got a question. i have a b7 a4 and recently installed a custom intake with an AEM dryflow cone filter and also replaced the stock intercooler hose with hard piping. I like it a lot and offers a lot more throttle response, but before the install i was hitting about 13-14psi and now it wont boost higher than 10psi. I guess what is asking here is how i can get that boost back? do i need to install a boost controller? and why would i lose boost with the new intake. Im interested in the mechanics of why it wouldnt be able to hold the boost past 10psi. I have a REVO flash and a Forge DV. it just seems a bit slower now. Any thoughts or suggestions are welcome. Thanks guys.

 

i had the same thing happen to me when i put a cone filter on. i lost a lot of power and my gas mileage went to hell. my turbo and diverter valve sounded amazing. as soon as i put the stock intake on power and mileage were back.

 

Chips are supposed to regulate the amount of boost dependent on various parameters, so perhaps with the new air intake it has determined it's not safe to boost higher.

This is just wild speculation now, but maybe your new intake is just sucking in hot air from the engine bay, and the intercooler isn't enough to get it cold enough, so the ECU won't compress it further. But I don't know for sure whether that's even reasonable.

 

im about to put exhaust on as well and then when thats done im going to throw it on a dyno and get it mapped. do you think that would take care of the problem? Also I have had the chip for a while now would it just automatically switch itself to a lower boost? and is there a way that i can control the boost? thanks

 

With REVO you can get a REVO select thing that you can plug in and adjust the parameters, including boost. It would probably be good to talk to the REVO folks before doing too much to see what they think.

 

that makes perfect sense. the original ram air intake design is tight.

 

The hard piping on for your intercooler is probably the problem. If you used larger piping than the turbo can put out you will lose boost pressure. Happens to the 1.8T guys all the time, install an FMIC with hard piping and the boost goes down 4-5 psi. At least until they install a larger turbo.

 

thanks guys for the help. Ill look more into the REVO SPS controller and see if i can find out more in general. I'll let you know how things turn out.

 

The piping from the intercooler to the engine is 2.5" same as the stock. could that still be a key reason why?

 

I thought the stock piping was 2.25, but if its the same and you're using the factory intercooler it should be ok. It could still be the piping though, its a quick test to put the stock piping back on real quick just to test it though, plus its free. If its not its most likely a leak in the intake or your forge DV may need servicing.