Ways to lower D/P

[TrentNell]

looking for ideas to lower drive pressure ? While mine is pretty dang good i really want it to be 1:1 , right now i have 62-65 psi drive pressure depending on gate setup @ 52-55 psi boost .
i already have feed pipes, cant gate it more because then boost would not be balanced , have ported and gasket matched the pedistall . last few things i can think of is porting/gasket matching the manifolds ,maybe headers , any other idea's ? or is it not possible to get 1:1 @ that high of boost ? another option would be a 16cm housing for the s300 but dont want the lesser spooling asociated with a looser A/R . and might throw off the boost balance jut like gating it looser .

 

[malibu795]

you sitting 1.2:1 ratio

but that .2 is goin to be $$$$$$$$$$$ to get

 

[S Phinney]

You can wastegate drive pressure and us a regulator to dial in the pressure. It is possible to get d/p and boost to within a couple lbs. You will need to exit a exhaust port (via same type port you would place egt probe) with an annealed stainless tubing made of 316 stainless. It needs to run approximately four foot to cool the exhaust gas then into a home a/c dryer to remove particulant. From there it goes into a paint gun style pressure regulator. It will exit this and go into a turbo wastegate. You will need a drive pressure gauge to read d/p. You will be able to adjust the pressure with the regulator and inturn bleed off d/p to balance with the boost. It is a simply way and pretty cheap to accomplish feat.

 

[TrentNell]

you sitting 1.2:1 ratio

but that .2 is goin to be $$$$$$$$$$$ to get

that was my same thought

You can wastegate drive pressure and us a regulator to dial in the pressure. It is possible to get d/p and boost to within a couple lbs. You will need to exit a exhaust port (via same type port you would place egt probe) with an annealed stainless tubing made of 316 stainless. It needs to run approximately four foot to cool the exhaust gas then into a home a/c dryer to remove particulant. From there it goes into a paint gun style pressure regulator. It will exit this and go into a turbo wastegate. You will need a drive pressure gauge to read d/p. You will be able to adjust the pressure with the regulator and inturn bleed off d/p to balance with the boost. It is a simply way and pretty cheap to accomplish feat.

sounds interesting , my secound thought is what the drive pressure reduction will be worth if its diverted around the chargrers ?should still be easier on engine components maybe even pick up some power ? if boost doesnt lower i would assume the turbo's still have the turbine power needed ? humm

 

[LarryJewell]

:nothingtoadd:

 

[TrentNell]

:nothingtoadd:

quit whoring up my tech thread Larry , dont make me exersise my Pimp hand :rofl: :happy2:

 

[LarryJewell]

Not whoring it up, just subscribing

 

[malibu795]

quit whoring up my tech thread Larry , dont make me exersise my Pimp hand :rofl: :happy2:

bout to say the same thing :rofl:

 

[bullfrogjohnson]

Bigger AR's is all I can think of. I think using a DP regulator would lessen the overall boost #'s. What would a 16cm housing compare too? A 1.00?1.10?

 

[TrentNell]

Bigger AR's is all I can think of. I think using a DP regulator would lessen the overall boost #'s. What would a 16cm housing compare too? A 1.00?1.10?

It would take it from a .80 to a .90 i beleive .

and with 52-55 psi i could come down to 48-50 and be ok with that as long as power didnt drop alot . it would be interesting to be able to play with the regulator idea on a dyno to see what it would do .

 

[Idaho CTD]

A bigger small turbine wheel and/or a larger exhaust housing would be the best bet.

 

[bullfrogjohnson]

Come on Trent.....a .90 is small:rofl: i wouldnt think twice about swapping to a .90 housing and worrying about lag. Thats still a tight housing in my book.

 

[TrentNell]

Come on Trent.....a .90 is small:rofl: i wouldnt think twice about swapping to a .90 housing and worrying about lag. Thats still a tight housing in my book.

remember i am high altitude , plus i still tow , wouldnt gaiting it more acomplish the same as a looser housing ?

 

[S Phinney]

With really high D/P you could actually increase boost while lowering D/P. Since your D/P isn't bad you probably won't gain any boost but you probably won't loose any either. There are very few using this technique. The cool thing about doing it the way I described in my other post is that you should never be able to over spin the turbo making it more durable.

 

[bullfrogjohnson]

remember i am high altitude , plus i still tow , wouldnt gaiting it more acomplish the same as a looser housing ?

The way I look at it is imagine blowing through a straw... You already have your wastegate to blow off the excess pressure so you have good pressure coming out the end but your cheeks dont hurt so bad (high drive pressure). I think if you add another passage for exhaust too escape you are going to loose overall flow (boost)out the end. If you increase the diameter of the straw (bigger AR) with the same amount of exhaust flow you will have less overall pressure ands keep the same amount of flow.

kind of off the wall but this is how I look at drive presure

 

[TrentNell]

A bigger small turbine wheel and/or a larger exhaust housing would be the best bet.

nathan how did maxed out feel when you guys put the 16cm housing on ? or did you end up not going that route .

 

[TrentNell]

The way I look at it is imagine blowing through a straw... You already have your wastegate to blow off the excess pressure so you have good pressure coming out the end but your cheeks dont hurt so bad (high drive pressure). I think if you add another passage for exhaust too escape you are going to loose overall flow (boost)out the end. If you increase the diameter of the straw (bigger AR) with the same amount of exhaust flow you will have less overall pressure ands keep the same amount of flow.

kind of off the wall but this is how I look at drive presure

damn good analagy Travis :rofl: , it does make perect sence too . i am not worried about it now but will tackle one of the 2 one day . i am really intreaged to test the reg. method even if it id not to my liking , i think its a good idea ! who knows i might end up with both

in am still open to idea's and think its a good subject to discuss also

 

[MAXLLY]

I housing is about $150 try it and see what happens. Dp is resistance to flow make the hole bigger it flows better, at a cost, you know the cost. It has been my experience when DP goes down boost goes with it... think about it, the only thing seperating the 2 is the exhaust valve... backside pressure increases front side pressure... less backside pressure means cleaner charge... bla bla bla. Try the housing... sheez $150! cheap effort.

Really wanna get fancy with it... have somebody make you a charger instead of the off the shelf junk.

 

[TrentNell]

I housing is about $150 try it and see what happens. Dp is resistance to flow make the hole bigger it flows better, at a cost, you know the cost. It has been my experience when DP goes down boost goes with it... think about it, the only thing seperating the 2 is the exhaust valve... backside pressure increases front side pressure... less backside pressure means cleaner charge... bla bla bla. Try the housing... sheez $150! cheap effort.

Really wanna get fancy with it... have somebody make you a charger instead of the off the shelf junk.

this charger is a custom S300 with the highest flowing wheel availible in a 14cm , with custom waste gate porting and high throw linkage . it is about as good as a s300 can get minus the stainless housing , wich if i switch the A/R i will get the 16cm stainless even though it is alot more $$ . but i agree with you on the above statement about pressure . i have always been curious to how much power can be had by reducing drive pressure, has any one tested the subject ?

 

[S Phinney]

Curtis H. has plenty of testing in the area of d/p, boost, and engine combo's. Give him a call there at Diesel Performance Research.