holding boost pressure

[cam1754]

i recently puta boost tap (turbosmart) on my car and all ive seemed to notice is that it spikes up to about 14 psi and drops back to 10-11. any reason for this? do i need to upgrade to an electronic controller?

 

[Guest]

manual boost controllers have a tendency to do this. ebc's will hold boost heaps better than a bleed valve but in saying that lots of people claim that the turbotech and gfb gated controllers hold boost as good as an ebc.

 

[frozen]

i have a turbosmart tee or whatever they are, and mine is perfect, holds at .8 bar and doesnt move the whole time. Also, worked the same when i had it as .9. Trick is to make sure you get someone good to install it i followed the guide on here and had problems (though followed it exact :S) so went back n payed 50 bucks to get them to do it...

 

[whiteleg]

Cameron - I run a Greddy Profec Spec b and it also drops psi high in the rev range but only 1 -2 psi max. When the car was tuned at Chip Torque they said this is normal and you wouldn't make any extra power if it held anyway as the turbo's at that point are past there peak output. I would say save your money as EBC are expensive and look at doing something else (Exhaust etc).

 

[cam1754]

awesome, so its not just mine doing it. yea sounds correct about turbos running out of puff high in the rev range.my car already has a fujitsubo cat back exhaust so prob do intercooler and hard piping next.
cheers

 

[Murph]

I have an EBC and it spikes just as much. The EBCs don't control boost quite as "actively" as everyone seems to think.

 

[Guest]

Do you have the standard BOV? A metal one like a EVO MR can hold boost better and higher.

 

[2000VR-4]

I have a GFB gated controller and it also boosts to 13 then drops off to 10-11. Think it is the BOV to blame IMO.

 

[whiteleg]

To test if its your bov put the car in 4th at about 50KM then plant your foot. You will hit full boost by 3000rpm and if this holds to about 4000 - 4500 rpm it is not leaking. If it was leaking you would see the boost drop during this time. The boost in 2nd and 3th falls off after about 4000 - 4500 and I think its just the small turbos not being able to supply enough air for the engine to maintain that boost.

 

[Murph]

Do you have the standard BOV? A metal one like a EVO MR can hold boost better and higher.

Yeah standard. Pretty sure doing the above mentioned test, I holds boost solidly.

I'm thinking the spiking is simply due to the long runs of small diameter tubing to each of the wastegate actuators. In an ideal setup you want this as short as possible....something that is of course impossible when your two turbos are a mounted a meter apart.

I need to look into this some more though.