rubberneck Posted October 27, 2010 Report Posted October 27, 2010 Well here goes, i am by no means a twin expert, but do have a little bit of experience on 12 valve pull trucks. We were running them before the current 62 and 64 mm switzer hybrids were on the market, so we didnt have those options. First set up was an hx35/21cm housing with a ht3b/26cm. it was an old mitchell puller set that we got as a partial sponsorship to run out here on the west coast. That set up was pretty good until we really cranked the fuel up. There were no wastegates on the system,so when the boost got above the 80 psi range, the egts were off the charts. We would peg a 1600 degree gauge about 1/3 the way down the track. We then stepped up to a Piers Stupid pump with 13mm plungers and the fuel was just way too much. So we put a holset H2e on top with an ht4b on the bottom, and then put an external gate infront of the small charger to limit max boost to about 100psi. Fine on the pull track but pretty damn laggy. Pulling just started to get way expensive, so my buddy sold the truck. Now another buddy ended up doing a set of mitchell street twins later on and he ran a hx35/14 nonwastegated housing on top with the same ht3b/26 on the bottom. In this set up they utilized an external wastegate before the small charger to limit drive pressure. Therer was an "adaptor housing" for lack of a better term between the exhaust manifold and the charger on which the external gate mounted. He had a popoff valve as a safety backup, but idealy you dont want to use the pop off for boost control. On your setup, Your 62 wastegate may flow enough, i cant answer that. I have a 62/14 myself, but it is one of the very 1st ones they started making and i think i have more like a 66 or 68mm compressor im not sure i have never measured it. The nice thing about it is that it wastegates both sides unlike the stock 35 gates so if it will flow enough then that is a bonus. if you dont mind spending the money the externals are nice because they are easily adjusted. Im thinking that you may be just fine with using the internal gate on the secondary charger you have and see where your drive pressures run. If you need to add a wastegate between the primary and secondary later on to control total boost then that wont be that hard. You dont have near the fuel that we had so it may not be necessary to go crazy with the gates. Nowadays, there are so many set ups that have been tried that i think somebody on the hot rod diesel sites could probably dial you in before you ever start cutting and welding. i will tell you that you will have more lag with that charger when it is in a twin configuration than it does now as a single. I have an old 12 valve sitting in the back yard now, when funds allow i plan on building a street machine out of it. My plan is to run my 62/14 on top with probably an s400 on the bottom, with gates on each. Quote
Dinner Posted October 29, 2010 Author Report Posted October 29, 2010 Thanks for your experience and thoughts As you say, I'm going to try it out with my internal gate on the 62 and see how that goes. With my current injectors (200's), TST Comp and Smarty (and supporting mods) I have way to much fuel for the little 62 by itself. I know there will be more lag, but heck as of right now my lag isn't bad at all unless I shift in OD and lug it on purpose. And as you say, I'm going to try to adjust my boost levels so that they peak out at their own psi...I'll just have the blow off valves in case for some reason it get's all crazy on me I know the BHT3B's are out dated compared to the S400 series...but hell what's $100 for brand new! I'm sure I'll have more than enough air once I get them running right. I'm also going to get two more boost gauges, one for each turbo and one for drive pressure. That way I can actually "tune" them instead of throwing them on and saying their good to go. Hopefully this helps out my EGT's and gives me the power increase/air I need. As of right now, if I put the TST Comp on 3 I can get over 1300 EGT's on a WOT run. I can easily bury my pyro gauge (1600) if I run anything higher on the Comp and for a certain distance. I got a few goodies in from Vulcan Performance this week, ordered some other stuff from Source Automotive that should be in shortly. Next month I'll get some more goodies (hopefully), then by the end of winter/spring I should hopefully have these things running Quote
rubberneck Posted November 3, 2010 Report Posted November 3, 2010 cool man, keep us updated. I love cummins diesels man, they just get in the blood. I have the itch real bad lately to get the 12valve conversion project going. Cant decide between a 69-72 chevy longbed truck or a suburban of the same era as the recipient. All i know is that im going to build me a "Big Boy" motor this time. Going to start at the Pan and work my way all the way to the top. Oh and dont worry about controlling EGT, you will never do it. If you do, you will just add more fuel to compensate. You know you will dont lie to yourself. LOL Quote
Dinner Posted February 12, 2011 Author Report Posted February 12, 2011 I have more parts, just no pictures,lol. I also have my new gauge pod and boost gauges, so will have 2 gauges for boost and one boost gauge for drive pressure. I'm hoping to maybe get it started next tuesday or wednesday since I have the week off..so we will see! Quote
rubberneck Posted February 12, 2011 Report Posted February 12, 2011 Nice, twins are just fucking cool period. They will sound wicked out of the ole stacks Quote
Dinner Posted February 14, 2011 Author Report Posted February 14, 2011 I actually got rid of the stack man! I was getting tired of the drone, etc in the cab all the time,lol. I have it dumping behind the rear axle right now, however once the twins go on it'll be 5" straight back to stock location with a 6" tip probably. Quote
rubberneck Posted February 14, 2011 Report Posted February 14, 2011 LOL I should have stated they will sound bitchin out of the stacks on somebody elses truck. I agree with you, to obnoxious while in the cab, but they do sound cool driving by. My buddy had 6" dual stacks and it only took a liittle while for me to realize they werent for me. Quote
Dinner Posted February 16, 2011 Author Report Posted February 16, 2011 Slowly coming together... Quote
locogato11283 Posted February 16, 2011 Report Posted February 16, 2011 Craig, here are some pics of a triple setup a buddy of mine built. I really don't even know if it ever ran or anything.. Quote
Dinner Posted February 17, 2011 Author Report Posted February 17, 2011 Triples actually spool faster than twins. They use 2 same size chargers (small guys) then one larger one. Fella here in Ontario us building a set as well, will be neat once they are done! Looks like your friend did a well job though Tyler, good fabing!! I'm just lucky to get mine thrown together and it works Here are a few pictures after today. Quote
locogato11283 Posted February 17, 2011 Report Posted February 17, 2011 That looks like a big fuckin mess!! How long before it's running? Quote
Dinner Posted February 17, 2011 Author Report Posted February 17, 2011 haha no shit eh! Well I got my one cold pipe fabed up tonight, friend of mine is going to weld it tomorrow. After I started it up to check for oil leaks, turns out one of my coolant lines for my tranny heat exchanges has a pin hole leak in it...so now I have to R&R that pipe,lol. Won't be too bad, I have a spare truck! So really get the coolant line done, jig up and figure out my cold pipe for the air-to-air, fiddle around a bit with my air filter then it'll be good to at least drive. I still have to get more air line for my boost gauges and what not, then weld up some bungs on my cold piping, but that can come later. Sooo it'll be drive able by at least sunday, cause I need it for work monday,lol. Quote
rubberneck Posted February 17, 2011 Report Posted February 17, 2011 Triples actually spool faster than twins. They use 2 same size chargers (small guys) then one larger one. Fella here in Ontario us building a set as well, will be neat once they are done! Looks like your friend did a well job though Tyler, good fabing!! I'm just lucky to get mine thrown together and it works I have heard it debated wether or not 2 small chargers in parrallel will spool quicker than a single larger charger. The argument being that even though you have smaller wheels, the combined mass of the 2 wheels is still greater than a properly sized single. You see twins in parrallel on a lot of V8 cars simlply because plumbing is easier. Im not sure either way cause i have no experience in that area. Could be true, could be full of shit. My comment about lag had nothing to do with it being tripples. Take a look at those pics of that set up again. The 2 upper chargers are the primary and the big honker on the bottom is the secondary stage. My assumption is that he set them up like that for room issues. Exhaust comes out of cylinders to the bottom charger then up to the 2 twins, and cold air looks to go from the 2 chargers down to the big dog on the bottom on to the intake. It looks like he is using about a bht3b as the secondary. If matched well and he has the fuel to turn it, that set up is going to move a metric ass ton of air. Must be a puller, they are the only people crazy enough to do that shit. LOL Quote
rubberneck Posted February 17, 2011 Report Posted February 17, 2011 Forgot to add good work. Did you put a support on that bottom charger? I have seen a couple of sets that simply hang off the exhaust and it is no good, lots of cracks. build a good bracket if you havent already. Keep us posted. Quote
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