I had a few questions about the commander 950 unit from holley.

1. why do they advertise "good to 450-550hp". What's the limiting factor?

2. Why can't I use my factory harness and sensors? Different connectors?

3. Does it come w/ a WB o2 or is that an upgrade. If so, how much?

4. How does it connect to my laptop? Printer port?

5. What do I do w/ the old ECU? Can I still use that to run the rest of my gauges?

6. Why is it so much cheaper than Accel's DFI? Or are they about the same?

7. Is the holley unit SD or MAF or both like the LT1 cars?

Finally, is there anyone around who can beat the price that summit has listed? Harness for 85-92 and ECU for ~$875

Thanks for all your help.

 

I believe that's only on their complete kits they advertise that...mostly based on injector size and, if using the multiport setup, throttle body size.

I think somebody here did that...just repinned the stock harness. But I just got the whole kit w/ harness to clean up the wiring and get rid of stuff I didn't need. The stock sensors will work with the TPI 950 kit w/harness.

You can get the optional WB upgrade from Holley, but it's very expensive. Part number HLY-534-188 is listed as the WB upgrade kit and lists for 990 from Summit. You're better off buying a seperate WB controller and O2 sensor like Innovative's and using it with the 950....it's much cheaper.

Yes...

The gages will function independent of the ECU.

Accel's stuff has more features like nitrous control, TCC control, and WB control (I think) all built in. It's up to you if you need all these features or not, which was the deciding factor for me to get the 950 setup instead. But if you're a beginner at this (like me) the extra features of the Accel may overwhelm the novice tuner.

SD

Yes, check Scoggin Dickeys....I bought the TPI kit (950-101) last year from them for 785.99. It was 805.74 SHIPPED to my door. I just checked their website a minute ago and it's still listed for the same price I bought mine! www.sdpc2000.com

Also visit the EFI forum on chevytalk.org. Bunch of guys run the 950 setups and can answer more questions about it better than I can.

 

WOW, thanks a lot. I really don't need any help w/ the N2O that's all working independently now.

The new harness will really clean up the engine bay. Does it come w/ sensors? Or were all those extra $$$. The guy at summit didn't know much about it. Tried to tell me it was a MAF set up.

 

It comes with an O2, MAP, and MAT sensor. You can still use the orignal IAC and TPS sensors, as well as the original fuel injectors.

Be aware also the kit does not use the knock sensor anymore, although Holley sells a knock sensor kit if you want to use one.

 

So the stock harness that I have now going to the ECM can all be ripped out? Everything else on my car (the rest of the electronics) can stay? I'm sure you said that lights, and dash controls are independant, but I want to be sure.

 

Its my understanding that your current stock ECM controls the Engine...hence Engine Control Module (please correct me if I'm wrong). Therefore your windows, gauges...etc etc etc, do not depend on the ECM!

 

You can remove the stock harness for the ECM and everything else will function...but have a wiring diagram handy. Basically I kept the factory wiring for the fuel pump relay intact so I wouldn't have to rewire the car. That way the factory relay kicks on just like stock when hooked up to the 950. I also used the factory wire that supplied the ignition 'on' power to the stock ECM, and connected that to the 950s ignition 'on' power wire. Again, have a wiring diagram handy!

 

Yes and if you want the commander to control your fans you can use your factory fan relay, just pin it into the commander's ECU. That is, take the end of the harness, remove the retainer clip, insert the pinout from the stock ECU into the harness of the commander 950, then lock the clip back together.

same thing goes for the factory knock sensor, just take the pin from the factory ECU and pin it into the harness of the commander 950.

If you wanted to re-pin your entire harness (as opposed to buying a new harness from holley) it is possible the only thing you need is the clip that plugs into the commander's ECU. You can get it from anyplace that makes those sorts of things, I got mine from a local speedshop that made harnesses for accelDFI and speedpro, they had one in stock for me.

It connects via SERIAL port, which is NOT the parrelel port used to connect most old printers, although some REALLY old printers were serial. serial is DB9, contains 9 pins and looks just like the monitor plug, except the monitor plug will have 15 pins where serial has 9. Also serial is always MALE on the laptop and Desktops, where the monitor plugs on your PC are female recepticals.

There are a few versions of the Commander 950 ECU to watch out for. the primary NEWEST and BEST version, is the commander 950 PRO version of the ECU. make sure you get this version! the older RACE and STANDARD versions are out of date and no longer supported by holley as far as software updates and the like.

the pro version will command a Wideband O2 sensor so long as you have the interpreter, such as the Innovative WB O2. If you decide to go Wideband, and use it 24/7 in your car, I would recommend the Volkswagon (LSU) sensor, since you can get it for $33-$38USD in case yours fails. If you choose to go with the OTHER sensor, such as HOLLEY'S sensor (NTK), it will cost $200-$300 instead to replace. Something to think about, if you plan on using the WB for permanent closed loop operation.

As for operation and simplicity, it is very simple and easier to use (IMO) than the accel DFI, although the accel/haltec/speedpro(f.a.s.t.)/etc... have many more options that you may or may not use. Accel DFI can control Sequential EFI (as opposed to the commander bank/bank or batch fire) and the accel will control torque converter lockup (no more switch)... however to get it to the wideband version of the Accel you need THEIR SPECIFIC interpreter, my attemps at using the innovative with it have so far failed... and it will cost $1100 as opposed to $350 (commander setup using innovative).

theres much more to talk about, this is just the scratch. Check out chevytalk.org under the EFI board, like 80% of the people there are using the commander with great success.