Infiniti Q45 Throttle Body [Merged 4-8]

[SilverJester]

first off, I am posting in this forum because this is where I found part of my answer...but please move if it's in the wrong place.


I have a 2g which means I have 4 wires going to the TPS. the q45 tps has one pig tail w/ 3 wires and a short harnes w/ 3 wires. So far what I've been able to find is the the short harness is for the actual TPS and the pigtail is for the "idle validation circuit". I'm not sure what that means but I found it on some supra forums. I know that the difference between the 1g and 2g tps is that the the 4th wire (which ells the ecu if the throttle is closed) is seperate on a 1g. Could this be the same thing as "idle validation"?

So far this is the info I have come across as far as wired and what they are for:

q45 tps harness (not the pigtail):
-Red is the 5 volt input wire
-White is the TPS signal wire
-Black is the sensor return wire

2g tps harness:
1 - Green/Yellow (+5v Sensor Power)
2 - Brown/Red (TPS output voltage)
3 - Yellow/Red (IPS switch)
4 - Black (Ground)

Ok so I'm still a little confused on what wires to connect so if anyone has experience or more info t add I would appreciate it.

 

[cs82685]

WHose corey?

Me, but Tom Marlton's pretty much nowhere near me so you'd have to be passing through to go by Mark if you were to stop by me

 

[Slippi84]

No more waiting enjoy

 

[Blitzeclips]

Awesome work bro. I admire that. Looks great.

Any info on the performance aspect of this mod?

Tell us a little more about the wiring you needed to do. Did you use the OEM TPS and IAC or another? What exactly did you change to make this work?

That's looking good though..

 

[link16]

It looks like a bored out OEM TB; I would assume he is using the stocker sensors.

Looks great, My IM gets lost next to my VC; it is so black from my dirty hands all over it.

 

[Slippi84]

It's a basic q45 tb of a Nissan Q4 obviously. It's a lot larger then a stock bored out tb here i'll take a pics of the tps and the adapter plate h/o

there you can see it doesn't have a IAC like ours it's controlled mechanically via a screw which you can see in the bottom right of the linkage picture. The TPS is a stock Q45 TPS and you just wire it in using three of the 4 stock wires I"ll look up in the other threads I was reading to find out which wire goes where so all the information for us 420a guys is in one spot on this mod.


I can not speak on performance aspect of this mod yet because I am doing my head at the same time cause my valve stem seals were bad and I was burning oil a little. If everything pans out I will have a stage 3 ported head with crowers 2's to compliment this mod. I can not wait to see this thing pull once that's done. The only thing people have said it you will have a twitchy throttle but that just sounds like something you adjust in your driving habbits and if anything sounds like quicker throttle reponse which is never a bad thing. You still want to do the obx mods that everyone came up with in that other thread like bullet did but after that your looking at MOST a $500 intake and tb setup that will blow a ported stocker with ported tb away.

 

[Blitzeclips]

It's a basic q45 tb of a Nissan Q4 obviously. It's a lot larger then a stock bored out tb here i'll take a pics of the tps and the adapter plate h/o

Have you installed this yet? I am curious to see how well it will idle, perform, etc..

Think the IAC will respond as OEM if you are distributing the power differtnly?

That TB will actually sine on the top end versus the low end. It's a larger opening so this will lower your velocity. Meaning it will take longer for the charge to efficiently produce power. So you will feel it pull much harder in the upper RPMs..

 

[Slippi84]

Have you installed this yet? I am curious to see how well it will idle, perform, etc..

Think the IAC will respond as OEM if you are distributing the power differtnly?

That TB will actually sine on the top end versus the low end. It's a larger opening so this will lower your velocity. Meaning it will take longer for the charge to efficiently produce power. So you will feel it pull much harder in the upper RPMs..

This is true but That's why I'm have a aem v2 style intake being custom made by a local muffler shop out just haven't decided on material but it will go from 4" - 3 1/2" just like the aem v2 just bigger The increased flow should make the diffrence in velocity almost null as this custom intake will have roughly twice the volume of my current intake which goes from 3-2.5

But it shouldn't matter anyway cause everything else on this setup will be geared toward top end anyway like the cams and head porting. I need to get my hands on a af/x ecu now : )

 

[InfiniteGSX]

the black box is mounted on the two braces it a called a vaccume box used for cruise control if u deleat it your just not going to have cruise control.

Then how come other 420A vehicles I have played with, including my 97 Eclipse right now, doesn't have that? Even tho yeah my cruise hasn't worked since I got the car... but my cruise never worked on the car that had the little black box... it had a huge hole on it for something, like a dump tank. But This 97 doesn't have it, that white 98 RS ... argh crap forget the RS part, I'm dumb. But yeah, my 97, I just pulled the head off recently and nada.

Anyways, Nice work on the IM! Make me one now!

you say nissan Q4, and q45, as in Infiniti q45... that ugly car with the dual projector headlights? Please say yes... there are hundreds in the junk yard....Pretty much, you moded it to hold this TB, and did the port job on the intake manifold to fix the runners, and thats it right? wonder how this will like boost... The Charge pipes are 3", made for an evo... the BOV is a 50mm Tial... the only small points in the charge is the port comming out of the turbo, and the damn stock TB and IM. To install the charge pipes, I had to add smaller cuplers before clamping.

BTW, what size is this again? 4" you say? And the MP TB is how big?

 

[Slippi84]

Oh yeah sorry I keep callin it a nissan q45 it's a infinity q45

Yeah the tb's are a dime a dozen and looked at as one the best non stock(not really aftermarket) tb's you can put on a dsm because it has full shafts not half shafts and it's a good hgh quality OEM grade part from a company that doesn't make cheap shit. The only probalem I have ever seen with these is sticking open from high boost apps which there is a way to cure as well. The inlet is about right over 3" ID I can fit an entire 3" coupler inside the tb pefectly. About how it would like boost just do a seach this mod has been done on 4g63's for a while ith guys running big turbos and 3" piping and what not just not usualy don't on a small scale build so we'll see how it perfroms.

 

[GS-T_Newboost]

the vacume box should have a vacume line rane to it and it operates your cruise off of vaccume

 

[Slippi84]

the vacume box should have a vacume line rane to it and it operates your cruise off of vaccume

I'll run a line to that box alright a fuse with c4 and a flame on the other end. I would have had this done and been driving for a week now if it wasn't for this box and now that I used a pry bar cause I thought the manifold was just stuck that bracket is even harder to get tok I need to know what size bolts and how you guys got it off anyone who has done it.

 

[InfiniteGSX]

I think the bracket is a 12mm. if not its a 14mm. I just took it off recently. I should know b ut can't remember.

Alot of the 420A's I've played with don't have that box, except one.

 

[BigRand]

I'm not sure (someone can correct me if I'm wrong) But I believe if you were to go turbo and run megasquirt, megatune should be able to run that mechnical idle screw, using the PWM and fast idle settings.
Just a thought for those worrying about what to do without the IAC

 

[Slippi84]

I'm picking up my head with cams and gears up tonight so I should have the new head on by this weekend with some performance updates.

 

[InfiniteGSX]

Take pictures... invest in a camera hehe.

Is it going to be a problem to have a manual IAC over the stock IAC?
Just supposed to control how much air the car gets during Idle right?

 

[link16]

Take pictures... invest in a camera hehe.

Is it going to be a problem to have a manual IAC over the stock IAC?
Just supposed to control how much air the car gets during Idle right?

That is correct, I know how these things work but I would love to see how the stock ECU handles it.

 

[Slippi84]

They idle just fine the 4g63 guys elimniate the electrical part of it just like i will. All you need is the tps and it will idle just fine. I use my phone camera to take pictures and upload em but I had left it any my boys house but I have it back just in time.

Last night I drove 4 and a half hours round trip for what has to be one of the best deals I've got since modding a dsm. My valve seals were bad so I was pricing out how much it would be to get the seals replaced and teh head cleaned and a 3 angle valve job at the local shop I sell parts too and it was like 250 for everything. Not bad. But then I saw heads on ebay for like 400 which came fully rebuilt with 3 angle valve jobs cams the works already assembled even better deal considering the time I would save on install. WHile looking I came across this guy selling a whole bunch of performance stuff and well..... I will llet the pictures speak for themselfs. I got everything you are about to see for 400 dollars all I had to do was dive and pick it up and throw in my old fmic which I don't need cause i'm going spray anyway.

and there's more

Ok just to clarrify that's $400 and a fmic and some piping for:

Stage 3 ported and polished head
Crower Titanium valve springs/retainers
1mm oversized SS valves
Crower Stage 2 cams
AEM tru time Cam gears
Top portion of a header system(Only bad part is I think it will cost more to get the rest made then to just buy another on ebay but oh well)

The guy said the head it was like 1600 worth or work and stuff and I beiliev it just looking at all this stuff. He got rid of his 420a for a turbo car and had stuff laying around. I can not wait to see how it all performs I'm trying to get it all on by this sunday so I can have some good info for you guys.

 

[link16]

Ask him if he has another head like that.... ...

Looks great and I hope you enjoy such a great buy.

Crower cams and valve train can be quite expensive. My machineshop would charge more than $1600...

 

[Slippi84]

Yours and mine both :sneaky I was gonn apick up stage 2 cams from a guy for 300 and I thought that was a steal.

 

[Blitzeclips]

Not bad of a deal. Are you running stock lifters and rockers?

 

[Slippi84]

I was thinking about that is it worth investing it new lifters and rockers?? I think now I"m gonna rev to like 8k maybe more the guy said teh head was built to rev to 10k but that's just nuts.

 

[InfiniteGSX]

Ebay has 420A head parts all the time. Last week they had pretty much everything to build a fully built race head for damn good prices.

So You mentioned whats wrong with your head... but did you notice any good from the Mani/tb? or is it not installed yet?

 

[Slippi84]

It's not installed yet and this isn't from some seller this was just a guy who put it up on there. No I still haven't got arond to getting this old manifold off cause I been busy doing other stuff like I did the motor mount install and the trans mount one took me a little while and running out of light it strectched to a two night job.

This weekend I promise I"m workin all day sunday getting the old head off this one with manifold and header on and some concreate info and if i can get a appointment to philly dyno some nunmber in the next week or so.

 

[InfiniteGSX]

You need a small guy like me gettin in there... everyone calls me because how I can get in places nobody else can ... don't know if thats a good thing or not...

 

[Blitzeclips]

Are you still using stock springs?

Sounds pretty similar to my set-up except you don't have lifters and rockers, also springs. I'm curious to see some results.

When do you plan on going to PDW? I was going to have them dyno my car but a local guy is giving me a nice price. I even know a guy who can dyno just the motor, seldom from the car itseld. That machine is cool. I'd also like to see what kind of HP my cam gears can pull for me and yours for you (Slippi).

Why didn't you run a vacuum box with the manifold? Simplify the equation I guess you could say. Don't forget to post up the wiring situation for the TB when install time comes. If things turn out well maybe some other 420a guys can get some insight on the mod.