Twin Turbo Q45 With Venom Nitrous System

[trick240sx]

hello as the title states I am building a 1991 240sx with a 1990 Q45 vh45de engine with a twin turbo set up as well as nitrous. Right now I have the engine, an adapter plate to mate a 300zx tt trans to it the ecu and the fuel computer and module. I am trying to wire it all up in the 240sx. I need assistance with the specs, on the computer mainly. I am working with Venom on a nitrous kit for the Infinity and I need specs. I also need the specs so I can have the ecu flashed since I am running a 5 speed manual behind it. I need to know if there are fuel cut offs, rev limiter and what it is if so, maximum safe rpm the engine can handle, weather the tach signal is analog or digital since venom only works with square waves. shift points if any since it is an automatic and I am running a 5 speed and max power to rpm ratio for this engine. I know its alot to ask but with this info Venom can customize a computerized nitrous kit for the q45 1990 thur 1996. Yes my system will go a few steps further since its a 5 speed but they can do a basic set up for all the Q45 fans. Im just the test dummy. any help you can provide would be greatly apprecaited by me and anyone looking to have a reliable nos system for thier Q. you can also email me at [email protected]

[elwesso]

Just curious, but what adapter plate do you have?

Are you looking for specs to redo an ECU yourself, or for someone else to reflash the ECU?

You're not going to be going too far on stock injcetors, so thats something youll want to upgrade...

Rev limit is 6900 RPM stock, that should be pretty safe. The ECU doesnt care if theres no AT behind it, so dont worry about that. The trans control is controlled by a seperate computer.

Is the nitrous wet or dry? You're going to have to do some pretty exotic tuning to get this to work right... The nitrous is the hard part if its gonna be a dry shot... Mapping the ECU for boost shoudlnt be a big deal, I already have a boost map that just needs to be tweaked (mainly with timing, I think)...

My personal suggestion would be to get your boost setup running flawless and then add nitrous. Dont try and do it all at once because you will most definitely blow the motor up...

Why are you wanting to run nitrous AND twin turbos? What kind of HP goals do you have?

I also think this would be more suited in the VH/VK forum.

[trick240sx]

I plan on having someone else flash the computer. If you can send the mapping you have done I would appreciate it. Im going to run nitrous and turbos just because its cheaper with my set up. Since the 300zx turbos are small and the VH will have them spool up almost instantly they will run out of efficiancy quickly and just produce excess heat and back pressure on the exhaust side. I plan on tuning the turbos for max effieciency and have the waste gate open at that point to reduce heat on the backside of the pistions. At the same time I plan on having the Venom computer inject nitrous at that RPM that the turbos start dropping out. I mean Venom is doing the computer for free for me and the turbos were like 300 for the set. The kit was 550. So that is only 850. For a good size turbo match for that engine would be far more. Plus due to the increase of people trying this swap I want something totall different. I am doing the trubo set up first and then incorperating the nos but Im trying to get all the info I need now since Venom is ready to start work on computer. Does nayone know the max effiecency on the 300zx tt T25s with the 4494cc engine compared to the standard setup on the 3.0 engine. I know it will be more air flow quicker spool up which will kill effiecency sooner. If anyone knows that # it will help so I can have Venom set that in the computer they are programming. They are starting with a base map of the vh45 and the changing it to my setup so the system will be availible for the basic Q45 1991-1996

[elwesso]

what are you doing for fuel? I sitll think that is something you need to consider... I dont know what you're thinking along those lines... From the sounds of it you are either going for huge power or a powerband flatter than kansas, either way its cool as hell.

I dont thikn anyone has put on T25's onto a VH45, the smallest turbos I know of on the VH is T25/T28s.

I think what most people do is they forget that this is a thermodynamic air pump, so they think boost numbers matter, when really its power that matters... With that said, I woudl say you could go as far on the T25's fairly safe as you can on a Z32. I dont know what that is, but I'd say thats about 400WHP (so call it 480HP).... On a VH, thats only going to be like 8lbs of boost (assuming roughly 22HP/lb boost).

on a z32, max boost you can run is about 16psi [peak efficiency] on the 3L so I woudl say I woudlnt run anymore than 10-12 on a T25 (Since the 4.5 acts 1.5x bigger)... Really a T25 isnt a real bad choice for a VH since on stock injectors you cant run much more power than that.

[elwesso]

zer...22306

[trick240sx]

Im looking for max Hp and max drivability. Im thinking I can run the turbos to max efficiency heat wish and boost wise. At that point set the wastegate to open. At that same time have the venom notrous kit kick in at that RPM and carry it the rest of the way. I like that idea because with the 5speed and the small turbos I should be able to launch off the line very easily expecially when the turbos should be spooled at 3000 rpms. And drag racing that is about what you leave at. The plus side is I can drive it on the road with no problem because its just turbo until i hit the track or unless I deside to be sneeky on the road everynow and then. So big picture

3000rpm launch at the track 8 to 10 lbs of boostturbos hit max effiecency at 5000 to 6000 rpms wastegate opens/nitrous engages spraying until 8000 8500 rpmsof course these are not the actual rpm marks but just an example

I know what about the high rpms. I plan on trying the prelude double value springs in the heads also.