KA-T Dyno'd: Hacked MAF vs JWT

[:: orion ::]

Cut and paste from this thread on Freshalloy:

- - - - - - - - - - - - - - - - - - - - - - - - - - -

So I finally got on the dyno again today...

Since the last dyno, I've:

Added an intercooler, switched to a standard draw through MAF setup, put in a fresh(er) KA, and played with timing alot...

This time I was out to test the 'Hacked MAF' setup vs JWT Turbo ECU (Stock MAF + 370cc injectors).

Current setup: T3/T4 (57 trim compressor, .63 A/R Stage III wheel on the hot side), RevHard manifold, 2.5" crush bent exhaust (to be gone next week), TiAL 35mm with an MBC set to 8psi, 370cc injectors, S13 cams, GReddy VSPL intercooler, ASP pulley...

The results were as expected:

Hacked MAF: 8psi, stock ECU, 2.75" ID MAF, base timing at 16 BTDC, 4th gear pull = 248rwhp and 255rwtq

JWT: 8psi, stock MAF, base timing at 20 BTDC, 4th gear pull = 239rwhp and 238rwtq

But the big difference is the torque = 20ft/bs more from 3500 until 5000 with the Hacked MAF setup...

And it was the clear winner across the board - At no time did JWT make more power.

The A/F was interesting:

Hacked MAF: Started at stoich when I hit WOT and slowly but steadily dropped to mid-to-high 12s by 4200...and continued along at 12.5:1 until redline.

JWT: Dropped to 12:1 at 2700 when I went to WOT...and continued a slow rise to 12.5:1 at 5500, and then off to 13:1 at 6300.

- - - - - - - - - - - - - - - - - - - - - -

And here's the chart:



Later - Brian

[Structure240sx]

impressive

[DriFt3r]

how do you hack the maf?

[Structure240sx]

theres a couple threads on it already hes explained in detail

[SingleCamSam]

Wow. Now that's not what i expected to see when i opened the thread. JWT is starting to look more and more like a rip-off. But isn't 2.75" disproportionate to what it should be to run injectors that are 37% larger than stock?

I'm wondering now how the dual MAF setup will work with 550's.

[Projex240]

Good post. I like the guys who are willing to try something new.

Can you post dyno sheets?

[:: orion ::]

From the original post above:

[quote=" :: orion :: And here's the chart:



[/quote]Hehe...

Later - Brian

[Xero]

wow...very nice...I thought it'd be more accurate, then imagine what you could do with a AFC-II, do some fine tuning if needed, (doesn't look like it was) that's great for being $10 at Home Depot, compared to $600 for the ECU,

[Projex240]

You forgot some very important things.

1- SPEED LIMITER!!!!2- REV LIMITER!!!!!3- adjusted fuel and timing curves for boost. afc's dont do that for those who dont know.4- you can only run 50lb'ers at most...and good luck tuning those with an afc. 72 lb'ers wont run without JWTS extra circuit board and resistors.Hacked mafs may make horsepower on some cars, but finely tuned ones will not benifit at all, its too much of a risk.And besides- I would never put ANYTING hacked on my ride- why would you guys?

[SingleCamSam]

If it works, why wouldn't you want to save the money? For 370cc injectors this seems like the best option with a little afc tuning.

Also another thing. Apparently the stock ECU will run a Cobra MAF and 50lb injectors, but again an AFC is needed to tune up the idle.

[TurboKA37]

wow! that is very impressive. its like the hacked MAF powerband was a good 1000 rpm earlier than the JWT. the JWT never appealed to me. i always thought it was over priced and u also have to wait for it to get tuned. Project240: ur right about a hacked MAF running large injectors cuz the intake piping would get huge but then again if ur serious about power and need that large of injectors ud be better off with a stand alone rather than a hacked or JWT.

are those runs done on the same engine just one run with the hacked set-up and the other running JWT? what surprised me the most was the A/F ratio, i think that is mostly cause JWT would rather run rich and safe than risking it being too lean

[Xero]

as far as what was stated about the ignition timing, just back it off as much as stock will allow, that's just fine...if you rmaking more power, than like was said, the Hacked MAF is not the best way to go,

[:: orion ::]

As I've stated before, I would reccomend this for 370s at the largest...any more power potential and you need precise timing control.

And TurboKA37 - Yes: Same car, same day, same dyno, etc...I just swapped ECU and MAFs, and set timing as needed.

You forgot some very important things.

1 - SPEED LIMITER!!!!2 - REV LIMITER!!!!!3 - adjusted fuel and timing curves for boost.

...I would never put ANYTING hacked on my ride- why would you guys?

1) Cut 2 wires (or put a switch on them) and it's a non-issue

2) You don't need more revs from a KA...you can see the power is dropping quickly after 6K. Sure, it'd be nice, but not needed for a quick street car.

3) Stock curves with a retarded base is FINE for ~250rwhp..."refined" timing ala JWT lost over 20ft/lbs, as you can see on the chart.

And ANY piggyback does the same thing..hack the stock ECU and change something. I didi it by a physical means, others use electronics and technology...

6 of one, half dozen of another...

Later - Brian

[HolyShiznit]

And besides- I would never put ANYTING hacked on my ride- why would you guys?

Just because you won't do it doesn't mean that it doesn't work. Proof is shown in the dyno and on Orion's car. And like what he said any piggyback does the same thing. *shrug*

[Projex240]

yep, but a hacked maf wont do anything in the long run...its only a temporary fix for the time being. most folks want more power than stock timing curves can offer. Retarding the timing that much all the time would cause loss in daily driveability. Which to me, is like taking steps backwards. Have you treid to see if the larger maf would run the same numbers with the jwt ecu. what about a z32 or cobra maf? The comparison is a good one, but not fair. With the stock maf in place, there was a huge restriction in the intake piping. The computer can only compensate for what airflow comes in...Also, try that hacked setup and see what numbers come up. That may be interesting. Its not a good comparison to test 2 different ecu's. Its like apples to oranges. Test the ecus on the same setups, and see what you get. Saying that the JWT setup made less power at no time was a no brainer- it was at a disadvantage. It couldnt flow as much air through the stock maf sensor due to the size. I also saw that the timing wasnt the same on the two test runs. That also puts jwt at a disadvantage. would didnt you bump the base timing up(turn the distributor) to have it get to 16 deg? That would have also helped to level the playing field.

One of the first rules when conducting a test/experiment, is to make sure that all of the variables are the same to ensure that there are no advantages to either side. -airflow-timingYou cant compare the ecus because one was run the way it was supposed to be( the jwt with stock maf)the other was run in an altered state( larger maf ID).they both should have been run stock or both run altered.

[Projex240]

i forgot one thing- when you put a switch on your car to disable the speed limiter, doesnt that lose the tach?I think that would suk to be able to go as fast as you want to but not know when to shift.

[huguetpj]

i forgot one thing- when you put a switch on your car to disable the speed limiter, doesnt that lose the tach?I think that would suk to be able to go as fast as you want to but not know when to shift.

I you remove the speed sensor on the transmission you would loose the speedometer. If you put switches or cut the wires near the ECU, that would be after both tack and speedometer, then the latter won't be affected. But then the ECU won't know your speed/revs and I think that would affect the fuel/timing curves, not sure though.

[:: orion ::]

yep, but a hacked maf wont do anything in the long run...its only a temporary fix for the time being. most folks want more power than stock timing curves can offer.

Projex, you just don't get it...

The Hacked MAF is a substitute to the JWT setup, or an AFC...it's a means to run larger injectors on the stock ECU.

Quote »1) Retarding the timing that much all the time would cause loss in daily driveability. Which to me, is like taking steps backwards.

2) Have you tried to see if the larger maf would run the same numbers with the jwt ecu. what about a z32 or cobra maf?

3) The comparison is a good one, but not fair. With the stock maf in place, there was a huge restriction in the intake piping. The computer can only compensate for what airflow comes in...

4) Also, try that hacked setup and see what numbers come up. That may be interesting. Its not a good comparison to test 2 different ecu's. Its like apples to oranges. Test the ecus on the same setups, and see what you get. Saying that the JWT setup made less power at no time was a no brainer- it was at a disadvantage. It couldnt flow as much air through the stock maf sensor due to the size.

5)I also saw that the timing wasnt the same on the two test runs. That also puts jwt at a disadvantage. would didnt you bump the base timing up(turn the distributor) to have it get to 16 deg? That would have also helped to level the playing field.

6) One of the first rules when conducting a test/experiment, is to make sure that all of the variables are the same to ensure that there are no advantages to either side. -airflow-timing

7) You cant compare the ecus because one was run the way it was supposed to be( the jwt with stock maf)the other was run in an altered state( larger maf ID).they both should have been run stock or both run altered. [/quote]

1) It's not noticeable in the 1000-3000rpm range...and then boost hits and the timing is appropriate.

2) If you run the larger "Hacked MAF" with the JWT ECU, it would run VERY lean...since the tube is larger, it doesn;t 'see' all the air, and wouldn't give enough fuel.

3) Stock S14 MAF is 2.453" ID - Turbo inlet is ~2.5" ID...hardly a restriction.

4) Makes no sense...

5) JWT had MORE base timing, which is more potential to make power!!! Yet it made less!!! The point is, if you run 20 degrees base with the stock ECU at 8psi, it will blow up sooner or later. JWT has conservative timing maps built in, so it can run stock base timing. The test was fair b/c with the stock ECU and retarded base timing, the #s are similar to JWT under WOT pulls, like dyno runs.

6) HP is dependent on airflow, so more HP = more airflow. but it's not as if we had the MAF pulling air through a straw...and I adjusted the base timing as to eqalize the total timing under boost at WOT...what more can you ask for???

7) That's like saying if you dyno and mmake power with an AFC you're cheating...if you run stockECU and MAF and 370s you're WAY too rich. Hacked MAF and JWT with 370s is WAY too lean. One is a sytem, the other is a comparable system. They were tested back to back, one came out ahead.

I think you may be confused as to what the Hacked MAF is supposed to be used for...it's a REPLACEMENT to JWT for less than ~250rwhp, or the limit of 370cc injectors. And it just happens to make more power in a FAIR test.

Later - Brian

[TurboKA37]

i think i can explain this to him a little better. both the Hacked MAF and JWT ECU retune are ways to make sure the engine runs a correct A/F ratio with the injectors u use. the hacked MAF does this by increasing the same % of air and fuel that enter the engine without the ecu noticing a difference, so the engine runs at almost stock A/F ratio. while the JWT ecu makes a good A/F ratio by retuning the ECU's fuel map for larger injectors. if u were to remove the larger diameter intake on the hacked MAF set-up u would essentially be removing the device that keeps a good A/F ratio. i could go on but dinner is ready and i need to eat.

[SingleCamSam]

Orion, would there be a difference in part-throttle or cruising drivability between the JWT and hacked maf?

[:: orion ::]

The part throttle was lackluster with JWT...from the "data logging" I did, JWT drops timing to 18-20 total with ANY stab of the throttle, even if only part throttle. That kinda makes it respond slowly until it decides either:

a) You're not bosting and need more timing.b) You're boosting and the timing should remain low for safety.

The hack, on the other hand, has quite good throttle respnse b/c the stoich (maybe even lean) condition it runs in and timing. That's really my only concern with it - Lean (13.5:1) and probably a little too much timing right at the torque peak - Could cause a little detonation if the conditons aren't right.

That's the only place where I'd like adjustability...fuel tuning. I'd like to be able to add a little across the 2500-4000 range...

If you pound the gas, it reacts well, and there's no risk IMO...but at part throttle (I like to feed it gas and let it hold 1-2psi while the revs run up) around town, so the wastegate doesn't dump all the damn time.

Anyway, long-answer-short...it's more lively with the "Hacked MAF", but probably at the expense of a little safety.

Later - Brian

[SingleCamSam]

Think it could be "enriched" so to speak through the 2500-4k range by changing the diameter of the MAF? I'm really interested in experimenting with a set-up like this.

[SingleCamSam]

So by increasing the stock MAF diameter 12.5% to 2.75" you're able to run injectors that are 100cc's larger than stock. Theoretically wouldn't this mean you'd be able to run 480cc injectors by increasing the diamter another 12.5% to 3.08"?

[WDRacing]

The one thing I think Brian has forgotton, well not really forgotton, just not used, is a simple $145 boost dependant timing retard controller. Crank the timing back to 20 and I KNOW you'll make more power then the JWT. You will also more then likely be able to run more boost, since your no longer dealing with such a high base timing curve. So for $155 you get all the timing control and the ability to run 370's. Not a bad damn deal by any means. Is it better then a standalone? No, but then again nowhere in this thread is it claimed to be. Brian has done us all a great service by dyno testing, its allows everyone to see other options and thats really all he's trying to do here. So allow me to be the first...Thx Bri.

WD

[:: orion ::]

Yeah...For me, it's either that...or run the a 3" hacked MAF with the JWT computer and pop in some 550s.

That way I have a MAF that's not maxed until ~12psi, enough fuel for 15, and timing control that's decent for that kind of boost.

But in any event, your welcome

Later - Brian

[cosmo]

The one thing I think Brian has forgotton, well not really forgotton, just not used, is a simple $145 boost dependant timing retard controller. Crank the timing back to 20 and I KNOW you'll make more power then the JWT. You will also more then likely be able to run more boost, since your no longer dealing with such a high base timing curve. So for $155 you get all the timing control and the ability to run 370's. Not a bad damn deal by any means. Is it better then a standalone? No, but then again nowhere in this thread is it claimed to be. Brian has done us all a great service by dyno testing, its allows everyone to see other options and thats really all he's trying to do here. So allow me to be the first...Thx Bri.

WD

So if you get this part, and you want to only run 8-10psi with 370's this is all you need? Who makes this?

[240_2NR]

hey what about e-manage that retards timing and such its like $300 or something like that and u could use lager injectors,Because the GReddy turbo kit comes with it and 370cc injectors

[SingleCamSam]

The universal MSD BTM is only $80, so that 's even better. Orion have you ever considered using an RRFPR to get a little more out of the 370's and richen up the area where boost first starts to come on? Or what about just jumping up to 3" on the stock ECU to run 480-500cc injectors?

I can't believe this thread just faded away.

[hannibal]

Finally some good dyno evidence that the hacked MAF works great for lower boost levels. The word "hacked" scared me for awhile. But now I'm understanding the benefits. Thanks Orion (the hacked MAF pioneer... I think).

Just say no to JWT!!

Jay

[WDRacing]

JWT isn't a bad thing, it allows a non experienced tuner to install a turbo and simple bolt ons without having to do anything that will destroy his engine. The "Recalibrated" MAF is a great way to get those few extra lbs of boost we all want.

I agree with Brian that 370's are the max I'd use with the Recal'd MAF setup. A RRFPR say 2/1 ratio might work, but his AF ratio's aren't that lean. I've always found the most power to be made at 12.7 while still maintaining any safety net. SO he's sitting right there.

SingleCamSam where did you find the MSD BTM for $80. I couldn't find it under $145. That will help out a ton.

WD