693 at DDP yesterday

Camotanker

Camotanker

All American Retard
Joined
Sep 24, 2007
Messages
871
Well... got some issues going on and any help would be appreciated.

I would of suspected a higher number, but I feel I'm up against some turbo issues.

I rolled 650 w/smarty. 650 w/PPE.
smarty stacked with TST spraying a small amount of water netted 693.

with the parts however, I feel that the numbers are about 100hp low.
dual cp3's, II 62/14 over s400, flux 4.8's, studs, fass, and helix2.

the truck on the dyno has well over 24kpsi in the rail, but is limited to about 60psi of boost on the dyno and on the street. doesn't matter if the boost elbow is closed or open. the smoke never clears up so i know there is more power there. at 660hp with a single cp3 the truck would clean up to nothing.

here is the sheet... what are you thoughts? waste gate issue? i'm going to get the boost gauge on the s400 hooked up asap.


CCI00011-1.jpg
 
Camotanker said:
i don't know. i assume plain jane whatever that is... 71?
Click to expand...


I'm still learning here as well (as I hoping for twins soon), but do you know if that setup is Capable of more psi ?? Maybe it needs a Large wheel..... "luvinacummins" went with an S400 with the 80mm wheel.....That may help you push more air....

Have you called Nathan at MPI yet....He may be able to help Big time....
 
I think the dyno at DDP knows you have flux injectors.:poke:
 
Im no pro.... But i think its the secondary thats holding you back... What kind of temps did you see at the top of the run?? 62/S4...isnt that a "Towing" set up.
 
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S400 specs posted here. The map is for the 75mm wheel.

If you do have a 71mm S400, then you are out of air, and nothing other than Nitrous will make more power...remember, it's a 2.8 class turbo.

If you have the bigger 75mm S400, it should be making 30 psi. You can push the top turbo to get 70 psi total, but it will be hot!!! Still, for the power you want, a standard 75mm S400 is a bit small.

Call Rip and get a 66mm S300 and a 80mm S400 and give that motor the air it needs!!
 

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ETH/DEE said:
Im no pro.... But i think its the secondary thats holding you back... What kind of temps did you see at the top of the run?? 62/S4...isnt that a "Towing" set up.
Click to expand...

i was seeing 24K+ and at the upper rpm range 26K+.

not sure if this was considered a towing setup or not.

i'm sure it has a 71 wheel. might know more this weekend depending on what the hurricanes do.
 
Diesel Freak said:
S400 specs posted here. The map is for the 75mm wheel.

If you do have a 71mm S400, then you are out of air, and nothing other than Nitrous will make more power...remember, it's a 2.8 class turbo.

If you have the bigger 75mm S400, it should be making 30 psi. You can push the top turbo to get 70 psi total, but it will be hot!!! Still, for the power you want, a standard 75mm S400 is a bit small.

Call Rip and get a 66mm S300 and a 80mm S400 and give that motor the air it needs!!
Click to expand...


thanks cliff. i'm going to try to get the bottom turbo boost gauge hooked up this weekend to see what its doing.

the way the rod is set up on the wastegate, its not opening until about 32-35psi.
 
I've had the best luck with my wastegate set so that the linkage goes loose at around 25-27psi. I doubt that you are out of air from the primary. My 75/83/1.1 primary made 711hp with this goofy p-pump conversion. I am running a 64/71/.8 on top and it helps keep the boost down a bit. I see about 35-37 out of the primary and 65-68 overall. Common rails usually make more power with the same size charger so something is up. Your primary probably has the larger exhaust side and should not be choking at the level you are at.
 
If you find that your lower charger is not producing what it should then lossen up your top gate and drive the lower turbo harder.
 
Do you have a gage in your cold pipe between turbos?

Whay is your split at 20,30,40,50 and 60 psi at the intake?

That would help us tune you...

You need a 75 or bigger primary...
 
32-35 psi cracking pressure for the top turbo wastgate is a bit on the high side. It should be between 24-26 psi when running a 75mm bottom turbo with a 62mm top turbo. You may need a different actuator if you can not get it adjusted with the rod.

If you went with a bigger bottom turbo and ran 80-90 psi total boost then the wastgate seting you currently have would work better to run the system "more compounded" But the turbine on the top turbo would eventually turn into a cork....regardless of what you did with the wastgate.
 
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IMO your maxed out on air... I don't think you can hit 800 with those twins on fuel only anyways... anything's possible but your drive pressure is gotta be wicked high..

You definately need a s480 on bottom...

I am running a 62/71/13 over s480 and i can only hit 65 psi because i am draining the rail pressure and starving for fuel..AGAIN!!!:bang:kick: So dual cp3's are coming here shortly...

Also get your second boost guage on so you can tune them better I agree your bottom charger is coming on tooo late...
 
IMO, It needs Air. Also need to up get the Rail Pressure UP. Looks like it peaked at around 3100rpms? What tune are you running?
 
wow... tons of information here.

i'm going to get the 2nd boost gauge set up this weekend. i have "heard" of people running the same or similiar twins cracking 800hp but i can't find anyone. however, i do feel that these twins should be making more boost than 60-65. i figured 75-85 would be more inline WOT.

the wastegate is a plunger style. just above 30psi the rod plunges down opening the wastegate.

i'm going to try to lengthen the rod and see if i can get the wastegate to fire around 20-25 depending on what the bottom turbo is doing... just to see the effect overall.

the tune i'm running is the smarty revo on level 9. tq on 4, timing on 3, and rail on default. i use the tst to bump up the rail.
 
One of the worst mistakes people make is trying to correlate more boost with more airflow :poke:

You need more air, not more boost ;) Remember, the max airflow in a compound setup is determined, and limited by the capabilities of the primary. The compounded boost value is merely a function of the primary boost compounded by the pressure ratio of the secondary turbo. Increasing the total boost by running the chosen turbos out of their efficiency merely creates more heat and higher drive pressures, not more air ;)
 
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