max boost 14psi??

[Guest]

if my search on hea is right the 1996 vr4 can only boost 14psi and it can handle it, how can i get it to 14psi to i have to get a boost tap

 

[Sydo]

if my search on hea is right the 1996 vr4 can only boost 14psi and it can handle it, how can i get it to 14psi to i have to get a boost tap

Yes. Manual boost control from ebay - ~$40.
Easily fitted in a few minutes.

 

[Guest]

i already done for EBC for my vr4 legnum... set it to 1bar boost... but when it reach 1 bar, my engine jerk (boost spike).... how to remove that boost cut or increase the boost cut.....? in my country vr4 legnum is tiny group and no tuner for this khind engine.....

 

[frozen]

turn your boost down - or go aftermarket ECU. If it does it every time, chances are you have it way too high... a boost spike is when the boost goes a bit higher than you have it set before leveling out to where it should be (ie. you have it set to 13psi but it hits 15psi momentarily first)

But yes, to remove boost cut, turn your boost down or go aftermarket ECU.

 

[Guest]

i already done for EBC for my vr4 legnum... set it to 1bar boost... but when it reach 1 bar, my engine jerk (boost spike).... how to remove that boost cut or increase the boost cut.....? in my country vr4 legnum is tiny group and no tuner for this khind engine.....

Sorry to inform you but its absolutely pointless to up the boost to 1bar/14psi, all you are doing is baking the rear turbo thus shortening its life. Oh yea by increasing the heat to the rear turbo you're also creating hairline fractures in the manifold. Safe way, use any electric boost controller set it to 13.2 psi for high and leave it ALONE. Use it only when needed, stock 7psi for low

 

[godzilla]

Sorry to inform you but its absolutely pointless to up the boost to 1bar/14psi, all you are doing is baking the rear turbo thus shortening its life. Oh yea by increasing the heat to the rear turbo you're also creating hairline fractures in the manifold. Safe way, use any electric boost controller set it to 13.2 psi for high and leave it ALONE. Use it only when needed, stock 7psi for low

13.2psi you say

 

[OVR444]

13.2psi ? wow... I was thinking how 14 didn't feel like much pull from other turbo cars I have owned.

 

[Scottie]

Sorry to inform you but its absolutely pointless to up the boost to 1bar/14psi, all you are doing is baking the rear turbo thus shortening its life. Oh yea by increasing the heat to the rear turbo you're also creating hairline fractures in the manifold. Safe way, use any electric boost controller set it to 13.2 psi for high and leave it ALONE. Use it only when needed, stock 7psi for low

Sorry, but are you saying that by dropping boost by .8 PSI i am going to incrase the life of my rear turbo?

Also, i have been running 14-15PSI everyday for over a year and a half without any problems. Would have covered about 50,000km.

 

[happymatch]

Sorry to inform you but its absolutely pointless to up the boost to 1bar/14psi, all you are doing is baking the rear turbo thus shortening its life. Oh yea by increasing the heat to the rear turbo you're also creating hairline fractures in the manifold. Safe way, use any electric boost controller set it to 13.2 psi for high and leave it ALONE. Use it only when needed, stock 7psi for low

what? 0.8 can actually save lives of turbos? if it is true, all the turbo companies probably designed their products very differently.
I am not a turbo god but i run my car with around 13~14 psi on high boost and its fine. I think at any boost level, if you "abuse" your turbo, you will have all sorts of problems

 

[mills_88]

After fixing all the little boost leaks my car had when i got it it was running like 10psi stock so i think 7psi for low is a bit too low. And im now running about 13-14psi for high with an ebc and its fine, granted i normally leave it on low but still been fine so far.

 

[SiliconAngel]

Sorry to inform you but its absolutely pointless to up the boost to 1bar/14psi, all you are doing is baking the rear turbo thus shortening its life. Oh yea by increasing the heat to the rear turbo you're also creating hairline fractures in the manifold. Safe way, use any electric boost controller set it to 13.2 psi for high and leave it ALONE. Use it only when needed, stock 7psi for low

Interesting you say that Bernard, but I believe Brad's been running 17psi on his stock turbos for a couple of years now without issues (including some pretty heavy abuse on track days). Can you provide further details on what lead you to that conclusion?

Oh and for those reading this, forget about running boost higher than 14psi unless you have all the supporting mods (exhaust, injectors, fuel pump & fpr, IC & piping and importantly aftermarket ECU replacement).

 

[bradc]

Indeed I have been, and my car makes 228kw at the wheels, it is moving a fair amount of air through. I will admit it has only done 7000km on those turbos from new, but they show no signs of having any problems at all, and I do tend to trash it. The Pukekohe raceway must be hard on turbos, accelerating from ~80kmh to ~235kmh each lap, then from ~60kmh to 205kmh as well, each lap is only 1:10s long as well!

However I don't think that Bernard is saying 13.3psi will lead to immediate destruction, 13.2psi translates to 0.9 bar which is where that figure comes from.

 

[SiliconAngel]

Haha Brad you really don't drive your car enough...

 

[bradc]

Corolla work car remember In the same time I've also done about 5000km in my white VR-4, 10,000km in the ST-R and a few hundred km's in the Turquiose VR-4. And about 110,000km in various 2005-2006 Pulsars and Corolla's

 

[jet150]

14 psi should be fine but as you wind up the boost the turbo runs hotter and is less efficient. Even with mods like an exhaust and bigger cooler the stock turbo is quiet small and running them at 17-18 psi will slowly cook your turbo and engine and you probably wouldn't feel a difference than if the boost was set to 14 psi.
To have the motor running efficiently at say 18 psi I would Hi-flow the original turbos or fit bigger ones.

 

[frozen]

when i had my car at apc originally, they aid that any more than 12psi and i was just going to run inefficiently, and that the extra 2psi if i did want to run 14 wouldnt really add much power wise cause the extra heat made.

 

[SiliconAngel]

Depends if you have the right supporting mods - if you can't take proper advantage of the higher boost with adequate fuel delivery, correctly optimised timing, increased cooling of the intake charge, improved exhaust flow giving faster and more responsive turbo response etc then indeed you are wasting your time. However if you have all the above adequately covered then there are definitely advantages to be had from going higher, and they should be relatively safe advantages too.

Remember every car is different, so what goes for one won't necessarily apply to another - if your car is basically stock, 12 PSI is probably as much as you should run. But as we've seen from Brad's car, a well thought out upgrade path can lead to a very responsive and powerful vehicle using the stock turbos at boost quite a bit higher than 12psi.

 

[happymatch]

Where is that guy who said lower your boost 0.8 psi..

 

[frozen]

my theory is that with the tuning to match etc, brad could probably make the same power he does on 17psi on 15psi. I could very well be wrong, im not trying to start a fight I dont have half the experience with these cars any of you have Im going to test the theory with my car soon hopefully...

 

[pu-11-me]

Efficiency will always be the issue when raising boost from factory specs.

When you increase the boost, you then need to tune the car, and replace the inhibiting components for running that amount of boost. (Aftermarket parts, computer etc). You will notice a difference up to a point where the inefficieny will stop further gains in power.

Also, colder, denser air at 12PSI will make more power than hot thin air at 15PSI. Think about it that way