I could have sworn somebody was having a GB on them at http://www.groupbuy.com for $80 plus shipping but i can't find it anymore. Cheapest i can find now is $165 at good o'l summit racing.
I meant also maybe he could use the RRFPR to get a little more HP out of the 370's without having to upgrade. Or like i said maybe make a 3" ID MAF to run 480's.
KA-T Dyno'd: Hacked MAF vs JWT
I think not. You need to relate the % increase of the injectors to the % increase of the AREA of the MAF. Not the diameter.SingleCamSam wrote: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"?
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SingleCamSam
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Exactly. That's why the diameter originally calculated by Orion was way too big, because area wasn't taken into account. I think the original method was to increase MAF diameter 37% to run injectors that were 37% larger. Turns out you only need to increase it 12.5%, and all else being equal another 12.5% in diamteter should increase the area accordingly to allow another 100cc.
Theoretically you would have to run a 17% bigger diam to have 37% bigger area, but I'm sure Orion had some trial and error on there to run the 370cc injectors.
So theoretically you would need a 33,4% increase to run 480cc injectors. Which as you can see is not exactly a 17%*2=34% increase.
What I mean/meant before is that increase need to be calculated from the orginal area/ID.
Hope I explained myself.
Code: Select all
ID Inc Area Inc Inj2.44" 4,676"^22.75" 12.7% 5,940"^2 27% 343cc2.86" 17.0% 6.406"^2 37% 370cc3.08" 26.2% 7,451"^2 59% 430cc3.26" 33.4% 8.323"^2 78% 480ccWhat I mean/meant before is that increase need to be calculated from the orginal area/ID.
Hope I explained myself.
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aleph1
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Ok, so let me get this straight, for a good daily driven 250whp setup:
-2.75" ID Hacked MAF (To make sure, this is where you get like PVC piping and cut a hole and put the MAF sensor in and seal it up right?)-370cc Injectors-SAFC-II-BTM controller
Right? If so, this would be perfect for me. Relatively cheap, decent control, and makes more power than a JWT =)
-2.75" ID Hacked MAF (To make sure, this is where you get like PVC piping and cut a hole and put the MAF sensor in and seal it up right?)-370cc Injectors-SAFC-II-BTM controller
Right? If so, this would be perfect for me. Relatively cheap, decent control, and makes more power than a JWT =)
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SingleCamSam
- Posts: 498
- Joined: Sun May 11, 2003 4:37 pm
Quote »Hope I explained myself.[/quote]
Yup. It's basically what i said except i think you explained it a little better.
Quote »Right?[/quote]
I don't think you'll need the AFC. I'd agree with WD and say he's not running THAT lean when boost first comes on. If you wanted you could probably make it slightly richer with an RRFPR for cheaper. Of course it depends on what margin of safety you wanted.
Yup. It's basically what i said except i think you explained it a little better.
Quote »Right?[/quote]
I don't think you'll need the AFC. I'd agree with WD and say he's not running THAT lean when boost first comes on. If you wanted you could probably make it slightly richer with an RRFPR for cheaper. Of course it depends on what margin of safety you wanted.
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aleph1
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Well, I know the AFC is sort of optional, but I think it wold be a good investment seeing as I will probably upgrade to 550cc injectors and a Z32 maf when the boost bug bites....as well as more detailed control of the fuel with the hacked setup. But I understand what you mean, I will probably purchase an AFC later, but the hacked maf and BTM should be fine I suppose.
On another note, I have an S13 and I hear its very hard to hack the S13 maf, and the S14 maf doesnt work that great on the S13, correct? Any ways around this problem?
On another note, I have an S13 and I hear its very hard to hack the S13 maf, and the S14 maf doesnt work that great on the S13, correct? Any ways around this problem?
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240marcuSX
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E46 M3
aleph1 wrote:Ok, so let me get this straight, for a good daily driven 250whp setup:
-2.75" ID Hacked MAF (To make sure, this is where you get like PVC piping and cut a hole and put the MAF sensor in and seal it up right?)-370cc Injectors-SAFC-II-BTM controller
Right? If so, this would be perfect for me. Relatively cheap, decent control, and makes more power than a JWT =)
No need for the hacked MAF if you are gonna purchase the SAFC-II (specially the II) anyway. The hacked MAF is used to change injector sizes in a very cheap way, but if your gonna dish out the dough for the SAFC then you don't need the hacked MAF.
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aleph1
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huguetpj wrote:No need for the hacked MAF if you are gonna purchase the SAFC-II (specially the II) anyway. The hacked MAF is used to change injector sizes in a very cheap way, but if your gonna dish out the dough for the SAFC then you don't need the SAFC.
I see, but wouldnt the larger diameter MAF housing flow more air? Or is the stock MAF not much of a restriction anyway?
The problem with the stock MAF is not how much of a restriction it is on the air flow but the maximum amount of air flow it can measure. In the case of the stock KA MAF the max amount of air measured will net you about 250HP. If you want to go past this you'll need either a Cobra MAF (350HP) or Z32 MAF (500HP). I think JWT can do both, the SAFC II can do the Z32 MAF conversion.
Now the idea behind the hacked MAF is to have more air go by the heated element without it measuring the air. Because of the bigger area, theoretically, a hacked MAF would be able to measure more air than a stock MAF before reaching the 5V max value. How much? Dont' know
Now the idea behind the hacked MAF is to have more air go by the heated element without it measuring the air. Because of the bigger area, theoretically, a hacked MAF would be able to measure more air than a stock MAF before reaching the 5V max value. How much? Dont' know
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aleph1
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huguetpj wrote:The problem with the stock MAF is not how much of a restriction it is on the air flow but the maximum amount of air flow it can measure. In the case of the stock KA MAF the max amount of air measured will net you about 250HP. If you want to go past this you'll need either a Cobra MAF (350HP) or Z32 MAF (500HP). I think JWT can do both, the SAFC II can do the Z32 MAF conversion.
Now the idea behind the hacked MAF is to have more air go by the heated element without it measuring the air. Because of the bigger area, theoretically, a hacked MAF would be able to measure more air than a stock MAF before reaching the 5V max value. How much? Dont' know
Well I know how the hack maf setup works. I was originally planning on stock, maf, 370cc, and afc2...later upgrading to the z32 maf, but the hacked maf setup seems like it would be a more cost effective first step than springing for the afc2 right off the bat. then I would upgrade to the z32 and afc2 at the sametime. The only real issue I have is if the hacked maf setup is truely daily drivable without a hitch....
Like I posted eariler, is the hacked maf an option for me? as I own an S13.
Sounds like a good plan.aleph1 wrote:Well I know how the hack maf setup works. I was originally planning on stock, maf, 370cc, and afc2...later upgrading to the z32 maf, but the hacked maf setup seems like it would be a more cost effective first step than springing for the afc2 right off the bat. then I would upgrade to the z32 and afc2 at the sametime.
Quote »The only real issue I have is if the hacked maf setup is truely daily drivable without a hitch.... Like I posted eariler, is the hacked maf an option for me? as I own an S13. [/quote]
I'm still hoping Orion jumps in here cause that I can't answer
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:: orion ::
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Yo...
Allright - In terms of daily driveability, it's IDENTICAL to the JWT setup, except boost comes on a little stronger (it's a little more lean through the midrange with a 2.75" ID). There's no bad idle, no roughness, no backfire/popping, nothing.
Only thing that could possibly affect the driveability of it is the retarded base timing.
But the possible issues I see:
2.75" ID runs pretty lean through the midrange, and even a little lean for my tastes at redline, so that's a concern. I plan on making another 2.6-2.65" ID MAF once my wideband gets here...should be this week.
And the lean condition right at thge torque peak could cause a blow-up once things get hot...i.e. track day - Both the open track events I've run recently (Solo I type events, both 60-70 second runs, on a road course, no cones) I've run race gas for safety. Still not 100% confident that I won't kill it with hard abuse and pump gas (93).
And in cold weather it seems to run lean all the time - I am hesitant to boost hard on cold nights (50-60 F) b/c the autometer blinky A/F gauge shows a few green with some orange lights illuminated...which on the dyno was 13.5-15:1 A/F on the wideband. I don't know if it's the gauge, or the car's actually running lean...we'll know once the wideband gets put in.
So how to solve these issues???
I'd say run a 2.6" ID MAF for starters and check the A/F with a wideband. It'll be a little rich up top, but good through the midrange - From what I can tell, hacking the MAF is a non-linear change, just as the voltage curve is non-linear, so there is error introduced. So it's more lean when the airflow is low, and then correct as the airflow increases...
Anyway, this is all FYI - Proceed at your own risk...we can't say it's tried and true'd, but it makes good power (that's the easy part), and seems safe enough...
Let me know what you decide to do...
Later - Brian
Allright - In terms of daily driveability, it's IDENTICAL to the JWT setup, except boost comes on a little stronger (it's a little more lean through the midrange with a 2.75" ID). There's no bad idle, no roughness, no backfire/popping, nothing.
Only thing that could possibly affect the driveability of it is the retarded base timing.
But the possible issues I see:
2.75" ID runs pretty lean through the midrange, and even a little lean for my tastes at redline, so that's a concern. I plan on making another 2.6-2.65" ID MAF once my wideband gets here...should be this week.
And the lean condition right at thge torque peak could cause a blow-up once things get hot...i.e. track day - Both the open track events I've run recently (Solo I type events, both 60-70 second runs, on a road course, no cones) I've run race gas for safety. Still not 100% confident that I won't kill it with hard abuse and pump gas (93).
And in cold weather it seems to run lean all the time - I am hesitant to boost hard on cold nights (50-60 F) b/c the autometer blinky A/F gauge shows a few green with some orange lights illuminated...which on the dyno was 13.5-15:1 A/F on the wideband. I don't know if it's the gauge, or the car's actually running lean...we'll know once the wideband gets put in.
So how to solve these issues???
I'd say run a 2.6" ID MAF for starters and check the A/F with a wideband. It'll be a little rich up top, but good through the midrange - From what I can tell, hacking the MAF is a non-linear change, just as the voltage curve is non-linear, so there is error introduced. So it's more lean when the airflow is low, and then correct as the airflow increases...
Anyway, this is all FYI - Proceed at your own risk...we can't say it's tried and true'd, but it makes good power (that's the easy part), and seems safe enough...
Let me know what you decide to do...
Later - Brian
ive got an idea for fine tuning the hacked MAF without a AFC. would adding something in the piping, right where the MAF is located, to reduce the overall area that air can flow through the hacke MAF act just as decreasing piping diameter? i cant really think of any material that would be good for this right now. only thing that i think might go wrong would be possibly the air increasing volocity only at the MAF because of the decreased area for the air to flow through which would pretty much cancel out the point of this, but im not sure if that would happen. other than that i imagine it would interupt with air flow quite a bit if it wasnt a nice smooth object added to the wall of the piping. hope i explained myself enough cause i have to go to work right now. be back on later tonight!
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aleph1
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fiznat wrote:pretty sure the hacked MAFS is only an option for s14 MAFS, s13s were made differently...
if it is pretty much impossible to have a hacked maf setup on S13 that sucks...It was a good plan, but I guess Ill have to go back to AFC2 and 370cc injectors. Later to upgrade to 550cc injectors and Z32 mafs.