ls7, MAF or mafless?

[Boosted LS1]

Hi, I'm wondering what your thoughts are on this subject. Has anybody here ran their engine with the factory ecu, TB and MAF before swopping to an aftermarket set up? I'd like to hear about the real life pro's and con's if possible. Thanks.

[Bigjussin]

When you say aftermarket, do you mean oversize TB, IM, and MAF? Stock LS7 stuff is really good, and lots of people have lost pwoer swapping to aftermarket IM's and TB's that are too big

Little trick around here is to have your ECU tuned for MAP only, and use the piece from the Cobalt SS

[Boosted LS1]

^ Thanks. I like the idea of GM plug and play reliability but some people say it pulls far to much spark advance and that an aftermarket system releases more power. I'd use a stock TB and plenum whichever ecu I used.

[Storer]

I'm no expert on this topic (or any other, for that matter) but the GM ECU can be tuned with the correct software.
I don't know if you can change everything but with a decent free flowing exhaust and air inlet setup my standard LS7 produced 575hp.


Paul

[deadscoob]

I run mine mafless - with a decent exhaust, intake and cam. No issues whatsoever to any drivability.

Using efilive or hp tuner you can adjust spark anyway?

[Boosted LS1]

Thanks, this is a project with a friend. The idea is to get it up and running with the least fuss and as all the parts haven't been purchased yet there are cost considerations. I'm leaning to the stock GM set up but he'll need a MAF and pedal arrangement. If he uses his 'simpler' after market ecu he'll need to change the TB and may run into expensive mapping costs :-(

He could fit a carb instead :-)

[deadscoob]

With efilive I think you just disable the maf?

[bluesatin]

I would go to HP tuners web site- you may well find a map similar to what you need which would be a good starting point.

[Rscocca]

Im using HpTuners on an LS7 with GM E67 ECU, electronic throttle body, MAF all stock sensors. Near 730HP at rear wheels.
The factory ECU is very tunable and reliable.
Engine mods include Mast 305 head, Mast HO cam, Fast intake and Nick Williams 103 Throttle body, Injector Dynamic 850 injectors

With out the MAF sensor you would need to go to a speed density tune that will require and aftermarket ECU such as Holley Dominator EFI (Dual O2 Sensors) Fast XFI (single O2 sensor) or Mast EFI (Duel O2 Sensors).
All of these companys have harness that can be made to fit the Ultima.
All of the after market ECU are very good on there own merits but require someone with knowledge of that system to tune properly.

Most harness's that are designed for the Ultima are based on the GM ECU. If your good with a solder iron, you can make them fit the after market ECU's.


Hope this helps.

PS. If you need a HP tuners file to get you in the ballpark I can email it to you.

Edited by Rscocca on Wednesday 13th April 22:19

[Boosted LS1]

^ Thank you very much. That's a lot of power. :-) The ecu is a reflashed e38 from years ago. It looks like we need a pair of lambda's, a pedal assembly and a Maff or GM Maff cartridge. The plenums a later item with a gold TB blade inside. Also having problems establishing if there's a twin roller cam sprocket that's E38 compatible? If not it'll have to be a single roller chain set and sprocket.

[deadscoob]

As said, am running mafless, tune done via efilive, no 3rd party box needed....