Holley HP install and tips

DaveP

DaveP

Active member
Re: Holley HP install and tips

You could install a stand-alone 2-BAR MAP sensor for the boost gauge. Get the 5 Volt reference from the Holley. The wire to the boost gauge is in the 10-pin white connector by the ECM. I THINK it is lt green once it is in the dash harness.

Minor detail: The VSS sensor is on the T-case, not the transmission. But most guys that have retained the 700 like you have will continue to use the T-case sensor and stock DRAC. With the 4L80e, and a Dominator for trans control, the Dominator has an output that can drive the speedometer. On Paul-Z's however, I retained the DRAC and continue to use the t-case sensor for the speedo. One less thing to configure in the Dominator.

Someday I'll come to Florida again for some reason. I'm going to bring my GM connectors and terminals and spend a day with your truck making a stand-alone harness for the C100 to engine harness so you can remove your stock engine harness altogether. It bugs me that you have that cluster of un-used wire and stuff behind the distributor. I could probably make you something and send it to you too, but I'm not sure how you've interfaced fuel pump, A/C clutch and TCC. But I may do that too.

Take care, buddy.
 
randy merritt

randy merritt

Donating Member
Re: Holley HP install and tips

Thanks Dave for the info. Always a pleasure hearing from you. Speaking of Florida, I intend on going to Gary's meet in Feb. It would be nice if you could find a way to make it.
 
tbauer03

tbauer03

TRBOBOX
Re: Holley HP install and tips

randy merritt said:
You do have to fill in the timing table yourself, and the guys at SME can help with that. One downside is there really isn't a way to easily run a knock sensor.
Click to expand...

Randy I finally got my truck running and now mobile. Still need to do a lot to get up to 100%.
Anyway I bought my cam from SME too and I was just wondering if you could post a picture of your base timing table or send me a global to compare against.
 
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randy merritt

randy merritt

Donating Member
Re: Holley HP install and tips

Here is my table. I have messed with it quite a bit, so it is not the same as SME gave me. It is not perfect, and any feedback would be welcome. I set the timing low at idle because that is what my truck seems to like. Some say that I am not running enough timing, but I think this timing table is very safe. Note that I run meth for knock suppression. I did figure out how to hook up the stock knock sensor and make it work, BTW.
IMG_20170514_070730899.jpg
 
tbauer03

tbauer03

TRBOBOX
Re: Holley HP install and tips

JSM said:
Simple razor blade is all that is needed, and you just need to cut a slot in 2 places I believe for the indexing part of the map sensor.

Rescaling of sensor inside the holley software takes all of 30 seconds. I think on one of the trucks I even selected holley sensor and it worked fine. Been a few months now though since I messed with one.
Click to expand...

I haven't really done much with mine yet but it is now running. I have a GM 3 Bar sensor in the truck and I selected the holley sensor in the softeware. Do I need to do any scaling/calibrations with it? If so how?
 
randy merritt

randy merritt

Donating Member
Re: Holley HP install and tips

I'm going to try and write down what I have learned on how to make a stripped down firewall harness (C100) to use with the Holley. This may be a bit rambling, but I will edit it as time goes on and others have input.
NOTE. As of today, I have not installed this harness on my truck. I have verified all of the needed wires with DaveP, though.

I started off with a junkyard harness off of a 4.3 automatic S10 or blazer (4wd I think). I cut the wires at the ECU and on the instrument panel side of C101.

harness.jpg

Get the entire harness including the VSS and TCC connectors on the transmission as they are tied into the harness and will be needed. Be sure to get the Instrument Panel connector (C101) with the harness, as it contains the white wire from the coil that will be needed for the tach. None of the other wires on the engine side of the C101 are needed.

C101:
IMG_20170519_083629236.jpgIMG_20170519_083629236.jpg


C100:
C100.jpg

The wires that will be needed are as follows. I have include the connector name, and the cavity location on the C100 connector.

Wiper Motor - Connector C155 cavity H3, G3, B3, A3
VSS - Connector C163 cavity H2, G2
CTS - Connector C153 cavity E2
TCC - Connector C139 cavity F2, B1
Purple starter wire - cavity H1
Ground - cavity c2 - Note: if you have removed the stock fuel pump relay, it seems that this is the only system ground needed
Oil Pressure Sensor - Connector C129 cavity D2 Note: I will be taking the oil pressure switch out of the fuel pump circuit. Only the tan wire is needed to operate the oil pressure gauge on the dash.
Main power wires - cavity D1, F1 Note: these wires just loop from C100 to the alt then to the power block on the firewall then back to C100.
Coil power wire - Connector C120 cavity C1
Alternator harness - Connector C118 cavity A2, B2
Fuel pump power wire - cavity E1 Note: I will be using the Holley directly hooked to this input to power my fuel pump. It goes into the dash, then back out the rear light harness.
A/C (if you have it) - cavity B2 Note the other wires in the A/C harness that go to the ECM can be cut off.

The white wire that goes off the coil needs to be kept on the C101 IP harness connector in order for the tach to work.

All other wires to all other sensors can be removed.

This is what I ended up with. Ready to install when I get motivated.
IMG_20170519_085046708.jpg
 
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TurboGuy87

TurboGuy87

New member
Re: Holley HP install and tips

how does this install effect factor computer and wiring such as sensors and windows or any other electronics in the vehicle? ive never installed anything like this but just curious does it just replace stuff to the engine and everything else remain? just confused
 
randy merritt

randy merritt

Donating Member
Re: Holley HP install and tips

This takes the computer out of the system all together. This is only done if you have a stand alone computer for the fuel injection and engine management.

I have installed the harness, and everything works great.
 
T

tunerpike

Donating Member
Hey Randy... I'm going to head to the yard tomorrow and get a harness.. Do you have any more pics of the finished product before putting it in the truck?

Do I actually need the IP Side of C101? It seems that I will only be modifying the new engine side of C101 to plug into my factory C101 IP side??
 
T

tunerpike

Donating Member
I just wanted to update this post, I ended up pulling a wire harness out of a 93 Jimmy which had a 4.3 CPI Engine with a 4L60E Transmission... The harness was very similar to ours, all the same connections where there as far as C100 and C101 for tach input.. The main difference on this harness is that the speed input for the DRAC module comes in on C101 instead of C100, so I cut these wires to move them to C100 .. The wire locations in C100 on the 93 harness are used for something else, so I just twisted the two wires together making them a twisted pair and soldered the wires that I removed from C101..

I also ended up keeping locations G1 & E1 out of C100 as well.. G1 was originally the 10 amp constant that was switched by the fuel pump relay that created E1 for the fuel pump prime.. The fuel pump relay is only used for priming the pump and the oil pressure switch seals in the circuit once oil pressure comes up .. I ended up crimping weatherpack connections on both G1 and E1.. I'm connecting the fuel pump relay (Green Wire) output from the dominator to E1 to control my double pumper and G1 is just there incase I need a 10amp fused circuit in the future..
 
Sean Krupa

Sean Krupa

Moderator
^^^^ Stock Gauges work just fine. Nothing gets removed that has to deal with the gauges. You simply Tap in the C101 connector for Tach signal from Holley.
 
Sean Krupa

Sean Krupa

Moderator
Yes Sir. All there is to it. I can hook you up with Part numbers and a reputable dealer to get it through for a great price!
 
randy merritt

randy merritt

Donating Member
I did a write up somewhere about modifying the wiring harness. The tach signal comes off the coil using the stock wire going to the cluster harness.
 
cloneman315

cloneman315

Active member
So all the gauges work? So is the Holley talking to them ? I saw the write up great job. Don’t want to reinvent the wheel. Maybe some quick notes?
 
Sean Krupa

Sean Krupa

Moderator
Yes, everything works. Holley has nothing to do with Fuel, Oil Pressure, Voltage, Speedo gauges. Holley is just for engine/trans control. Tuck away or Remove stock and install New. Thats it. I run Holley Injectors (160lb) on E85.
 
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