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Need Help Rb25det Problem!

l0WRB

By l0WRB,
in Engines & Forced Induction

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aphid Proficient

aphid

Posted
Posted
im running a HKS GT2530kai with a stock ECU and SAFC II, is this bad? can the same prob. occur with mine if i boost it too much?

it all depends on your ability to tune the SAFC, but if the SAFC is tuned with acceptable air fuel ratio's and the engine isn't pinging out of it's brain, as in this case, then no.

MKDR33 Mentor

MKDR33

Posted
Posted (edited)
it all depends on your ability to tune the SAFC, but if the SAFC is tuned with acceptable air fuel ratio's and the engine isn't pinging out of it's brain, as in this case, then no.

my SAFC was originally tuned with the stock turbo was on, i havnt tuned it with the 2530 yet, but it seems to be running fine at 1 bar so far, anything over 16psi and i get fuel cut..

im hoping a Z32, Walbro pump and re-tuning of the SAFC will fix this problem..

P.S. Sorry for stealing thread l0WRB

Edited by MKDR33
l0WRB Mentor

l0WRB

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yeah i woudnt be boostin it over 7psi! trust me i never heard once Detonation, i owned 2 vl calais turbos b4 my 33 and i know wot detonation sounds like! then again once aarons highflow turbos come onto max boost there fkn loud as!

l0WRB Mentor

l0WRB

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wow look at the green 32 in the background of the photo 7 of the first group of pics.

looks like it goes alright haha.

yeah its only got 400rwhp and some random dude called nick81xd owns it, how random he is building my engine 2? haha the white skinny guy in the pic!

l0WRB Mentor

l0WRB

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quick update

ive decided on putting in a set of wiseco forged pistons with new rings and some big end bearings and new head gasket and bolting it all back together..i dont know if it's worth shot peening the rods..anyone else had problems with standard rods at 300rwhp?

Adriano Grand Master

Adriano

Posted
Posted

rods will be fine, are you fitting oversize pistons? i would agree with paul, that there is no way the highflow has caused this directly, i would be checking your fuel pump, and your breather setup. I bought a vl with an r34 motor with 4 cracked pistons due to the breather hooked up to the intercooler piping, which meant the turbo was pressurising the crankcase causing detonation at 7 psi.

l0WRB Mentor

l0WRB

Posted
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rods will be fine, are you fitting oversize pistons? i would agree with paul, that there is no way the highflow has caused this directly, i would be checking your fuel pump, and your breather setup. I bought a vl with an r34 motor with 4 cracked pistons due to the breather hooked up to the intercooler piping, which meant the turbo was pressurising the crankcase causing detonation at 7 psi.

i installed a walbro 255ltr fuel pump and car had a catch can hooked up both breathers were venting to a filter thru the catch can so i dont think it would be any of the above...hmmm mite get the injectors cleaned and flowed

Adriano Grand Master

Adriano

Posted
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Im not sure, but ive heard bed things about the walbro's ability to flow at higher fuel pressures, i doubt that its injectors, as 4 of them would have to be blocked for this to happen. I suppose the other thing that could cause this is an afm problem causing it to run lean. How do the plugs look? And is the cas near the centre of its adjustment?

l0WRB Mentor

l0WRB

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Im not sure, but ive heard bed things about the walbro's ability to flow at higher fuel pressures, i doubt that its injectors, as 4 of them would have to be blocked for this to happen. I suppose the other thing that could cause this is an afm problem causing it to run lean. How do the plugs look? And is the cas near the centre of its adjustment?

walbros seem fine if u get a proper one,i know of a few mates cars making 400rwhp with this same pump..when i first imported the car start of last yr it felt really sluggish..noticed the timing was set at 0 degrees..set it to 15degrees and left it at that..and the cas is more like all the way left arm down..

proengines Rising Star

proengines

Posted
Posted
quick update

ive decided on putting in a set of wiseco forged pistons with new rings and some big end bearings and new head gasket and bolting it all back together..i dont know if it's worth shot peening the rods..anyone else had problems with standard rods at 300rwhp?

Have a quick look arounf for a set of RB26 rods. They should be cheap as dirt given how cheap aftermarket ones are. They are a straight bolt in and vastly stronger than the 25 rods. I've seen plenty of broken RB25 rods, never seen a broken 26 rod in that type of application.

Guilt-Toy Grand Master

Guilt-Toy

Posted
Posted (edited)

hahahahahahaha OH MAN. that is so funny. Who the hell did that?

ohhh yeah can we see some clear pics of the broken pistsons?

cheers

rods will be fine, are you fitting oversize pistons? i would agree with paul, that there is no way the highflow has caused this directly, i would be checking your fuel pump, and your breather setup. I bought a vl with an r34 motor with 4 cracked pistons due to the breather hooked up to the intercooler piping, which meant the turbo was pressurising the crankcase causing detonation at 7 psi.
Edited by Guilt-Toy
l0WRB Mentor

l0WRB

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hahahahahahaha OH MAN. that is so funny. Who the hell did that?

ohhh yeah can we see some clear pics of the broken pistsons?

cheers

this is the best piston outta the 4..the worst one i left in a mates car!

but you can see the cracks pretty easy

also a picture of the bore in cyclinder 3 where the piston ringlands fell apart once the pist came out

not a mark in there

post-29137-1173229076.jpg

post-29137-1173229152.jpg

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