You guys have any EFI or Nitrous Questions? [Archive]

Doug F.

Dec 5th, 10, 8:16 AM

Doug,

If I were to dyno-tune this motor, do you just change the WOT AFR's or should one go to the tables and richen/fatten everything a bit? Same for spark?
Hi Vince,
The closed loop works very quickly so there is no need to touch the base tables. Just change the target AFR table to whatever you want. Makes it quick and easy to do back to back pulls.

As far as timing, as you know, you have to change the table as it is an "open loop" deal. Timing will be whatever the table is.

Just some points on tuning. As far as WOT, the ET slip with its mph, although not showing power at a given RPM, is a great indicator of correct tuning. Especially if you have full incrementals. Also assumes the car repeats at the track. Same goes for fuel and timing.
Your car with the manual trans and over-powered launch makes it harder to repeat though.

69-CHVL

Dec 5th, 10, 6:33 PM

Thanks Doug. Its just runs so good that I feel like somethings wrong and I need to tinker :D

72BB Nova

Dec 5th, 10, 8:51 PM

Doug F.

Dec 6th, 10, 12:42 PM

Doug

Talked to you thru email about a month ago. I have another question on the ignition systems. You said that the DIS system would probably be overkill for what I was building, but how much difference would I notice in performance, driveability, durability between the DIS and the Dual-sync ignitions? Thanks Jeff

You mention "how much difference would I notice". Regarding ignitions in mild engines, it takes a lot to "notice" much differences seat of the pant. For the most part you need enough ignition to light things off, and for engines that don't have a lot of cylinder pressure, most ignition systems will do that. You basically need "properly installed, quality" parts for milder engines, which some people don't do using a cheap chinese distributor, etc, that may have problems. The front mount 60-2 trigger wheel will make the timing rock steady, something you see, but don't "feel" compared to a distributor. But for nitrous or other power adders, having the timing rock solid is very important. Durability has to be compared to something, an oem system, or a cheap aftermarket deal for example. The Holley DIS uses OEM type coils we drive, so durablity should be very good.

So "notice" is kind of the relative term. For ignition, you need enough to get the job done, which is why I said the DIS is overkill for what you have, but certainly not a bad idea to run. It just isn't going to give you much benefit per dollar for a mild deal.

bluzman2004

Dec 6th, 10, 2:16 PM

Doug, are you going to be at PRI this year? I'll be there cruizing around. Hope to see you. :beers:

Doug F.

Dec 6th, 10, 3:28 PM

Yep, be there noon Thurs and staying from then on. See ya...

the heckler

Dec 6th, 10, 4:12 PM

I have a fresh 496 with about 750 miles on it. all forged rotating assembly. when we built the motor I ran a .024 top gap and .030 2nd ring gap (srp w/18cc domes). motor is 10.7:1 w/edelbrock ovals. thinking about a nitrous setup for next year. havent really researched it yet but what about fuel requirements and such for an absolute beginner....thanks !!

Doug F.

Dec 6th, 10, 4:39 PM

greenlion

Dec 6th, 10, 8:03 PM

the heckler

Dec 7th, 10, 10:04 AM

Doug F.

Dec 7th, 10, 12:31 PM

Doug,
Can the BBC avenger mpfi system be easily modified to handle a few more ponies (700ish). Self tuning with larger (60lb) injectors? Need a bigger pump?
I'm interested in going EFI (currently on propane!) on my 496, but am probably close/slightly over 650 hp.
Thanks
Adam

The answer is yes, but something I'd tell someone case by case. You can enter a base calibration, which is for 48 lb/hr injectors and go in and change them to whatever size you need easily. The pump that comes is a 255LPH Walbro which I use in my car. At 700HP you are squeezing the pump pretty tight to its limits. I usually tell people to cap it around 650HP.

Doug F.

Dec 7th, 10, 12:37 PM

sorry for the delay doug. I have and plan to keep the 850 cfm dp holley on top of the weiand stealth intake. using a mechanical fuel pump now and have had no issues so far. the cam is a comp solid flat tappet XS290S (252/260 @ .050, 598/598 - 110 lobe center). the motor made 607 hp @ 6100 rpm. looking for no more than 125 + hp at the strip next season (those pesky fox bodies you know).
block is a 4-bolt main gm 454 + .060....thanks...

I know there are tons of people running nitrous hap-hazzardly, and some getting away with it, but when I run it, whether a little or a lot, I like to do things "right". I don't know how much you know about mechanical pumps, but as flow increases, pressure decreases. That is not much of an issue with a carb within limits, but nitrous pressure = flow. YOu want and need consistent flow. If you have a high pressure pump, that requires a regulator, you might be ok, otherwise an electrical pump is desired, but you have a similar issue, as pressure increases, you have less flow. So you need a pump that flows needed fuel volume AT THE PRESSURE you want to run the nitrous fuel side at which is usually around 5.5-6 psi.

So you need a pump/fuel system that can maintain 5.5-6 psi, regulated pressure.

Then you need a good way to retard timing, even with just a 125 shot.

I'm not a big fan of the distribution of the intake you have, but for 125 HP you should be ok.

Too rich with nitrous is not what you want, as well as having too much timing. Both of those combined can damage things, even with a small shot.

But I'd say get a fuel system that can maintain pressure, retard the timing, and use a good nitrous/fuel jet combo and you should be fine. I like WB02 sensors a LOT to see what is going on if you have one.

greenlion

Dec 7th, 10, 3:42 PM

Thanks Doug. I've got head gasket issues and the motor is out. I'm gonna change cams while it's out and probably end up smaller. I will talk to Cstraub about that and have him figure for the change to EFI. I will get back with you when the changes to the combo are settled. I have a laptop and can do the HP EFI if it works out easier.

greenlion

Dec 15th, 10, 1:50 PM

Doug,
I'm gonna pull the trigger on this while summit has a 15% off coupon code (today or tomorrow). Gonna do the HP system with separate fuel system and injectors. I have a laptop and don't mind tuning with that. Few questions for ya:
Are these the correct injectors- HLY-522-5008 50lb/h high impedance. If not which ones? these seem kinda high priced. Also would rather have some about 60lb/h I think (possible 700+ hp)
Planning on using the FAST fuel setup with the aeromotive pump (1000hp system). Think this will work with the HP EFI? Happen to know what size the AN fittings are? Line size needed? (-6 probably enough?).
What about ignition? I have a MSD pro billet dist, can I use this for now? I'd like to go to the computer controlled timing soon, though. What is needed MSD small cap hei/ext coil? Any coil or specific one?
Sorry for so many questions, but want to get the right stuff while the discount is good. If I don't hear from you soon I'll just do the efi sytem, fuel cell and pump setup and wait on injectors, lines, ect.
Thanks a bunch!
PS- Also gonna pm you.

Doug F.

Dec 15th, 10, 5:41 PM

greenlion

Dec 15th, 10, 6:03 PM

Enjoyed talking to you Doug, and appreciate the help.
Got most everything ordered (except for some plumbing, gonna wait and see what I need).
For others reference when searching I'll be using these parts:
Vic Jr oval port EFI intake (29045)
Fuel rail kit (eddy 3633)
60# injectors (eddy 3686)
Holley universal mpi computer/harness (550-604)
Holley mag p/u harness (558-303)
Holley 4bbl 1000cfm throttle body (pn?)
aeromotive a1000 pump, regulator
Wish me luck!

Tom Mobley

Dec 16th, 10, 1:14 PM

so you didn't like the propane? care to say why?

greenlion

Dec 16th, 10, 3:34 PM

so you didn't like the propane? care to say why?
The main problem with the propane was refueling. It was a pain to say the least. I was using forklift tanks which only hold 8-10 gallons and a 600+hp BBC can go through that pretty fast. They had to be refilled at the propane place, weigh 70# in a full tank that had to be swung over the side of a 44" tired rockcrawler twice a day and I had to haul around extra tanks. The limited range and inconvenience wore me out. I was also leaving 60-80 hp on the table since propane makes less power than gas, but it was the fuel situation that made me decide to switch. It actually worked really well. No electrical, ran good and would run at any angle, bouncing around, whatever. And it made good power. I still think propane is great for a lot of rockcrawlers with less engine and would still run it on something like a toyota buggy.

Tom Mobley

Dec 17th, 10, 1:31 PM

what's the octane rating of the propane?

what were you using for "carbs"? I realize they're not really carbs, but the propane carb deals I've seen were forklift size. I've never seen anything for propane that looked like it would feed more than one cylinder of hard running 496.

greenlion

Dec 17th, 10, 4:41 PM

What I've seen for octane ratings varies from 104-110, but people use propane in 12:1 motors commonly and without problems. Doing this allows you to gain some of the power back you'd otherwise be losing over running gas (but makes it hard to swap over to pump gas later if you want). My engine is about 10.7:1 so I think I'll be OK. I built it like this just in case I wanted to go to gas or put the motor in a car later on down the road.
I'm using two Impco 425 mixers, which bolt to a standard square bore throttle plate (I'm using 4150 baseplates from proform). The mixers flow about 460 cfm each and can feed about 325 hp.
I'm glad I tried the propane, as there is not a lot of info out there on propane use for a high performance motor and I learned a lot. Tuned it with a wideband o2 meter.
link to mixer example:
http://www.propanecarbs.com/impco/425carburetormixer.html

Tom Mobley

Dec 17th, 10, 5:56 PM

congratulations on having the gumption to go where few others have gone. Glad you were able to get it worked out. Too bad it's not a viable long term solution.

trackman

Dec 19th, 10, 4:15 PM

FYI.....The fuel rails will interfere with the Holley throttle body linkage with the eddy intake. If you have room for a spacer that will help. Linkage may have to be tweaked as well.
I had to do both. I think I would just port the Holley intake if I could do it over again.

greenlion

Dec 20th, 10, 4:32 PM

This is going in a rockcrawler, not a chevelle, so I don't have the same hood clearance probs as most of y'all here. I've got room for a spacer. And I'm not afraid to "modify" it as needed. Function over form here.

71 chevy

Dec 24th, 10, 1:49 PM

first off, I love the holley software. It plugged into my engine in five minutes and was running in another 10 minutes.

I like the 31x31 table and the closed loop and learn are pretty awesome.

there are some weaknesses(datalog viewer is quite bad lol, boost control is not there yet,and there is no batch downloading of logs yet) but overall its an amazing piece of software/hardware

here is my question doug. was there ever the ability to export datalogs? I could have sworn that I saw this option when I first started playing with the software but now it is nowhere to be found.

if it does not exist, can you give us an option to export the data logs so we can use our own viewer?

LLB

Dec 24th, 10, 10:06 PM

hello I am running a 8.1 vortec G.M. based Indmar marine engine in a 67 Chevelle with no o2 or maf runs out very well.It has a problem called idle stall (so the boat guru I work for says) its running a MEF4 control box was wondering if any one can change some of the settings or if I need to buy a new control box :confused::confused:

greenlion

Jan 10th, 11, 11:49 AM

OK- I have a couple more HP EFI questions.
- I have a msd pro billet distributor, 6al box and blaster coil, currently locked out; it is my understanding that I cannot use this setup for computer control of timing (or can I?)
If not, what are my options; I don't think batch vs sequential will really matter for me but I don't know the details. It looks like the FAST dual sync dist is a good way to go. If I do that what wiring harness do I need or will I have to splice one up? Other way is small cap/ext coil HEI? If I do this can I reuse my 6al/blaster? What PN for a distributor? Get an autozone replacement for a factory part? I think my 99 suburban 7400 uses this setup (flat looking dizzy, separate coil). Harness part number for this? What seems to be the most plug and play to get going with computer controlled timing?
EDIT: I found this http://www.summitracing.com/parts/MSD-8366/ at summit, seems to wire up like hei/ext. looks easy enough, but
also found this: http://www.summitracing.com/parts/FST-305005/
which would get me sequential. Just not sure how to wire it up. No diagram in Holley's info for this one (that I can find). I'd like to use this one; is there a wiring harness or diagram?

-Also, fuel supply. I have an a1000 pump, -6 lines from pump, reg; all that's ok I think. Pre-pump I have some walbro tank pickups with 5/16 lines. I'll be using 4 of them and plan to plumb each side (2 pickups) to a -6 bulkhead and then both -6 to a -8 y fitting, adapting -8 to -10 at the pump.
I'm concerned that
1: the two 5/16 pickups to a -6 fitting is too small and
2: that the -6x2 to -8 y is insufficient. Any thoughts?

Sorry for the long post, but I appreciate any opinions. BTW motor will prob be around 650 hp ballpark (10.7:1 496 , 249/255 .708/.708 110 sr, afr 265 cnc, vic jr, 2/3.5 headers)
Thanks!

64duece

Jan 10th, 11, 11:03 PM

You can use your Msd for computer controlled timing. It's equivalent to a "crank trigger" and would require the points output to trigger the Msd/coil (modify 558-304 harness). Next would be GM or MSD 8366 which uses a module. Similar to above and can be used stand alone or in conjunction with your Msd/coil (uses 558-304 harness) No sequential control of with either of course.

Fast XFI dual sync is the easiest distributor option to get cam/crank reliably. We make adpater harness for that specific setup. Diagram for HP ECU and Fast is in each of their instructions.

As for the fuel supply....your description is abit confusing to read. I'll just say you need to give your pump the best supply you can. A larger inlet is better (-10) make sure it's not reduced down from transitions/merges or whatever. If you need to make 2 #6 into 1 make sure they go into #10. Don't skimp here!

greenlion

Jan 11th, 11, 9:10 AM

Ok thanks, it looks like I can wire from diagram 8.6 in the technical manual for magnetic crank pickup and use what I have. Great.
Gotta find a -6x2 to -10 Y somewhere now.
Thanks for the help.

greenlion

Mar 2nd, 11, 9:13 AM

Doug, do you mind a few more questions before I light this thing off? I've posted a few questions here in the past while I was getting parts together to convert my 496 from propane to efi and now I'm in the final stages of getting it together and fired up.
Questions:
1. What is the purpose of the small gauge solid red wire that is loose in the harness? I guess just connect it to always hot. This is a different wire than the red/white tracer keyed hot wire.
2. The harness for magnetic pickup ignition that is to connect to my msd distributor has a shielded wire; what do I connect this to? Dizzy only has the two wires; connect the shield wire to a ground or leave unconnected in the harness?
3. The holley throttle body has a couple of small vacuum ports near the IAC; are these ok to use for MAP sensor connection and fuel reg manifold reference? Wasn't sure if they were ported vac or what.
4. Why no plug/pigtail in the kit to hook up to the inputs/outputs plug on the harness? I just connected fan switches by cutting the wires and using butt splices, but a weatherpack connector would have been cleaner.
Thanks, excited to get this thing going.

Doug F.

Mar 2nd, 11, 9:20 AM

See below..

Doug, do you mind a few more questions before I light this thing off? I've posted a few questions here in the past while I was getting parts together to convert my 496 from propane to efi and now I'm in the final stages of getting it together and fired up.
Questions:
1. What is the purpose of the small gauge solid red wire that is loose in the harness? I guess just connect it to always hot. This is a different wire than the red/white tracer keyed hot wire. >>> Powers the relay which powers the injectors and fuel pump.

2. The harness for magnetic pickup ignition that is to connect to my msd distributor has a shielded wire; what do I connect this to? Dizzy only has the two wires; connect the shield wire to a ground or leave unconnected in the harness? >>> Don't connect the shield. It is connected back at the ECU. YOu only want to ground one end of the shield or it becomes an antenae. As far as the two wires to the pickup, one way is correct, the other isn't and the engine will run poorly when the positive and negative aren't correct fyi.

3. The holley throttle body has a couple of small vacuum ports near the IAC; are these ok to use for MAP sensor connection and fuel reg manifold reference? Wasn't sure if they were ported vac or what. >>> Fine for MAP and regulator. Don't tee anything else into the MAP.

4. Why no plug/pigtail in the kit to hook up to the inputs/outputs plug on the harness? I just connected fan switches by cutting the wires and using butt splices, but a weatherpack connector would have been cleaner. >>> It is an option, 558-401 I believe is the PN. Splicing in is fine with a good splice.

Thanks, excited to get this thing going.

greenlion

Mar 2nd, 11, 9:30 AM

Wow that was quick! Thanks.

greenlion

Mar 16th, 11, 10:18 AM

Got all this hooked up and running. Engine runs great after it's started but is a little hard to start and I'd like your thoughts on this. Starts OK when cold but cranking time seems a bit long for an EFI motor. Engine turns over for 4 sec probably before it cranks, but it will always crank cold. Hot start is a problem; only rarely will it crank after it's up to operating temp (180). Difficult to turn over (like too much timing) and wants to hit once and then stop. Cranking settings are stock from the 650hp 496 file. Cranking timing is 15* (checked w light). I don't smell raw fuel in the intake after trying to crank hot. Mini starter and 1100 ca optima. No hot start problem before with same engine, timing locked at 40* but I would turn it over a couple of seconds and then turn the ignition on. Everything is flawless otherwise; just need to troubleshoot this issue and get it cleared up. May add a second battery, battery is in the rear of the vehicle.

Doug F.

Mar 16th, 11, 4:41 PM

Send me a datalog of the cranking, cold and hot and I can take a look.

greenlion

Mar 16th, 11, 8:32 PM

OK, I'll figure out how to get that for you.

Doug F.

Mar 16th, 11, 9:09 PM

One thing I"d do is figure out the difficult cranking. Disconnect the injectors and crank. If it is slow, it has nothing to do with the EFI.

greenlion

Mar 18th, 11, 10:11 AM

Doug F.

Mar 18th, 11, 12:23 PM

I played with it some last night. I think I'm on the right track with it. I initially increased the cranking fuel, thinking this was most likely, but ended up having to hold the throttle down (clear flood) to crank. So, then went the other way with it. Actually was taking fuel out and cranking when a buddy came by and said "well, you're getting plenty of fuel" (smelled raw fuel behind the truck). Ended up cutting cranking enrichment a good bit and got it to start hot. Increased IAC park % also. I'll play with it some more this weekend and take out a little more fuel if I need to. Cranking RPM is in the 100-150 rpm range and seems OK. It's turning over easier with the fuel taken out. I think it was juuuust hitting on a flooded condition before and kicking back a little.

What you said isn't uncommon, thinking you need more cranking fuel. The base maps, if anything tend towards the richer side and shouldn't need more fuel. Having it too lean usually results in it cranking a little more than needed, but it will start. Too much and it may not fire and/or require some pedal to add air because there is too much fuel.

Sounds like you are going in the right direction.

barraza

Mar 29th, 11, 12:27 PM

I have an Accel Thruster DFI system for a small block. I haven't installed it yet, because it is too tall to fit under my hood. The manifold looks like I could mill an inch off the top, what effect would that have on how the engine runs? Would it be exactly like taking that much out of a carbureted manifold. The engine is a pretty normal 400hp / 355ci, so the Accel single plane Pro-Ram manifold is a little bit too high up the rpm range anyway. Would reducing plenum volume help or hurt?

Doug F.

Mar 29th, 11, 7:01 PM

Likely won't notice much on a 400 HP engine.

Mrbud

Apr 28th, 11, 8:14 AM

Hi Doug,This maybe long, 2 years ago purchased a 82 El Camino with the old Projection 2D system has worked fine till now.Lost Fuel pressure talked to tech line found the internal ground on ECU green wire to pump went bad so grounded the - side to ground got pump to run. But now have to much pressure around 80 psi on the inlet to the throtle body. Took return loose, hose to bucket method pressure dropped to around 20 psi Checked Return line for blockage all clear to tank did bucket test at tank still around 20 psi. They used the Vapor line on the sensor unit as a return line. Blew air into line seems open but still jumps to 80 when hooked back up. Do i need to replace sensor unit with modifing the vapor line or can i change to a 3 inlet sensor? Has the original tank. Thanks for any Help Bud

Doug F.

Apr 28th, 11, 8:55 AM

Did it used to work the way it is hooked up now or is there changes?

Sounds like there must be some restriction in the return. A 1/4" return line likely won't work.

If it works at the tank, but doesn't work when connected to tank, must be a restriction on the inlet of the tank I'd say.

Mrbud

Apr 28th, 11, 8:36 PM

It seemed to work fine. Seemed to miss when cold but ran good when temp came up. Didn't check pressure before having any trouble.If it was this high wouldn't it had loaded up bad? Will be dropping tank tomorrow to check the inlet. Will let you know what i find.Thanks for answering me. Bud

Mrbud

Apr 29th, 11, 10:16 PM

Dropped the tank today.They used the vapor line as a return line. They did cut of the Defusser on the line but left the brass pin hole in the line.Have a new sensor and float will be using it with a clear line.Will be putting back together tomorrow.Will update on what i have afterwards hope not any major problems.

Mrbud

Apr 30th, 11, 10:07 PM

Put it all back together today around 18 pounds of pressure runs like a champ. Thanks for listening Bud

Tom Mobley

May 2nd, 11, 3:05 AM

>>> "left the brass pin hole in the line."

Ouch. Nothing like paying for somebody elses mistakes. Good troubleshooting skills there.

Mrbud

May 2nd, 11, 8:13 PM

Yes, Maybe Brass pin is to vague it was like a pin hole top of the vapor dispersor.Just wish the Fuel gauge worked now.For some reason it stopped will have to take tank down again.Boo! But going to drive it a few days to make sure all is well.

Mrbud

May 4th, 11, 10:07 AM

Well new wrinkle today.When tried to start today ran a few minutes then quite like straving for fuel.When trying to restart The Fuel pressure goes down when turning over. Like when swtiching to run.Could the ECU be bad now?

blue66

May 7th, 11, 6:37 AM

Mrbud

May 7th, 11, 9:57 AM

Hello, Yes seems to when extra ground is on the pump voltage is cylcing from 11.5 volts down to 1 or 2 then back up. When it's removed comes back up to 12 volts and stays. When first replacing pump and the addition of the ground wire had a steady 12+ Volts and ran for the 5 days. Thanks for Answering Bud

Mrbud

May 12th, 11, 10:04 PM

Found that i had a bad injector. Running again Yeah!! Thank You Woody from the Holley Tech Line.

greenlion

Jun 6th, 11, 9:51 AM

An update on my engine's hard starting issues:
The distributor had gotten loose and I found the timing to be over advanced a few degrees. Corrected this, but still had a hard starting issue with the engine hot. Turned out to be a bad optima redtop. One new battery (re-badged deka intimidator from batteries plus) and everything works as it should! Thanks for all the help here; I'm really enjoying the engine and Holley EFI system.

ctheusa

Jun 8th, 11, 11:03 AM

My question is about a TPI conversion I am finally finishing in my '66 Chevelle. I have a factory TPI unit from a '90 Camaro on a '75 350. Where do I hook the factory heater hoses to on the throttle body? Which is in and which is out (top or bottom) on the factory hoses on the heater core? I live in Missouri and probably won't drive the car much if at all in the winter. Should I run a hose from the manifold to the throttle body? Where do I run the factory heater hoses to? I have looked all over the internet and can't find an answer. I bought my harness and computer from Street & Performance and can't get a reply from them.
Hope you can help!!

cwill62

Jul 8th, 11, 2:06 PM

Doug I have a 69 Chevelle with the stock 6 cylinder engine have you or do you know of anyone that has converted one of these engines to a EFI set up?

14BFF

Aug 28th, 11, 12:55 AM

greetings,

I got hold of a used cutler BBC EFI setup (manifold, rails, throttle, sensors & harness) without injectors
I know Cutler was bought by Holley and from the pics it seem to be identical to Holley Avenger MPFI kit

can anyone confirm the height of injectors used in Holley setup
their part number is 522-488 for the 48lb/hr but I couldn't find any info about their dimensions either in Holley website or jegs or summit

http://www.holley.com/522-488.asp
http://www.jegs.com/i/Holley/510/522-488/10002/-1?parentProductId=
http://www.summitracing.com/parts/HLY-522-488/

thanks,
Ahmed

http://www.chevelles.com/forums/attachment.php?attachmentid=44526&stc=1&d=1314506816

http://www.chevelles.com/forums/attachment.php?attachmentid=44527&stc=1&d=1314507618