alright lady and gents.....i finish getting her fire ringed and cranked the boost up and i was amazed how thick the black smoke was still with the boost spiking 84 PSI......i keep turning out the wastegate and she will not go beyond 84psi.....is this the end of the line for Twins?............by the way the rush of power when she gets up to boost is what i call dang right creepy......... the responce is more less like this...... 0-40 mph it feel like it did when i was boosting 60 psi but from 40-100 mph it dang right scary......you blink and youll be pegging 100 already........ remember the old racing games in the 90's where they would just fly to 100 that how it looks when you watch the speed

 

It might be time to book a little dyno time to see what boost makes peak power......at 84 psi, I wouldn't assume it is making more power. The turbo(s) could be over speeding......is your egt higher or lower at 84 psi? As for 84 psi being the limit of twins.......well no, not really - it depends on how much they were designed to flow......for a small set of twins 84 psi is probably too much.....but for some of the big twins set ups out there, 84 psi isn't much at all!

 

Talking with bd, they said anything past about 58psi on a 2nd gen is doing no good. I'd hate to see what your drive pressure is at 84. I'd bet thats why your smoke isn't clearing up. Drive pressure > boost pressure= less cool boost into the cylinder.

 

What twins do you have? 84lbs is a relative # depending on the chargers.
Are your injectors stage 5's or 275RV's ?

 

I read somewhere that 1 pound of boost equals 10hp. This makes sense with my setup. I get 28psi so I figure I'm right around 280. But could this hold true when you get into big boost numbers like 84psi? The way storx is talking about flying up to 100mph, maybe you are in the 800hp range?

 

actually I think you need 1 pound of boost for every 10 horsepower to keep everything in check.

 

The 1lb boost to 10hp cant be correct. Maybe in certain situations, but its not accurate by any means. I was making 40psi with my stock housing, and im probably only around 270-280hp.

Eric

 

I'm making about 36psi and I dynoed at a measley 260. I'd say get on the dyno and see where the power is being made. What size twins are the BD's?

 

diddo. I was running 34pounds and dynoed at 230hp

 

Agree! The original concept has been misinterpereted and turned around.
More air can't hurt but 1 psi boost per 10 hp, under heavy throttle, should cleanly burn the fuel required to get to that hp level.
Even a little less will work with big enough turbo. Example: a full B-1 or a Sledpuller 66, at 40 psi boost should comfortably handle 500-600 HP.

Keep in mind that this boost needs to be usable; cool air from compression...not pressure from heat expansion (over-reving too small a turbo).

RJ

 

beleave it or not my EGT was 1300 under WOT tell 100MPH.........its a BD twins kit with S400 big turbo and S300 small turbo......and the injectors are rv275 bodies with stage 5 nozzles.......i want to find out the hp/tq numbers because she feels lot more powerful then the last time i dynoed her out at 591hp

 

HOLDY $QUAT BATMAN


That is a lot of boost!!!


I just can not emagine ridding in a truck like that.


I have had many motorcycles and cars that were fast, but a 7000lb truck that accels like a video game wow!!!!

back to the original thread lol

 

If you pull back on the wheel...does the front end lift off yet??

I believe CTDNut is correct. For your smaller set of twins...you may be overboosting them.

Jim Fulmer (800 hp+/-)...with a B-2 on the bottom and an HX-40, I believe, on top is at about 80 psi.

Might want to experiment with a little less testosterone?

Who did the Firering job for you?

RJ

 

Hows the innerrcooler like'n all that boost.

 

its not given me a problem yet....i had to take it out and soak it in a solvent tank because of all the carbon buildup inside it but other then that its running great...