Help me decide fuel management, please...

[23109 N8]

Ok, I hope this is the right section for this.

I have a 91 GSX with the following mods:

- open element filter
- big 16g ported/clipped 10deg/ 34mm wastegate (TRE)
- custom PWR FMIC and 2 1/2" piping
- Ported 1g intake manifold
- Greddy Type R BOV
- Blitz Dual SBC boost cont
- Blitz FATT TT
- Boost and EGT Guages
- upgraded fuel pump with rewire
- 2g ported exh. manifold
- Evo 2 1/2" PORTED O2
- full 3" DP and exhaust w/ no cat

I am looking for advise on fuel and management...
I am about to order new fuel injectors...
I have a S-AFC (new not installed yet)
I have not modified the stock MAF
I do have a custom intake with the electronics mounted outside the intake tube, which supposedly will flow better.

the current plan was to install S-AFC with 625cc injectors and possibly remove the lower honeycomb. and tmo eprom mods.

I keep reading of different options (like vpc's, GM MAF's, modded MAF's, 2g MAF's, etc) and need input

I don't plan to go with high dollar stand-alone.

here are some pics so you know i am not b.s.'n:
(just got back from paint)

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[NOSLO2PT0]

Keep the pump (if it's 255lph or bigger) and the 625's are ok. Not the best IMO, that's reserved for teh Denso 660's. Keep the AFC and get the MAFT. It's a very nice unit, very easy to tune (once you know what you are doing), and it makes good power.

I'm only about 3mph behind guys running similar setups and full standalones, or water injection/piggyback timing modules, etc. I run the stock ECU, MAFT, AFC combo and do quite well. Currently #15 on this times list, and i'm still running pump gas.

There are other options. The VPC is a many time proven performer, but at $800 for a used system, lucky if you get sensors, it's not bang for the buck. I'm very happy with the MAFT so far. Some will not haev teh same opinion as they haven't gotten a chance to get it dialed in or may experience some problems.

BTW, that's a very nice looking car. YOu yank the entire motor/drivetrain to paint it? Do it yourself? Details on the paint work, please.


Mike

 

[23109 N8]

thank you for your opinion...
I pulled EVERTHING from the firewalls, the radiator, hoodlatch, wiring, fuseblocks, etc. and moved everthing i could to the motor (zip tied) for paint (no motor pull).
The car was painted by kanhitit (1g/2g/3g) and has a custom front and rear bumper.
I will post more pics once it is complete.

So the MAFT = GM MAF + Translator?

 

[NOSLO2PT0]

Originally posted by 23109 N8
.

So the MAFT = GM MAF + Translator? [/B]

Yes. I would recommend the 3" GM MAF with the smaller turbo.

 

[TwoLiterV8Eater]

A 2g MAS and an AFC is also another option you can go with. The 2g MAS doesnt require any hacking and will flow more than a hacked 1gmas with none of the idle problems.

 

[Cirus_93TSI]

since your car is OBD1 u may want to look into the APEXi power fc, its a full standalone system that uses its own comntroler and does not require a laptop, its about $1300 with optional boost control
then u need to find somewhere with a dyno to tune it, thats what will eventually go into my car, whenever it gets to the point of needing engine management

 

[NOSLO2PT0]

If you are going to spend $1300, just get the AEM EMS. It's been proven to made tremendous power with our cars and the technical support is good as well.

Or, cut your teeth on something simple like a 2G MAS/AFC combo, and then once you are familiar with how everything works (timing, a/f, knock, etc) then step up.

 

[GRNDSM]

Unfortunately, AEM has also been proven to destroy quite a few engines… It is not a finished product, yet! There are a lot of bugs and blown engines as a result of those bugs.

If you are on a budget, get the translator but if you can spend more and can find it, get the VPC. It is still the best thing out there for a 1G… Too bad HKS is not selling it anymore, so you need to find it used.

Leon
RR

 

[Slappster]

Aem is the best for your money. Most of the bugs have been solved with the new software and better software is always in the works at aem. Once you have the ems you'll wonder how people tune without it.

 

[GRNDSM]

>Most of the bugs have been solved with the new software and better
>software is always in the works at aem.

Right… As in: I wouldn’t even consider it another year or so until ALL of the major bugs are gone!

They keep telling people that bugs are gone, while people are blowing motors (and intake systems…). AEM keeps saying: “well, THIS time it is REALLY all gone”… I would not want to take this risk…

Leon
RR

 

[Slappster]

Originally posted by GRNDSM
>Most of the bugs have been solved with the new software and better
>software is always in the works at aem.

Right… As in: I wouldn’t even consider it another year or so until ALL of the major bugs are gone!

They keep telling people that bugs are gone, while people are blowing motors (and intake systems…). AEM keeps saying: “well, THIS time it is REALLY all gone”… I would not want to take this risk…

Leon
RR

Have you even used the ems? The bugs are a minor drawback that can be solved with downloads or by anyone whose used the system for a while. Theres a reason why extremely high powered supras, dsms and other groups are having great success with aem.

Granted they say its plug and play which isn't true unless the car is completely stock. This system is only for those that have the time to learn.

 

[TwoLiterV8Eater]

I wouldnt give any company my money if they expected me to pay full price for a "beta" copy of a program. AEM sure did figure it out though. Instead of spending money to thoroughly test the system for bugs, they found "customers" to do it for them. AEM is being PAID to have their software tested. Amazing.

 

[gbpkr]

Off topic.....awesome car....."speed contest"

 

[GRNDSM]

>Have you even used the ems?

HELL NO!!! It is NOT a real product yet…

>The bugs are a minor drawback that can be solved with downloads
>or by anyone whose used the system for a while. Theres a reason
>why extremely high powered supras, dsms and other groups are
>having great success with aem.

I have two local guys, one a 9 sec DSM other is a 800hp Supra with blown motors. While they can’t prove that it was AEM, it looks VERY suspicious… Neither guy ever had this type of failure prior to switching to AEM…

There are also countless others…

Leon
RR

 

[23109 N8]

Judging from all that I have read so far, it seems that 550cc injectors can still lead to fuel cut at high boost and 660cc's are possibly too big for my application, so the Hahn Racecraft 625cc's should be a good middle ground (and it seems they have had much luck using them in conjunction with the S-AFC, which I already have). The 625cc's are supposed to be 15% more flow than the 550's.

I have access to a hacked 2g MAS or should I just go with the GM MAF w/Translator. I have seen nothing but positive and happy posts about the GM route.... what do you think?

 

[Big Woo]

This is off the original topic, but I have my own feeling about the AEM EMS.

I have had an EMS for my 1g since Oct. 2002, it has preformed without fail, or motor destruction since. The serial number on my EMS is 00010, and it originally came with version .79 software, now they are up to v 1.02 if I remember correctly. Yes they are continually updating the software; any remember Windows 95 or D.O.S. For my application an AEM EMS, Haltech, Motech, or Autotronic standalone ECU was a requirement. However they are not for everyone, they take time and specialized equipment to tune properly. Also required is a very, very through knowledge of engine management. If you go it alone, and you think you know what you are doing, there is a good possibility that you will blow up your motor. Nevertheless this is not a problem with the EMS it is the tuner’s problem, nuff said.

Bashing a product that you have no first hand knowledge of is shameful. Is the only requirement of a “Wiseman” is too have a big mouth, you should know better. Please don’t bash products just because you don’t posses the knowledge to use them correctly.

Back on topic going to a standalone for the project car mentioned in this thread would be excessive. A GM MAF and AFC would be a good combo, that is not too pricey, and will net good results. The proven VPC GCC combo would work good as well, but at a much greater expence.

 

[NOSLO2PT0]

Originally posted by 23109 N8
Judging from all that I have read so far, it seems that 550cc injectors can still lead to fuel cut at high boost and 660cc's are possibly too big for my application, so the Hahn Racecraft 625cc's should be a good middle ground (and it seems they have had much luck using them in conjunction with the S-AFC, which I already have). The 625cc's are supposed to be 15% more flow than the 550's.

I have access to a hacked 2g MAS or should I just go with the GM MAF w/Translator. I have seen nothing but positive and happy posts about the GM route.... what do you think?

660's on a 16G is fine. YOu just have to lean it out a little more to compensate for them. Leaning the car out with an AFC pushes fuel cut much farther away than, say, 550's would. Plus, I recommend the Denso 660's because they are a VERY GOOD QUALITY unit. I've heard on more than a few occasions of teh HRC 625's not quite flowing to spec.

A hacked 2G MAS? Don't even go near it. NOTHING on the 2G MAS should be hacked, especially at lower power levels. You might be able to get away with taking out the side HC's only, but that's about it. 2G MAS is good up to about 400whp, then it could possibly start missing counts.

For a total of $500 ($300 = Translator + GM MAF + couplers/clamps, along with $200 for a decent used AFC), it's a very easy system to use. The MAFT will get you very close to where you need to be, while the AFC will dial it in on the nose for you. The MAFT adjustments are VERY sensitive. They only allow for +/- 5% changes, while AFC allows for 1% changes. Also, those changes made by the MAFT are more drastic since the unit seems to be more sensitive.

I'd start with something easy to use and simple to learn on, then move on to something that allows for greater parameter controls, such as a standalone, or an E-manage.

Mike

 

[23109 N8]

Thank you everyone for your input so far.

I already have a brand new S-AFC, so I will install that.
And it seems that I will be purcasing a GM MAFT and Translator.

Is it the concensus that 660cc's would be best?

Are denso's the only recommendation?

 

[GRNDSM]

>Bashing a product that you have no first hand knowledge of is
>shameful.

But I did have first hand experience of watching my friends spending over $2k (when it was all said and done) on AEM EMS and then regretting it... Take it as such…

Leon
RR

 

[jdmawd]

Originally posted by Slappster


Have you even used the ems? The bugs are a minor drawback that can be solved with downloads or by anyone whose used the system for a while. Theres a reason why extremely high powered supras, dsms and other groups are having great success with aem.

Granted they say its plug and play which isn't true unless the car is completely stock. This system is only for those that have the time to learn.

Dude do you have a AEM EMS? That's right you don't even have a dsm(we know we know you had one) Leon has gone faster then you will ever go and has done more in his dsm then Most. How dare you question his suggestions. You have no first had experience with anything being discussed. Quit magazine racing and add something relevant to this thread or simply BE OUT. Leon suggests the HKS VPC, and i agree it simply works nuff said.

 

[23109 N8]

What brand injectors are reccommended (or not reccommended)?

 

[TwoLiterV8Eater]

Denso's are definitely the best quality in my opinion (it's what i use personally) but I suppose there are alot of cars out there using RC's or other brands. Supposedly the new Injector Clinic injectors are pretty good, but I dont have any first hand knowledge of anyone running them.

 

[Kevin Jewer]

My 2g sensor, unhacked (screw out flush though, small change) started to miss counts as it approached 50 lbs/min. Which is right where the limit seems to be, 380 g/sec or 50 lbs/min. Thats a good bit of power, so the 2g sensor is defintely good. But by switching to the GM maf in blowthrough, I saw MAJOR gain in the lag department. ~200 rpm faster in boost threashold, and over 1000 rpm faster on the 2-3/3-4 shift. So even though it doesnt miss counts, its a decent restriction still at high flow levels. Just a little more info...

 

[23109 N8]

So, GM MAFT is for sure, I have SAFC, going with the hahn racecraft 625cc injectors unless i am convinced that 660's would be necessary.

95GSXracer is recommending the MAFT as a blow-through?
How does it do as pull-though vs. blow through?
I am at a point where my custom piping can be set up either way.

I would think that a blow through MAFT would be more restricive than a pull through, but obviously blow through would be more accurate.

 

[NOSLO2PT0]

If you can afford it, get the Denso's. I'd buy a used set of Denso's before I would get new HRC 625cc, in a heartbeat. As for the blow-thru/draw-thru method, both ways work. The amt. of restriction (if any) is the same either way. Practially NONE!! That's why it's an upgrade, due to the restriction the 2G MAS presents once you hit a certain hp limit.

And to be quite honest, if you are only going with a 16G, a 2G MAS setup is cheaper and will flow plenty of air for your applications, but if you are hellbent on the MAFT, go for it.