Random thoughts...


If you needed more air in a Duramax, one possible option would be putting a Vortec style centrifugal supercharger in the 2nd alternator slot to pre-feed the turbo.


Relatively low cost, it would also reduce turbo lag because it's boost is related only to RPM, not engine loading. It would reduce the load on the turbo thereby decreasing EGT's (at least until you get up past a certain PSI). Might also stop most turbo bark.


Just thinnin'...








Edited by: McRat

Sounds GREAT! You're the first person I've seen mention that! They had that set-up on some old 2-stroke diesels.... might work.





Burner---------------> http://www.dieselplace.com/forum/smileys/smiley4.gif

Wow McRat....thats a brilliant thought http://www.dieselplace.com/forum/smileys/smiley32.gif


Now lets see how long before one of the experts tells that it can't be done http://www.dieselplace.com/forum/smileys/smiley19.gif

I know everyone has been lookin for a way to put 2 turbos on a Dmax. but has anyone seen this??http://www.ststurbo.com/inc/iview/258?idx=13&p=7755

Been looking at that myself. Question is, Pre or post Turbo.

The Paxton for the 8.1 would fit and have enough volume. Would have to have custom brackets
http://www.dieselplace.com/forum/smileys/smiley36.gif

Current 8V-92's have the mandatory blower and twin turbos. I saw someone races an all aluminum 6V-53 out of a M113 APC boosting to 66 psi. I'd think a good use for a supercharger would be to boost the low end until the turbo spooled up and the pressures exceeded the SC.

The Vortec is ~$2000 and could be adapted to use the GM 2nd alternator bracket (if there is room). #1 hurdle would be belt slippage at higher boost levels.


I would go pre-turbo. You would have to overdrive the centrifugal super a lot more if you go post. As it is, you will have to overdrive it twice as much with the diesel's low redline.

I've thought about it before but for the cost of the supercharger you can put a bigger turbo or a second turbo on the truck

The Vortec is ~$2000 and could be adapted to use the GM 2nd alternator bracket (if there is room). #1 hurdle would be belt slippage at higher boost levels.


I would go pre-turbo. You would have to overdrive the centrifugal super a lot more if you go post. As it is, you will have to overdrive it twice as much with the diesel's low redline.




Actually works out the same, it is more a matter of having enough CFMs from whatever is first in line. If you go post, the Turbo is cabable of spinning faster as load varies making up the CFM difference. The Super pre would not compensate as well.

Each "stage" reduces the volume of a given slug of air by some %. This increases the pressure. So if a super or turbo would give 15psi of boost, it is really reducing the volume of the charge by 50%. Stack two 50% turbos and you get the same % squeeze again. So now the charge is ~1/4 the volume or about 45psi,

I think the limited rev range of the diesel might be an asset. The super could be geared to make a whole lot more boost earlier than a gasser where you have to worry about red lining super at the high RPMs.

I've thought about it before but for the cost of the supercharger you can put a bigger turbo or a second turbo on the truck

Easier to plumb the air than the air and exhaust. Also probably the only bolt on solution for the LLY's for a while.

Often wondered why they never came up with multi staged turbos on a single shaft. The multi-stage centrifical compressors in industry run off a single shaft and make huge air. Maybe the pressures are not enough justify the complexity.

so nobody has even thought about the sts turbo kit?

Dumb question....... can you put a clutch on the thing? You know, like the ac pump, it runs when you want it to run. I don't think that we need to worry about running lean. http://www.dieselplace.com/forum/smileys/smiley36.gif





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so nobody has even thought about the sts turbo kit?


Compounded twins would be better than the paralell setup that the remote mounting would require... besides, the remote mount would have brutal boost lag IMO and be susceptible to puddle ingestion that might give the DMX in-digestion.... boom!


Just my .02Edited by: Got Juice?

Actually we have been meaning to try this out for some time now. The thought has been in my mind for close to a year! Add a second turbo in the downpipe (like the STS setup )and stack it with the stock one. My only wonder was how much boost the factory head gaskets will take. There are a couple manufactors now doing these setups, and several turbo options are available which are better then the ones used in the STS kits.

The NTPA is adding a diesel 4x4 truck class next year and rumor is they will allow up to 2 turbos single stage configuration. I was thinking about actual twins. Gut the stock turbo, up-pipes, downpipe, manifolds, exhaust, intercooler, intercooler tubing, ect. Make up a set of tube header/manifolds that each turbo would directly bolt to. Plumb the air from each turbo into the stock intake manifold along with direct port water injection for cooling. Twin pipes out of the hood for an exhaust system.
Edited by: mtomac

With all the worries about how much boost a Dmax can support, how much EGT's are too much, I believe pre-supercharger to be the safest "off-the-shelf" option. Very little fabrication would be required, and changing the supercharger characteristics means a pulley, not a new turbo. Cuts back on R&D time.


No, you could not "disconnect" the blower on the fly, but it wouldn't be necessary. You need it to spin at all engine speeds to avoid intake restriction.


My guess is it would take you safely up to 45PSI, or capable of ~750rwhp on #2 under perfect conditions. You would need one the size that supplies a SBC 15PSI @ 7000. Fabrication would involve: Brackets, 2 hoses (1 pressure), custom Vortec pulley, possibly a custom crankshaft pulley if belt slippage becomes an issue. Much simpler than twins or a remote compound.


I talked with someone ~4m ago about the remote compound option. Here's some problems - water/mud (these are trucks), oiling, reduced efficiency of primary turbo due to restriction downstream.

Made me go out to the truck and look. http://www.dieselplace.com/forum/smileys/smiley1.gif My opinion is that unless you stack at least the compressor sides, you can't get the huge boost you need to force feed the engine. Splitting the exhaust stream is gonna make it real painful building boost.

For a bolt on, I still think a centrifical is the way. Take a used F1 like this (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7925184384&category=33741) and you will have lots of air. I would put a huge one like this pre turbo. It has more than enough CFM to keep the stock turbo fat and happy with boosted air. http://www.dieselplace.com/forum/smileys/smiley17.gif

If the two twin turbos are sized right you would have plenty of boost with minimal lag.

The supercharger does seem like the easiest "bolt on" solution but I wonder how much boost the stock turbo would make if it was being force fed 20psi? The other problem is you don't get rid of the restictive exhaust housing of the stock turbo and the restrictive stock downpipe that are eating hp/tq.

Ideally a bigger stock turbo and 4" downpipe needs to be done first then add a bolt on supercharger for classes allowing 2 turbos. Edited by: mtomac

Made me go out to the truck and look. http://www.dieselplace.com/forum/smileys/smiley1.gif My opinion is that unless you stack at least the compressor sides, you can't get the huge boost you need to force feed the engine. Splitting the exhaust stream is gonna make it real painful building boost.

For a bolt on, I still think a centrifical is the way. Take a used F1 like this (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7925184384&catego ry=33741) and you will have lots of air. I would put a huge one like this pre turbo. It has more than enough CFM to keep the stock turbo fat and happy with boosted air. http://www.dieselplace.com/forum/smileys/smiley17.gif


IIRC, the Procharger is sealed oiling, so it would be easier to hook up than the Vortec, which requires oil feed.

If the two twin turbos are sized right you would have plenty of boost with minimal lag.

<font color=BLUE>For volume, I agree, but to get the high boosts? Unless you stack, you might as well just get a bigger single turbo. I'll have to look at the charts some time and see. The twin independents are usually used cause they need more flow than they can get out of a single. I don't think we(you) are there, yet. There are several singles available to feed 1000+ HP (1600CFM @ 20LB boost)</font>

The supercharger does seem like the easiest "bolt on" solution but I wonder how much boost the stock turbo would make if it was being force fed 20psi? The other problem is you don't get rid of the restictive exhaust housing of the stock turbo and the restrictive stock downpipe that are eating hp/tq.

<font color=BLUE>There is little doubt the stock exhaust path could be improved. I would like to see a true 4" or bigger pipe off the turbo. That alone would help a huge amount. Maybe a squeezed 5" for clearance.</font>

Ideally a bigger stock turbo and 4" downpipe needs to be done first then add a bolt on supercharger for classes allowing 2 turbos.

<font color=BLUE> I think if you keep the boost levels lower or even stock coming out of the stock turbo and feed a belt driven charger, you could make big gains. The stock turbo will flow 1000 or more at low boost (if I read the specs right) Still have to dump the exhaust. The nice thing about the belt driven is it doesn't bogg down on the dense air charge coming from up stream.</font>

yep

When you compound boost you have to start interpreting your efficiency maps with a different train of thought.


For instance lets say you are using a turbo that is efficient to 25psi @ 1 atmosphere (14.7psi if my high school memory is accurate)


Take a BIG charger (with roughly twice the flow of the small turbo) and feed the face of the smaller turbo with 14.7 psi, now your small turbo is ingesting two atmospheres. The compound setup in this example is then efficient to 50psi


This is a way over simplified version of the compounds I've been building on other vehicles for the last few years.


Next point-


The air follows this path


Air Filter-BIG Turbo-Small Turbo-CAC-Engine-Manifold-Small Turbo Exhaust(for fast spool and flow)-Big Turbo Exhaust-Downpipe-Tail Pipe


Now to use the compuonds the stock wastegate can be used, however I always advise the use of a high flow aftermarket wastegate (Race Gate, Turbonetics New Gen{My Choice}, Billet Extreme, etc...) The waste gate should be routed so as to bypass the small turbo but not bypass the large turbo(spool up suffers otherwise plus most trucks dont need to bypass the large turbo)


This is the simple version. If you have any questions post em up or PM me or call me. Your choice.


I left a lot of stuff out just because this is a casual conversation.


But, I will answer any and all questions you may have.


Later,


Wes

The NTPA is adding a diesel 4x4 truck class next year and rumor is they will allow up to 2 turbos single stage configuration. I was thinking about actual twins. Gut the stock turbo, up-pipes, downpipe, manifolds, exhaust, intercooler, intercooler tubing, ect. Make up a set of tube header/manifolds that each turbo would directly bolt to. Plumb the air from each turbo into the stock intake manifold along with direct port water injection for cooling. Twin pipes out of the hood for an exhaust system.



So do we assume u won't be driving it to work http://www.dieselplace.com/forum/smileys/hihi.gif

Dmax tim....


There is someone I know that has currently a twin turbo cummins motor.. making somewhere around 600+ horse .. daily driver and snowplows with it... and runs 11's in the 1/4...


Pete

What your saying crawler, is that you would put a belt driven Super (with twice er whatever the CFM of the turbo) before the stock turbo.

Big belt driven Supers are harder to find. First glance would say 2000 CFM, but then I realized the stock turbo is not flowing it's full 1000 CFM. Maybe 800. I have seen some 1600's around for a reasonable price..

When my brother worked for vortech, he said that they did make a supercharger for the duramax.

Dmax tim....


There is someone I know that has currently a twin turbo cummins motor.. making somewhere around 600+ horse .. daily driver and snowplows with it... and runs 11's in the 1/4...


Pete





Yea but is he running dual stacks thru the HOOD?

Tim,


No he is running is out under the bed ... its a 5" exhaust...


Pete

This has been done on a much larger scale.


I saw a program on the science channel and this truck went 228mph on diesel, 3500-4000 hp.


4 turbos and 2 superchargers.


I think it was a Freitliner. A separate semi pushed it for take off, and damn, a semi going over 200!Edited by: blowinsmoke

Fingers thats one way to go about it.


We already did this to a Cummins a buddy of mine has.

Dmax tim....


There is someone I know that has currently a twin turbo cummins motor.. making somewhere around 600+ horse .. daily driver and snowplows with it... and runs 11's in the 1/4...


Pete Would this be John?

I think that tractor that did 228 mph was powered by a Detroit 16V71. Been a few years since I saw it, don't remember all the details.

Gator


Yes that is John, I guess everyone knows the TV star, Diner owner, Golf Course Host and Snow Plower... Yep that's him


Also back on the subject on supercharger I found this item





http://www.esuperchargers.com/



<TABLE cellSpacing=0 cellPadding=0 width="100%"><T>
<T>
<TR>
<TD vAlign=top bgColor=#ffffcc height=29>
<DIV align=center>Jet Stream™ Electric Supercharger</DIV></TD></TR>
<TR>
<TD bgColor=#ffffcc>
<TABLE cellPadding=3 width="98%" align=center ="cellSpacing=0"><T>
<T>
<TR>
<TD bgColor=#e3f4ff height=126>The Jet Stream™ Electric Supercharger is capable of boost levels up to 2psi!! Finally for or a fraction of the cost of a normal Supercharger you can receive similar increases in horsepower. With our instructions you will be able to build and install your own Jet Stream™ Electric Supercharger within a matter of hours. The total cost of all parts needed is less than $80.00. Our kit takes absolutely no mechanical skill to build and install and will immediately be capable of delivering a 5-20% boost in horsepower throughout the entire RPM band GUARANTEED or your money back!
These units are extremely easy to install and operate, and offer performance gains unmatchable for the price!! Up to 30 Horsepower on some vehicles! Along with this horsepower increase you will also benefit from a savings in your gas mileage up to 10% or more! The Electric Supercharger is available for all vehicle makes and models and parts are readily available from a variety of sources worldwide! Stop wasting your money on expensive mods that only add a fraction of power and download your Electric Supercharger Instructions Today!</TD></TR></T></T></TABLE></TD></TR></T></T></TABLE>


It also has the logo AS seen on TV right on top... which make me think


PASS!!!!!!!!!!


As most of the stuff from there is junk or only works once


Pete
Edited by: gslam88

Gator


Yes that is John, I guess everyone knows the TV star, Diner owner, Golf Course Host and Snow Plower... Yep that's him


Also back on the subject on supercharger I found this item





http://www.esuperchargers.com/



<TABLE cellSpacing=0 cellPadding=0 width="100%"><T>
<T>
<TR>
<TD vAlign=top bgColor=#ffffcc height=29>
<DIV align=center>Jet Stream™ Electric Supercharger</DIV></TD></TR>
<TR>
<TD bgColor=#ffffcc>
<TABLE cellPadding=3 width="98%" align=center ="cellSpacing=0"><T>
<T>
<TR>
<TD bgColor=#e3f4ff height=126>The Jet Stream™ Electric Supercharger is capable of boost levels up to 2psi!! Finally for or a fraction of the cost of a normal Supercharger you can receive similar increases in horsepower. With our instructions you will be able to build and install your own Jet Stream™ Electric Supercharger within a matter of hours. The total cost of all parts needed is less than $80.00. Our kit takes absolutely no mechanical skill to build and install and will immediately be capable of delivering a 5-20% boost in horsepower throughout the entire RPM band GUARANTEED or your money back!
These units are extremely easy to install and operate, and offer performance gains unmatchable for the price!! Up to 30 Horsepower on some vehicles! Along with this horsepower increase you will also benefit from a savings in your gas mileage up to 10% or more! The Electric Supercharger is available for all vehicle makes and models and parts are readily available from a variety of sources worldwide! Stop wasting your money on expensive mods that only add a fraction of power and download your Electric Supercharger Instructions Today!</TD></TR></T></T></TABLE></TD></TR></T></T></TABLE>


It also has the logo AS seen on TV right on top... which make me think


PASS!!!!!!!!!!


As most of the stuff from there is junk or only works once


Pete





It would be more effective to run a hose from your rectum to the manifold after eating at Jose's All You Eat Bean Palace.


Small electric motors do not generate near enough power to supply large volumes of compressed air. The motor on a 5HP garage compressor couldn't make 2 PSI at the volume required by a V8 engine running WOT.

What about a really good ducted fan? I've seen pretty big electric jets fly with them..... pretty wicked little motors.


But, will they work? http://www.dieselplace.com/forum/smileys/smiley5.gif





Burner------------&gt; http://www.dieselplace.com/forum/smileys/smiley4.gif

It's a HP Thang...


It takes a lot of power to compress air, especially large volumes continuously. No matter which method you use, you need a big electric motor to pull it off.