint) ....

I believe Aeromotive is high quality. The diaphragm and valve appears well above GM(TBI) quality. check their website.

 

Centrifugal blowers are more costly, more noisy, less efficient, don't have the low end for street cruising, have a more frequent maintenance cycle and are fugly. Though this gear drive version is news to me...maybe it can change my opinion. Where do I buy and how much $$? Got a part number for a carb/tbi kit?

 

That's not my point. They won't all necessarily be rock steady. but just because it's an Aeromotive doesn't mean it will automatically be perfect. I've used their pumps too, they're loud IMO.

 

Procharger style is belt driven. The step up to impeller is a gear driven at about 5 to 1 ratio. the gears run in self contained oil bath.

 

So you aren't saying I shouldn't get the one he suggested? As far as pumps go I don't think it's possible to get louder than that POS Holley Black that's on it now, it's louder than my very short exhaust at cruising speeds.

 

P-SC1, C-2, F-1??? Too many choices!

 

Yes correct. Aeromotives' are fine, just don't expect them to be perfect like he said, they're not.

 

GM Delco LT1 may flow enough?

 

I was thinking of running one of those 255LPH Walbros, heard a lot of good things about them in the past. Basically the upgrade for the TPI internals, will be a whole lot more quiet!

 

May need a larger return line? See MFG specs on that...

 

Talked to procharger, not the price I'm looking to spend so I think I'll stick with the maggie kit. I'll be calling F.A.S.T. tomorrow to ask them a few questions about their throttle body, any questions you think I should be asking besides about the injectors?

 

Yes, good pumps imo, and quiet.

 

Just thought of a new question... is there any reason why any of these 4-bbl TBI setups wouldn't fit nicely under a drop based filter? As stated I'm trying to get this project under the stock hood and every inch counts. Will be doing a bit of measuring on it this Friday to see if I need to be ordering a cowl hood or not.

 

No shouldn't be a problem especially with the Retrotek or FAST.

 

So after doing a bit of digging and a phone call later to F.A.S.T. it looks like the injectors supplied with the system should work perfectly. He said they're 85# @ 58psi and shouldn't have a problem running a few extra psi to raise it to the required PPH. Basically said they tell people to limit it to 60# because most fuel pumps won't push that kind of PSI for long periods of time. The 255lph walbro HO is rated for 80psi @ 210lph (50gph) which should be plenty for my fueling requirements, right? Thinking it should also be even less of a problem since I'll be running a variable pressure regulator and won't be going WOT all the time. And F.A.S.T. tech says they're modified LS7 injectors and they have to custom make each one so no other injectors will fit there, so does that mean they're PNH?

Good info on EZ-EFI

So parts required:
TB with fuel components - FAST 304150 - $865
Wiring harness - custom made - ?
Fuel pump - Walbro GSS340M-400-835 - $100
Fuel lines - Currently adequate - free
Fuel pressure regulator - Boost referenced - $95-$165 (would like one with a gauge port, any suggestions for the regulator and gauge?)
Air cleaner - drop based - $20-$100
Computer - EBL flash - $350+install+donor ecm
2-bar MAP - GM 2131631 - $50 (is this the correct PN for use with TBI?)
Cable Bracket - TCI 376705 - $28
Geometry Corrector Bracket - TCI 376715 - $35
Universal 700R4 TV Cable - TCI 376800 - $34
Computer controlled Distributor - Summit 850200 - $232 (is this a good choice to use with my 850702 ignition box?)
Misc lines and connectors - ~$100

Total - ~$2100

Am I missing anything or should anything be replaced?

 

> 2-bar MAP - GM 2131631 - $50 (is this the correct PN for use with TBI?)

I don't recognize that part number. Here is some part numbers and apps for the proper sensor:

# 16009886
New Numbers: 12247571, 16040609

91-93 GMC Syclone & Typhoon 4.3 turbo
87-90 Pontiac Sunbird Turbo 2.0
84-86 Sunbird turbo 1.8
86-87 Grand National
Also turbo Grand AM and turbo Grand Prix (about '87 through '91)

2-bar MAP sensor (AC-Delco #213-1520) = 12569241 (formerly 16040609, AC-Delco #213-184)

As for the injectors. The EBL Flash ECM will drive four port style PnH injectors in stock form. Or four saturated port style injectors. So no issues there.

RBob.

 

So how would I go about modifying a harness to run the 4 injectors? Could I hook up a splitter to each injector connection on a regular TBI harness or should I use a TPI harness and slice half of them off? Or if I sent in my harness along with the ECM could you modify both for the setup (I'm terrible with wiring)?

 

I think member S10wildside on this forum makes custom harness and maybe an adapter?

 

Need to check which connector the injectors use. There are some now that are not the same as the TPI style injector connectors. Best would be to splice them into the current harness. Putting two in parallel on each driver.

RBob.

 

A lot of ordering going on... only things left are the MAP, EBL and fittings which I'll be ordering tomorrow.

Realized when I had the car dropped off before my deployment to get put together (would have done it myself but ran out of time) the tuner removed the stock lines. So will be running -6an stainless braided to and from with all the proper fittings to include quick connects to attach to the factory fuel sending unit so I can switch back to an in tank pump. The lines, fuel filter and all fittings will be close to $350 (ouch!)

Was told the injectors are high impedance and in stock configuration are PnH but depend on the driver and not the injector. They're run in parallel on the EZ-EFI kit so it won't be a problem running them that way for my application either. The connectors are EV6/UScar and I picked up a four pack of them for $15 plus shipping direction from F.A.S.T.

Decided to go with a 13109 Aeromotive regulator since the fittings for the EZ-EFI kit are -6an so just stuck with that throughout the fueling.

 

As far as fuel lines go take a look at the "push fit" as well as fittings. I used Aeroquip but I see Summit offers a lower cost option on those. Reusable and much easier to work with. Rated for high press EFI.

 

Best to get low impedance PnH port injectors. With a TBI type set up the injectors fire more often then in a MPFI set up. This can constrain the injector duty cycle at upper RPMs.

Using a low impedance PnH injector alleviates the duty cycle concerns to a higher RPM.

Note that with 2 & 2 high impedance injectors the drivers will never peak off.

Going to four 12 ohm injectors (still high impedance) on a single driver will peak off. Then the injectors don't open...

RBob.

 

I was looking into this and it seems that some people were having problems with these types leaking and needing to be replaced frequently. Maybe I just came across the one section of people with problems though.

EDIT: Did some more digging and it seems like the only people that have problems with the socketless hose are the ones that don't assemble it properly. Can save about $60 this way.

The injectors that it comes with are the only ones that fit. They're also capable of running at 100% duty cycle. If they're not going to work, then I've jumped the gun on this and need to start returning parts.

 

I think that the information given to you is confusing. Note this statement:

"Was told the injectors are high impedance and in stock configuration are PnH but depend on the driver and not the injector. "

You can't run a high impedance injector in PnH mode. Well, maybe if the voltage to the injectors is boosted to about 60 volts.

If you have the injectors measure the resistance of one.

RBob.

 

The F.A.S.T. tech said they were high impedance injectors so I asked if that means they aren't PnH and he said something to the affect of "I guess when they're run in stock configuration they would be PnH" (meaning before modification in the stock LS7) So it didn't sound like he was 100% sure on that part but they are for sure high impedance. The way they run them on the ez-efi kit is in parallel like you were suggesting but I'm guessing they're driven differently from the EBL vs the ez-efi ECM?? Is this where the concern was? I'm just not seeing the problem but don't know all the technical stuff about EFI so I'm trying to catch up here.

 

The difference is that a low impedance PnH injector opens & closes faster then a high impedance saturated injector. This allows more time to deliver fuel.

As I mentioned you can't run a saturated injector in PnH mode unless the voltage is boosted (way up).

Wiring the injectors two on a driver in the EBL will run them as saturated injectors.

RBob.

 

So at this point what would be the best solution? Voltage boost, ditch the ez-efi, or run them as separate injectors (each with their own wires) or....?

How much compensation is done from the MAP vs the AFPR tables? I looked at the instructions to the EZ-EFI kit and found that it says to use an AFPR with the kit which leads me to believe that it has AFPR tables built into the kit. Reason I'm asking is that it would be a whole lot easier to run the complete EZ-EFI kit out of the box rather than hooking up the TB to an EBL. If drive-ability and power are highly dependent on using the MAP to compensate for boost only then would it make sense to go through the extra effort to use the EBL (then of course there is the spark control too). I could just be getting burnt out at this point and just wanting to quit but I might accidentally be on to something too.

With using the EBL will I need a knock sensor? If so, where would it go since I don't have a modern block? And which knock sensor would I use?

 

Also found this:
http://www.summitracing.com/parts/MVC-951150/ (actually an 1150CFM unit)
http://www.motorvation.tv/billet_throttle_bodies.htm
Will be calling motorvation tomorrow to ask them some technical stuff about it...any specific questions I should ask about injector requirements and all that. I'm sure you've noticed I'm mostly ignorant on injectors. If you had a very specific type of injector that I could reference that would also be of great help.


And then of course I finally got an email back from retrotek speed (powerjection III) and they say with the 75# injectors and upped PSI I could easily run it on the blower as it comes in the complete kit. Asking them a few more important questions ie; ignition control and closed loop operation (remember it only has a WBO2) but will see what they say before even considering it.