which is better for fuel/ignition management?

 

Depends on what you want to do. Accel has a much larger base here in America. Thus it has a very good support with lots well experienced tuners as well as factory support. I don't think that Haltech has near the customer base here. You will find ACCEL and FAST in most circles with Corvettes and F bodies and other GM performance cars and especially at the drag strip on EFI drag cars, where you won't see to many Haltechs. I for one have never seen a Haltech in a drag car here. The Accel box will do anything the Haltech can and will accept more inputs and various ignition systems and has a built in wide band support.

 

so if i get an accel system do i need to get a wideband system aswell? im gonna do a supercharged 355,12 psi boost, with a stealth ram. 1000cfm TB 510/510 220/230 at 114 hyd. roller cam. full length headers 3" exhaust with electric cut outs. 3.73 gears. 3000 stall converter.... on my 90 L98 motor ....what do each of these systems(accell and wideband) run? alsowill ti work with the msd-6BTM i have for my car? I also saw sumthin about tht Big3 or sumthin also....i forget wut its name was.

 

Its called BIG STUFF Three. I haven't seen it yet. But its basically made or rather developed by the guy that originated the old Accel DFI gen 6 systems. I can't say much about it cuz I don't know anything about that particular product. I do know a lot about the DFI G 7 systems and I can say it works well and offers a lot for the money.

You can use your MSD 6 but there really isn't any sense using it because you can map all the timing in the DFI box using a 2 bar map sensor. The systems are not cheap, for your car I recommend a piggy back wire harness and a ECU from Accel. The harness is roughly $470 plus the cost of the ECU and what sensors that you may need. A ECU with the programming software and cable which is the pro version would run you somewhere around $1075 or thereabouts.

A wide band system would run you another $800+ for the Accel system. And it is a wise investment on a blown engine. You can use your old distributor or you can upgrade to a dual sync to give your full sequential fire capability which does offer better tuning with more radical cams. Contrary to beleif peak Hp is the same be it batch or sequential fire modes provided both are optimally tuned.

 

It's definitely packed with some neat features including dual WB02s, native 4L60/4L80 operation and self-learning. I'm sure that it tops the charts in features (and price) when compared to FAST and Accel DFI, but John Meaney (developer of DFI and FAST) builds some crazy stuff.

Here's a PDF on their upper end system:

http://www.bigstuff3.com/gen3sefi.pdf

Ron

 

does the ECU come with the sensors? and what exactly does a wideband do?

 

Generally, the ECUs do not come with sensors. FAST just marketed a "GM Sensor Pack" which is your basic sensors required to turn a carb'd setup into FI. In your case, you should have all of the required sensors to run the aftermarket ECU (TPS, IAC, TCC Solenoid if your ECU will handle that, O2, KS)

When you hear people talk about "narrowband" or "wideband" O2 sensors. The narrowband sensor measures the actual air fuel ratio relative to the stoich metric of 14.7:1. If you're above 14.7:1, you're leaner than stoich and below 14.7:1 means that you're richer than the stoich. This is measured by a voltage change in the narrowband O2 sensor.

A wideband sensor will actually tell you what air/fuel ratio that it's measured. Most of these sensors can accurately measure air/fuel from ratios as rich as 9.5:1 to as lean as 15.94:1.

Most motors like ours like an air/fuel ratio of roughly 12.7:1 - 13.1:1 at WOT. If you had to tune your motor to this using a narrow band O2 alone, it would be difficult (not impossible, just more difficult) whereas if you had the wideband O2 in your aftermarket ECU, you could more easily monitor the actual air fuel ratio that your motor sees as the ECU would report it to you. This is why people go to a dyno and get a wideband sensor hooked to their cars (for these more precise readings).

When you get into boosted applications, running the correct air/fuel mixture is even more critical -- thus further bolstering the case for the wideband O2 sensor.

Ron

 

ok, so the accell with wideband is the best things ican get pretty muhc? will these "tune on the fly" ? like the haltech?

 

Absolutely and the Accel will also datalog and self tune as well. Try that with a Haltech!

 

You can...the ecu is now E6GMX with new windows based software.

Jussi

 

I've played with just about every aftermarket engine management system out there... From the original Accel 6.0 DFI (I've used it for 10 years) to the newer Gen 7 stuff, FAST (which I use frequently), Electromotive TEC 2&3 (which have THE best ignition of ANY system), Haltech, Holley Commander, and MoTec... All of them basically do the same thing and have largely the same maps but the user friendliness is where the new Gen 7 DFI, FAST, and Electromotive units really shine. I used an old Haltech E6GM on an F-body several years ago and it's very similar to my old DFI system. Tom's an Accel EMIC and has a considerable database at his disposal, I would strongly consider using him as a resource.

My suggestion is to purchase a setup with the wide-band option; if you don't have access to a dyno and an A/F meter the above setup is definitely the way to go and makes tuning much easier. For my personal use I usually just buy one of the standard systems because I have a A/F meter (two of them actually) and access to a chassis dyno; so I can save some money over buying the wide-band setup.

I'm getting ready to call John Meaney and talk with him about his Big Stuff 3 system...I'd like to try it out and see what new features he's offering over the other systems. The fact that I'm running a very radical and unique combination leads me try ANOTHER new piece at the same time. I've been very interested in it since the rumors started flying several years ago when he left Speed Pro (when they sold to Comp/TCI and became FAST) and started building his own system. If anyone can build a killer piece it would be either him or Lance Ward (one of the other originators of DFI).
-Jeb

 

Jeb,

Very interested in your testing results. There's finally a little more information about the BS3 starting to surface and more of those units are getting into cars now. Looks like an interesting system, but I'm sure that there's more features than they seem to elude to on the website.

Some of the more interesting stuff comes with their control of the transmission (4L60/4L80) where you can log TCC Slip and other driveline measurements. Seems that these features have been absent in "consumer" level EFI units and left to the more advanced units like EFI Technologies and MoTeC.

Take care,

Ron

 

yeah iwas reading in PHR and troy trepanea from rad rides by troy uses john meaney's stuff alot.....swears by it....tht sells me right there.....

 

Troy built John's 1200HP C4 with motor work by Moran in Michigan. I wonder which ECU he's running? <grin>

Ron

 

from wut isaw, he custom made an ECU and made his own software.....tht car has crazy amnts. of wiring goin through it..... and it also from like a 120 MPh roll still pulls like it wouldfrom a dead stop at WOT