Back Pressure....How Much Is To Much?

[weather man]

Thanks; I am not a turbo know it all, all I can do is ask the questions from Justin@ Comp and discuss with the customer....and I am sure as with anything out there people have their thoughts and opinions about product X or Y, there are good stories about Comp and then there are issues with Comp, just like any business.

Justin at COMP would have saved me a whole lot of grief by saying "not the right turbo for your setup" I get that he wants to sell shit, but sell me the "RIGHT" shit.

 

[Greg Hazlett]

What is interesting about that is when I call for a turbo price he asks me what I think are the important questions;

What size engine?
Stick or automatic and if an automatic what stall?
Stock/ported heads and if not stock what cam specs?
How much boost?
How quick to spool?
Inlet/outlet size?
What ar?
Type of connection it is mounting to?

 

[Makdaddy]

So Brian after reading this thread for like the 10th time lol

I assume you are changing the turbo and seeing if that makes a difference?
Can you borrow one, maybe someone has the size you need ?

Anxiously waiting

 

[JoshK]

I have my precision off right now.

 

[weather man]

So Brian after reading this thread for like the 10th time lol

I assume you are changing the turbo and seeing if that makes a difference?
Can you borrow one, maybe someone has the size you need ?

Anxiously waiting

I am gonna install a EGT and see where I am. If I am OK, I will push it as far on 91 as I can go with the EGT, AEM boost controller and my pump setup (dual boost a pump, if I have to). If I can get to 600, call it good. I might try E85, which would lower the EGT temps 200 to 300F.

I actually have good access to E85, but 91 you can find anywhere.

Car is parked for winter...not sure how fast I will move on this.

 

[one eyed willy]

Justin at COMP would have saved me a whole lot of grief by saying "not the right turbo for your setup" I get that he wants to sell shit, but sell me the "RIGHT" shit.

Pretty sure we have the same turbo, with my old hot side I had zero issues! Over 650 hp with 16 psi. Not sure about my new hot side yet.

 

[aleborjas]

3-1 back pressure is way to high.

My 1st guess is going to be not only is the AR too small but so is the turbine.

Hell K series Hondas have bigger turbos then that

X2

.96 A/R is ok but turbine size is too small i've had the same isue with a friend's car when youy turn up the boost over 16 the started to slow down at the track and ECT starts to creep up and rpm range 5800-6000 over that the engine was like chooked and i just bought a 7675 .96 precision have not tested....

 

[weather man]

My first custom kit I built was 3:1.....it took about 2 weeks to bend a rod. Your motor is built so you won't have that issue. The higher BP will create more heat, I'm not sure how those seals will hold up.

That's why on my second kit I built I used 3" from the manifolds to the turbo, I had 1:1 at that point....now I'm switching to a THP hot side and not sure what I will have.

I don't understand why your BP is so high, mine was high because when I built my first kit I actually built it with a 2.5" down pipe, had the wastegate recycling to the down pipe and had 2.5" over axle pipes. I dropped that first kit to 2:1 with 3" down pipe, 3" magnaflow exhaust and vented the wastegate....your already there with all that.....

Whelp, I went back and looked after our other conversation...wish I had paid a bit more attention to this. The borla touring catback is 2.5". So many pieces to the puzzle.