Outer Limits 4x4 Board

guys and gals im in the middle of doing an ls1 conversion on an 80 and need help deciding whether to go maffless or run an air flow meter, anyone had any experience with them in commodores etc? cheers for the help guys
rob

All the blokes chasing more ponies out of their LS1 Commodores seem to go the mafless tune, obviously there must be benefits to be had.

yea had one on my old clubby the biggest benifit i found was being able to step up the complete intake to 100mm including the throttle body, snake racing actualy sell these gives noticable power increase,

The MAF offers some restriction on the intake, the MAF is a very accurate means of measuring air quantity so the accuracy of the tune is better, slighty better economy potentially and less variation in mixture dependent on various atmospheric conditions. Primarily for emissions. A MAF-less tune takes longer but will make more power.
Some common mods for the LS1 are no MAF big intake, throttle body, extractors and exhaust which will typically gain 20-40 rwkw on an accurate dyno, some people may quote larger gains but that is more to do with the type of dyno and the operator.
I use EFI live for tuning LS1 to current Gen3 and Gen 4 engines.

Cheers

Joel

I may be slow but this is an interesting topic. But what exactly is a Maf less tune?

basically tuning the car to run without an air flow meter

So is this also effective on Aussie 5 litre engines?

Cheers

Struth wrote:So is this also effective on Aussie 5 litre engines?

Cheers

I don't think they had MAFs?

I do know that larger a throttlebody can have a good increase on higher powered 5L engines though.

And in regards to the LS1;

The MAFless tuned car never happened in the USA as the C5 Corvette with the same engine was always fitted with an MAF. It featured larger MAF meters than the ones installed in the Australian cars.

However, tuners of the LS1 in North America tend to prefer retaining the MAF, instead overcoming intake tract restrictions by installing an MAF with a larger diameter body.

So in saying that, drivability is decreased somewhat with the MAFless tune, and the same power can be obtained with a larger MAF as used in the states.

The problem with MAF airflow meters in 4wd applications is if you dunk it under water and happen to get moisture thru to the airflow meter your motor will probably see it as a fault and go into limp home mode.

HotFourOk wrote:

Struth wrote:So is this also effective on Aussie 5 litre engines?

Cheers

I don't think they had MAFs?

I do know that larger a throttlebody can have a good increase on higher powered 5L engines though.

And in regards to the LS1;

The MAFless tuned car never happened in the USA as the C5 Corvette with the same engine was always fitted with an MAF. It featured larger MAF meters than the ones installed in the Australian cars.

However, tuners of the LS1 in North America tend to prefer retaining the MAF, instead overcoming intake tract restrictions by installing an MAF with a larger diameter body.

So in saying that, drivability is decreased somewhat with the MAFless tune, and the same power can be obtained with a larger MAF as used in the states.

The VT 5.0 has a MAF, I have been told that if the MAF plays up not to expect good power, economy or much useful at all really.

Cheers

I would rather go with a less restrictive MAF sensor than none. But I don't know about the LS1s specifically.

Struth wrote:The VT 5.0 has a MAF, I have been told that if the MAF plays up not to expect good power, economy or much useful at all really.

Cheers

It does? Ive never taken any notice All the other 5.0's run a MAP sensor.

chimpboy wrote:I would rather go with a less restrictive MAF sensor than none. But I don't know about the LS1s specifically.

As stated above they are a PITA offroad. They dont like oil or water.

If u look on the commodore forum one of the first enine mods people do is put on a over the radiator cold air intake and get a mafless tune for big hp increases. The inside of a maf sensor does look very resticted.

I have installed the cam, 3.5" exhaust and just fitted the otr intake, just need to get it mafless tuned.
The 6ltr utes are enough fun with stock power.... cant wait

So, where does the engine get airflow info without the MAF sensor?

I think you run a MAP sensor instead?

So getting one mafless tuned is done thru the computer?

Yep it is tuned on a dyno. LS1 can be chipped LS2 needs to be pluged into a laptop.

jeep97tj wrote:Yep it is tuned on a dyno. LS1 can be chipped LS2 needs to be pluged into a laptop.

The ls1 and early ls2 use the same computer, the later ls2 and l98, l76, use the later e40 and e38 ecu, all are a flash ram, none require a chip as the origional tune in the ecu is reflashed.

The earlier Holden engines are a Memcal that are chipped (VN to VT series 1), in that there is a plug in eprom that can be erased with a UV light and a new tune programmed into the memcal.

The VS series 3 Holden was the first to run a MAF of the V8's, it is the same engine in the VT series 1, it was a roller cammed sequential injection engine unlike the earlier engines.

Joel

sorry your right i was thinking of the capa site when i said that, just had a look they can reprogram your LS1 computer but not the LS2, any idea why??

chimpboy wrote:So, where does the engine get airflow info without the MAF sensor?

LS1's have both a MAP and a MAF

Shane you got a 6lt ute sweet