OlderThanMe Posted October 25, 2006 Author Share Posted October 25, 2006 I have a way around the T3. I have thought out a way and I'll have some sort of valve to engage the instant pressure turns to vacuum in between the T3 and the bigger turbo. It will be a simple vacuum switch that will open a passage around the T3 when I am at WOT in higher RPMs. I have been playing with this consecutive idea for a while but the restrictive T3 was holding me back from thinking it usable. When I woke up one morning and had the idea of an intake bypass wastegate kind of idea to pass the T3. There was a thread a while back where the restriction was discussed and nobody came up with an answer to the problem on a consecutive turbo system. I spent plenty of time in my school library reading about turbocharger systems and there was a CAD picture of a consecutive system for a truck and that is when I saw that an "anti-vacuum valve" could be placed around the high pressure turbocharger and vent air to the low pressure turbo when the high pressure turbo has reached full air flow. Quote Link to comment Share on other sites More sharing options...
Chewievette Posted October 28, 2006 Share Posted October 28, 2006 Couldn't you rig up the turbos to a Y (one on each leg) then as the rpm comes up feed in the larger turbo with the waste gate? At high rpm exhaust would flow through both turbos, more through the larger one due to the least path of least resistance thingy. But I suppose at that point it would be just like a twin turbo setup but with unbalanced turbos. I dont know, I'm just thinking out loud. Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted October 28, 2006 Author Share Posted October 28, 2006 I thought of that but the problem you have is the smaller turbo would not spool until after the big one or just really late. I'll put up a little diagram of my idea. Quote Link to comment Share on other sites More sharing options...
Chewievette Posted October 28, 2006 Share Posted October 28, 2006 Ah, got it. Isn't this also considered a sequential twin turbo system? I'm pretty sure I asked about it a while ago. I seem to remember there is a japanese sports car that runs one of these, supra maybe? Either way, I'll have to keep an eye on your build. Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted October 28, 2006 Author Share Posted October 28, 2006 yes... but most people think side-by-side turbos when they hear twin turbo... Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted August 16, 2007 Author Share Posted August 16, 2007 Wow.. I made some "interesting" comments in this thread. I'll continue it with a little more...umm... fact. Short story long: I'm abandoning the L6 for this car in favor of a VH45DE(T) Updates on here later. OTM Quote Link to comment Share on other sites More sharing options...
bschiltz Posted August 19, 2007 Share Posted August 19, 2007 Wow.. I made some "interesting" comments in this thread. I'll continue it with a little more...umm... fact. Ahahaha! It's always fun going back and reading old posts, huh? Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted December 19, 2007 Author Share Posted December 19, 2007 I am in the process of determining the condition of my VH and seeing if it needs to be rebuilt or not. It has 120k miles on it so I hink I am just going to run it and not worry about it. The camshafts on the passenger silde look great. I'm going to pull the driver's side valve cover and see if it is in just as good shape. For the intake I want to make runners the same length as stock which was 420mm but with straight runners. Aparenly the VH45 which is "based" off of the R390 engine is a LOT different. The Racing Nissan V8 engines didn't use rocker arms but directly actuated the valves with the camshaft(through lifters...). OTM... Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted January 24, 2008 Author Share Posted January 24, 2008 Here comes project F/I VH45DE!!! Right now I'm about 90% sure that a turbo is in the future for my engine...about 9% sure that a supercharger will be in there... and 1% sure that there will be both. The nice thing about a supercharger is that you have boost at just above idle. The thing with a turbo is the low restriction and high power levels...at high RPMs. What I want is lower horsepower over a longer RPM range. Maybe 500RWHP(stock flywheel HP was 278) but over a 4,000 RPM range. That is 250~ish hp over stock. Most guys slap on a big turbo and have power starting at 5,000 and then rev to 7000. Scenario 1: VH45 with a Holset HX40(bigger one), hx50, or BW S300(if cheap enough) mounted on the passenger side of the engine bay( I doubt I could afford twin turbos...along with twin wastegates...). Mounting the turbo up front is nice but in the battery area would be more practical (40 pound turbo...weight and center of gravity for the car). I'm planning on replacing the wiper movement inside with one from a Q45 or other nissan/infinity. The Q45 wiper motor is about 2/3 the size of an L6 starter motor so I'd say that isn't bad. Running inside the cowl or just below it inside the car I'll put air/water intercoolers or just air/air intercoolers and vent air pressure out of the cowl to the side of the car. Scenario 2: Supercharged, Don't know much about supercharging... Eaton M90's seem readily available in Junkyards so one of those may do. Should get good all around performance but would be out of breath by the time my intake VVT comes on. Scenario 3: twincharged. Pop a M90 on top of the VH and run a single turbo. an intercooler would be needed before and after the S/C. Air would need to take this path unless I use a centrifugal type supercharger: atmosphere---turbo---intercooler---throttle body---S/C---intercooler---intake manifold. I'm going to go eat dinner and think on this some more and maybe I'll be smarter by then. Cheers Quote Link to comment Share on other sites More sharing options...
TrumpetRhapsody Posted January 24, 2008 Share Posted January 24, 2008 Twincharged! woooo Quote Link to comment Share on other sites More sharing options...
jbk240z Posted January 24, 2008 Share Posted January 24, 2008 Well, if I was doing this project, I would pursue option 1. The stock HP is enough for most street driving, but the turbo is there when you mash the pedal! Anyway, good luck on whatever you decide. Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted January 26, 2008 Author Share Posted January 26, 2008 Yeah I'm just leaning toward the single turbo. Most viable... If I want to do the twincharged setup that can always be added in. Not likely though. I may do a twin turbo setup though with an externally gated HX35 and an HX50/52/55 turbo as the larger one. Setting them up to push air in parallel with the large turbo blocked off at lower RPMs. Think RX-7... sort of like twincharging but without the power loss of the supercharger. Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted January 27, 2008 Author Share Posted January 27, 2008 Just seperated the engine from tranny. Good grief. I could have dismantled about 2 L6 motors in the time it took to get that tranny off. Now I have to get the torque converter off by getting to the bolts from the starter hole. I now am going to buy a socket for the crank pully to turn the engine over to get at all the bolts. Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted February 1, 2008 Author Share Posted February 1, 2008 Broke my finger when I dropped teh VH45 torque converter on it. Broke on the tip right behind the finger nail. Got an L28ET exhaust manifold that I'm going to practice porting on. May even build a whole turbo setup including head, turbo, intake manifold, intercooler piping, etc... Who knows. Anyway I'm going to try to get the VH on the engine stand in the next couple days with 1.5 hands. Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted February 6, 2008 Author Share Posted February 6, 2008 Pulled the passenger side head tonight. I'm going to try to get to the driver's side head as well. For 120k miles I'm impressed. I can see some slight scoring but can't feel it with a fingernail. I'll keep my thoughts on the shortblock to myself until it gets pulled apart because the bearings could possibly be toasted. The head gasket is a Nissan part so that is good. Probably the orginal ones. The top end above the heads had been re-done with that nasty orange goo. I think I'll put the $$$ into a nice Nissan gasket set for the rebuild. I'm considering either getting new sleeves with an overbore to allow for about 5 liters and forged pistons or just leaving it until it blows up. Oh yeah... The timing chain guide on the driver's side of the passenger side was just gone... They were made of plastic until 93... Mine just happens to be a 93 model. I'll get metal guides for a 94-95 model before it goes back together. Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted February 7, 2008 Author Share Posted February 7, 2008 Started cleaning the passenger side head on the chamber side today. Looks like there is some fine FOD on the passenger side cylinder head. Hmm. It's not THAT bad ... Just little pits. It looks as if the pieces of material that caused the FOD may have caused the very slight scarring in the bores as well. I think that I'm just going to wait and buy forged pistons rather than put the $$$ into rebuilding it and just have it blow up from too high of a CR(10.2:1) or some other problem. There may be other problems with the internals but I'm crossing my fingers as it all looks OK. Thankfully I have a work bench now to work on the heads on now. It is made from two pairs of tires stacked 2 high, one bare L6 block on top of each stack of wheels/tires, and a pair of 6x6 logs across the tops of the blocks. In-between the logs I have some fiber-board stuff that was laying around. It's a sight to be seen but it works! Quote Link to comment Share on other sites More sharing options...
mario_82_ZXT Posted February 7, 2008 Share Posted February 7, 2008 Pits can be detonation damage as well btw... How's working on stuff with the broken finger? It slows me down a lot but atleast its healed enough where i don't need a splint! Mario Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted February 7, 2008 Author Share Posted February 7, 2008 Mario, Well it's slow... Took me 2 days to go from longblock to one head off... LOL. On my own too. I ran 3.2 very hilly miles yesterday and my finger was throbbing by the end pretty bad... I'll probably end up re-surfacing the VH heads and doing some unshrouding of the valves and maybe even some singh grooves. I'll probably get another set of heads ($80 for two heads or $140 for the whole motor...lots of sense there) at the JY and use these ones for my crazy rebuilding work. The car that this motor was from was sort-of maintained. The top end had been pulled apart down to the longblock with the valve covers off. Makes me think the longblock was a replacement one from Nissan or bought as a rebuilt motor. The odometer said 120k miles... Most of these VH45 motors in the yards have 250,000-325,000 miles on them... That is pretty good IMO. Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted February 7, 2008 Author Share Posted February 7, 2008 Turbo headers: Made from 304 stainless tubing .10" thick for durability. Flanges from 1/2" or 3/8" thick 304 stainless. JGS 50mm wastegates I'm going to bottom/side mount the turbos so that they will clear the stock VH starter on the passenger side and the Z steering shaft on the driver's side. That means the passenger side turbo will be shifted forward and the driver's side turbo will be shifted rearward. These pics are taken with a junk Holset H1E for reference Passenger side turbo that will clear the starter: Front shot: Rear shot: Now thankfully the Holset is a little larger than the Mitsubshi turbos that I'm thinking of using so they would have a little more space. I'd engineer the intake tube for the turbo to pass through the engine mounts so that I can use an air cleaner. Quote Link to comment Share on other sites More sharing options...
mario_82_ZXT Posted February 7, 2008 Share Posted February 7, 2008 You're lucky your junkyards are so "reasonable". Haven't been able to drive the Z cuz the starter went out, but at least I can drive the daily with one hand. For $140, why not buy a whole engine, part it out, and use a bare block as a mock up so you can build the other one up while you get the thing mounted in there? It's about $500 for a VH here from a u-pull-it... Mario Quote Link to comment Share on other sites More sharing options...
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