LI_Max_WOT

iTrader: (9)

So, soon I'll be going 3.5" LRMAF, 3" exhaust w high flow cat, with VAFC2 and A/F monitor.. After install, the max will be street tuned in 3rd gear. My questions:

1. Is this the correct 3.5" LRMAF? From a 03-04 LR Discovery / 99-03 Range Rover.

http://www.ebay.com/itm/120811064432...84.m1423.l2649

2. What have people experienced after going with the 3.5" LRMAF housing? How does this affect power distribution and throttle response?

3. Going from a 2.5" y-pipe back exhaust, what difference can I expect as far as throttle response and power distribution from low-mid-high ranges?

4. Would it be bad to place the a/f monitor behind the high flow cat? Would this result in inaccurate readings because of the flow through the cat?

5. Can the VAFC2 be wired up to the VIAS Solenoid and control operation at certain rpm using the function on the VAFC2 that controls the VTEC operation? Would altering this signal possibly cause the ecu to throw codes?

6. And my MOST IMPORTANT question: What is the switchover point for closed/open loop operation? I've seen different rpm #s and throttle positions all over the place, and this will be vital to a proper tune.

Sorry in advance if any of my terms are a little off, I'm no mechanic but I've picked up a few things over the years. I've done lots of research on the site, and I wouldn't start this thread if I had found the answer anywhere. Basically, the bottom line is I don't want to do all these modifications without any prior knowledge of how it will affect power distribution: aka I don't want to lose all low end power going with such a large setup N/A. Also, any general tuning advice would be greatly appreciated. Thanks

NmexMAX

iTrader: (22)

I'd get a SAFCII, better bargain, easier tuning re: MAF scaling.

Go with a 3" test pipe

Yes, it would be bad to place it behind the cat, yes, inaccurate readings will result.

Yes, the VAFC can be wired to the VIAS, but, who has functioning VIAS these days anyway? Also, the OEM design of the VIAS is not a 1 step process, 0-1800, then 1800-3800, done. Get an SSIM or BOP.

Open loop/closed loop is dependent on load, which is defined as throttle angle/ MAF reading, and RPM, so if you get all those the same every time, it will be the same every time, but that is extremely unlikely to occur, so I'd try not to solve that one. If you're wondering about the AFC function, there is a diagram in the manual that explains what means what when certain RPM and throttle positions are seen, it's all proportional, just like what is decried as "load". I used SR20DEN's advice, and have not changed the throttle positions since. Now the correction points, I change that all the time, but, that's easy to get, understand, and see a difference.

clintb3astwood

iTrader: (10)

I plan on running the same setup very soon 3.5 maf hosuing and intake as one pipe, 3" exhaust and I have a high flow cat as well ready to install. I have the ssim and pnp manifolds done with vafc2. But what's the difference between the vafc and safc? Also where would be the best point to place the o2 for the wideband?

02whitemaximase

iTrader: (38)

Put the wideband in just after the collector of the y pipe. Unless you have two wideband o2's then it is self explanatory.

NmexMAX

iTrader: (22)

VAFCII has more adjustment points, SAFCII has easy MAF scaling ability, that's it. And IMO, you really don;t need that many tuning points and I'd gladly give up more points for easy MAF scaling. But from you asking that, seems as if you missed this sticky, as well as a boat load others:


http://forums.maxima.org/5th-generat...ng-thread.html

http://forums.maxima.org/all-motor/3...s-reading.html

Fairly dated, and since then I cannot remember if the IN/OUT feature was ever figured out for the VAFC.


O2 bung placement:
http://forums.maxima.org/all-motor/3...g-welding.html

Here's mine:

clintb3astwood

iTrader: (10)

Thanks for the info and links, it seems my wideband was horribly placed LOL must be relocated.

NmexMAX

iTrader: (22)

Also, here's this:

LI_Max_WOT

iTrader: (9)

NmexMax, thanks for the info I was hoping I'd catch your eye with this thread. I already have the VAFC2 all wired up, so I'm gonna give a shot street tuning with this when I get everything put in about a month from now. Yes, I know I'm one of the few that doesn't have a block plate on, but IMO the VIAS system is probably one of the best features of the intake system and with the right tweaks really kicks it up a notch in higher rpm and maximizes tq curve. The only reason I was going to put a high flow cat on was because with a similar y-pipe to a 6th gen (2 flex pipes) there's a bit of rasp with a 2.5" without a resonator or cat, especially with the variable case g35 sedan muffler installed.

The rasp occurs at low rpms, while the second exhaust tip is closed, so I'm hoping that maybe this will be cured with a free-flowing muffler design? I'm thinking this rasp comes because of too much backpressure at low rpms, when the muffler is restricting the exhaust flow? Where do you think I will gain power in the power curve with such a large setup? Is there any possible loss of power? Also, do I have the correct Land Rover MAF housing picked out? I'm gonna check my in/out settings on the VAFC2 because they've been working fine since install, IIRC I've been using what was being used for the SAFC2s.

Greg, I wish I was able to wire up 2 widebands and really be able to tune properly. Then I'd be able to really even out the power between bank 1 and bank 2. I just don't want to bite off more than I can chew, and I'm going to wet my feet tuning before I go all out with a setup like that.

Reizy

iTrader: (48)

Your VAFC settings will not work when you add the 3.5" intake. I sold you the VAFC and went with the SAFC because I did exactly what you are doing in adding the larger MAF. The best settings that I tried were 2 in and 8 out. In the end I should have kept the VAFC because it seems like my adjustments were about the same with either.

Rods03Max619

iTrader: (5)

So what Mods do you have on this car? And not to go off topic but were you the one who Made supposedly the BEST INTAKE FOR a 5thyou gen or was that another member....

LI_Max_WOT

iTrader: (9)

Could you explain more about what problems you had with the VAFC adding the 3.5" intake? You're saying the in/out settings had to be adjusted and the end result was about the same compared to the SAFC?

Haha IT WAS ME!! I was saying it was the best without the need to tune tho. I'm applying the same principles to this setup, I'll post some before and after videos and I guarantee you will like. I've just got a few "bolt-ons"

Rods03Max619

iTrader: (5)

Another top secret guy, do I need Delta clearance to have a look....

LI_Max_WOT

iTrader: (9)

Yes, you do


Last question I have I think... What is the purpose of the vacuum hose connected to the intake system on a 5.5? Does the air only travel one way, or is it variable depending on engine speed, throttle position, off-throttle condition or something like that?

So after doing a good amount of research, I'm trying to figure out if I could fit the LRMAF in place of the stock maf, in the stock intake setup. I don't have anything to measure, but it looks like the LRMAF is the same length as the stock housing, so all I would need is to weld an adapter plate onto the end to bolt it into the stock airbox, right? I'd prefer to keep the helmholtz/pcv/ribbed coupler in place, and the only way I see this possible is to slip the LRMAF right in where the stock is.

I'll give up a few secrets now, because I plan on unfolding all very soon once all is completed and I have some track times to share. I have a 4" ram air intake system, into a modified stock airbox, which has yielded quite impressive results. That addition from a similar 3" setup, along with an extended equal length y-pipe has bumped my peak kPsa +20. No issues with water being sucked up, however the setup will need some tweaking to stop getting so much dirt and rocks kicked up in there. The ram scoop is below the bumper, set back about 4 inches made of a gutter scoop from home depot. If anyone attempts this, make sure you have a way for air to escape because in throttle-off you will have a very high air buildup and drag caused from the scoop.