Do you know what his boost was? The 62/14 may be a little tight? Maybe not...the 14 is a 14...whether it is 62 or 64. LOL

 

777 on the dyno with only two runs is great. I'm sure on the street that over 800 can be had. Those twins have enough air for 900hp on #2.....about 80psi....I bet that max boost was less than 67psi. Without firerings and water 777 is a very good number. ks

 

Depending on what wheel is on the S-400...900 hp on #2 alone is a big NO WAY. Even with a wastegate on the S-400. IF he has the 135 lb wheel and a wastegate on the S-400....maybe.

My guess it is a 115/120 lb wheel...since it is coupled with a 62. 800 hp may be all they got on #2.

 

Banshee is right with the reliability issue. Myself, Timinva and some others are having trouble with a poping noise coming from the engine under hard power with the tst box turned up. when the engine pops, it appears to be blowing some coolant mist from the radiator cap. Seems as if the head is lifting and pressurizing the coolant. Engine doesn't leak or drip anything, no oil in coolant, no coolant in oil. The higher the level on the tst, the more the engine pops. So, yes the numbers are low, but 777/1299 come from the tst on just 3/1, with 26,000 psi rail pressure and egts at 1250. plenty more fuel, plenty more air, just need to figure out the pop noise.

 

This truck needs a lot more tuning. As Banshee has said, this was two shakedown dyno runs. As for the s-400, it has a 2.9 inducer wheel and a 132 non-wastegated exhaust housing on it. I also use a tial 44 mm external wastegate. These twins should flow ample air to make low to mid 800's. They should flow certainly more than some of the big single chargers that have made 800+ runs lately(silver bullet, a5000).

 

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FWIW, I have a similar twin set-up on my 96' Dodge CTD 12 valve as what "dperf" is running. I have the larger wheel on mine and saw 809 HP.
I was there at the shop when Bobby ran his truck on the dyno and there is NO DOUBT in my mind that if he had gone somewhat higher on the TST he would have EASILY gotten into the 800's, maybe 820-830. There has been alot of debate about this, but IMO the twin turbos are the way to go for max airflow and EGTs!

Again, great job Bobby!! 777 HP is a darn good number!

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John_P

 

dperf, Have you modded your thermastat like Tim has done. When dynoing the thermastat pops open and closed alot. If you drill some holes in the thermastat the sudden pressure release is lessened so you don't get a pressure build up then a sudden relief. Just a thought. There are people making over 800hp with twins with an s400 without a wastegate. ks

 

I agree about the twins...I have a 64/13 SS - S400 combo on the bench right now!

I am not a single advocate....however...I love the one I have. I am ready to step it up a notch. 575hp was great with the A5k. Ready for more!

 

I would love to hear how those two turbos do together.

One day, oooone day, whan I can afford twins I was thinkin about use some type of the new SS as the top turbo.

 

The 64-13 SS has a real big wastegate too! I have been saving for a year for this. They are only 200 more than a 14 housing...

 

AWESOME BROTHER !!!!! Amazes me to no end the power you guys are tweaking out of this lil ole 5.9 ........ I drove concrete trucks for yrs with L-10 ,M-11 ,N-14 ,ISM and of course the driveline destroying non electronic 855 big cams and NOT ONE was over 425 hp !!!!

Smoke on gentlemen

 

abc4yew:
I have modded the thermostat and have removed some material off the fins on the water pump itself. i also have a blocking plate on the rear freeze plug. Did some running at the track today and figured out that the poping noise was coming from excesive timing. Had to back my tst timing all the way to 3 degrees. definately feel like i lost some power from decreasing the timing, but think i can make it up now with a little more duration. Definately more testing to be done. Have done my shakedown dyno and drag, know what i need to adjust, and will try again as the viscous cycle continues. IMO, my twins had excesive drive pressure with only the stock wastegate in the 62/14. tial 44 reduces this and helped in return with egts. thanks for the input!

 

It's all in the tuning Bobby! Keep at it and that thing will be a beast!