How do you acheive steady boost throughout the rpm range?

ZavzTy547

ZavzTy547

Senior Member
I've been fighting boost issues for what seems like forever, so I bought a gready profec spec II, thinking It would fix the flutuating boost but it didn't (same characteristics with the STG chip controlling boost also).

Example: When I dial-in the boost at 17psi, it will stay their until it shifts, then it falls off to 12-14 psi and start to slowly creep back to 17psi as the rpms rise back.

I thought it may be knock related but I checked DM and it only shows a couple of degrees during shift points. I tested for vacuum leaks and can't find any.

My voltage tends to drop while in WOT (to like 12.7volts). Could that be part of the issue?
I also noticed a psi drop when my TC locks up...
I'm suspecting ignition but I'm not sure were to start first. Any recomendations would be appreciated.

Thanks.
Zav.
 
Last edited:
bezerk

bezerk

New member
Re: How do you acheive steady boost throughout

Re: How do you acheive steady boost throughout

you still have a cat on it?
 
bezerk

bezerk

New member
Re: How do you acheive steady boost throughout

Re: How do you acheive steady boost throughout

have you tried shortning the wastegate rod a bit?
 
midnightbluS10

midnightbluS10

Banned
Re: How do you acheive steady boost throughout

Re: How do you acheive steady boost throughout

He running the RPM stage 3 bolt on turbo if that tells you anything

http://www.raceprovenmotors.com/cart/product_info.php?products_id=418

DSC00494.JPG
 
TurboJunk

TurboJunk

questionable
Re: How do you acheive steady boost throughout

Re: How do you acheive steady boost throughout

correct me if im wrong.....
but should the boost drop off slightly? as torque drops before every shift the boost level will decrease because it has used up the power for that gear.

5 psi is alot but shouldnt it loose like 2-3 psi?
 
SpoolingTurbo6

SpoolingTurbo6

Donating Member
Re: How do you acheive steady boost throughout

Re: How do you acheive steady boost throughout

You can't build boost with out torque.But it shouldn't drop 5 psi unless the turbo needs huge amounts of exhaust.What converterdo you have?
 
TYTILIDIE

TYTILIDIE

METH HEAD
Re: How do you acheive steady boost throughout

Re: How do you acheive steady boost throughout

It s very possible you dont the EBC set right. Whats your setting at? What boost are you trying to run? SET and SET GAIN work together with this type of situation. It takes a while to really get it where it should be.
 
ZavzTy547

ZavzTy547

Senior Member
Re: How do you acheive steady boost throughout

Re: How do you acheive steady boost throughout

TYTILIDIE said:
It s very possible you dont the EBC set right. Whats your setting at? What boost are you trying to run? SET and SET GAIN work together with this type of situation. It takes a while to really get it where it should be.
Click to expand...


I'm running a 3" Cat and a 2800 stall TC..

Profec settings:
My "SET" setting is at 37% which gives me roughly 18.5 PSI.
I've set the "SET GAIN" between 5%-35%. At 5% it will drop from 18 to 14.5 (roughly base boost). If it's set to 35% it will drop from 18.5psi to 15psi

Same characteristics with the stock solenoid/STG chip, so I'm assuming that the actuator must be out of its range and needs adjustment, since RPM stage 1-2-3's comes with the heavy duty actuators...

Does anyone have a right up on how to find this "actuator range" to control boost without the KABOOM factor?

Thanks again for your replies.


Zav.
 
TYTILIDIE

TYTILIDIE

METH HEAD
Re: How do you acheive steady boost throughout

Re: How do you acheive steady boost throughout

If youre still dropping to 15, raise it higher. The setting that says GAIN , only, you have to be careful of. I leave it alone unless it spools too fast. What is the GAIN set at? Not SET GAIN. GAIN is how fast it will spoool up.
 
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