[Mk2] [Turbo] Boost question

[NORRISMR2]

Hi all me again, I was wondering the boost on my rev 3 seems to come in full at 4500 in 3rd gear etc which to me is very late... the idle sits at 1100 rpm

is this linked also what should it be kicking in at...

the car is running standard boost, upgraded pistons and gutted cat...

ne ideas y it is boosting so late... i have checked pipes going from throttle body to intercooler and from intercooler to turbo for leaks all is tight... anywhere else should check or clean?

[BenF]

Any more details on the spec of the build on your car?

Wild cams, big turbo would cause this.

Standard car you should get boost in all gears once the engine is above 2krpms - the higher the revs, the less the lag.

[NORRISMR2]

Spec is as follows...

1995 rev 3 turbo...

running standard boost
gutted cat
fujitsubo exhaust with 3 inch pipe cat back
standard turbo that i know off

engine is bored .5 and running wiseco forged pistons
hks metal head gasket
acl race bearings

car is running intercooler fan constand and radiator fan constant if that would do nething...

[honda_crf_04]

thats what my standard rev 2 turbo has just started doing.but not all the time.seems to only do it when its really cold.

[Bry]

should be hitting full boost at about 3200rpm in 3rd, how thick was the H/G you fitted ? and were the pistons you fitted the same compression ratio as stock items ?

[NORRISMR2]

Head gasket was 1.2mm thick not sure dont think they were as they are forged pistons

[dawolf]

To compare, my rev 3 is standard (apart from exhaust system and air filter). Mine starts spooling up just after 2000rpm then it rises steadily up until hitting max boost at about 4000rpm or just before. It doesn't sound like yours it that far off but with a gutted cat aswell I'd expect it to hit max boost around 3500rpm really, especially with the nice cold air. Not sure what the cause could be. Is it running okay apart from this?

[Bry]

just wondering if the reason for the boost to come in the late could be down to you running a lower compression engine after the rebuild

[BenF]

If the Lag is a lot worse than a comparable standard - I'd wonder if the cams were timed up correctly - if they were a way out, that could also cause additional lag.

FWIW reducing the compression a little ( I went from 8.8:1 to 8.38:1 on my Rev2 ) plus a larger Hybrid turbo only increased lag slightly compared to a standard Rev2 - you'd only notice it driving it back to back with a standard Rev2.