OMG!!! Twins Rock part II

[Mark_Kendrick]

that makes sense.



What were the stock drive pressures?

 

[Diesel Freak]

Originally posted by Mark_Kendrick

You are also increasing the amount of air in the motor with the bigger wheel. . this creates more exhaust so now you are forcing more air through a turbine that has more resistance to motion but somehow drive presssure drops????

you are forgetting something. Remember the "valve" in the exhaust housing... . and the turbo's swallowing ability when it opens?

 

[Diesel Freak]

Originally posted by Mark_Kendrick





What were the stock drive pressures?

I cant remember..... nor did I write them down.

 

[Mark_Kendrick]

I have a much bigger 'valve' in the exhaust so I'm hoping that drive perssure will have dropped also.



the gate on my setup is 1 5/8", stock is less than 1".

 

[smoky]

12 valve

So you are saying a Hx35/18 or 21 exh housing with an ht3b would work pretty good?? I was thinkin maybe an H2e with an Hx-40, or the hx35with an H2e or hx40 Let me know what you think but i really like your setup using stock turbo. Jered

 

[Mark_Kendrick]

The Hx 40 is only about 1/6 larger than a 35 and a H2E is about a 1/3 larger... you need 2 X the flow.



The 16+ cm housing will allow more air out of the motor w/o a wastegate though you will still need one. The p-pump will spoola larger housing a lot faster than a 24v. they are really a different animal where fueling and housings are concerned. If you like you could use a BHT3B to get a 19cm housing on the big turbo and spool it quicker. I would still go with the HT3B and the 22cm housing(the way it comes in the box).

 

[J.R. Adkins]

FWIW

I have run the 27 and 32 housings on my ht3b and the truck runs better with the 32. Cool down times are quicker and spool up really isn't any change. But the mid and top end are !!

It still smokes very heavily @ 60+ psi!!





Mark,



If you don't have any More smoke you need some bigger injectors. IMO







J. R.

 

[Mark_Kendrick]

Where can I get the larger exhaust housings? I may get a few to do some testing.



I have LITTLE smoke at WOT w/o the FMS. with it is stills smokes a good bit but not anything like it did before.

 

[J.R. Adkins]

After more testing on the 27, its hard to watch the road, keep the truck straight, and look @ the gages. I did see the egts rise faster with the 27 vs the 32. I can still peg the 1500 deg gage. (i am very heavily fueled)



Mark,



PM me if you want.





J. R.

 

[jimk]

boost pressure

Mark if you can increase the cylinder head flow, cam shaft design, after market inner cooler, use marine piping to feed the intake system or any thing else to increase flow will the result be lower boost pressure.

By reducing the pressure will this reduce the temperature of the air charge? Will the reduced drive pressure result in more torque if the pistons see less resistance to movement.

thanks again Jim

 

[Mark_Kendrick]

If you increase flow to the cyinder. . heads and cam and such. . you drive the turbos quicker and get more air in the cylinder. A larger intercooler is great for reducing pressure drop across the intercooler but the real limit to sustained HP is heat soaking' of the intercooler and radiator.



Cams, heads and intercoolers are essetial to VERY high HP applications. You may not see the real benefit of each of them w/o one or two of the others.



ex. a head/cam that flows more than the intercooler will not be realized. an intercooler that flows more than a head will be 'wasted'.



FWIW,

Mark

 

[Mopar-muscle]

mark , have you had a chance to measure drive pressure yet ? inquiring minds want to know ...

 

[Mark_Kendrick]

I'm still working on it... .



It seems to be working well. I had pretty good numbers at the DFW dyno day.

 

[Diesel Freak]

mark, you need some dyno time on a loading dyno. This is not for getting peak HP numbers, but to allow you to load your engine at specific RPM's and loads to get your wastgates dialed in.



you will need

1. a 0-80 psi gauge for drive pressure

2. a 0-50 psi gauge for secondary boost pressure



load the engine at 1500, 2000, and 2500 rpm to 20-30 psi of boost, and check drive pressure, then do the same at 3000 RPM.



repeat the same at higher boost levels untill drive pressure starts to get high.



the idea here is to ballance the opening setpoints of your wastgates to lower drivepressure as much as possible while maintaining the spool up time you want.



A dynojet is useless as a diagnostic tool for a test like this, but a mustang dyno can give you a wealth of information.



Good luck, and have fun

 

[CRoth - BD-Power]

Unfortunately even with the wastegate dumping excess pressure, the drive pressure will still rise, mainly do to the flow inefficiencies of the plumbing and the additional turbulence that this system causes.



Best case, you want your boost pressures to be slightly higher than your drive pressure. But I can guarantee if your using the stock intercooler you will have a significant pumping loss because of the flow restriction the intercooler causes.

 

[Diesel Freak]

Originally posted by CRoth - BD-Power

Best case, you want your boost pressures to be slightly higher than your drive pressure. But I can guarantee if your using the stock intercooler you will have a significant pumping loss because of the flow restriction the intercooler causes.

Very true. Another reason drive pressure rises even with constant boost pressure is that as the engine RPM rises the turbo has to spin faster to provide constant pressure to the intake... ... basicly if boost is 30 psi at 2000 RPM, it takes more air to feed the engine with 30 psi at 3000 RPM... so the turbo has to spin faster... . to spin it faster you need more drive pressure.



too bad there was not more room in front of the radiator for a larger intercooler. You could cut your pressure losses by almost 25% if you doubled the flow area of the intercooler.



But I think you may have already thought of this.

 

[Diesel Freak]

#ad




For example, if I were using the above turbo at a PR of 2. 2 and a mass flow rate of 35 LBM/MIN which in my example I will say is equivelant to the air demand of an engine running at 1500 RPM. Now I rev the engine up to 3000 rpm but the turbo is still operating at a PR of 2. 2. Now the air demand of the engine has theoreticly doubled, so it needs 70 LBM/MIN to operate. compare the two points on the graph, and then find the Turbo rpm required at those two points. What happened?



Turbo RPM went from approximately 75500 RPM up to 87000 RPM. Compressor efficiency went from 75% down to 65%.



what does this mean?

 

[TxDieselKid]

Got any maps like that for Holest turbos? Let's say the HX50 and up?



Andrew

________________

It's never really over... .

 

[Diesel Freak]

Originally posted by TxDieselKid

Got any maps like that for Holest turbos? Let's say the HX50 and up?



Andrew

________________

It's never really over... .

nope... . Holset wont give them up without a fight. Friggin *******s!



but if you have a "complete" holset map... 1LBM/HR =. 03667KG/SEC

 

[JTMcCracken]

I didn't follow the former, now closed thread originally, but went back and read it today, and I have to say this: This kicking people out and closing threads strikes me as overcontrolling. The thread got off the subject and you had to close it? Give me a break, your the same guys that defend some guys post about" how much human waste have you produced in your lifetime"! Talk about off the topic. I enjoy this site but these things are begining to wear on me. JTMcC.