Justin00Stang

Michael's 2007 4.0L Has an X-Charger Non-intercooled roots supercharger kit with a 2.8 pulley (10psi). 39/42lb pencil injectors, the stock fuel pump, and a larger maf housing/CAI are utilized. The car has duals and 3.73 gears.

I have done a ton of work with centrifugally supercharged SOHC 4.0s, but this is the first x-charged car I have tuned. After a little tweaking the spark tables that I came up with for the Vorteched 4.0 work well with the X.

We ran the car several different ways on the dyno, starting with no water/meth injection. The best power that way was 281RWHP/294RWTQ. With a ~90F ambient the dyno pull would start with an air temp of 110F and end at 160F. This is not bad for a 10psi non-intercooled kit. You would see about the same from a non-ic Vortech.

Next we ran it with water injection (no meth). The air temp ran around 110-120F during the entire pull, I set my tune up to add in several degrees of timing automatically. The A/F did not change because water does not burn. Final #s were 288RWHP/296RWTQ. If the water injection kit failed to function the ACT sensor would detect the higher air temp and pull timing, so the tune is extremly safe.

Pump gas tune with and without water(only) injection:


We drained the water from the reservoir and filled it with windshield washer concentrate. I keep some Ford Motorcraft windshield washer concentrate around the shop. It seems to have a very high methanol content, as it richens up the A/F a lot. The blue windshield washer fluid you can pick up at the autoparts store has barely any methanol in it. I will say that W/M worked better on this car than it has on most of the centrifugal blower cars I have worked on. With the water/meth mix spraying the A/F started in the high 8s and came up to high 10s by the end of the run. Over several runs I adjusted the commanded lambda to lean the air fuel out, this is the correct way to tune for W/M. Changing the maf xfer function is not the correct way, as it will cause the tune to be off in other areas.

This is where a boost based progressive controller could be of benefit. The car would not run as rich at low RPMs, and I think the air temp would still be relatively low. At higher RPMs I would say the nozzle is sized perfectly (Doug's kit I believe).

Unfortuneately due to time constraints I did not have time to compare straight water and water/meth mix. The meth richens things up, but it's more condusive to combustion since its burns. The only negative, if you lean the tune out and your W/M injection fails you could be in trouble. I gave Michael one fool proof street tune for use with or without water injection. Then an aggressive street tune that must be used with meth mix.

The third tune I gave him is for water/meth mix and race fuel. This tune adds a bunch of timing and leans out the a/f to account for all the fuel the meth adds in. I tried three times to crack the 300rwhp barrier, but it would not happen. The final numbers were 299.5 RWHP and 310 RWTQ.

Race Fuel Tune:

beaustang

Is this a repost of his original tune or did you do it recently?

Justin00Stang

This is a repost for this forum, I tuned it a few weeks ago.