Forge Valve install/impressions

[shadrag]

Less VTA discussion, more forge impressions.....pwetty pwease?

 

[subparpunk03]

http://www.mazdas247.com/forum/showthread.php?t=123657477

I stand corrected on the temp issue, but its not quite 200 after the intercooler, its 80 to 130.

80 is ambient in my book, it gets up to 130 at the hottest, so its not ambient.

We're both right. And don't feed me BS about "oh its 100-130 with no IC fan" bc when you're driving, the car is MOVING. NO IC fan is not the scenario we are talking about here.

 

[SuperStretch18]

if i remember correctly cobb tuning did a test of the intake temp after turbo was like 260 degrees and post intercooler like 190degrees, its somewhere on tis forum., so 16psi of 190 degrees being shot back into the intake tract is a colder than room temp? you guys are brilliant..lol

Not trying to encourage this arguement, but just keep in mind that gases cool as they expand, so even if the cold pipe was 190 degrees, the gas expanding out of the BPV would still wind up being much cooler. And again, it's not a constant flow of 190 degree air, it's a half second burst that would clear the intake tract very quickly.

I agree that the discussion is pointless though. If someone has a dashhawk, they can log IAT & MAF Temp with and without VTA to see if there is a significant difference one way or another...

 

[subparpunk03]

also, notice how little the power output changes when the air temp in the cold pipe is 170 vs 100.... thats a 70 degree difference, and you're going to tell me that VTA makes a noticeable difference in power levels?

It may be b/c it makes the car run a little richer, but not b/c of temp.

 

[patty AT forge]

it does dude, the power is much sharper, i acutally put my recuiric back on yesterday cuase of the farting between shifts i don't want to blow out my cats, Jordan at cp-e is making me a map for the standback to fix that. Car feels signifacnlty slower by comparison. That slam of of boost is gone, definatly a big diff in power. With the vta the boost is hard and sharp.

I don't doubt you are seeing a difference in power but it is my suspicion that is is a result of the factory valve leaking (as it is known to do) and your VTA valve not leaking. The temperature of the charge air probably plays little part in it and if it does it isn't a result of the VTA aspect of it (fresh air versus twice compressed air) but rather from the turbo being in a slightly more efficient part of its map due to the reduction of shaft speed from the decrease in the leak. Make sense?

 

[sleeper3]

dude put a dash hawk on it and watch the intake air temp sensor. I guarantee it's not changing much.

 

[Powerslave]

could be true i did gain at least a pound of boost from it holding more, but the boost feels much stroger than just one pound of boost the torque really slams you back in your seat... like some time i run 17.2psi and sometimes 18.2 can tell a diff in power , but i would say running vta is "double" that really. The car is signifcanlty less powerful running recuric. that my butttdyno opinion..lol

 

[Ryz]

???

I am not sure what you are trying to imply here.

That you don't know what you're talking about.

 

[subparpunk03]

That you don't know what you're talking about.

oh. ok. I guess I'm wrong since I have an opinion on the sound of the valve


(fu)

 

[patty AT forge]

could be true i did gain at least a pound of boost from it holding more, but the boost feels much stroger than just one pound of boost the torque really slams you back in your seat... like some time i run 17.2psi and sometimes 18.2 can tell a diff in power , but i would say running vta is "double" that really. The car is signifcanlty less powerful running recuric. that my butttdyno opinion..lol

You might only be picking up a pound or two up top but at boost onset at any given RPM point you might see a gain of 3-5 psi. This isn't a byproduct of going from recirc to VTA, its a result of going from a valve that leaks like a sieve to one that holds boost.

 

[speed3shon]

i too think the valve sounds annoying.

VTA < RECIRC

and more power cuz of temp differences due to vta over recirc? bologna. end of discussion.

 

[Powerslave]

yeah balonga 200degrees vs room temp, your genuis..

 

[sleeper3]

why do my threads always turn into a flame fest.

 

[Powerslave]

lol

 

[sleeper3]

yeah balonga 200degrees vs room temp, your genuis..

do you know how fast the air that is vented would be used by the engine? so fast, you wouldn't even notice.

 

[Powerslave]

yeha you notcie cuase the explosion in side the cylender is less powerful cuase the air is hotter, with a colder temp bigger explosion inside the cylender wich gives you more power and torque it doesn't matter if the air went to get a beer, went to the resromm etc...lol

 

[sleeper3]

you're missing the point. the volume of air being vented by the bypass valve probably gets used up in 1 revolution of the engine. when you're spinning 4,000 revs per minute, do you think you can feel a 20 degree difference in intake air temperature in one of those 4000?

 

[Powerslave]

if my theory is correct than the over all temp is reduced by much more than 20 degrees and its the overall temp of the air entering the engine at 1rpm or 4000 rpm what diff does it make what rpm? the intake charge is way colder cuase its not getting that 190degree splash from recuric.

 

[Powerslave]

good discussion headen to lunch....

 

[speed3shon]

yeha you notcie cuase the explosion in side the cylender is less powerful cuase the air is hotter, with a colder temp bigger explosion inside the cylender wich gives you more power and torque it doesn't matter if the air went to get a beer, went to the resromm etc...lol

ha. first of all. cylinder.

now that thats out of the way...

do you even know how heat relates to an engine? it actually causes the air fuel mixture to burn easier... which is called detonation in the event that it combusts in the cylinder before the spark plug fires... thus, for hotter air, you need more stable fuel (higher octane, because it burns slower) to prevent detonation...

cooler air is more dense (more oxygen particles in a given space), all that means is that you can push more fuel into the cylinder, thats where the power comes from...

yes, heat robs you of power.

no, venting off hot air will NOT gain you power, because you know what the motor will do? produce MORE HOT AIR.

give it a shot. use any logging tool, and log the differences in IATs vented and recirced on the same vehicle in the same conditions. you wont see a difference.

IF... and thats a big ******* if.... you see a difference, do you even know where to look for it on the logs? it will be during, or in the 1/1000ths of a millisecond after a shift (where you will be running too rich anyways, oops, there goes your power from dumping hot air). when you are not accelerating. try again to convince me it will make a difference

its called physics numbnuts. read a freakin book.