booost lag

[cerealkiller]

car went for tuning 8v performance


need advice please i have a huge boost lag issue we have check timing on the abf every thing is in when it boosts to 0.5 at 3000rpm roughly up to 5500tpm then it shoots to 0.9bar anybody every had such a problem

[panic-mechanic]

turbo sizing
wastegate adjustment
exhaust leak
boost leak
turbo clearances off
low compression
dual scroll plumbed incorrectly
take your pick. Without a lot more info one can't even begin to comment.

[Killerwatt]

Yup. Without knowing your setup it would be hard to say.

But are you sure you don't have boost creep?

[cerealkiller]

size gt35 82/63
38 turbonetics wastegate
not a twinscroll single gernel
scat rods
arias pistons

UNFORTUNALTY RC PERFORMANCE DID THE BUILT SO ITS BEEN TRIAL AND ERROR FOR TWO YEARS AT THE MOMENT

so i ll strip the wastegate to check if the sealing ring was installed properly

[dcmk4]

That turbo is way too big unless the car is running some super high compression with high octane fuel

[Jueshen]

size gt35 82/63
38 turbonetics wastegate
not a twinscroll single gernel
scat rods
arias pistons

UNFORTUNALTY RC PERFORMANCE DID THE BUILT SO ITS BEEN TRIAL AND ERROR FOR TWO YEARS AT THE MOMENT

so i ll strip the wastegate to check if the sealing ring was installed properly

My project car is also there.

gonna pm u

under new management now.

[panic-mechanic]

For that size turbo it is behaving exactly as expected. Now just rev the motor to 9000 and you should be just fine..
It's too big if you wanted spool low down.

[Killerwatt]

I'm actually surprised that you see 0.5bar at 3000 rpm.

[cerealkiller]

so i removed the wastegate wasnt to tight gonna check that put in a different boost spring also noticed the intake of the turbo full of oil when i removed the intake pipe

[panic-mechanic]

Stiffer spring will not make it come on earlier. Will just give you more boost when it does unless that thing is standing open or creeping hugely from 5500 onwards.
Does the breather go into the intake. Again without knowing or seeing the setup it is hard to comment on some of your questions.

[cerealkiller]

i know panic im tryig in the evening as much as i can, sarel 8v performace said the turbo size is fine there is something else that is the problem when he dynoed it , no breather pipe ,

[panic-mechanic]

If no breather into the intake then your turbo has a leak at seals.
There is no way that turbo is going to give you full boost on that size engine at 3500. I think you are barking up the wrong tree with anything else you change. Were you chasing massive HP or why such a large turbo?. It's specced for 670 HP. is everything else built to support that?.

[dcmk4]

Any pics of said turbo and setup?

[cerealkiller]

If no breather into the intake then your turbo has a leak at seals.
There is no way that turbo is going to give you full boost on that size engine at 3500. I think you are barking up the wrong tree with anything else you change. Were you chasing massive HP or why such a large turbo?. It's specced for 670 HP. is everything else built to support that?.

whatsapp you a pic of my engine bay , as i said sarel 8v said the turbo size is fine. i wanted 350kw to 400 for now as im gonna check the turbo,sarel tuned a few cars with that turbo!

[cerealkiller]

me i dont bark i take the tree down

[Killerwatt]

If that's the power you want then you need to accept the lag.

What kind of boost control do you have. It is a bit odd to hold 0.5bar for 2000 rpm then boost 0.9. But for the power levels you want you need to be around the 1.5 bar mark anyway.

[cerealkiller]

just please keep in mind i didnt buy the turbo RC performance did so i wont know if the turbo was a problem from the beginning some people like to swop parts and tell a person its new

[cerealkiller]

If that's the power you want then you need to accept the lag.

What kind of boost control do you have. It is a bit odd to hold 0.5bar for 2000 rpm then boost 0.9. But for the power levels you want you need to be around the 1.5 bar mark anyway.

im using that

https://frsport.com/isr-is-mbc2-v2-manu ... ller-black turbo nipple to bottom wastegate nipple

[Killerwatt]

If that's the power you want then you need to accept the lag.

What kind of boost control do you have. It is a bit odd to hold 0.5bar for 2000 rpm then boost 0.9. But for the power levels you want you need to be around the 1.5 bar mark anyway.

im using that

https://frsport.com/isr-is-mbc2-v2-manu ... ller-black turbo nipple to bottom wastegate nipple

Throw that thing away! Had a similar one on my jetta, piece of crap.Basically its a pressure regulator and does not do well as a boost controller.

Try running a line directly from a boost pipe to the bottom wastegate nipple. Boost should hold steady and will be controlled by the wastegate spring stiffness. If boost is fine then add a ball and spring type boost controller.

[cerealkiller]

ok will do , ive got a few springs im gonna change the spring to get it to 0.9

[cerealkiller]

just a question what can i use to seal the turbo and wastegate

[dcmk4]

just a question what can i use to seal the turbo and wastegate

Gaskets...

[cerealkiller]

thanks bud , have another question how much play can a turbo have when moving the shaft

[Jetta2]

Turbo should have very very little play when moving the shaft up and down or in and out.
The bearing clearances on journal bearing turbos are usually less than 0.04mm. That is tiny, thinner than a normal sheet of A4 paper.

[cerealkiller]

sweet thanks i think my turbo is shot with the comp housing off i can move it abit more than that