Suction type or blow through maf?

bradystrib · Post by **bradystrib** » Mon Dec 08, 2008 8:36 pm

Okay, so if you didnt know yet, I have a 240. I plan on building a KA-T. Already have some 550cc injectors, z32 maf, gt2871r (or stock sr t25),safc,blitz dd bov, some more stuffs......uhm so anyways yeah, I have heard different things as far which is better. I have heard about stalling issues and idle issues with a suction style. I also hear about exploding MAF's with the blow through. I don't plan on running more than 15-17 lbs with the 2871 on high boost and maybe 8-11 on low boost. Any thoughts???

JJ Alfano · Post by **JJ Alfano** » Mon Dec 08, 2008 8:54 pm

stock ecu or stand alone? if its stock with safc, i would just run suction since its easier

the bogging is from the a/f ratio going rich when the blow off valve releases

P.Haire · Post by **P.Haire** » Mon Dec 08, 2008 9:05 pm

blow through is real deal race car stuff.

foilman · Post by **foilman** » Mon Dec 08, 2008 9:07 pm

Well, I've got a lot of experience there.
DO NOT RUN A STOCK SR TURBO ON YOUR KA. It's not even big enough for the SR it comes on and it will probably be worn out and tired when you get it anyway... but even if it's brand spankin' new, seriously, don't do it.

My FOERST turbo setup back in '02 was blow through and so were the 2 after that. I even tried the 3rd setup both ways at JWT's behest since they supplied the ECU, but after a few days was like, "no, fuck this, it works tons better my way". I never had a problem exploding the MAF, s14 or Z32. The response, stumbling, mileage, all better blow through. I have seen 1 MAF popped by boost, but he was running a lot. I was usually running 9-15 psi, 18 for a little.

bradystrib · Post by **bradystrib** » Mon Dec 08, 2008 9:18 pm

foilman wrote:Well, I've got a lot of experience there.
DO NOT RUN A STOCK SR TURBO ON YOUR KA. It's not even big enough for the SR it comes on and it will probably be worn out and tired when you get it anyway... but even if it's brand spankin' new, seriously, don't do it.

My FOERST turbo setup back in '02 was blow through and so were the 2 after that. I even tried the 3rd setup both ways at JWT's behest since they supplied the ECU, but after a few days was like, "no, fuck this, it works tons better my way". I never had a problem exploding the MAF, s14 or Z32. The response, stumbling, mileage, all better blow through. I have seen 1 MAF popped by boost, but he was running a lot. I was usually running 9-15 psi, 18 for a little.

well, good deal then. The 2871r it is. And i think i am leaning more towards the blow through set up. Thanks a ton for the info mr. shorts.

P.Haire · Post by **P.Haire** » Mon Dec 08, 2008 10:56 pm

go bigger.
t3/t4!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

bradystrib · Post by **bradystrib** » Tue Dec 09, 2008 8:48 am

P.Haire wrote:go bigger.
t3/t4!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I've thought about it....arg. I dunno, i like the simplicity of bottom mount stuff....but top mount is ballin...

ChadMK4 · Post by **ChadMK4** » Tue Dec 09, 2008 9:46 am

Then whats the safe psi range for blow through? I've been thinking of this too but I was told that the chance of popping to MAF is to great. I'm gonna be running the 20g. I don't know what amount of boost yet. I would assume 14+. But I know that the bigger the turbo the less boost needed to make more power. I"m assuming because of the volume of air being forced is greater with a bigger turbo.
But that has always confused me too. Because in the end, when it reaches the plenum it's still 14 lbs...? 14 lbs is still 14 lbs right? Anyone got a conclusion to my confusion?

POOPscandal · Post by **POOPscandal** » Tue Dec 09, 2008 9:53 am

its cause pressure =/= volume or something to that effect.

ChadMK4 · Post by **ChadMK4** » Tue Dec 09, 2008 9:56 am

Uum............. What?

I'm not an equation kinda guy. :-*

Post by **andysapp** » Tue Dec 09, 2008 11:41 am

That's right. He's a happy meal and a Blockbuster kind of guy.
Cheap date = FUN date.

kOOpA · Post by **kOOpA** » Tue Dec 09, 2008 12:18 pm

ChadMK4 wrote:What?

the amount of pressure the air is under is not equal to the volume of air going into the motor. saying you're running 20lbs of boost is not saying how much air is entering the motor, it's just saying how dense the air particles will be.

air particles entering the motor = air particle density * air volume

ChadMK4 · Post by **ChadMK4** » Tue Dec 09, 2008 4:16 pm

So it's not based on pressure?

Post by **andysapp** » Tue Dec 09, 2008 4:22 pm

ChadMK4 · Post by **ChadMK4** » Tue Dec 09, 2008 4:58 pm

andysapp wrote:

ok its settled.. ^^next years Halloween costume!!