Less boost when hot!!!

[Mcblow]

Hi all,don;t know if anyone out there can put my mind at ease,i have a 2000 a3 1.8t quattro,the car has been remapped has a split-r dv(which i'm not happy with) and i have fitted a J valve,when the car is cold the turbo kicks in hard and pulls like a train,after a while when the car is getting warmer it doesn't seem to pull as hard,and the turbo kick is lees noticable....is this normal?...as this is my first turbo car i don't know exactly what to expect?,i don't have a boost gauge,so don't know if the boost is dropping,i'm convinced the dv is leaking boost,but intend to upgrade my pipes when i have the cash incase it is one of them,any input appreciated....sean

 

[s3_kev]

you should'nt be boosting the turbo untill its warm anyway

 

[vanilla_ice]

Sounds like heat soak to me...

Bigger intercooler is required to compensate for the extra heat.

ICE

 

[Prawn]

if you're thrashing it, you are experiencing what's called Heatsoak.

As the turbo boosts, it heats everything up, in time, the small side mounted intercooler becomes very hot, and is unable to cool the charged air as well.

As a result, inlet temperatures rise, and pre detonation becomes a risk. The knock sensors will come into effect, and pull back the timing to a safe level, making the car much slower.....

 

[Mcblow]

you should'nt be boosting the turbo untill its warm anyway

thanks for the advise,i had been told this before,have now got into the habit of letting it run for a bit when i park up aswell,what kind of intercooler is needed,does it need to be massive?,or can i get away with a front mounted one that isn't huge?as i have brand new one from denzo (cousin works there!!) it is 12" x 6" and looks like it would be ideal for mounting in the front bumper?,also how do you rate the split-r dv? thanks for your help people

 

[Prawn]

the split R valve is a waste of time, stick with a 007P.

As for a front mount, what thickness is the core you have? 12x6 is hardly bigger than the standard side mount, so it would have to be very thick!

My FMIC is 20x6x2.75'' on the core, and 24'' total length including tanks.

It sits neatly behind the front bumper, and does an AWESOME job of cooling.

 

[s3_kev]

i have the split r valve and think its ok, plus you can adjust the spring rateing to compensate for extra boost after modifications etc,, although alot of people on here seem not to rate them think mostly because your wasting 35% boost to atmospher when your dumping and also because it goes tsshhhh

 

[s3_kev]

also look on this thread the intercooler mattm has fitted should be a good size and fit for your application http://www.audi-sport.net/vb/showthread.php?p=629549#post629549

 

[Mcblow]

Looking at those pics i'm gonna need a much bigger intercooler!!!