LS-1 MAF translator vs ARC-2/ VPC

[Kevin Jewer]

Originally posted by peregrine
sorry resubscribing. i accidentally purged my subscribed threads.

Wouldnt it be easier to "click here to subscribe to this thread" at the bottom of the page? Maybe I'm missing something

 

[DrZiplok]

91 octane horsepiss; best you can get around here.

Did some more tuning on the run home from work; with the WOT setting at 3 and the MID setting at 2, the tip-in knock remains. I dialed in about 5% more fuel from 4000rpm upwards and managed to get it down from an easy 43 counts to about 25 or so, but I'm still getting a *lot* of timing pulled.

I'm going to try dropping the BASE setting one to see if some more fuel across the board will help. Beyond this, though, I'm afraid that I'm going to need a bigger intercooler and perhaps water injection to keep knock under control. At only 15psi, this is pretty ridiculous.

 

[Kevin Jewer]

You may have already checked these, but just in case... Be sure your base timing is correct. I have seen quite a few cars personally that had high knock because base timing was 15 or 20 degrees Another thing that plagued my car all last year was 1-2mm of crud on top of my pistons, and they were only ~8 months old. Cleaned them off in the process of a head gasket change and the knock was completely gone. I added 7 degrees of timing in with DSMlink, for a total of 23 degrees on pump, with no knock at 24 psi. . So check that stuff out just in case its an easy fix, if you havent already.

 

[Kingdom]

Originally posted by DCJ98GST
I would not want a translator without adjustments and here is why:

It seems to me that the fuel adjustments on the translator are superior to the SAFC. The bad thing about the SAFC is that it has throttle based adjustments that is not always very acurate. Here is an example:

Say you have just an S-AFC and let's pretend that you have a laggy turbo, where boost begins at 3400 rpm in 4th gear. So what happens, if you are driving around in traffic at around 2800rpm and mash the throttle? The SAFC sees that you are at WOT and kicks over to the high fuel map (since it's basing its map on TPS) and begins dumping fuel despite the fact that the car hasn't begun making boost yet. So, the car now runs shitty for 600 rpms because it is rich, and bogs from the overrich condition until the car hits boost. This over rich condition will make the turbo lag seem even greater.

The translator fuel adjustments are based on actual air flow not Throttle postion and should eliminate this problem.

The more responsive spool time may not just be because of the increased flow but also proper fuel mixture at the lower rpms!

The translator should be used in conjunction with the S-AFC for fine tuning, but the bulk of the tuning should be done with the translator.

I have tried to read/skim all of the posts in this and the other threads, and if I am wrong please tell me.

my eyes hurt, i just read all 20 pages.

This really looks like a nice piece.

Just a few questions.

Why not just lower the fuel curve at the high setting on the afc so it wont dump alot of fuel.

For example, lower the fuel at the rpm points that u have lag in at the high setting only. This way it wont dump alot of fuel.

running the blow through method. Why would u have more lag between shifts?

If u run the MAP method u dont have more lag, this should be the same.

If it will still create more lag between shifts, why not recirulate the BOV anyways?

Also, how much HP will the 3inch Impala SS map support in the blow through method. estimate?

 

[DrZiplok]

Kevin, thanks for the suggestion. Base timing is 5deg, and I MCCC'ed the engine a couple months back.

Plugs are relatively fresh, plug wires are NGKs and also relatively new.

I did some freeway tuning today; dropped the BASE setting back a notch to see what that would affect. With the AFC adding fuel from 4000 up, I can keep tip-in knock down to ~20 counts, but pulling hard in first the engine bogs and staggers badly - I have to take fuel out to get it to pull at all well. Through all this, O2s are in the high .80s and EGTs aren't making it much over 820C.

On a hard 3rd gear pull, after the initial tip-in knock and immediate timing retard, knock slowly falls off and timing slowly increases to match. This is *really* frustrating.

Mike/Bob, if you're still following this epic, would you recommend adding more fuel either at MID or WOT for this, or would you be looking elsewhere to try to resolve the issue?

 

[brads]

Have you checked for boost leaks since installing the MAFT? If you posted this I missed it.

Brad

Originally posted by DrZiplok

On a hard 3rd gear pull, after the initial tip-in knock and immediate timing retard, knock slowly falls off and timing slowly increases to match. This is *really* frustrating.

 

[DSMraver]

What condition are your lifters in?

What happens when you tip in above 4k? Do you still get the knock? How old are your injectors, and fuel filter?

 

[ECLIPSE4x4]

Have any of you 1G guys seen this?

http://www.dsmtuners.com/forums/showthread.php?s=&postid=378937#post378937

 

[Motohead1]

Originally posted by ECLIPSE4x4
Have any of you 1G guys seen this?

http://www.dsmtuners.com/forums/showthread.php?s=&postid=378937#post378937

I think thats a ford unit mas. Never seen it before but i bet it aint $200.

 

[Tallen]

i'll stick to ym translator...the car is now running BEAUTIFULLY...well cept the clutch needs to be bled...but thats not ramchargers fault.

oh yea, anyone with a logger, what is your MID setting at?

 

[DSMraver]

Originally posted by ECLIPSE4x4
Have any of you 1G guys seen this?

http://www.dsmtuners.com/forums/showthread.php?s=&postid=378937#post378937

Yes, it's the Split Second ARC-2. It's an expensive POS, imho. Give me the Translator, any day!

 

[BobTurbo]

Doc Ziplock, It sounds to me like you're getting some 'air steering' in the pipes. Try reorienting the MAF and re-tune.

Bob

 

[Tallen]

Originally posted by DSMraver


Yes, it's the Split Second ARC-2. It's an expensive POS, imho. Give me the Translator, any day!

ditto

 

[Tallen]

Originally posted by DSMraver


Yes, it's the Split Second ARC-2. It's an expensive POS, imho. Give me the Translator, any day!

ditto

 

[ttawd3s]

Funny if you guys only knew the arguments I had to suffer though to get the 3/S guys to reallize that the translator is better !!! The arc-2 isn't a POS though, but not $1300 worth ( yes, $1300 with the 3.5'' MAF ).

Bob and Mike knows what I'm talking about, sometimes I'd think the 3/S guys would want proof that a 50 shot of nitrous would make more power vs just listing to people that know it will.. Anyway, they know now..

 

[DSM90AWD]

Originally posted by DrZiplok
I'm still pulling 20+ knock counts on sudden throttle transitions though..

Did you have this problem with tip-in-knock prior to installing the MAFT?

This seems to be a common problem on DSMs which is recognized once you start to datalog. FYI.. there is list on YAHOO called Phantom Knock which was setup specifically discuss this issue.

A recent (and timely) theory on the list hypothesizes heat-soaking the MAS temp sensor as a potential cause (of which the MAFT does not utilize).

 

[DrZiplok]

Thanks for the responses folks; collecting several into one reply here:

Did you have this problem with tip-in-knock prior to installing the MAFT?

Not significantly; I'd managed to tune it out with a little more fuel in the 4000-5000 range.

Doc Ziplock, It sounds to me like you're getting some 'air steering' in the pipes. Try reorienting the MAF and re-tune.

Bob, can you elaborate on this? I am using the Dejon 3" inlet with the GM MAF oriented divider-vertical; there's about 6" or so of linear flow out the back of the MAF before the downard bend. Would you recommend switching to divider-horizontal or some other angle? Is this a "magic" aspect of these MAFs?

What condition are your lifters in?

What happens when you tip in above 4k? Do you still get the knock? How old are your injectors, and fuel filter?

I have the revised lifters, in now for about 12 months. I get < 10 seconds of lifter tick at startup, even on cold mornings.

I see tip-in knock from 3500rpm upwards.

The injectors are < 3mo old; filter is probably the original unit - I have a replacement but have been unable to get the old one out.

Have you checked for boost leaks since installing the MAFT? If you posted this I missed it.

I have not, thanks for the suggestion.

Just a brief update today; shifting BASE back to 3 (510cc baseline) results in the "too much fuel" surge on overrun. I'm going to try some of the maintenance suggestions here and retune with BASE at 4 and more WOT fuel.

Bob/Mike, you mention "more octane" a lot in the instructions; do you have any suggestions (beyond the obvious "more fuel") for those of us that have to live with crappy west-coast gas?

 

[DSMraver]

Change that fuel filter, and get yourself some water/akly injection for that POS 91 octane crap.

 

[Ramchargers]

Originally posted by DrZiplok


Bob, can you elaborate on this? I am using the Dejon 3" inlet with the GM MAF oriented divider-vertical; there's about 6" or so of linear flow out the back of the MAF before the downard bend. Would you recommend switching to divider-horizontal or some other angle? Is this a "magic" aspect of these MAFs?

I see tip-in knock from 3500rpm upwards.

Just a brief update today; shifting BASE back to 3 (510cc baseline) results in the "too much fuel" surge on overrun. I'm going to try some of the maintenance suggestions here and retune with BASE at 4 and more WOT fuel.

Bob/Mike, you mention "more octane" a lot in the instructions; do you have any suggestions (beyond the obvious "more fuel") for those of us that have to live with crappy west-coast gas?

Typically the sensor does not care which way it is clocked in the pipe. to eliminate potential problems with air swirling in the tube that is just something to try.
I might go back to the BASE 3 and remove fuel with the other controls.
Lots of other folks are removing their screens and not having problems so what ever is going on it seems so far unique to your car. If you have knock that is real knock there is only two ways to get rid of it, reduce boost or reduce timing. I would reduce the base timing a couple degrees and work from there you can alyways add it back.
Mike

 

[QuickSilverGSX9]

DrZiplock, or Ramchargers, which DejonTool intake piping would you sugesst getting w/ the 3" Imapla SS MAF? They sell a 3" straight pipe, and a 3" curved pipe, I'm pretty much looking for opinions and why. Also, I noticed on the intake pipping (stock) near the OEM MAS (I have a 1g GSX) there are two vacum lines that head towards the firewall, I'm actually not sure what they're for? And the DejonTool piping doesn't look like it has tubes for those vacum lines, so..do I need them and what do they do? Thanks in advance for atleast reading this "noob" questions.
-Bill

 

[Formz]

Originally posted by QuickSilverGSX9
DrZiplock, or Ramchargers, which DejonTool intake piping would you sugesst getting w/ the 3" Imapla SS MAF? They sell a 3" straight pipe, and a 3" curved pipe, I'm pretty much looking for opinions and why. Also, I noticed on the intake pipping (stock) near the OEM MAS (I have a 1g GSX) there are two vacum lines that head towards the firewall, I'm actually not sure what they're for? And the DejonTool piping doesn't look like it has tubes for those vacum lines, so..do I need them and what do they do? Thanks in advance for atleast reading this "noob" questions.
-Bill

One of those lines is for the charcoal canister. The other is for the valve cover breather. Both can be removed from the intake without any negative consequences.

 

[QuickSilverGSX9]

Good ol Formz, thanks bud. (QuicksilverGSX from MachV) So, I can simply disconnect them, or I've heard of people putting catch cans (or filters?), I guess, for both? So..I guess all that matters now is either a shorter straight 3" intake pipe, or the stock-looking 3" curved intake piping, any ideas?

 

[Formz]

hehe

Well, the one going to the valve cover people put either a breather filter or catch can (or catch can with breather filter attatched to it.) The charcoal canister line can just hang there.

As far as the intake goes, its your choice! They make a few different kinds all will be suitable. I don't suggest the one that goes into the fender well though unless you're running a blow through setup (otherwise you may suck up water and damage the MAF.) HTH

 

[QuickSilverGSX9]

That was a concern of mine, so thanks once again. Also..what type of head unit is that? I think we have the same kind...do you have the four 'colorful' buttons on the head unit as well? The colors are that cool cobalt blue, a dark purple and then those four freaking buttons..if you do..you'll know what I'm talking about .

 

[Formz]

Nah the one I have a panasonic cqdf400u or something. It's 3 years old. I just checked dejon's website and they have the intake thats MADE for the GM MAF out! So you could pick one of those up complete with the filter from them.