Boosting or Timing Issue ??

[72nismo]

Stock KA24DE,Stock MAF,T3 Turbo set at 7lb boost,JWT ecu,370cc Inj,Intercooler,BOV,,3" pipe w/Apex exhaust on a Datsun 510.
Here's my problem,seems like after I added the 3" exhaust I started noticing that when I am boosting and hit 7 lbs the boost just drops when before it didn't do that.So I am not sure if it has anything to do with the 3"set up or something else is going wrong. Boost & Rpms completely drop.I want to say at about 4500 to 5000 k. Any Ideas??Pic of my set up.
http://i129.photobucket.com/albums/p235/72nismo/IMG_0382.jpg

[slothonaleash]

get a z32 maf...this could or could not be the root of your problems, but with any ka-t setup you should upgrade your mass air flow sensor

[KA-T_240]

That is some crazy Intake piping!

Let me get this right, your boost drops off after you switched to 3inch exhaust? Have you tried using the exhaust you used to have and seeing if problem still exists? Changing exhausts effects backpressure which would change spooling. But I don't think it would cause you to start dying out up top. The exhuast size shouldn't affect your timing.


What do you use for boost control? Try adding a MBC and Getting it set for 7-8psi it mayhelp you hold boost. Check to make sure your turbo and WG are working properly.

[emersonLP]

Well do the free stuff first, check for timing, boost leaks, etc but I tend to agree with sloth, I say it is fairly likely you are maxing out the MAFS. Try getting an n60 or n62.

[KA-T_240]

he is not maxing out his maf. maxing out your maf isn't going to cause your boost to fall off. It will more then likely put you in limp mode.

my old car had a 50 trim and 10psi on stock maf and made 260whp with no issues. 7psi on that turbo is nowhere neat maxxing out that turbo.


Also, check for boost leaks, exaust leaks, oil in your IC pipes, and like i said earlier try swapping back to the other exhaust if you can.

[emersonLP]

I could be wrong, but I think if he is maxing his MAFS the car will run really rich, and power will drop off. I'm no KAT expert though, so if the KA MAFS can run 10psi and 260hp, then its probably not maxing out.

[GSXRJJordan]

I could be wrong, but I think if he is maxing his MAFS the car will run really rich, and power will drop off. I'm no KAT expert though, so if the KA MAFS can run 10psi and 260hp, then its probably not maxing out.

Maxing the MAF makes the car run lean, because you're pulling in more air than the sensor can read - it basically starts alternating between 5V and 0V, then the ECU goes into "limp" mode.

I agree, that doesn't seem like enough air to max the KA-DE MAF.

The exhaust won't have anything to do with what happens once you hit boost - might delay you hitting boost for a tiny bit, because of less backpressure though.

Your problem is electronic, or leak related.

[72nismo]

Ok so today I adjusted the actuator and I raised the boost to 10lbs car seem to perform normal.I even had my friend test drive and it ran fine until I drove it home it did it to me once.So I thinmk I am going to get a new actuator 1st and check for leaks & maf.

[KA-T_240]

check your timing, and for leaks and plus and all that stuff before spending $$$ on something

[johngriff]

Less backpressure on a large internally gated t3 = wastegate control issues.

Cummon guys...

[72nismo]

So you think the wastegate is to big for turbo??