Whose Twins?????

[Junior]

Alright everyone this has been talked about a lot. I am looking at PDW, RIP, OPOOLE, and BD, twin kits. Anyone have info on the good and bad of any of these. When i tow the trailer is about 12,000 max. once or twice a year.



May end up moving out to CO, if that may be a factor.



Talked to most of them and seems BD turbos are 57 and 62.



RIP has a kit keep hx35 and add B2 to it. What size compressor is B2 and who makes it?



I want quick spool but also top end,go figure.



Any info will help out mating them with probably mach 4's. and Smarty. maybe tst comp in future.



this truck goes cross coutry so don't want to lose driveablity of it







Well that should not be hard



thansk

 

[Cummins724]

Don't forget about Industrial Injection or High Tech when considering twins... . they can set you up with whatever your needs.

 

[paulb]

The B2 is an S400, and the one Rip uses has a 75mm compressor wheel. I have Rips twins and I like them a lot.



Paul

 

[Junior]

Paul what do you think it will be like with the Stock hx35 or a hybrid like Dodgezilla or something with the B2

 

[paulb]

Paul what do you think it will be like with the Stock hx35 or a hybrid like Dodgezilla or something with the B2

A lot of people are using twins with the hx35 as a top turbo. If you are going to use it, at the very least you should modify the wastegate. I believe Rip has an exhaust housing for using the hx35. You should talk to him about that.



NoSeeUm on here has a Dodgezilla on top of a S400 (another set of Rips twins), you can ask him about those.



The hx35 on top will probably spool the quickest, but will suffer the most on the top end. The spool of the Dodgezilla will be close on the spool, but will breather a little better on the top end.



Paul

 

[NoSeeUm]

Unless you get a killer deal on a hybrid or already own one, I think I would go with the Hx35. Maybe slap a 14 CM2 WG turbine casing on it and maybe like Paul says mod the WG to flow a bit more. I already owned the DZ so I used it. My truck is an 02, so my HX35 had the new WG design and I would have needed to buy an older style turbine case to make the WG work in Rip's kit.



There are allot of s300 hybrids out now to spend money on. I think they will perform better over a hybrid. Spending your money there is probably a better option I would think vice putting close to the same amount into a hybrid. So if it were me, I would start with the Hx35 and run that until you felt it is outgrown. That way you can reduce the $$$ thud sound when you first buy a kit.



I should say that, with my set up I am not really pushing the DZ to the absolute limit yet. I just today hooked up a drive pressure gauge and should have some M4's installed soon. I will let you know how it works after that.



Don't forget you will need to likely add in as a minimum, if you have not installed them yet, the cost of head studs. They make a little $$$ thud sound just by themselves.



In this TDR Thread I asked this question.

Is it typically exhaust or intake restriction that limits most twins?



It seems to me that with properly sized compressors, multi stage compression would almost always be more efficient than single stage.

And I got this answer, which is probably one of the best explanations I have seen.

It's best if you think of it like this: Twins amplify the power capacity of the smallest turbo while keeping close to the same drivabilty/spool up as the small turbo.



Bypassing the turbine side is probably the most critical part to making big power with twins. Non wastegated primaries and undersized wastegates on the secondaries severely limit the power output of a twin system because turbo are needlessly over driven which costs hp. Two turbos take more hp to turn then one turbo so it's not always more efficient. They do have a more efficient powerband, meaning they have a broader range of usable power.



.....



Idaho CTD

So from his point of view at least, the better the secondary turbo the better the set up. I have found this to be true. And, as you keep upping Hp it is also the exhaust side of the secondary turbo that limits you. So the exhaust side of a stock HX35 could be a real factor. And and, the biggest advantage of twins is the much broader range of usable power.



Hope this helps;

Jim

 

[Junior]

what is derive pressure gauge for and would i need one. Seems i am leaning towards BD towing twins and rips set up, HX 35 with the B2. Both are close to price with each other

 

[AFarmer]

Here's a pic of the twins built for me by fellow TDR member BPonci

 

[Forrest]

Schweeeeet pic. What are the details of the turbos?

 

[AFarmer]

HTT 64 and a Modded S400. Did all of the dressing up when they got here but Brad put some great ideas into building them.

 

[pwerwagn]

are you using the internal wastegate on the 64 Gus?



--Jeff

 

[Junior]

those are sweet. How is spool up, take a little to kick in?



Alright guys What will i have better luck with the B2 or BD 62 for the larger turbo, or ios the primary more imprtant.



Bd primary is a 57 what is the HX 35 considered?

 

[pwerwagn]

The primary is the large turbo, the secondary is the small.



I am surprised that BD runs a 62 for the primary. That is a small turbo for a primary. Thats a good single turbo. The 57 they use is simply an HTBG Schwitzer.

The HX35 is usually around a 56mm wheel. Depends on the year and other stuff. A hybrid hx35 can be a 58, 60 or even slightly larger wheel. I forget the size of the turbine off hand.

the S300g is a more robust turbo than the HX35 is.



Id personally prefer a B2 (S400) for a primary over the 62 from BD, or an HTB3.



--Jeff

 

[NoSeeUm]

what is derive pressure gauge for and would i need one. Seems i am leaning towards BD towing twins and rips set up, HX 35 with the B2. Both are close to price with each other

Drive pressure is the pressure in the exhaust manifold. It is the pressure that is used to "drive" the turbo(s). It acts as back pressure on the engine exhaust and reduces Hp output as well as cause EGT to increase. In a good set up twins, single or otherwise the drive pressure is really close to boost pressure. That is the goal.



I have heard good things about the BD twins. Seems they stay spooled almost constantly, but that is just from reading other peoples comments. An advantage they have is the primary and secondary turbos are wastegated for better boost control. I guess with that set up head studs are optional.



BD is building or has built a larger set of twins, using a s400 primary and a s300 secondary.



And yeah, BPonci does some very beautiful work. I am not sure of the price.



Jim

 

[NoSeeUm]

HTT 64 and a Modded S400. Did all of the dressing up when they got here but Brad put some great ideas into building them.

What size external are you running?



Jim

 

[Junior]

Kind of figuring things out guys thanks for all the info.



Seems like it is BD there towing or newer set or Rips set with Hx35 adn B2 to start off, then maybe upgrade to hybrid of some type.



How is the s300 compare in spool up , flow more than the HX or the hx hybrids, how compare to hx40?



Don't want to go to a 62 for secondary because i want the quick spool up also, reason i am looking at twins, if i where doing a single probably be 62/14 from II.

 

[AFarmer]

I'll be using both wastegates to control things. External is a Turbonetics Evolution.

 

[NoSeeUm]

I did a few runs yesterday. My drive pressure boost pressure ratio seems to stay close to 1:1 until about 35 psi. I did not not get much over 45 psi boost so I can't say how it would go beyond that, but the drive pressure was still not out of control. I did this test with the TST on 7 so I am guessing my HP level would be right around the performance with M4's alone. This is not really the best test through, because I end up being MPH limited in very short order. It would be better to climb a grade towing.



Going back to drive pressure and its importance in engine output, consider your typical exhaust brake. In my case driving down a hill at 60MPH with my camper and boat loaded my truck will almost always speed up. My GVW is up around 15K with that set-up and the boat does not have its own brakes.



If I turn on the exhaust brake my truck will slow down. Typically to prevent from going too slow I have to cycle the brake on and off. During those times I rarely see higher than 40 psi of exhaust (drive) pressure.



IMO that just ends up being ALLOT of braking power.



So.....



Going the other way, when you are trying to make Hp with the engine. Drive pressure is the relative amount of braking Hp that is exerted opposite to the output Hp of the engine itself. It is significant.



Jim

 

[Junior]

Who makes th B1 abd B2. what is size of B1?

 

[AFarmer]

The B1 is most commonly replaced with a 62/14 turbo. B1's are made by TAD.