Exhaust got boom sound at 1bar boost

[CSx8213x]

Bro out there ... anybody can help me on this problem ??
When i boost my engine to 1bar ... after 4000rpm .. the exhaust got blow sound .... and the car can't go smooth ....

If i set the boost at 0.8bar ... then the problem gone ....

Why my car can't boost high ? I'm using microtech LT10 ... dyno check the air/fuel ratio very nice ....

 

[Joeker]

Maybe ignition missing under boost.

 

[dolly]

do you have an afr log when the problem occurs? your lt10 can log the data.

what do you have your boost cut at?

 

[CSx8213x]

my boost cut is off ....
the lt10 show the max boost is 15psi ...

 

[AlucarD]

I suspect MAF overun and ecu cut-in lots of black smoke after the "Sonic Boom"

 

[dolly]

if he is using lt10, it comes with built in map sensor, doubt he is running an airflow sensor

CSx, do a full log of ignition timing, AFR (hope you have wideband) if you dont have a wideband o2, go to a mech who has, and stick it up your exhaust pipe.

did you tune your ecu to 15psi? If all else fails, check your plugs/cables... btw what plugs are u using

 

[AlucarD]

Oh My bad. didnt read the details!! >< Me & my dino era ecu ... hahahha. Want to down grade to NA now, Petrol price just increase 30c .....

 

[dolly]

haha late edi ma, tomorrow no need to work ka :P

noneed go NA, time for you to invest in forged 10.5 cr pistons!

 

[xtremeleo]

lt10s doesnt come wit an ignition module, dats y joshua alwiz couple dis unit wit an x4. Csx, r u running the lt10s alone?

 

[CSx8213x]

lt10s doesnt come wit an ignition module, dats y joshua alwiz couple dis unit wit an x4. Csx, r u running the lt10s alone?

dunno ... last time Joshua install for me without the x4 ....
and my engine original dun have a ingiter wan ... then he used the 4g91 igniter for me ... is that okie ? From Joshua .. he said no problem woh ....

 

[CSx8213x]

if he is using lt10, it comes with built in map sensor, doubt he is running an airflow sensor

CSx, do a full log of ignition timing, AFR (hope you have wideband) if you dont have a wideband o2, go to a mech who has, and stick it up your exhaust pipe.

did you tune your ecu to 15psi? If all else fails, check your plugs/cables... btw what plugs are u using

Yup I got the built in Map Sensor ...
Bro ... wat u mean a full log of ignition timing ??
I'm using platinium plug ... forgot NGK or Denso already ...

 

[xtremeleo]

try to avoid the platinum and go iridium instead bro, ive heard dat platinum doesnt mingle good with high boost. i cant remember where i read dat, but iam using denso iridium with good results. just try to borrow sum iridium cold plugs and see how it goes.
if the lt10s module was tuned by joshua, den i have all the confidence dat the setup is good. i worked at mma and never saw a single engine blown unless touched by the owner who gatal tangan and just blamed josh did dis and dat. igniter is just dat, it waits for signals from the ecu / sensors den ignite sparks, so using whatever unit isnt important as long as the unit fires at the perfect time. ur engine doesnt ping, rite?

 

[CSx8213x]

Emm ... if low boost at hi rev got abit ping ....
mean if i go hi rev .... and release the pedal ... and press it again ... it got pinging around 0.5 0.6 0.7 like that .... if reach 0.8 .. then okie ...

 

[CSx8213x]

try to avoid the platinum and go iridium instead bro, ive heard dat platinum doesnt mingle good with high boost. i cant remember where i read dat, but iam using denso iridium with good results. just try to borrow sum iridium cold plugs and see how it goes.
if the lt10s module was tuned by joshua, den i have all the confidence dat the setup is good. i worked at mma and never saw a single engine blown unless touched by the owner who gatal tangan and just blamed josh did dis and dat. igniter is just dat, it waits for signals from the ecu / sensors den ignite sparks, so using whatever unit isnt important as long as the unit fires at the perfect time. ur engine doesnt ping, rite?

mean the 4G91 igniter and 4G93t igniter also same rite ?? Emm ... i will try to get a iridium plug and new plug cable to test first ...

I trust Joshua also .... coz everytime after he touch the setting .. the car can feel more powerful .... My fren CRV turbo .. after tuned by JOshua ... now no more pinging and go quite fast ... can tapau stock GSR ...

I just worry izzit any of my engine part got problem and coz this boom sound ... i asked Joshua before ... he also not sure which part got problem ... so hope to solve the problem from the sifu sifu out there ....

 

[xtremeleo]

mean the 4G91 igniter and 4G93t igniter also same rite ?? Emm ... i will try to get a iridium plug and new plug cable to test first ...

I trust Joshua also .... coz everytime after he touch the setting .. the car can feel more powerful .... My fren CRV turbo .. after tuned by JOshua ... now no more pinging and go quite fast ... can tapau stock GSR ...

I just worry izzit any of my engine part got problem and coz this boom sound ... i asked Joshua before ... he also not sure which part got problem ... so hope to solve the problem from the sifu sifu out there ....

u shud change the plug cable when the spark misses, means spark delivery has leak sumwhere. just try a set of iridium first and see wether the problem will be rectified. borrow from ur fren and take a run out for an hour? ping in high revv is a bad sign bro, avoid high revving before u rectify dis prob ya. ask josh to check ur ignition timing, for over advance? i never tot spark timing will be inacurate in an electronic dizzy, unless the crank angle sensor is sumhow farked up. well.. sumthing new everyday ;) ive heard a gen-2 wit a dis farked up sensor had to be sent for overhaul after only 7 month of usage. ping is a really bad sign, imo

 

[CSx8213x]

Thanks for the information ......

another thing ... if i wanna get a iridium plug .... which number one plug is better ?? like denso got ik16 ik22 ik24 ....

 

[xtremeleo]

actually iam having a lil of problemo wit the rating regarding the denso plugs but u shud use comparatively a colder plug ie grade 7, 8. i think josh shud know what rating to use bro, or u can just go to NGK / denso's site. sorry if i cant help much ya ;)

 

[wej7219]

http://www.densoiridium.com/find_part.php

 

[CSx8213x]

thanks alot ...

 

[xtremeleo]

hi bro wej, thanx a lot for the help :)