Author Topic: boost comes at redline...doesent peak (Read 6090 times)

carrizog60 · « **on:** January 05, 2007, 11:07:18 am »

I made all the "fast" pump mods and to incresase boost i put the wastegate bolt all the way in.(kkk24)
my problem is that the boost acts like it was a supercharger, it keeps rising as the rpm goes up...it doesent peak.
i think if i could make more boost at lower rpm i could clear all the smoke it does.
i hit max 1.6 bar at redline but at 3000 i only get 0.8/0.9 bar...

is it normal to boost react like this? or if i put a boost controller i could get full boost at less rpm?

sorry to Xpost this also in the french forum but it hasent had many replyes... :roll:

jtanguay · « **Reply #1 on:** January 05, 2007, 01:03:04 pm »

sounds like your wastegate might be stuck open, or opening too soon? try disconnecting the wastegate. you will probably have to cut a piece of the metal line to splice into it though. plug it with something and voila.

carrizog60 · « **Reply #2 on:** January 05, 2007, 01:11:05 pm »

before messing with the screw i tried to take off the line and that way it would react the same way...
i was in the mood to put a MBC but the line of the turbo to WG is smaller than the one of the MBC so even with the tightest hose i can fit on the MBC it would be sloppy on the metal line...don't know how to hook it ...

so what is the normal boost reaction? peak at a certain rpm and hold till red line right?

jtanguay · « **Reply #3 on:** January 05, 2007, 02:37:44 pm »

boost should start to come on at around 2000rpm and peak at 3000 rpm provided your foot is in the right position. i rarely floor the pedal and so if you do, you may get peak boost sooner

carrizog60 · « **Reply #4 on:** January 05, 2007, 02:47:39 pm »

thats the problem...the boost starts to build at +-2000 but it doesent get max until red line...
i floor the pedal but it doesent peak boost ,it keeps rising as the rpm go up...

here are some videos...
i reaaly feel the extra power almost at redline... :roll:

http://www.youtube.com/watch?v=59r3-c9-12g

http://www.youtube.com/watch?v=ELnJKeUmEU0

jtanguay · « **Reply #5 on:** January 05, 2007, 06:16:34 pm »

thats pretty quick

should let your car get up to temperature before driving it too hard though... stresses the aluminum from the heat of the turbo.

sounds to me like your wastegate is stuck open, or leaks. mine works flawlessly and i have since disconnected it and can spike 20 psi if i stay on it in the right rpm. (not for more than a few seconds though... no IC yet!)

RabbitJockey · « **Reply #6 on:** January 05, 2007, 06:48:14 pm »

yeah always let ur car warm up

carrizog60 · « **Reply #7 on:** January 06, 2007, 06:58:36 am »

it was warm.
i stopped to mount the camera and then as soon as i strat the car o went off.

how do i disable it?
i ran without the line going from the turbo to WG and still did the same...(the hole on the turbo side remained open so i could cause this).

so what can i do? should i mount a MBC?
any idea on how to mount it?
the hose i have for the MBC fits too large on the turbo line... :roll:

jtanguay · « **Reply #8 on:** January 06, 2007, 07:32:10 am »

you need to block off the hose coming from the compressor side. your boost air will just leak right out and as a result, egt's may rise.

my temp gauge reads just over half way when warm... maybe you should look into getting a new thermostat :wink:

has anyone tried spraying some sort of lube into the WG boost intake to free a 'stuck' wastegate?

DVST8R · « **Reply #9 on:** January 06, 2007, 04:04:33 pm »

With enough fuel mine would never peak either. With out a boost controller, and the wastegate closed I would see in excess of 35psi (gauge limit). However with only 1.6bar max boost I doubt this is the case. More then likely your wastegate is slowly coming open and as such is bleeds off the boost, to a max of 1.6 bar. The easiest way to diagnosis this is unplug the wastegate from the turbo take it for a drive (be careful with enough fuel you can destroy the turbo if it hits ~2bar+ let off the accelerator) If you make more boost quicker and your max boost is up, then it was a wastegate problem and you need a manual boost controller (well really, you need one anyway). If it didn't make boost any quicker or any more max boost, then you have a tuning problem, or a turbo problem. For complete diagnosis steps from here check the FAQ.

carrizog60 · « **Reply #10 on:** January 06, 2007, 05:44:24 pm »

well i ran without the line comimg from the turbo to WG and its the same.the hole where the line gets pressure was left open so that could be the problem...

how can i hook up my MBC?
cant figure out a way to get a hose that fits the MBC on one side and fits the line on the other... :idea:

jtanguay · « **Reply #11 on:** January 07, 2007, 08:17:34 am »

your best bet is to go to a store and get any kind of hose that is as big as you need it. use hose clamps if you need to. heck.. flare the end of the metal line

and that hose is sure not to come loose! you're only talking about 20 or so psi... :lol:

carrizog60 · « **Reply #12 on:** January 07, 2007, 10:30:19 am »

i just wanted to get the same boost i have now but sooner.
all the cars i know that are modified tend to peak and then hold till red line but mine just keeps climbing...
it looks like my G60... :?

RabbitJockey · « **Reply #13 on:** January 07, 2007, 10:53:20 am »

my td does the same thing, it's because the wastegate is stuck sure, i'm gonna assume your car is the same, what is the max boost at red line? my car ran the same, i've since turned down fueling, but 3500-4800 was like an amazing range for power, everybody that road in my car when it was like that was amazed and highly impressed, that was peaking at 25 psi, usually by 4k i could have 25psi. so yeah in a sense it's gonna look like a supercharged car since the higher you rev the more air you're moving through and the more boost you're going to make, even thougha supercharger is the faster the engine spins the faster the charger spins, same thing really. the other cars that peak like you say is because their wastegate works. i bet you have the kkk turbo on your car?

carrizog60 · « **Reply #14 on:** January 07, 2007, 12:58:43 pm »

i hit 1.6 bar max.
even without much fuel i would hit 1.6bar.

i have the KKK24 turbo.

what can i do if the WG is open?i dont want to ran like that because that way i always have more fuel than boost...