Thread: Decided on Blowthrough

Fixed a few boost leaks, MAF adapter was one of the culprits.

I'm still only building 7.5 PSI. Is blow through more sensitive to boost leaks over Draw Through?

Nevermind

It makes 0 sense as to why, I'm confused and about to put a freaking check valve before the wastegate hahaha

one of the drawbacks of blowthrough... any leak before the maf won't really be noticed until the turbo is overspooling and you can't build boost.

Wait can you say that again? I'm not following to why it would make a difference on the wastegate.

The wastegate is pressure dependent right? So Draw Through or Blow Through it should be getting the same pressure right? Unless it has to deal with how fast the engine it self spins up. In which case it would still go to at least stock boost.

Blow through is less sensative then draw through. You can have all the leaks you want and your car will feel the same on blow though. Unless the leak is in that 12" between the maf and the TB. Unlike draw through where you have 10' of piping and IC between your MAF and TB.



You will not overspool your turbo if your getting your wastegate source from the manifold and not from the hotside piping.

Well yes I know that, and I'm liking my idle with blow through a bit more. Hasn't been stalling as much (rpm dipping that is).




I thought you were supposed to use the cold side of the piping for the wastegate. At least that's where the stock Avenir BOV has it.

I would think if nothing else was changed except moving the MAF and your dipping problem went away that you had a small leak somewhere and you just moved the maf before it.

It doesn't matter whether it's hot or cold. Alot of people tap the actual turbo outlet so they have instant action on the wastegate (which would be hotside).

My first turbo outlet had it on there. I'm thinking about getting something closer too. I would tap the turbo, but fill icky about doing that.

I will check a few things today, the performance has been a bit worse, but that's because the A/F dips to 10:1 as soon as I press on the gas. So once I figure out the PSI deal, I can tune it out. That is if I stay with blow through.

Yea, that doesn't make any sense.

Any boost leaks are going to lead to the turbo spinning faster to acheive the same boost pressure, regardless of where the leak is. It will just be perceived differently based on maf placement.

If you have a boost leak on pull-through, the car will just run really rich. If you have a boost leak on blow-thru (before the maf) then you won't even know unless you can hear the boost leak. Good luck with that.

The wastegate will only open when the boost pressure is acheived, and boost leaks WILL cause issues with compressor efficiency and you could overspool the turbo.