Competition dual turbos

[Jim Fulmer]

CUMINNTSTRKN or DBR, do either of you have pics of your set up or any info you could feed me. I'm going to get a Piers HX-40 next and my though is I could work on fabbing up a twins set up after that using the 40 and the 35, I'm not looking for crazy HP it's just if I have them both and have the time and resorces why not go for it. I really think a 40 and a 55 are way to much for me. If you have the above info you can PM me or E-mail me at -- email address removed --.



Thanks, Jim



Or what would a Mitchell kit cost without turbo's!

 

[DBR]

Jfulmer, go to the top of the tread, I have a link which has a progress of my build-up. I presently have the twins of the truck, as I am making modifications.



I now have a metal lathe at home, so if you need some pieces turned let me know.

 

[CUMINNTSTRKN]

here is a pic of daves turbo's, mine look the same. #ad
you might call them and ask if they sell the kit without turbo's.



jim

 

[HoleshotHolset]

DBR: Where's the link to your 'twin-turbo progress page'?



Matt

 

[Gizmo 007]

Ok guys, sorry it's taken so long to get back. Here is what I had in mind.



HVAC, I'm shooting for the lower ~ mid 400 HP range for now. And I tow a substansial amount of the time, so temps are important. I also like to race my truck from time to time (not bad for a dually). I can almost peg my 1600* pyro at will . That sort of bothers me. I've also had a few complaints about the "freight train on wheels" by a couple of the locals.



I MAY be able to get my hands on a Garret turbo (can't think of the number off hand) that is larger than the HX35. I was going to play around with it to try and get my EGT down while towing, and to get a quicker boost response. If I can get my temps down, I'm going to put bigger injectors... BD step 5's ought to be big enough . I'm just thinking for the long run right now. The second turbo will cost little to nothing, and I can fab the pipes fairly easily.



There is nothing concrete about this yet, but I am trying to gain everything I can from all of your posts. Keep it up guys, you're helping a lot.



I will try to get the Garret turbo number and dimensions to show you what I am looking at. If nothing else, I am going to have fun trying .

 

[TxDieselKid]

If nothing else, I am going to have fun trying

That's the most important part!!



Andrew

 

[Cummins Corvette]

Originally posted by Diesel Freak





See if you can find the minimum allowable oil pressure for the turbo..... most Holset turbos require a minimum of 30 psi within 4 seconds of startup

I don't have any specs on it. I don't think that is an issue though, it was built with an 800 hp chev. 350 in mind. It will flow at least enough for that. I am really starting to think it might work for a second turbo. It's huge. It's got a 5" exhaust outlet, and a 5" opening going into the intake. Oo.

 

[Mark_Kendrick]

Originally posted by DBR

Mark;



My twin set-up works well for towing and doubt I have more than 325 hp to the rear wheels. I don’t know if there is a single turbo out there that is able to produce 30 psi at 1500 rpm; I want my power down low, real low.



I don’t waste-gate the primary turbo as it is my opinion that it is not necessary. I’ll be calling Piers soon to purchase a non-waste-gated 14cm housing to replace my waste-gated 14 that I have now. Anyone want to take a guess as to why you may not want to waste-gate the primary if it’s an “hx35” ? “Havac no fair answering the question”

I can't think of a reason not to wastegate it. . HVAC probably won't answer because we're getting into his bread and butter here. I've been talking with him about this and will not comment any further in twin design here out of courtesy to him. He's spent too much money on this to take it from him.





on another note... "I don’t know if there is a single turbo out there that is able to produce 30 psi at 1500 rpm"

I have a hard time watching my boost during acceleration but...

I can build 40 psi at just over 2k. when lugging 30+ psi below 2k is easy.



I don't get it at 1500 because I have enough gears that is never necessary.



I'll latch onto 6-8k of trailer next weekend and let you know. I'd like to get more boost at low rpm for the track.

 

[Garry Verheyden]

Diesel Freak,

I had the same ideas as you with taking the ATS manifold and turn it upside down to make more room for the larger turbo underneath.

I've tried this during my early stage experimenting with my twin set up and it doesn't quite work. When I turned my ATS manifold upside down and bolted on the HX35, the compressor housing hit the manifold. The only way you could fit the compressor housing on would be to turn it towards the intake manifold similar to on the older non-wastegated engines. I've since cut the flange off the ATS and will still be mounting it upside down, but with slightly less of an upward angle so the compressor housing no longer touches the manifold. Hopefully I will soon have some time on my hands so I can continue playing with my truck and eventually take the HX60 off my bench and tuck it nicely under the HX35.

Garry

 

[DBR]

Mark,



Funny thing, I have 10 speeds and still find the 30 psi @ 1500 fun (and that’s when I’m empty, loaded is even better). Maybe it’s the fact you live in flat-land country…you don’t need all them gears. The last time I drove through Kansas, I don’t think it ever dropped out of 5th until I stopped in Salina!



From my personal experience, one reason you don’t want to waste-gate a stock HX35 when used as a primary is due to the waste-gate configuration. The exhaust on our trucks is split into two streams, one for the front three cylinders and one for the back three cylinders. Each stream is fed into a separate flute of the turbo exhaust housing. The waste-gate on the turbo is only waste-gating one flute of the exhaust housing, the back three cylinders. The gasses from the front three cylinders have to pass through the drive wheel into the chamber of the second flute in order to be bypassed out the waste-gate. So, at very high boost pressures, the stock twin flute HX35 cannot pass the exhaust gasses from the three front cylinders causing a differential between the front and rear cylinders and uneven back pressure.

 

[Jim Fulmer]

From my personal experience, one reason you don’t want to waste-gate a stock HX35 when used as a primary is due to the waste-gate configuration. The exhaust on our trucks is split into two streams, one for the front three cylinders and one for the back three cylinders. Each stream is fed into a separate flute of the turbo exhaust housing. The waste-gate on the turbo is only waste-gating one flute of the exhaust housing, the back three cylinders. The gasses from the front three cylinders have to pass through the drive wheel into the chamber of the second flute in order to be bypassed out the waste-gate. So, at very high boost pressures, the stock twin flute HX35 cannot pass the exhaust gasses from the three front cylinders causing a differential between the front and rear cylinders and uneven back pressure.



Now that is some good stuff to know! I was thinking if I could get this HX-40 this Summer I might start playing with it on the weekends. I figure by then we should have lots of info out, anyone want to rehab my house so I can buy truck parts!



Jim

 

[Mark_Kendrick]

Originally posted by DBR

Mark,



Funny thing, I have 10 speeds and still find the 30 psi @ 1500 fun (and that’s when I’m empty, loaded is even better). Maybe it’s the fact you live in flat-land country…you don’t need all them gears. The last time I drove through Kansas, I don’t think it ever dropped out of 5th until I stopped in Salina!



From my personal experience, one reason you don’t want to waste-gate a stock HX35 when used as a primary is due to the waste-gate configuration. The exhaust on our trucks is split into two streams, one for the front three cylinders and one for the back three cylinders. Each stream is fed into a separate flute of the turbo exhaust housing. The waste-gate on the turbo is only waste-gating one flute of the exhaust housing, the back three cylinders. The gasses from the front three cylinders have to pass through the drive wheel into the chamber of the second flute in order to be bypassed out the waste-gate. So, at very high boost pressures, the stock twin flute HX35 cannot pass the exhaust gasses from the three front cylinders causing a differential between the front and rear cylinders and uneven back pressure.

Kurt and I talked about that the other day...

you can fix that witha little creative grinding on the housing or putting a spacer between the manifold and the HX35.

 

[DBR]

There are a couple other ways as well, but it is at the cost of spool-up. I prefer using a mill as it's a bit cleaner then grinding.



One answer is using a single flute housing, such as the hy35, with a modified waste-gate port.

 

[JB @ C and L Machine]

Re: Twin Turbos

Originally posted by HVAC

My first twin charger configuration-

#ad

Was this SB 1st system??????

 

[Jim Fulmer]

Ok guys, I talked to Mr. Mitchell today(Thanks Jim) and he gave me more insight on the subject, he has some good thoughts on it, It is just lack of knowledge on my part and lack of money, but like I told him do you beat around the bush or so you just suck it up and go for it! On his behalf he is trying to put out a product that he has spent his time and money on and obviously it works, no he won't just sell the parts minus the turbo's and I'm cool with that, just want to keep this going, and yes I read the other post and printed out all the pages.



Jim(were like kids with a new toy... lol)

 

[Johnboy3]

My First Try At Twins.......

I know it's not a Cummins, nor as purdy as Nowel's, but it's a set of experimental twins non the less.....



#ad

 

[Jim Fulmer]

Cool pic, reminds me of a ford bubba today that was saying, 60 PSI what a passing gear



Jim

 

[csutton7]

WOW---hope they work for you---are you going to have to modify the hood or will it fit with the stock one---good job----chris

 

[HVAC]

Twins

JB, help me out-



>Was this SB 1st system??????



SB = ???



"My first system" should pretty much cover it description wise.

I went over/under for my second system and

my third system absolutely ROCKS!!! Actually I'm selling my twin system now that I have it worked out the way I feel it should work.

 

[HVAC]

Johnboy

You ROCK!!!



You are to be commended young man



I can honestly say that I have not seen a twin system on the "F" brand. I encourage you to R&D that system and maybe the PSD set can be the benefactor.