djdosile

Having a boost issue and i've run out of ideas of what could be causing it.

Basically the car will only reach 11 PSI of boost no matter what i've tried. Please note all turbo kit parts are brand new (Go-autoworks Street Kit).

Engine is a JDM SiR B18C (B18C4) with forged rods & pistons in an Type-R EK9.

So far i've:

- Eliminated the wastegate being the issue (ran boost to the top port of the wastegate to keep it shut and still only achieved 11 PSI - should have spiked out of control - also done on dyno with visual of wastegate to verify it isn't opening).

- Checked for any boost leaks using a tester.

- Examined Intercooler & piping for any restrictions.

- Checked for any exhaust leaks from head to turbo - fitted brand new gaskets and bolts to make sure of a good fit

Turbo is a T3/TO4B Turbonetics and should be able to easily achieve more boost.

On saturday we are going to take off the exhaust system and see if its that but causing a restriction but i'm doubtful as its a 5zigen 2.5" system and should be spot on.

After that i'm stumped.

NotARaCist

iTrader: (1)

What gear are you testing in? Have you tried completely disconnecting the wastegate? Is the blowoff opening, or possibly leaking?

justYncredible

iTrader: (1)

What map sensor are you running?

turbomaniac

as you allready checked for air leaks (hope you checked well), i suggest (as given sequence):

check the boost controler settings (if there is any)
disconnect the BOV and tap the hole and if fixed replace your bov.
disconnect the waste gate and if it boosts to heaven, replace or repair the actuator

djdosile

2nd - 3rd - 4th - All the same.

Blow off didn;t open or leak while pressurising the system - its a brand new Tial BOV with a good 1/4" line direct to the IM.

Hondata 4Bar - and AEM Boost gauge - both readings match.

Yeh used a turbo tester plug thing and compressor to pressurise the system.

BOV block off might be worth a look so thanks for that suggestion. I have my doubts, would be audible if it was leaking wouldn't it.

Wastegate was tested with a big spring in it and boost going to the top nipple (should of boosted to heaven) we had the dump tube off and you could put your hand in front of the outlet while on the dyno (nothing coming out - dont recommend trying that at home... LOL) so the wastegate is 100% not the cause here.

wantboost

iTrader: (2)

What ems are you using? there could be a boost cut somewhere in a menu.

djdosile

Hondata - good thought but sadly not it - boost cut is set at 14 psi. Hondata Map sensor is reading a max of 11.

KevinEF7

Based on the pretty thorough troubleshooting youve done, sounds like a tune setting problem

djdosile

Any thoughts on what it could be? Boost control isnt even coming into it and AFR is good.

A tuner has also looked at it (with a Road Tune using AFR gauge) and couldnt work it out either which leads me to hardware rather than tune.

boostjunkie757

so youve used a manual boost controller to try to up the boost it sounds like..


have you tried one that was known to be in working condition? or are you using an electronic boost controller that is known to be in working condtion?

youve given a plethora of information, but not what is necessary for the assistance requested.

djdosile

Sorry, just to be clear I'm 100% certain that the wastegate or any boost control is not at fault here.

We have had the car on the dyno with the dump tube off (so we can see & feel the valve operating) and the wastegate did not open (we had a 14 PSI spring in the Tial Wastegate and the boost going to the top port of the wastegate to keep it shut - with a boost cut set at 14 psi for safety).

With the wastegate definitely shut it still only reached 10-11 psi. It should have spiralled out of control which leads me to believe its something else.

boostjunkie757

if the wastegate did not open then you should have had more boost than you knew what to do with.


i dont know if youre going to be able to get the solution online. especially not with the way you ask your questions and respond when someone asks questions that might point in the right direction. you didnt say what you are using to control the boost other than the wastegate and turbo. if you dont actually have an mbc or ebc hooked up to the wastegate, it doesnt matter whether you say you see it isnt opening...if you dont have anything hooked up to it it WILL open at the spring pressure that is in the wastegate. just cause youre saying you dont see it opening doesnt mean anthing.

djdosile

Yep totally, but instead of doing that it just stops at 11 psi with the wastegate still shut & a 14 psi spring in it.

I appreciate the suggestions, didnt mean to sound blunt or condescending so apologies. I was just hoping someone might throw up some things that i might of overlooked.

I do have boost control (the Hondata + MAC valve method + Tial Wastegate) and have tried everything to get it to boost above 10 psi. Bigger springs, checking pipes, changing settings...

Not sure by what mean with "just cause youre saying you dont see it opening doesn't mean anything". Guess the point I was trying to make is that I know it's not the wastegate or boost control causing the issue as essentially i've seen it run with what is in essence a blocked off wastegate and it still stopping at 11 psi.

TheShodan

iTrader: (14)

So, based upon that logic, and you obviously know how boost control and these apparatuses operate, how would you narrow it down? its either Boost control, vacuum lines, wastegate, or something in between. These other suggestions were made so that you can deduce your most probable possibilities.

boostjunkie757

i appreciate the change in approach, i know i can come across like a complete dick sometimes but i dont let it bother me..


even if you have all parts & electronics that are proven to be in adequate condition to perform the tasks they need to, if you dont have the vacuum lines all plumbed in the most efficient manner, you can still experience problems like this.

for your sake, i hope someone that actually lives near you is already in contact with you and can check it out in person because seriously, if you havent dealt with cars with this level of mods for an extended period of time, you could be overlooking something blatantly obvious.

turbomaniac

have you checked for cracks to you turbine housing or at the exhaust manifold?

djdosile

Thanks man

Sadly I live in a area in the UK that is pretty deprived of Honda or even Turbo specialist...

I'm removing the exhaust system tomorrow and taking it for a run to see if its a restriction thats causing the problem - i'm hoping thats it.

I really do hope it is something blatantly obvious so i can punch myself in the face for missing it... Ha

The last thing i guess could be a bad turbo.

Yeh had it all off for inspection a few weeks ago and couldnt see any signs, would a crack leave some blow by/black soot somewhere around the turbo?

boostjunkie757

damn, i didnt realize where you were..

turbomaniac

yes if there is a crack before the turbine wheel, the wheel could not spin fast and prduce efficient pressure...

its like having an external wastegete that leaks..

djdosile

Right we tore off the system and found the issue.

Turbo is fine - however the exhaust system - a 5zigen ProRacer ZZ Cat-Back - which i thought was true 2.5 inches - is no-where near 2.5 inches all the way through.

Two of the mid silencers essentially go down to a diameter of 1 inch.

Took the system off and drove up the road, I hit boost cut (@14 psi) at 5000 rpm.

All is good again

Will most likely try the Skunk2 70mm system as a replacement.

Thanks again for everyones suggestions.

turbomaniac

your lucky that your pistons didnt melt.

djdosile

Lol thanks, it was driven conservatively anyway and only really driven in anger when trying to see if the issue had been fixed or resolved.

Hopefully this wont cause any future issues. I never let the Oil temp get above 100 degrees C and also run a full width radiator. Plus they are Wiseco Forged Pistons and Eagle Rods.

wantboost

iTrader: (2)

That's what gets a lot of people... it might be 2.5" piping but most of the time the resonators or pre mufflers can be tiny.

my next suggestion was going to be to remove the pressure signal from the wastegate and do a gradual 4th gear pull. this would essentially act as though you had no wastegate and the turbo, if everything else was ok, would make as much boost as possible.

but now you know why a lot of people monitor exhaust backpressure. had you had a simple analog gauge or digital sending unit you would've noticed the issue almost immediately.

but at least you got it sorted, it's bad when something's permanently ****s fucked lol.

I would still recommend a 3" system, even if you have to import a piping system from kteller or have a local fabrication company do the fitting. they flow well and can be made very very quiet will little impact on the overall flow of the system

boostjunkie757

that sounds about right.



i should have thought about that. exhaust will do that..