V3500

I need help. I have a V3500 4 by 4, that weighs approx. 6K lbs. I had the motor bulit and I installed. Took it to a mechanic to check things out. I had a mail order chip and I thought it ran well. The motor had to come back out for a head related problem. After the machine shop disassembled they told me they thought it was running lean. Valves were white in color. I am putting a different set of heads on, and im affraid im going to be really lean. I am posting here because of the knowledge of many people. My old set up was approx. 300hp (I am guessing). New set up should be 350 to 375hp. This truck is not a daily driver so time is not a factor. I will list the specs of old set up and new set up. I know I will have to tune this thing my self, My main questions right now are fuel induction.

Old specs:
*383tbi Roller Motor
*Stock 64cc Heads with 1.94I/1.72E Valves
*Edelbrock 3704 bored
*Holley 502-6
*1.5 RAR Roller Tip Rockers (this was the Head issue, I kept breaking them
*Shorty headers 1 5/8, Custum y, 3" single into flowmaster muffler (no cat)
*Mild roller cam @.50 211/212 Duration .456/.459 Lift
*9.24 compression
*Edelbrock 3594 Fuel Pump
*14' by 4" Open element air filter
*Turbo 400 trans
*4.10 Gears maybe 4.56 ( Im over 3K rpm at 60 mph, Thats why I want different heads)


New Specs Same as above Except:

New aluminum 190cc 2.02/1.60- 64cc Heads
Compression Might be little higher
13301 AFPR
Edelbrock performer rpm manifold with adapter
EBL Flash ECM
1.5 Full Roller Rocker


I calculate that i will need 100pph of fuel to support 375hp. Can the holley injector hold 30 psi? Should I go to bigger injector? The injectors are 522-43 60pph @ 12Psi or 85pph @ 21 psi. I am choosing the ebl because it seems simpler than using my ecm. Any comments would be greating appreciated.

Ronny

iTrader: (1)

This will tell you the BPC you need as well as the fuel pressure you need. I have no knowledge of Holley injectors other than I heard the early ones were not the best. I would contact Holley and ask what their 80 lb units can handle as far as higher FP. I believe their 80 lbs is rated as 80 at 20 lbs FP. so a Holley 80 is not equiv to a GM 80 as GM is rated at 12 lbs FP.

http://www.users.bigpond.net.au/ben_...ctorsizing.xls

V3500

Thanks for the reply. My holley tbi has the new style injectors. I'm still learning all the terminology. That spead sheet was some good info. BPC stans for base pulse width? How do I use this information. Spead sheet said those injectors should be good for around 379 to 406 hp. Thats in my range ( I think). Is there any way to estimate horsepower? Has anyone used the edelbrock mpfi with the ebl flsh ecm with any sucess? I also need help with the tuning. What I'm hoping for is to learn to tune and run a wideband 02. I uderstand the basic princables but that about it. What I really need is an understanding of where to start.

RBob

iTrader: (1)

There is a SS on the CD that will calculate the BPC table. It also provides HP estimates based on the fuel flow. The best place to start tuning is with VE Learns. This gets the vehicle driveable so that other items may be worked on.

To start off check the Information doc. There is a short list of items that you should check/change in the callibration.

With the fuel pressure that you are running I would connect the 13301 to a manifold vacuum source. Then check the VRFPR box on the BPC SS. This will set up the BPC vs VAC table with a varying BPC.

First off, check/set the Initial SA value. This needs to match the distributor setting. Then set up the BPC table. Check/set the rev limiters. With the TH400 trans, there are several calibrations that have the TCC set up for kick down control.

You didn't mention which aluminum heads were used, if Vortec in design can copy & paste the SA from the provided callibration. Otherwise the 5.3L engine ('113 heads) SA table may be a good starting point.

What you want to do is to use one of the calibrations that meets most of the requirements, and copy & paste pieces from other calibrations into it. With the TH400 I'd start with a cal that has it set up. Too many items to copy & paste for it.

Don't worry about the VE table too much. The VE Learn can make short work of it.

Then copy & paste in the main & extended SA tables from a cal that most matches the head/chambers. Then set the Initital SA and BPC table.

RBob.

V3500

Thanks for the reply. I dont know exact the flow numbers. I think they are Patriot Performance 190cc. I will get the numbers when i get the motor back. I want to install a wideband o2, maybe not to run with the ecm, mainly so I can see where its running at WOT. Where is the best place to install the wideband o2?

Ronny

iTrader: (1)

My WB sensor was originally just behind the long tube header flange on passenger side. NB mirror image on driver side. I had issues with the short life of the WB sensor so Innovate suggested I add the "extender" which places it higher out of ext stream and also suggested I move it back a bit. Now it is 20 inches behind ext flange and living a long life. dual exhaust (2.25 in. ).

RBob

iTrader: (1)

You do want to wire the WB unit into the EBL. A gauge doesn't tell you enough. Such at what RPM & load the current AFR is at. Shoot, the EBL will even auto learn the VE tables via the WB input.

For the heads, it is the chamber shape not the flow that defines the SA.

RBob.

V3500

Thanks for the info. I have been reading on this site for almost 3 weeks. 1 person says 1 thing and another says another. The ebl ecm and VAFPR seems like the way to go. From what i have read, if you want the most out of your motor, switching to a carb might be the way. I really dont want to do this. I have spent a lot of money on this adventure all ready. Switching to a carb is going to cost money, and I would rather spend it on fuel injection. My questions that I keep fighting with myself are: Will the holley injectors support 350-375 hp at higher psi? Should I put the gm Pod on the holley tb with bigger injectors (seems like there are pro and cons to going to bigger injectors)? If I went the edelbrock mpfi or built my own mpfi, would I be able to tune that comination? Im not looking for the best bang for the buck, but the best overall set up for performance in a 6 pak 4 wheel drive street truck. I dont mind spending more money if it helps the cause (mpfi setup) , but if it not needed I wont. My truck is a 89 V3500, it has the pre 88 body style, so its kinda a sleeper. When I open the hood people ask what all the wires are going to the carb. Just a litte of what Im am thinking. Thanks agin in advance

RBob

iTrader: (1)

Common for public forums. After a while you'll get to know who has the better advice.

With higher fuel pressure a VRFPR really does make a difference. I recommend it once over 20 psi. Although it can be used as low as 18 psi.

Once you have a decently tuned EFI setup, you'll never be happy with a carb. It may take a bit to get the EFI to where you understand what is going on. But once you do it comes together quickly.

If you saw Tbi-MAX's latest thread you can see that he is quite happy with the TBI (and a 408 ci engine). He does his own tuning now, and at the same time hit the learning curve. He has a thread on the DIY_PROM board that is a worthwhile read. I'll find it and post a link.

The Holley injectors should be 61#/hr at 13 psi. Otherwise it won't be a stock replacement TBI (other then the larger bores). The Delphi injectors that Holley uses will easily handle 30 psi of fuel pressure. That will support about 350 HP. Taking the fuel pressure to 35 psi is good for about 375 HP.

Of course using the 13301 as a VRFPR is highly recommended. Just set the VacRef box in the SS and the BPC vs VAC table is calculated for you. Can then copy & paste into TunerPro.

I'm not sure the Edelbrock MPFI set up will buy much. It is a low/medium rise single plane intake. Where the Perform RPM carb manifold is a high rise dual plane. Which I think is a better choice for your engine/vehicle.

RBob.

{edit: here are a couple of Tbi-MAX's threads:

https://www.thirdgen.org/forums/diy-...ened-your.html
https://www.thirdgen.org/forums/diy-...-wot-help.html
}

V3500

Thanks for the info. This is what i going to do. Should I block off the holley FPR, or can I just install VRFPR and leave the holley FPR alone. Where is a good place to hook the VRFPR for vacuum? The more I read, the more questions i have. Do I need an IAT or and MAT sensor? If I do, where is the best place to install them. My application doesnt have either ( I think), what application would work. Could I hook them up to the ebl ecm like the wideband o2?

RBob

iTrader: (1)

I prefer to install a block off plate whent he stock FPR isn't used. Eliminates a possible point of failure.

A VRFPR needs to go to manifold vacuum. Can connect it to a port on the intake, a port on teh TBI unit, or make a port on the adapter plate. If a TBI unit poty is used make sure it is manifold vacuum, not 'ported' vacuum.

An IAT helps with more consistent fueling. It should be located that most closely reports the incoming air temperature. To wire it in it goes to pin C12 of the ECM. There are wiring diagrams on the web site.

RBob.

V3500

Thanks again for the info. Which adapter is best for the edel 7101 manifold?

RFmaster

V3500

Edelbrock 7101 is a square bore flange manifold. You can use Trans-Dapt TD-2210 adapter plate which allows for TB to be center mounted. Please note that TD-2210 is designed for SBC TBI's (42.8mm bores) where BBC and Holley TB sports 50.8+mm?? bores - so some minor machining maybe required. Since you have plenty of hood clearance I would also go with 1/2 to 1" spacer (TD-2535 = 1") as this will increase intake manifold effective plenum - this may improve throttle response. Raising TB also allows for easier fuel line access, but be prepared to modify them any how.

All of the above may require mock-up to determine if you have necessary clearance, throttle and kick down cable length adjustment, bracket relocation should be looked at closely.

Good luck

RBob

iTrader: (1)

With the wide BBC bores may be better off with the Edelbrock 7104 intake. Performer RPM for a spread bore. I had to cut/taper in quite a bit with the 7101 intake. The bores are wider then the flange (with 2-1/16" bores).

RBob.

Ronny

iTrader: (1)

Quote from RBob: "The Holley injectors should be 61#/hr at 13 psi. Otherwise it won't be a stock replacement TBI (other then the larger bores). The Delphi injectors that Holley uses will easily handle 30 psi of fuel pressure. That will support about 350 HP. Taking the fuel pressure to 35 psi is good for about 375HP. "

When I spoke to Holley quite a few years ago it was explained to me that Holley rates their injectors based upon an assumed FP of 20 lbs attained by use of their Holley higher pressure fuel pump. The Holley TBI System was designed to be a replacement for carbed engines.

I note on Holley website the following:

they list their 72 lb injectors as flowing 50 lbs @ 12lb/hr fp or 72 lbs at 21 fp
their 85 lb is listed as 60 " @ 12 fp or 85 " 21

Instruction manual states to set initial fuel pressure to 21 lbs for the 950 TBI system.

RBob

iTrader: (1)

That isn't what Holley's web site states:

From: http://holley.com/502-6.asp

"Holley designed these throttle bodies with all relevant emission provisions and hook–ups for a true 50–State legal installation. They are engineered for a “bolt–on” installation on stock factory Manifolds for the applications cataloged. The one barrel throttle bodies have been assigned California Air Resources Board (C.A.R.B.) Executive Order (E.O.) number D–115–4. The two barrel throttle replacement bodies are considered to be the functional equivalent of the original equipment throttle body and, as such, are considered to be 50–State legal. Therefore, the C.A.R.B. E.O. number is not required.
Two Barrel TBI Model 3210 Throttle Body Injection 670 CFM

Installation Notes
Fits 1987–89 5.7L V8 Full Size Chevy/GMC Truck


Features

* Direct Replacement For OE Units
* 2 in. Throttle Bore
* 42% Area Increase Over Stock TBI
* Including Air Distribution Ring
* Increased Torque and Horsepower up to 25%
* 50 State Legal

Technical Information
Instructions for Part# 502-6
Shipping Dimensions
L 11.250 in. x W 11.630 in. x H 7.880 in.
Weight 5.437 lb."

RBob.

V3500

Thanks for all the info guys. There seems to be a lot of confusion on these tb's (including myself). I have personally talked to holleys tech support twice. The first time I wasnt asking the right questions. I thought 5.7 injectors were 61 pph. Fuel pressure on stock 5.7 i thought was supposed to between 13psi. In the directons to the holley 502-6they specify 11psi. Heres the link I think. The directions in the lnk are ecaxtly what holley sent.

http://static.summitracing.com/globa...199r9813-4.pdf

The second time I called about 3 weels ago, they said the 502-6 at the big injectors. The holley part # for these injectors are 522-43. Here is the summit link.
http://store.summitracing.com/partde...5&autoview=sku
I pulled my injectors out and they look exactly like the ones in summit picture with the light purple ring. If you read the directions for the holley 2 barrel pro-jection tb, it will say that it has 85 pph injectors. I think they are the excact same product, rated at different pph based on fuel pressure. if you look in the holley catalog and find 522-43 injector, the rate them @60pph @ 12psi and 85pph 21psi. Now I dont know if this is 100% correct, it just my uderstanding from my own investigation. If you read the summit information, it says advertised 85pph. This is why I was asking if anyone has ran those injectors at high psi. Another thought I have: If this tb was meant to be a direct factory replacement, why would they suggest the same amount of fuel when increasing area by 42%? I have read that alot of people ran rich when using has a factory replacement. I am not a mechanical engineer by no means, but common sense tells me that if you had alot more air thru a motor, then you had better add alot more fuel too. Too much air in relation to fuel would cause a lean condition(that is how my truck was running) . I think what holley did is adverising alot of different size injectors when in fact they only have a few. Any more input would greatly be appreciated.

V3500

Just another thought. Holley rates thier projection tb to 275 horsepower. I used the excel spread sheet (at the beginning of this thread), If I entered their ratings of the injector and .85 duty cycle and .5 BSFC it came out to like 271 horsepower. I guess I am going to find out just how much pressure they will hold. Im going to possibly take them to 35 psi.

RBob

iTrader: (1)

The GM service fuel pressure spec is 9 to 13 psi.

The Pro-Jection systems are for retro-fitting to non-EFI vehicles. Note that they don't have an IAC.

RBob.

V3500

Ok. I will call Oregon Fuel Injection today, and see if they can flow test them. I will let every body know what i find out.

RBob

iTrader: (1)

Be sure to have them specify the conversion factor they use to go from volume of flow to pounds of flow. And that they are tested at the GM TBI specified rating of 13 psi fuel pressure.

(been down this road before...)

RBob.

Ronny

iTrader: (1)

I was refering to the Commander 920 Throttle Body System (920-2S) as a replacement for carb engines. I wish I could copy paste the .pdf install manual page called "first startup"? It states to set the fuel pressure to 21 lbs for start up.

I see Holley offers the 670 cfm TB unit as a "stock replacement part" for current GM TBI unit.

The earlier "first generation 502-2S" did in fact suggest the operating fuel pressure to be 15 lbs.

V3500

The holley injectors in 502-6 are the 522-43. They rate them by fuel pressure. 60 pph @ 12 psi and 85 pph @ 21psi. Holley only offers 4 dfferent injectors for tbi. There seems to be a lot of different applications that use the same injector and dfferent fuel pressures. Must be a money thing. RBob, I went into the fuel injection shop, They said they could do a side by side flow check, cleaning, and the could tell me how many cc they in 30 sec. He didnt seem like to think it would be a very accurate formula. They wanted 100 bucks to do that. I didnt do it, I think I could buy flow matched Injectors for $200 a pair. I think i will just bump the fuel pressure way up and see how it works. If it doesnt, i will get bigger GM injectors and run the GM pod.

V3500

Called Holley again today. Tech guy verified that the 502-6 TB comes with 522-43 injectors. I was hoping I could get some opinions on my cam shaft. Roller cam with these specs: 211/212 @ .050 duration, .456/.459 lift with 1.5 RAR, 14.4 LSA. Keep in mind that this is a 1 Ton, 6 pack 4 wheel drive with 4.10 gears. Thanks again.

V3500

So I still havn't got my motor back yet, and I'm not real happy about it. I have been researching cams for the last couple of days. I have some questions. Is there a certain number of overlap that the ecm doesnt like? I am thinking about this cam.
http://compcams.com/Cam_Specs/CamSea...0Part%20Number. This seems like a really good all around cam. I think my cam now has 41.5 and the comp cam would have 48.5. How much is to much? Thanks again in advance.