BBA

stock hx-35/b2(s400)

dieselfan

i thought that was a quick spooling set of twins?

BBA

Me too!

Its just something is wrong with them i guess and I have had them for atleast 6months now and have yet to get them tuned right. So I figure if im going to have the slow spool why not atleast make better power and hopefully spool a hair sooner if im lucky!

Diesel Doc

is your wastegate functioning properly it almost sounds like it isn't closing properly

BBA

I have no idea? I know that I have it set where I only hit 45psi right now and it does that just fine. I was about to get headwork and I could open it up a little better but with it being such a slug i decided to just go the route of a single.

Diesel Doc

that setup should start winding up around 13-1400. I would check the gate first before you give up on the twins.

HOHN

... I think you may have a turbo mismatch. The B2 has a large 1.32A/R housing which makes good power up top but takes awhile to get rolling.

So here's what you have with your combo-- a stock charger with a tight housing that lights (or should light) early, and a big charger with a largish compressor and a huge turbine housing that lights a good bit later.

I think that your stock turbo is both too small and has a leaky wastegate. The problem is that the turbo is making a lot of boost (or trying to) just to get the big charger going, so that by the time the primary lights you have no room left in the top charger.

IMO, you need either a larger top charger, a smaller bottom charger or both. Usually, you'll find an HX40 or an S300 over a B2. Those chargers flow a lot more air on the hot side.


Here's my personal rule of thumb: you should have no more than 20psi of total boost before you see boost in the cold pipe from the primary. Ideally, it would be more like 15psi.

JMO

Diesel Doc

the way I have mine setup I see only 10lbs total boost before the primarry starts lighting by 15 it is singing good. If I mat it it builds like stock to 10psi and then jumps lightning quik to about 55-60 and builds from there.

Mike Holmen

Check for exhaust leaks, boost leaks and/or wastegate isn't closed. Something is off, and prior to spending $$$ its always good to look into things abit more.

BBA

I have one small exhaust leak and other than that i havent seen anyother exhaust leaks and I have checked over everything but cant find any boost leaks. Im not sayn there isnt any boost leaks but i cant find any. Its just a pain in the u know what trying to keep these things in tip top shape. I will probably just go with a single for now and maybe go back to the twins at a later note when I have another vehicle to drive instead of having a horrible street truck.

Mike Holmen

I just plug up the turbo inlet and pressurize with air the entire system from the cylinder head back to turbos. You can usually hear a hiss from the bad leaks. You always get leaks after putting some good pulls on the engine. These truck weren't designed to run 80psi of boost, and its a different game then only pulling 50psi of boost. I can relate to the truck issues. They seem to fall apart when ever you need to use it.

BBA

Yea I have been told to do this but cant ever seem to find all the parts I need. Yea seems like everytime I dyno I have everything in good workin condition leave the house play around on the way because were normally in a caravan go dyno see low numbers find a boost leak that wasnt there before I left! So Im going to just go to a single and see how that plays out.