boost spikes

[lan evo]

what cause boost spikes?

 

[DRFT_240sx]

i think the more accurate terms is boost creep... happens when u change to a bigger exhaust where pressure difference is bigger thus leading to your wastegate not opening fast enough to maintain the desired the boost level...

thats why it will go up then come down again...

cheers

 

[Doink]

can explain more details???plus pics or something???would like to know more dude...

 

[zaki]

boost spike & boost creep are two different things. boost creep happens when your boost keep increasing as RPM is increasing. if u set the boost at 1 bar, it will stay at 1 bar for some time but after some treshold the boost will rise.
the cause of this problem is backpressure. u should check your turbine housing down to the O2 housing (if you have one) and your exhaust pipe.

boost spike - the boost will overshoot(it may not) and decrease to the preset boost pressure (it may go lower). this is due to intercooler piping from compressor housing -> intercooler -> throttle body. see whether got any leak or not. other things that u might want to check is the actuator/wastegate.

 

[Cow]

I thought boost spike and boost creep are 2 different things?

as far as i know, boost spike is a common problem with manual boost controllers? (ie. tulang ikan? or those fish aquarium valves) and it happens when the boost controller is open all the way and the hose is too small, so all the boost pressure builds before hitting the wastegate and fights its way through

and boost creep is usually because of a faulty wastegate? because the wastegate is faulty, it is unable to bypass the extra amount of exhaust and thus the turbine will just keep creating additional boost.

Do correct me if i'm wrong..which I think I am :P

 

[zaki]

Originally posted by Cow@Jan 2 2005, 17:46
I thought boost spike and boost creep are 2 different things?

as far as i know, boost spike is a common problem with manual boost controllers? (ie. tulang ikan? or those fish aquarium valves) and it happens when the boost controller is open all the way and the hose is too small, so all the boost pressure builds before hitting the wastegate and fights its way through

and boost creep is usually because of a faulty wastegate? because the wastegate is faulty, it is unable to bypass the extra amount of exhaust and thus the turbine will just keep creating additional boost.

Do correct me if i'm wrong..which I think I am :P

u r rite, i was wrong on the boost spike.

 

[Cow]

haha we posted at around the same time

i think must wait for some sifu to come in here and explain to lan_evo ler

later the fella all confused and go cabut his IC piping, his wastegate, his boost controller... hahaha

 

[vestax]

creep usually happens when you do alot on the intake side , ie : high performance air filter , bigger throttle body , shorter intake manifold , port & polish , port the turbo , but then fail to do the hot side . in other terms , you are sucking alot of air and compressing more mass air then before , but then the wastegate opening is still the same , partial of the exhaust gas is bypassing the blades but then still not enough to slow down the blades , so boost still builds up when your rpm is still raising , there is when you get creep . basically when you do the intake side , make sure to port the wastegate & change to a bigger flapper too and not to mention a bigger o2 pipe , so that you won't get creep .

 

[huakenny]

sorry to ask one Q here......evo 3 wastegate located at where a? how does a original wastegate look like? i only saw those aftermarket one la...original dunno how it looks..

 

[ftzone]

http://www.vestax.fivio.net/4G63/turbo/50trim.jpg
U see the gold color round thing? That is the internal wastegate also known as actuator.

 

[huakenny]

so if we put in external wastegate....the original one shold be remove?

 

[AlucarD]

Original i.e. internal gated one will be welded shut..

 

[huakenny]

but if we din boost high..there is no need to install external wastegate rite?

 

[monsterv6]

meaning of boost spike..?what arr.?is it..when u floor the boost comes kicks in but your car still not kicking like auto transmission..?

 

[Maxx]

have a read here:
http://home.arcor.de/hildst/asBTerms.html

 

[lan evo]

what causes boost creep?my car having boost creep now even with or without boost controller.i heard somewhere that air fuel ratio also will cause boost creep.means richer or leaner airfuel will cause boost creep?



exhaust side:using 38mm thailand trust wastegate,with hks elbow,downpipe and 3 inch piping

intake side:with 2.5 intercooler piping and uprated intercooler and open port filter

stock turbine

 

[ondgennis]

ftzone,
can this actuator to be replace or service ha?
because lately my found out my boost is getting hard n hard to reach the boost i set at my ebc.
normally it cost how much?

thanks

 

[cypress8]

ftzone,
can this actuator to be replace or service ha?
because lately my found out my boost is getting hard n hard to reach the boost i set at my ebc.
normally it cost how much?

thanks

PM me if you are interested to get a used (3 months old) mitsu e3 actuator which I bought brand new from Tong Turbo.

http://www.zerotohundred.com/newforums/showthread.php?t=63582

 

[Lord_darkslide]

thanks for the inifo on boost spike and boost creep...

i nearly have a heart attack when my stock std gsr (usually boost at 0.6) boosted up to 1.0 bar...

i happen right after i change my stock std air box to 6" K&N air filter open pod..

how please all sifu can please give suggestion on how to eleminate boost creep...heheheh dun say change back to stock air box coz i really like the swooshing sound of the turbine now... hehehhehe

engine setup: stock std gsr(big i/c)..normally boost 0.6... hmmm and K&N open pod air filter (this is the culprit made the boost creep)...thats all..

thanks