LS-1 MAF translator vs ARC-2/ VPC

[KRAZYKOREAN]

OK...I was trying to read and all this stuff...I know I missed..my only question is...Is it better if you have the gm maf on the intake pipe..just like the stock location...or before the thottle body..like i have seen some other people to...what are the pros and cons of either one..if this has been typed already..can you tell me what page its on...i went over it twice and I didn't see it...

 

[JayHass]

Originally posted by KRAZYKOREAN
OK...I was trying to read and all this stuff...I know I missed..my only question is...Is it better if you have the gm maf on the intake pipe..just like the stock location...or before the thottle body..like i have seen some other people to...what are the pros and cons of either one..if this has been typed already..can you tell me what page its on...i went over it twice and I didn't see it...

Go back three posts.

Edit: Just in case you don't want to read two pages of engineering jibba jabba I'll summarize.

They both measure the air the same way.

After the turbo:
Pro:
After the BOV/Compressor allows you to vent the BOV to atmosphere. ( BUT you should have a long taper no more than 7 degrees to step up to the MAF size or use 3" IC pipe and the 3" MAF.)

Less turbulence by keeping the MAF in a relatively long straigh piece of pipe away from the compressor.

Con:
The risks are turbo failure taking out your MAF by coating it with oil. (If it's metal shavings you got more than the MAF to worry about)

Before the turbo:

Pro: You don't have to worry about failure/you don't have to cut up your IC pipes and/or can easily adapt it to work with your existing intake tube.

Con: Turbulence introduced if you put the MAF too close to the compressor inlet. (Roughly 12" is about as close as you should go)

That's about it off the top of my head. Maybe someone else can expand the list.

 

[KRAZYKOREAN]

Oh ok... damn I am blind or something..thanks man...so basically reading it..It doesn't matter where its mounted then...its personal preference then...

 

[MaxBoost]

Sorry if this is a little of the subject. I know you can just slap on bigger injectors change settings and be good to go, but with the MAF translator is it safer to run bigger injectors than recommended for your turbo? I ask this because I have a big16g and want to get 650's, but I heard that it will be overkill. Will the translator make this less of an overkill situation? Less limited than a Safc?

 

[MaxBoost]

Sorry if this is a little of the subject. I know you can just slap on bigger injectors change settings and be good to go, but does the MAF translator also make it safer to run bigger injectors than the norm for a given turbo? I have a big16g and want to get 650's, but I heard that it will be overkill. Will the translator make this less of an overkill situation? Less limited than say... a Safc?

By the way, I did install this in a draw through with a 3.5in MAS and the results were excellent.

 

[Tallen]

ok, if you KNOW its overkill. WHY do you want them? just get 550's

 

[MaxBoost]

First, sorry for the double post.

Overkill in case I upgrade to an AGP lr1 or lr2. Or maybe I still will only need 550's for those. I thought it might make it safer to run over 20psi.

 

[RedlinedTSi]

Go for the big injectors. Especially if you might upgrade to a larger turbo later. Plus you can get away with more boost on lower octane gas with larger injectors.

 

[MaxBoost]

Thats what I wanted to hear.
I got another question about the translator. With stock injectors does it really help avoid fuel cut. I havent tried to run over 15lbs yet with my setup, but im about to try 18lbs. I mean does the fuel cut defense really work if you are still running 450's?

There is no way im gonna read this whole thread AGAin to find this answer.

 

[candela]

No it only works when you have 451cc or above injectors...

 

[MaxBoost]

Where can I get 451s?

Just kidin.

This translator is absolutely awesome. I'm done and back to the real subject.....

 

[JayHass]

Sorry abou the double post.

 

[JayHass]

Originally posted by MaxBoost
Sorry if this is a little of the subject. I know you can just slap on bigger injectors change settings and be good to go, but does the MAF translator also make it safer to run bigger injectors than the norm for a given turbo? I have a big16g and want to get 650's, but I heard that it will be overkill.

One thing LONG forgotten in the DSM community is fuel pressure up to a certain point has the same effect as putting in a larger injector.

It's not very hard to get your 550's to flow like 650's at all.

Injector flow rates are done at 43.5psi 99% of the time so the formula is as follows.

Divide new pressure by old pressure, find the square root of this number, multiply the old flow by the square root to find the new flow number.

60psi/43.5psi = 1.37. Square root of 1.37 ='s 1.17. 550*1.17='s 643cc.

There is a max value that becomes "too much" fuel pressure. In my experience that is around 85psi. Others claim you can go to 90-95psi.

Why don't I just crank up the fuel pressure to 85psi then? Simple. When your car goes into boost your fuel pressure regulator increases fuel pressure on a 1:1 ratio with the boost pressure. So at 20lbs of boost and 60psi of fuel pressure total fuel pressure will be 80psi. You do not see additional flow from the 1:1 increase as it is just balancing the manifold pressure with the fuel pressure. It's a wash.

I plan on doing this with my 550's not because I will be maxing them out...right away at least, but because I would rather the injector run at 70% duty cycle at full load then 90%. It just keeps everything happy.

This is how I made 409whp in my SE-R on 4 50lb injectors which are basically 525cc injectors. I ran 4 bar fuel pressure and tuned off of that. (59.9psi)

As a side note just be careful that your fuel pump can pump at those high pressures. (98% of what we use can). Some can not and all flow pretty much stops at X point.

Keep in mind all my numbers are very conservative. Many Honda guys toss a 8:1 regulator on and boost 10lbs with a base fuel pressure of 36psi and call it "fine". 8:1 ='s 80psi bump along with 36psi base makes for 116psi total!

 

[Pfunk47]

Bob turbo or DSMraver, since you two are the experts. I plan to go with a LR2 full package from AGP sometime in the future ($$ sucks right now, jsut bought a house). Bob you said you should go with the 3.5 MAS for this. I plan to run Blow-through setup, not set on it though, running a apexI BOV vented switching to HKS and finally tial if not happy but I don't see how I can fit a 3.5 on that UICP. I especially can't keep less than a 7 dgree increase from 2.5 to 3.5 (garrett physics, you have to love physics). so will the 3 inch be overrun from the LR2 (numbers don't seem to prove it will) or are you just suggesting 3.5 (bigger is better)??

Thanks

ps. has anybody ever fit a 3 inch UIPC on, haha

 

[jdk906s]

Originally posted by JayHass


One thing LONG forgotten in the DSM community is fuel pressure up to a certain point has the same effect as putting in a larger injector.

Increaseing your base fuel pressure will adversly and directly affect your idle characteristics. Yes, it makes them "over flow" like they were a bigger injector. Thats why you can't run a Walbro 250 hp on a stock FPR for most cars without idle problems or running too rich - you can't get rid of that much fuel through the stock return, so the injectors start flowing more than they normally would to let out the excess pressure.

Thats one of the ways injectors are tested for failure - increase the pressure to max or over and keep running it like that and they fail faster.

You can try to use a SAFC or other tuning tool to make your injectors use shorter spray times to counter act the overflow, but isn't that actually extra steps to try and tune it, rather than just tuning it from the factory specs. But the whole thing is, if you shorten those times, your back to where you started off at b/c your injecting the same amount of fuel - except your just adding additional stress on your fuel system.

Just my 2 cents.

 

[Formz]

Originally posted by jdk906s
But the whole thing is, if you shorten those times, your back to where you started off at b/c your injecting the same amount of fuel - except your just adding additional stress on your fuel system.

Just my 2 cents.

That's not true. Because as I'm sure you realize you can add/subtract fuel at idle and idle only with the SAFC. So you can raise the base FP, take out fuel at idle with the AFC, and enjoy the benefits of great idle, and lots of fuel when you need it!

 

[Kevin Jewer]

Originally posted by jdk906s


Increaseing your base fuel pressure will adversly and directly affect your idle characteristics. Yes, it makes them "over flow" like they were a bigger injector. Thats why you can't run a Walbro 250 hp on a stock FPR for most cars without idle problems or running too rich - you can't get rid of that much fuel through the stock return, so the injectors start flowing more than they normally would to let out the excess pressure.

I think you are missing the point of his post. This is for poeple trying to get more fuel from smaller injectors. So if the injectors flow more fuel, you have achieved the desired affect Naturally you need an AFC (or MAFT) to tune it back. While I wouldnt suggest trying to go a whole size bigger, a few psi increase may be all some people need to put of fuel cut, which I believe was what made Jay post this idea. Bigger injectors would be the ideal solution (short of TMO/DSMlink ECU) but a few more base psi may fix the problem. Thing is, an AFPR (~$200+) isnt much cheaper than injectors ($300+) unless you get the comandflow ($70), which will be useless if you go to a large pump, but could still be used with a 190 theoretically.

 

[XTurboSpYderX]

has anyone made an upper ICP to acomidate the GM MAF yet?

 

[QuickSilverGSX9]

95GSXRacer, in your last post you wrote, it looks like you're saying that getting bigger injectors would help fix the stock FPR over run, is that true? I've been led to beleive that an AFPR is not a total waste of money, but not truley necessary. There are many definitions of 'necessary', I understand that, however I'd rather purchase larger injectors then buying an AFPR and then buying larger injectors if I don't have to.
Ah, and one last thing, I talked with Mike from Ramchargers, and he told me I can't tune (with his MAFT or an S-AFC) without an AFPR, just wanted to know what other people have to say about that? Infact, he practically laughed at me when I told him I had upgraded my fuel pump and not my FPR, oh well, just wanted to share.
-Bill

 

[Kevin Jewer]

Originally posted by QuickSilverGSX9
95GSXRacer, in your last post you wrote, it looks like you're saying that getting bigger injectors would help fix the stock FPR over run, is that true? I've been led to beleive that an AFPR is not a total waste of money, but not truley necessary.

Bigger injectors will not help FPR over run. The injectors flow more, but by tuning them back to spec with an AFC, etc, the total fuel *consumption* remains the same. So the amount of fuel that has to be bypassed stays the same. No help there. An aftermarket FPR isnt "necessary", unless you want your car to run at the proper air/fuel ratio wile idle, cruising, or other low fuel consuption mode of operation. At WOT the AFPR wont affect anything, provided you have it set at the stock base FP. AFPR have other uses though, like the one myself and Jay mentioned above. But the "best" way to do things is to use a larger pump, afpr, and larger injectors. If you need the uprades of course.

Ah, and one last thing, I talked with Mike from Ramchargers, and he told me I can't tune (with his MAFT or an S-AFC) without an AFPR, just wanted to know what other people have to say about that? Infact, he practically laughed at me when I told him I had upgraded my fuel pump and not my FPR, oh well, just wanted to share.
-Bill

You were either misunderstanding Mike, or this is another fine example of a non-DSM vendor not understanding our cars/mods. MAnhy people use the 190 LPH walbro with no FPR overrun. Including me. I have my 660s at 90% IDC, with no sign of running out of pump, and I can tune to any AF ratio of 9:1 to whatever. I dont see the problem A 255 will require an AFPR, again, if you want trims to be correct at low load. Hope that helps.

 

[Tallen]

Originally posted by QuickSilverGSX9
95GSXRacer, in your last post you wrote, it looks like you're saying that getting bigger injectors would help fix the stock FPR over run, is that true? I've been led to beleive that an AFPR is not a total waste of money, but not truley necessary. There are many definitions of 'necessary', I understand that, however I'd rather purchase larger injectors then buying an AFPR and then buying larger injectors if I don't have to.
Ah, and one last thing, I talked with Mike from Ramchargers, and he told me I can't tune (with his MAFT or an S-AFC) without an AFPR, just wanted to know what other people have to say about that? Infact, he practically laughed at me when I told him I had upgraded my fuel pump and not my FPR, oh well, just wanted to share.
-Bill

i agree, he prolly just doesnt know that some fuel pumps provide us with better flow, but at the same pressure. ex: walbro 190 or RX-7 TII pump

 

[JayHass]

Originally posted by jdk906s


Increaseing your base fuel pressure will adversly and directly affect your idle characteristics.

Actually it's just the opposite.

I dont think you fully understand what I am saying here.

Larger injectors are harder to tune at low pulsewidth...that's why you hear "720's idle like crap". The invalid time is just too long with big injectors.

With a smaller injector running higher fuel pressure this is solved because you still have the smaller injector at idle which can handle small pulsewidth durations but you get the flow up top like a larger injector.

I'm not talking about just cranking your fuel pressure up. That's stupid and ghetto. This is for people who have a tuning tool (I.E. What this entire thread is about)

550's at 4 bar fuel pressure act exactly like 650's. You tune for 650's...period.

Yes, it makes them "over flow" like they were a bigger injector you can't get rid of that much fuel through the stock return,

Flow and pressure are two different things. In fact with fuel pumps generally when pressure goes up FLOW goes *DOWN*.

Thats one of the ways injectors are tested for failure - increase the pressure to max or over and keep running it like that and they fail faster.

What part of my post did you not read about max fuel pressures?

But the whole thing is, if you shorten those times, your back to where you started off at b/c your injecting the same amount of fuel - except your just adding additional stress on your fuel system.

You really just don't understand this whole concept. I suggest you read up some more.

 

[JayHass]

Originally posted by XTurboSpYderX
has anyone made an upper ICP to acomidate the GM MAF yet?

I don't think so. There IS a 3" UICP avaiable though so it's just a matter of hacking out a section the size of the MAF and getting some quality couplers.

 

[kutschca]

sorry, not to get too far off topic, but I've noticed that the general agreement is that with a 190lph pump, you can run the stock fuel pressure regulator without problems. Wouldn't it make sense then that for a 1g on a budget (much like myself) that you could run a 190 and a B&M command flow and not have problems with over-running the fpr while still enjoying the ability to increase base fuel pressure to your injectors for increased flow? I don't ever plan on going bigger than a 16g so I know that a 190 would be perfect for my needs. I think that the 190 and B&M combo would be a great and inexpensive way to upgrade my fuel system to suit my needs. Anyone see something wrong with my reasoning?

 

[JayHass]

Kut you will still need something to tune with like the GM MAFT.

450's act like 525's at 60psi so yes IMO you could do that and have good results.

Also don't forget guys...when pressure goes up fuel pump flow generally GOES DOWN.