Engine/Transmission (1998.5 - 2002) Twin Turbos

[Devildog]

I would like to install twins on my truck. Right now I have a B-1 turbo( for an auto transmission) in the truck right now with a ATF filter. I have my stock HX-35 sitting on the bench and I have a three piece manifold. I am wondering I any of these turbos would be useful in a twin setup for 350-700 HP or should I start from scratch.



What is the best turbo setup for the HP indicated above?



Thanks, Chas.

 

[V-Metalworx]

what turbo

let me start off by saying their are a ton of turbo's around as you know messing with singles, first thing, do a search on twins here.

alot of people on here have built and ran different setups.

so do you home work.

I built my first set for mine last winter and the reason other than the cool factor and cooler running I built them cheaper than buying a good single. :-laf

all i can do is tell you what I did and how it is working for me.

keep in mind I've still have some bugs to work out mainley intercooler pipeing and boots. I'm just running stock boots right now and they blow off at 48psi.

my set up is a HX35-12 with the stock wastgate blocked off.

I built a header with an external wastgate so I could regulate it

My bottom turbo is a HTB3E I think the compressor is 73 and I know the exhaust is 23cm this is kind of a old school set up but so far it,s working good.

have plenty of low end EGT's haven't been above 1100deg yet but like I said

I can't push it with the stock boots but a big difference over my single

it pulls a trailer excellent which is what I wanted for this truck.



the preferrence for the lower charger used to be an S-400 I would say you could build a set with either turbo you have and hit the HP#'s you want it just depends on what you want to do with the truck.

olee pool would be the one to talk to about your combo choices

and what would work best for you (everyone has their own taste)

what works good for one guy might not work for another. hope this helps good luck

 

[DCreed]

Your sig says you plan to use NOS. So an external gate is a must, the HX35 will be too small for 700hp as 650 is about it for those. the B1 is an older S300 with a 62 inducer IIRC and will serve you well as a top turbo. I wouldnt go much bigger on top with the tight converter you have. The HT3B and its variations are decent bottom chargers and fit well with the factory heat exchangers in place and a 5" exhaust. For exhaust housings a 22 is for towing, a 26 for hot street and 28-32 for racing, the larger the size the more RPMs it will take to spool but the less drive pressure it will hold. The S400's are a more modern turbo than the 3B and come in MANY flavors but will NOT fit easily with the factory heat exchanger and 5" exhaust, although it can be done.
Be sure which you want as they rotate in opposite directions and cant be swapped.
I dont suggest buying either of these turbos used (unless you know the seller) as the cost of a rebuild is nearly the same as a new turbo. I can send you links to some suppliers for parts if you want. feel free to ask more questions also. I have run about 15 different twin combos on my truck and currently have a T66/12 over a S480 so I have some idea about this stuff and no need to sell you anything. Source, Poole, Wicked, MPI, II, are all popular twin builders you can talk to and/or buy from.

 

[Devildog]

Thanks for the reply. I have had the NOS system for a few years now and never installed it, and I may not. After I bought it twins were becoming popular and was told there was no need for both.



With the converter I have there is a little lag at low RPM I could due with out. I do tow a heavy boat ( 12k lb) to the ramp from time to time and the truck does does fine as it sits, however, when I not towing I like the feel of acceleration with out the lag.



I have done some homework and I did find that some guys lose top end to gain bottom end or vise versa. I would like to have a good all around set of twins that works well through out the RPM range. I also have read where guys are still trying to tune in their twins after six plus months of running them.



I have looked on Piers, BD, and a few other sites whom offer twins they all seem to have what appears to be slight variations of the same packages, which claim to be the baddest on the street. This is why I'm asking you all what seems to be the favorable package for twins between 350 - 750HP



I am running "Diesel Dynamics" ( what happened to them??) super mental injectors, I also have a set of unused DD Mega Mental injectors sitting on the bench, I not sure if theses are ideal injectors for a set of twins..... any help is appreciated



Thanks, Chas.

 

[DCreed]

Dont know what the DD injectors are rated for? I run +250hp injectors on my daily driver, other than the slight haze at idle they run fairly clean as long as I dont lug the truck. with my mods I only need about 1700rpms to spool the twins and clear any smoke.
for the range you are seeking (and by the way, it is RARE for an VP truck to get over 700hp on fuel only!) I would run a S300G over a 475/1. 32 and then if you want to run the juice (less than a 150 shot) you can just port the gates on the top charger.
I can do that for you too, PM me, if you want.

 

[Devildog]

I'm not sure what housing part numbers equate to as of yet. In a perfect world I would like to see dyno charts with set up configurations ie. (cam, injectors, auto transmission and such) with mapping of the twins turbo setup efficiencies if any are available.



Thanks, Chas.

 

[DCreed]

I'm not sure what housing part numbers equate to as of yet. In a perfect world I would like to see dyno charts with set up configurations ie. (cam, injectors, auto transmission and such) with mapping of the twins turbo setup efficiencies if any are available.



Thanks, Chas.

WOW, you dont ask for much, huh? :-laf

whole lotta variables there. Best thing to do is figure out what YOU will be doing with the truck and then what it will take to get it there.

For most HP junkies it never ends. I thought 400 no wait 500 maybe just a bit more 600 would be enough yeah, NO! So I have run a lot of different stuff some worked great others not so great or no noticeable difference. But for me, I DONT sled pull (so I dont worry about their rules) I do tow often and the truck MUST work everyday and be wife friendly so no crazy smoke or other obnoxious tom-foolery, but I do like to drag race when I can and that has gotten me where I am HP wise.

What do you plan on doing with this truck? realistically?

 

[Devildog]

As stated, I do tow my 12,000 lb boat to the ramp, over a steep tall bridge at that, but mostly, I'm a power junky as well, I do like to drag race. I want my truck to perform like a gasoline hot rod while keeping in mind that I DO tow... . you know, the best of both world with out the constant tuning that I read about. I due have one thing to my advantage, in south Florida we are at sea level and the terrain is FLAT... . (except for the bridges and the land fill)

 

[DCreed]

I'm not sure where all the "tuning" is coming from but most twins only have one gate to "tune" and I only set mine up once. If done right there should be no reason to keep adjusting it unless you drastically change something. Have you done headstuds yet? to make 700hp some serious air/fuel are needed and studs/rings are recommended also a . 010-. 020 gasket to lower compression and a grid heater delete, what ever you can do to help the engine breathe with 80psi boost safely will help keep it together.