Alfa Romeo Forum banner
1 - 6 of 6 Posts
G

·
As far as I know, you are unable to go any further than 1.2 bars of boost from the chip.

If you want more boost, you have no choice but to modify the wastegate actuator....

Juan
155 Q4 (chipped & decatted)
 

·
Registered
Joined
·
177 Posts
Yes Juan, 1.2-1.3 and 230-235 hp according to official Garrett dealer. But I didn't know the reason about the boost limit. Interesting. I also read about the Q4 that the fuel system couldn't match more than 1.3 bar of turbo boost. Don't know exactly why. But I am interesting to kow what kind of injectors the Q4 is fitted with. Do you know, Juan?

Anyway with the chip Maxiboost mentioned I think it was developed for a car with modified turbo, isn't I right?

Well, that is what I know about the limits of the Q4 original configuration. If anyone else have more knowledge or know more, please speak out!!!

Regards

A. Möller
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #4 ·
Yes ,
Sorry my incomplete word.

That chip from -96 Q4 ,check sum is EEC6 ,modified ofcourse.
Hybrid big turbo (which model I dont know) ,different map sensor (I think 3 bar map sensor),exhaust ,open air filter,chip also ,speedline different model black wheel,shock upsorber and spring ,Bov ,some fuel pressure up the from fuel regulator.(standard is 2.5 bar when idle)
And its going very strong and very good condition.
 
G

·
Andreas, I never heard of that limitation on fuel pressure.
In fact. Bazza (from Evocars) told me that with the std. configuration you can safely go up to 1.35 of turbo boost. But 0.15 should be managed from a modified wastegate actuator. From the chip, you are unable to go further that 1.2. More than that (and up to 300 bph at the flywheel) you will have to face more serious mods (bigger injectors, racelike cylinder headgaskets, stronger bolts, and so on...and ...yes...an uprated fuelpump..)
Opinion shared also by my mechanic, who modified my car's chip. He also used to have a Q4 modified to run 1.7 bars of boost. The cars runs reliably & very well (and was unbeatable in acceleration) till the date the owner have the 'idea' of cleaning the engine himself with SOAP & WATER!!!, and water came into the cylinders...and then blown the engine...The car end up with a bad done engine rebuilt and was sold it at ridiculous price...
As for the bigger turbo mentioned by MaxiB, I consider the standard one fairly capable. But its a matter of spending money, and BHP will be achieved.
 
1 - 6 of 6 Posts
Top