Help! Experienced Accel Gen 6 tuners.

[Nvrenuf]

Now you are talking in foreign languages I did find a tuner for the Gen VI. It is a temporary fix. But I also do have quite a range of altitudes with what I do. So I'm putting in a new FAST system in 2 weeks! It looks like this may be the start of what I thought was NOT going to be a project car. But this website doesn't help. I keep finding things I want to "spruce up" or just flat out change!

[deuce_454]

Originally Posted by swchopper

Now you are talking in foreign languages I did find a tuner for the Gen VI. It is a temporary fix. But I also do have quite a range of altitudes with what I do. So I'm putting in a new FAST system in 2 weeks! It looks like this may be the start of what I thought was NOT going to be a project car. But this website doesn't help. I keep finding things I want to "spruce up" or just flat out change!

sell your computer and enjoy your car...... if not you will end up doing a complete frame-off "spruce up" in no time at all... LOL

[Blown353]

Originally Posted by swchopper

Now you are talking in foreign languages I did find a tuner for the Gen VI. It is a temporary fix. But I also do have quite a range of altitudes with what I do. So I'm putting in a new FAST system in 2 weeks! It looks like this may be the start of what I thought was NOT going to be a project car. But this website doesn't help. I keep finding things I want to "spruce up" or just flat out change!

Don't bother with the new FAST XFI if you're looking for a step up when it comes to better performance over changing altitudes... because the XFI doesn't have true real time barometric compensation feature either and it still won't run right for your particular application if you drive the car to another altitude without a power cycle! The XFI firmware pseudo-comps for altitude with a "load indexed" speed-density strategy in their new firmware. The problem is it uses the main MAP sensor and thus can only update the barometric parameters during key-on startup and WOT-- which works OK with naturally aspirated setups as it can read the WOT MAP value every time you floor it and use that for the new barometric value but with your turbos the feature is rather ineffective to say the least because at WOT it doesn't see the true prevailing barometric conditions. Thus, for your forced induction application to have it refresh the barometric value requires you to shut the car off and then restart so it can read the key-off MAP value to get the barometric conditions. It's better than no correction at all like your Gen VI but still a pain in the butt as you have to pull over, shut the car off, and then restart it.

If you drive the car over a wide range of altitudes then forget the FAST XFI, Accel Gen VII, and the other boxes that get most of the advertising time; none of them treat this condition properly!

I've never used one of Lance's 882C boxes but I do like the specs & capabilities and I'm considering upgrading my ECU to one of his; Lance uses a separate MAP sensor to get the barometric conditions (i.e. altitude) so it can comp for weather/altitude changes in real time without a key-off reset.

[camcojb]

Originally Posted by Blown353

I've never used one of Lance's 882-C boxes but I do like the specs & software and I'm considering upgrading my ECU; Lance uses a separate MAP sensor to get the barometric conditions (i.e. altitude) so it can comp in real time without a key-off reset.

Bigstuff 3 also uses a separate map sensor for altitude compensation, at additional cost. It doesn't work............. If I had a do-over, I'd use a GM computer and tune it through HP Tuners of Efi Live if altitude compensation was a big factor.

Jody

[Blown353]

Originally Posted by camcojb

Bigstuff 3 also uses a separate map sensor for altitude compensation, at additional cost. It doesn't work............. If I had a do-over, I'd use a GM computer and tune it through HP Tuners of Efi Live if altitude compensation was a big factor.

Jody

That pisses me off. If it were me I'd be bitching at Meaney like there was no tomorrow to either get it working or to get a refund for the non-functional add-on! You paid extra for it!

I hear you on using an OEM ECU, but for this application an aftermarket ECU is just easier-- provided it's the right aftermarket ECU! That's why I know he'll be disappointed in the XFI-- it will not solve his current problem given the forced induction application.

Speed density and altitude compensation can work and the problem has been solved; look at all the old GM speed density EFI stuff from the 80's and early 90's. Granted GM had the advantage of time and money for each engine package, but they did real time barometric updates via one MAP sensor by reading the manifold pressure at specific RPM & TPS settings and then comparing the actual MAP values at that RPM/TPS to a table of "ideal" MAP values at that same RPM/TPS and using the difference between the two for the barometric compensation. That's a lot tougher to do when you're not an OEM and not tuning an ECU for one engine you're going to build millions of, but the principal is the same and can be easily accomplished in the aftermarket with a secondary MAP sensor. Given the wide variety of engines that an aftermarket ECU may be used with a secondary MAP sensor is the most logical choice.

If I stick with my Gen 1 SBC stuff I'm certainly going to upgrade to a more capable ECU such as Lance's 882C, but if I make the jump to LSX I'm going with a factory ECU and EFI Live.

[Nvrenuf]

This has become way more interesting than I ever thought it would be. I love learning this stuff. I somewhat mis-spoke though. I get typing faster than I can think.
My immediate reason to upgrade ECU's (to FAST, maybe now) is to be able to retard the timing under boost. Mine's not even doing that now. That's #1 priority. Altitude stuff is just another part of it. I don't really travel from hi to low or vice versa, but it would be nice to not have to screw with it. I will continue my research and check out Lance's. Jody, you know anything about these? Maybe I just need a boosted LS7

[camcojb]

Originally Posted by swchopper

This has become way more interesting than I ever thought it would be. I love learning this stuff. I somewhat mis-spoke though. I get typing faster than I can think.
My immediate reason to upgrade ECU's (to FAST, maybe now) is to be able to retard the timing under boost. Mine's not even doing that now. That's #1 priority. Altitude stuff is just another part of it. I don't really travel from hi to low or vice versa, but it would be nice to not have to screw with it. I will continue my research and check out Lance's. Jody, you know anything about these? Maybe I just need a boosted LS7

I do not have any personal experience with Lance's stuff, but he seems like a sharp guy. The altitude comp isn't a huge deal for me, at least not enough to swap ecu's. I have my high altitude map, only takes 30 seconds or so to swap it if need be. Would be nice if it actually worked though.

Jody