PDA

View Full Version : Cobra MAF



Sepp
11-11-2001, 09:13 AM
Am looking for some experience/expertise regarding the '93 Cobra MAF. I notice many turbo cars are using them. Some questions on their use with a KA24DET:
Are they plug and play with a JWT ECU mod?
If not, what tuning is involved?
When properly set up, what sort of difference do they make?
At what boost level do they begin to make a difference?
Thanks for any answers you can give.

**DONOTDELETE**
11-11-2001, 09:55 AM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by Sepp:
Am looking for some experience/expertise regarding the '93 Cobra MAF. I notice many turbo cars are using them. Some questions on their use with a KA24DET:
Are they plug and play with a JWT ECU mod?
If not, what tuning is involved?
When properly set up, what sort of difference do they make?
At what boost level do they begin to make a difference?
Thanks for any answers you can give.<HR></BLOCKQUOTE>


Unless you are turbo and over 250whp don't bother.

Sepp
11-11-2001, 10:36 AM
I am on both counts.

**DONOTDELETE**
11-11-2001, 11:54 AM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by Sepp:
I am on both counts.<HR></BLOCKQUOTE>

Ah, okay...didn't want to waste time typing for a NA ka. http://www.freshalloy.com/

To answer your question, the MAF has to be wired to your existing harness. (JWT supplies the diagram)

JWT will have to reprom your ECU for it.

The reason you do it is because the stock MAF is topped out. In other words, it's at max voltage and can't send the proper signal back to the ECU. Whith a bigger MAF, you have more air flow and it is properly calibrating voltage to airflow.

FYI, if you have stock 370cc injectors, they and the MAF top out about the same time. Soooo while the ECU is at JWT you might as well have them reprom it for larger injectors, and possible 4 bar fuel pressure if you are going to need that much fuel for big hp.

There are several Cobra MAF part numbers, so make sure you get the one JWT reprograms for. They sell them, and/or can tell you the part number you need to use.

Good luck.

Q45tech
11-11-2001, 03:20 PM
4 bar fuel [14.7 x4= 58.8 psi] is only 16% more flow than stock [43.4 psi] 370cc x.55 BSFC tops out at 270-280 HP [flywheel with accessories] on a 2.4 roughly [little less than] 255 grams per second of air.
To get this you need at least 10 psi after the intercooler [and no more than 100F output temp] and in each runner.
Plus lots of head work to overcome the valve curtain restriction probably easier to try to force in at 13 psi.

**DONOTDELETE**
11-11-2001, 05:28 PM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by Q45tech:
4 bar fuel [14.7 x4= 58.8 psi] is only 16% more flow than stock [43.4 psi] 370cc x.55 BSFC tops out at 270-280 HP [flywheel with accessories]<HR></BLOCKQUOTE>

I was talking about the 50lb injectors that JWT uses in their 4 bar, Cobra MAF combo. They also do 72lb injectors with the cobra MAF if you feel like making 500whp.

I put down 409whp with an SR20DE, with 50lb injectors, 4 bar, JWT fuel rail, 300zx TT fuel pump, stock lines, stock filter. A/F was a nice safe 11:1 pretty much across the board.

BTW, I know the injector flow rate is measured at 43psi but stock pressure is 36.

[ 11-11-2001: Message edited by: Jay Hass ]

11-11-2001, 07:34 PM
Nope, it's 34 psi at full vacuum, 43 psi with the vacuum line to the regulator disconnected.

Asad

<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by Jay Hass:

BTW, I know the injector flow rate is measured at 43psi but stock pressure is 36.
<HR></BLOCKQUOTE>

**DONOTDELETE**
11-12-2001, 06:17 AM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by asad137:
Nope, it's 34 psi at full vacuum, 43 psi with the vacuum line to the regulator disconnected.

Asad

<HR></BLOCKQUOTE>

Duh! &lt;slap&gt; Thanks, I had a brain cramp. http://www.freshalloy.com/

240sxTurbo
11-12-2001, 06:42 AM
Anyone FWIW, the same MAF is used on the 93 SC TBird, so its possible to pick one up in a junkyard, I've heard tale of getting a re-man from Autozone, and returning your KA one as a core, costs like $85....much cheaper than JWT.

joel burke http://www.unstable-hybrids.com

**DONOTDELETE**
11-12-2001, 07:08 AM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by 240sxTurbo:
Anyone FWIW, the same MAF is used on the 93 SC TBird, so its possible to pick one up in a junkyard, I've heard tale of getting a re-man from Autozone, and returning your KA one as a core, costs like $85....much cheaper than JWT.

joel burke http://www.unstable-hybrids.com<HR></BLOCKQUOTE>

Yes on the SC bird. And in fact, many fords used the Cobra/GT MAF..

Sepp
11-12-2001, 07:23 AM
So, as I understand the responses, unless I go above 9 psi boost, where JWT says the 370cc/min injectors and its tuned ECU max out, there would be no performance improvement to go with the Cobra MAF. But, if I decide to up the boost to beyond this, it would make sense to install the bigger MAF, 550 injectors and have JWT recalibrate the ECU accordingly.

**DONOTDELETE**
11-12-2001, 07:37 AM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by Sepp:
So, as I understand the responses, unless I go above 9 psi boost, where JWT says the 370cc/min injectors and its tuned ECU max out, there would be no performance improvement to go with the Cobra MAF. But, if I decide to up the boost to beyond this, it would make sense to install the bigger MAF, 550 injectors and have JWT recalibrate the ECU accordingly.<HR></BLOCKQUOTE>

Sounds right to me.

**DONOTDELETE**
11-12-2001, 09:57 AM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by 240sxTurbo:
I've heard tale of getting a re-man from Autozone, and returning your KA one as a core, costs like $85....much cheaper than JWT.

joel burke http://www.unstable-hybrids.com<HR></BLOCKQUOTE>

Hmm...I wonder who did that?

Dennis