I'm getting a little into autocrossing (UTA Racing school group got me hooked on it) in Texas SCCA. I ran the last event last year, will do a few this year.

First off:

The race last year (Le Grave Field), they had a wide sweeper going into a long straight. I was running in 2nd lockout on the shifter, but when i went to lay the throttle for the straight, it took about 1 second, for the trans to go from 2nd to first. Is this a product of computer delay, torque management, or ??

Second: I have a CEL code for a vacuum leak in the fuel vapor system. Is it more likely to be a cracked vacuum hose or a bad sensor?

Third: How can I pull that little bit more power? I was basically 3 seconds off the average PAX time, which is about 5-7 seconds real time. Street stock Mini Coopers were eating me for lunch. My quickest was a 75.6 Secs, Mini's were in the 68-72 bracket.

I'm thinking about running without the air cleaner (or putting a high flow in?), and depending where the airbox pulls from, put a nose duct in as upposed to fender. At Legrave i had all the windows open...I'll probably be closing the fronts on the fast tracks though. I know i was probably at pace speed if i was more aggressive, but i REALLY nead to practice my slaloms more. At the fast tracks, they usually have 2 or 3 slaloms plus 2 gates to keep speed "controlled". The gates i have no problem with, but the slaloms i need to work on.

Would the aero + weight effects of pulling the tailgate off do any difference?


Not great quality, but here's where I went up briefly on 2 wheels while hitting bumps at speed. The video isn't uploaded yet, but should be by the time most people see this.

dako_LG_slowmo.gif

 

The delay you speak of is the torque mangament in the PCM, Mopar Performamce PCMs delete the torque managment, also B&G and Tom Fox flashes can do the same thing. Its Very annoying, i put the Mopar Perf. PCM in mine.

The vacumm leak is more then likley the Fuel Door. Replace it or try turning it a few times, if that doesn't fix it you might need to replace all your vacumm lines, i replaced all mine at about 90k.

as for pulling the gate off.. i know every ~100lbs takes off about a thenth et at the track, i would do an free flowing intake, upgrade to a v8 tb, i have a friend that has 5 of them for sale they are stock v8 tbs bored to 50mm, they work great on the 3.9s as a upgrade, open up the exhuast a tad and maybe you can rip that extra 3 secs..

 

It's a 4.7 V6 (as noted in sig). And the video is up. I slowmo'd the 2 wheeled humpty dumpty at 0:22 to 0:24.

You're in Justin, my favorite place (10 years attendence and counting..suites last nov).

I've tried with both my stock and locking caps...light stays on either way. Would it auto reset, or would I need to reset it when i change caps?

How much is it to have the PCM's/flashes you speak of? One of my friends said he knew of a way you could wire a switch somewhere in the harness that would disable it, but not sure i should believe him.

FYI I'm at UT arlington.

If 100 pounds is that much difference, should i ditch the spare tire and jack unit in addition to the gate? I can leave them at the UTA pits on location so i'm still safe on the road .

I'm just doing this on the side as a fun deal, i dont want to spend alotta money on it (heck, entry fees are high as it is). Improvised stuff like dryer ducting from the grille to the airbox and shedding weight is what i'm looking for.

 

either the 3.9 v6 or the 4.7 v8..... theres no 4.7 v6 im aware of.

 

there is like two or three wires you can cut and/or splice and then wire to a switch to disable the torque management. i haven't read about it on here a whole lot but i've seen it on other forums. never really read into it that hard though seeing as i have a 5 speed but i'd say its definitaly something you should look into and your friend wasn't lying. the safer bet would be a performance pcm or superchips or something they'll minimize the torque management and give you a few extra ponies, i've read they do wonders for auto's.

 

I was going to say it might be a 3.7 but that was only 03&04 right?

 

03 was the last 3.9 year 04 was the only year the 3.7 made it into this body style so yeah your right

 

Just ran the VIN, it's a 3.9 actually...seems like it'd be bigger than that. Has enough torque to rotate the world, i know that.

also, i've taken it to some weigh scales at a local scrap yard. IT said the truck weight around 4000 pounds even.

 

like i said, i'm trying to do this on a budget. But if i could get my hands on a PCM programmer, then yea, I'd be switching between power and economy modes pretty often.


the superchips is $380

 

superchips... and this engine does not have the power to turn the world, i have it, varsis had it and we both will agree, its under powered for our trucks. its a good engine and can move the truck out of its own way but, it needs a v8 to get up a go.