I’m having some rather irritating late spool issues with my setup. The setup, stock B16, Spoolin performance tubular log manifold, T3 turbo (AR .50 compressor .63 exhaust), tial knock off wastegate with 6.25 spring, a Neptune base map.

Now the problem is the car is boosting seriously late, its barely making 5 psi and that’s not till 6.5-7k rpm. Now this obviously isn’t right and it should be hitting full boost by 4-4.5k rpm is my belief. I’ve pressure tested the boost lines, checked cam and ignition timing, blanked off the wastegate completely, the turbo spins freely and there are no exhaust leaks so I’m kind of at a loss. Its acting as if the turbo is too big for the engine but I know this isn’t the case.

If I pop the boost pipe off the turbo outlet and rev the engine up and try and hold my hand over the outlet there is no pressure trying to force my hand off at all. Is this right?

Any help would be great. Thanks

John

 

Get a new wastgate and make sure you dont have an exhaust leak before the turbo. Cheap wastegates can leak, have low resitance, or get stuck open or even worse stuck closed.

 

I realise the wastegate is far from ideal but at the moment it is completley blanked off at the manifold so it is ruled out of the equation. There are also no exhaust leaks pre-turbo.

 

sounds like you have a huge leak in your charge piping. reving the car up in neutral isn't going to give you any positive pressure.

 

You have a boost leak somewhere...Check all the couplers and clamps for starters.

 

my friend was having same issue oh his car, alomst the exact same setup, it turned out to be his turbo

 

Are you actually driving the car? Or just free reving in neutral? As mentioned above, you won't build boost in neutral cause there is no load on the engine.

 

and he's on a base map...

 

Geez people just dont learn or bother to read !! if your free reving it then its not really going to build boost ya jackass. the engine needs a load on it. get a real wastegate because those "maybe not ideal" wastegates do nothing but creep and fail time and time again, then take the car and get it tuned

 

Agreed

 

I realize most of the people in here didnt thoroughly read what you posted. It seems you already did a boost leak test found no leaks...since your car is on a basemap, what is your A/F ratio looking like? have you done a compression test on the motor? if u dont have any boost leaks then the motor might have seriously low compression in one of the cylinders...which would explain why its not building boost efficiently at all... 2nd is how sure the turbo u have doesnt have blown seals? this could also be the culprit as was said in a previous post... good luck let us know if/when you figure it out..

Please make sure you answer the question of whether all this is taking place on a neutral rev or actual driving conditions..