perk

Everyone keeps talking about bigger twins for super huge HP. What if I want to stay at or under 350hp, but want more low end power. I figure lower end boost would help. What about using HX-40 or equivilant for the big turbo? Has anyone worked on this?

billg

That's not the way it works. Boost doesn't make HP. The only way to make power is with fuel. The boost allows you to burn more fuel and keep your EGTs down. Your exhaust temps will dictate whether or not you need more air. When you hear these guys talking about twins you will also see they have some monster injectors they are working with. If you want power down in the lower speed you will have to do that with gearing and you can boost lower end torque with one of the fueling and timing boxes like an Edge EZ or box like that. They will change the timing and add a little fuel but I don’t think twins will help you there. If I’m off here than someone will correct me.
Just my $0.02 worth.

psalm69

billg and perk,
I wonder if perk didn't mean a little quicker spool up (perk if thats not what you meant, I didn't mean to put words in your mouth) for better throttle response. A little less lag maybe, I have often thought about some of the same things for my truck. I'm happy with the power I have from my edge comp running on 5*5, but if there was even less lag that would be perfect. What do ya'll think. Scott

billg

Are you having problems with your temps being too high, or are you makeing too much smoke ? If not I think you are fine. If you want to tune when the air comes in use something like a Turbo-Master. You can also open up the exhaust a little (remove the resonater and muffler) or go to a 4" system and that will help you spool up a little faster. That is about all I can come up with. If someone else has any ideas I'll be all . I'm no expert but I have read just about everthing on this site on this subject (and there has been a lot of good reading).
Hope this helps.

psalm69

Wastegate is shut and its a straight pipe all the way out. Temps are fine: I don't tow.

Don't get me wrong the truck works great, but if I could get it to have half the throttle respose my big block has: all the better.

So, there is the crux of the question, when overall performance is fine minus throttle response what is the mod that should be done. No gas of any kind either.

Sorry perk for hijackin' your plane here.

billg

I think for more response you will need more power to respond with (bigger injectors). I would look at a set of EDM Mach 1.5 or something equivalent or bigger from where you are now or a more radical box. Keep going along this path and there will be a point you will need more air. You can also look into water injection. I have read you can pick up a few ponies there. You will have to talk to some of the guys that have done that. Just do a search on water injection you will find some info to get you started.

Rhino

I have seen a couple twin setups with an HX35/HX40 combo. From what I know the low end and midrange was good but the top end was really lacking. This was some time back now. I wonder if those guys are still running the same setups?

psalm69

Really, thats all I'm looking for. Improving initial throttle response really helps around town where most of my driving is done anyway. Not a lot of my time is spent above 2500 rpm. How bout you perk? Is that what you were lookin' for too?

billg

The Dodgzilla HX40/HX35 is a Hybrid. Here is a little reading on that. https://www.dieseltruckresource.com/...ghlight=hybred
I know Chace at WTTD was working on something like this for towing apps.
http://wttd.proboards22.com/index.cg...num=1061997949
Useing them as twins wouldn't be cost effective (all the plumbing) in MHO, might as well go for a bigger setup to get the benefit of both worlds. Small turbo for spoolup at the bottom and big turbo at the top if you got the fuel to push them. But I have heard the HX40/HX35 do nice as a hybred in the mid range hp.
Just my $0.02 worth.

Jim Fulmer

A set of Twins that will work dang well on the very bottom end would be a 35/14 mixed with a HT3B/23 along with a divorced wastegate, this has already been test and it out on the market by Piers, called there towing set. It will cruise with boost and is unbelieveably spunkie on the street, no bottom end issues, heck my setup doesn't have any bottom end issues.

Jim

billg

In the first post he was talking about staying around 350 HP. Unless I have this all wrong (will not be the first time), twins would be a bit much for that.
Perk, Piers is a good site to visit for info on turbos. He is a top dog with turbos. Here is a link that will help with the planning.
http://www.piersdiesel.com/DodgeTurbos.htm

perk

psalm69-

You were right, I did mean quiker spool, but I also wanted to get max boost by 1200rpms.

I really don't care about the top end, I rarely get over 2500rpms. I was thinking something a little smaller than the 35 for the small turbo and have the HX-40 for the big one. I think that the small turbo will help to decrease lag, and help to give more boost in the lower end. I do understand that air + fuel makes power not just air, but without the air, fuel doesn't create power either. As far as plumbing goes, it just gives me more little projects to keep up on my TIG skills. I don't get to TIG much at work, but I love doing it.

Tartarus

I'm not sure there's any point to twins at that range of fueling and hp. The 40 compressor/35 turbine hybrid with a 12 or 14cm2 exhaust housing will get you what you want, without the expense and the durability issues of a far more complex unit.

IMO

However, if you go for it, and we're wrong -- please let us know.

psalm69

Hey perk,
Sounds like the beginning of a little project. If you end up doing it with the 40 as your primary and a smaller one for the secondary I would be very interested at the results. I too am RARELY over 2500 rpms. Thats what the race car is for. I just use my truck for everyday activities. Maybe I could help out in some way?