1994 Infiniti Q45 Rear Mount Turbo full writeup w/pics

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qsiguy
Posts: 1961
Joined: Sun Mar 20, 2005 8:12 pm
Car: 1994 Infiniti Q45 Turbo

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qsiguy wrote:....Jeff Taylor is one but wasn't able to find the thread on a quick search. If I remember correctly he was making about 450HP on about 6 lbs of boost. I'll have to dig around for the old thread.
Found a new thread over on the VH and Vk forum. Jeff just recently hit 681 hp @ 18 psi of boost!! He's still got a lot of tuning to do as it's still super rich but it's looking awesome.

Image


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Q-ZILLA
Posts: 325
Joined: Tue May 24, 2005 3:20 pm
Car: 1995 Infiniti Q45t
Rear Mount Turbo

R.S. Enthalpy Tuned on
Dynojet-5000lb roller
453hp/453lbft

2008 Nissan Armada
2009 G37 Convertible - SOLD
2004 Cad. Escalade POS - RIP
Location: Cape Coral, FL
Contact:

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No problem, just let me know when... 239-540-5400. I would like to dyno mine, just haven't got around to it yet. Still have parts to put on, I'm running 10lbs, no problems yet...

Heath
Posts: 232
Joined: Wed Oct 15, 2003 11:29 am
Car: 1992 Q45, 2000 Excursion (towrig), 2003 Yukon Denali (Wife's Ride)

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18 lbs of boost... Holy Crap... I'm guessing thats not on stock internals then is it? I didn't think the 10.5:1 ratio could handle anything more than 6-7 lbs of boost...

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Q-ZILLA
Posts: 325
Joined: Tue May 24, 2005 3:20 pm
Car: 1995 Infiniti Q45t
Rear Mount Turbo

R.S. Enthalpy Tuned on
Dynojet-5000lb roller
453hp/453lbft

2008 Nissan Armada
2009 G37 Convertible - SOLD
2004 Cad. Escalade POS - RIP
Location: Cape Coral, FL
Contact:

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Shane, do you know what Jeff did to his motor?

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qsiguy
Posts: 1961
Joined: Sun Mar 20, 2005 8:12 pm
Car: 1994 Infiniti Q45 Turbo

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No I don't. I know he started his build mostly stock with the turbo but has since done some magic with it. I'll have to do some research on it.

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Q-ZILLA
Posts: 325
Joined: Tue May 24, 2005 3:20 pm
Car: 1995 Infiniti Q45t
Rear Mount Turbo

R.S. Enthalpy Tuned on
Dynojet-5000lb roller
453hp/453lbft

2008 Nissan Armada
2009 G37 Convertible - SOLD
2004 Cad. Escalade POS - RIP
Location: Cape Coral, FL
Contact:

Post

I'd crap my pants if the internals were stock, but there's stuff out there about these motors that blows me away, so I wouldn't be shocked either. I'm rebuilding the top right now... I'm in the garage... Injector issues; sent my injectors out and they got returned with the wrong lower orings. Nothing quite like having to do it all again. Redid my valve cover gaskets while I did this.

User avatar
Q-ZILLA
Posts: 325
Joined: Tue May 24, 2005 3:20 pm
Car: 1995 Infiniti Q45t
Rear Mount Turbo

R.S. Enthalpy Tuned on
Dynojet-5000lb roller
453hp/453lbft

2008 Nissan Armada
2009 G37 Convertible - SOLD
2004 Cad. Escalade POS - RIP
Location: Cape Coral, FL
Contact:

Post

Shane,

Took my baby to the Dyno the other night, had to know... I was a little disappointed...
Image
Justin was having issues getting it all hooked up, but I guess it's right. The first run was virtually identical to this one, but it didn't print. I'm going to go by his shop and get a copy of the first run anyway. I beat an AMG S55, numerous Corvettes, etc., but it doesn't seem like I have that much HP. 340rwhp/393tq. The torque number is descent, but I would love to talk to Jeff Taylor. I was hoping to see some 400's on this graph. IDEAS?

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Unnatural1
Posts: 192
Joined: Wed Mar 07, 2007 4:58 pm
Car: 1994 Infiniti Q45

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John those really aren't bad numbers. You are looking at a 400+HP at the flywheel with a pretty basic setup. I'm guessing there are numerous improvements you are wanting to make and the biggest most immediate one is tuning. I'm assuming you've got a wideband O2. What sort A/F are you seeing? You might consider an EGT sensor too.

Timing on a turbo engine has a massive impact. The most timing you can run without detention for your target boost is the sweet spot you've got to find. You've got an added complicating factor: methanol injection. It can be a little tricky to setup. Basically keep playing with the tune and you will get closer to your goal. You running an intercooler?

User avatar
Q-ZILLA
Posts: 325
Joined: Tue May 24, 2005 3:20 pm
Car: 1995 Infiniti Q45t
Rear Mount Turbo

R.S. Enthalpy Tuned on
Dynojet-5000lb roller
453hp/453lbft

2008 Nissan Armada
2009 G37 Convertible - SOLD
2004 Cad. Escalade POS - RIP
Location: Cape Coral, FL
Contact:

Post

Thanks for that blurb earlier, some of these guys are tools. I just want to have fun with my car. I've had a '71 Challenger, a '67 Chevelle, but they are a piece of cake compared to all this electronic crap. I'm a rookie at this, but the bug has bitten me with My Baby...

I even think when I dyno'd it... 12:30am; after waiting 9+ hours @ dyno-day and tired... I think it was on the daily driver tune... Oops; I will re-dyno the car sometime soon to see the difference.

I was a little disappointed, but after thinking about the fact it's all stock and I think it was on the wrong tune... Guess I shouldn't be. This car runs flatout!

This is bad, I know... Shane (QSIGUY) tuned my ECU to his tune; both running similar setups. We hooked up ECU and that was about it. I do have a new set of AutoMeter gauges to install, but haven't got to it yet. One mechanic checked it out and said the AF was okay, but he thinks the injectors are maxing out or close to it. Yes, it is intercooled. So with that in mind...

I'm checking into either 800cc or 555cc injectors and a bigger/better fuel pump and regulator. I'm waiting to talk to Shane about it all. I did find a local guy that claims he can re-tune/burn my ECU.

I was looking at Jeff Taylors setup in a 240 w/ VH motor. Had his motor (claims stock) up to 872 whp, blew a rod around 820 whp, so the thread goes.

I've decided, come hell or highwater; I want at least 500 ft/lbs tq at the rear wheels. That would make me happy. Initially I wanted 600, but the new guy, tuner, talked me out of it... $$$$$$...

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Unnatural1
Posts: 192
Joined: Wed Mar 07, 2007 4:58 pm
Car: 1994 Infiniti Q45

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No problem, John! ;)

Having done no math what-so-ever, using the SWAG method (scientific wild-a** guess), I'm thinking 550-555cc injectors should be fine to get you to your goal. Also I don't know how hard it would be finding high impedance 800cc injectors that will work with the OEM ECU. Might be easy, I haven't checked. Sounds like a VH with proper tuning and upgraded rods and pistons would be ok well above 1000hp. That's pretty awesome.

You said previously you're running 10psi, right? Is that with the methanol injection or just the intercooler? The other thing is this, depending on what size your turbo is, you may be running way outside your turbo's max efficiency range at only 10psi. Meaning as you go up in boost, power may go up exponentially. The boost vs. pressure relationship is not linear; such as 1psi = 10hp for example. Turbo's work best when operated at in the max efficiency island specified on the turbo compressor map. Lower or higher pressure can make a pretty significant difference.

Of course, that's all just speculation. I'm guessing Shane may have better input since he knows your setup better. Definitely go for another dyno and see if that one was a fluke. I liked those torque numbers though. Almost 400ft/lbs to the wheels...NICE! :BnB:

User avatar
Q-ZILLA
Posts: 325
Joined: Tue May 24, 2005 3:20 pm
Car: 1995 Infiniti Q45t
Rear Mount Turbo

R.S. Enthalpy Tuned on
Dynojet-5000lb roller
453hp/453lbft

2008 Nissan Armada
2009 G37 Convertible - SOLD
2004 Cad. Escalade POS - RIP
Location: Cape Coral, FL
Contact:

Post

Coincidentally I just found a set of 750cc injectors, JECS, for a Q45 off Ebay, with 3yr warranty and returnable.

http://cgi.ebay.com/ebaymotors/8-JECS-7 ... 5644429765

I also found a 340lph fuel pump that claims can handle EFI engines up to 750hp, so.... I don't want to get into the motor... Not looking for 1000hp, just want to get around 500-600 ft/lbs tq. I obviously don't know enough about all this and will go by the tuner guy and run it by him, as I have not heard from Shane... I ran @ 10lbs with just the intercooler for a little over a year. My turbo is a Garrett 4094 BB. I just recently put on the Snow - Stage 2 system. This new guy has everything to tune/burn and even has a dyno.

Here's what I've got so far; you'll have to scroll down to get to it;

official-g50-90-96-q45-owners-check-in-t151212-640.html

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Unnatural1
Posts: 192
Joined: Wed Mar 07, 2007 4:58 pm
Car: 1994 Infiniti Q45

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Well, those injectors may be a good deal. Assuming the seller has a good reputation. You may also want to contact Deatschwerks http://www.deatschwerks.com/. I am currently running injectors (stock 370cc) from them. They used to offer multiple flow rates. You may have to call and ask them. BUT, definitely don't waste money on a fuel pump. Our Q's come with a pretty massive fuel pump stock (somewhere around the flow rate you mentioned). In fact, it's basically the same one that comes in a 300ZX TT and is sought by many 240SX owners. It's big and better (and more $$$) than a typical Walbro or similar fuel pump some people buy.

I looked up the Garrett GT4094. If I'm right, at 10psi and roughly 400hp (at the flywheel) you should be right around the highest efficiency island on the compressor map of 78%. So if that's right, never mind what I said before. That's a really quick and dirty estimate though. I would imagine at the power level you are at you're pretty much out of fuel due to the stock size injectors. The alky kit isn't going to do you much good without more fuel to add to the higher boost it should allow you to run.

It sounds like you've got a the help you need to tune it. The dyno is the best way to go. Just keep an eye on injector duty cycle and you're A/F ratio.

User avatar
Q-ZILLA
Posts: 325
Joined: Tue May 24, 2005 3:20 pm
Car: 1995 Infiniti Q45t
Rear Mount Turbo

R.S. Enthalpy Tuned on
Dynojet-5000lb roller
453hp/453lbft

2008 Nissan Armada
2009 G37 Convertible - SOLD
2004 Cad. Escalade POS - RIP
Location: Cape Coral, FL
Contact:

Post

Sorry Brendan, I got busy. I'll check them out though. I did find that AeroMotive Stealth pump - 340lph, so I'll get that if my Bosch gets too stressed. I don't want it to be "maxed" out all the time. I replaced that pump a couple years ago. Pretty sure I'll need/want something like this vs stock.

Saw somewhere on here... Don't know if it's true, because I haven't been able to find any spec sheet on the stock pump that lists flow; that it puts out 241lph, but I'm thinking not. The highest Bosch's I found on their site are around 200lph which they say is the max range for most EFI engines. A Z32tt uses a 227lph from what I found, so I would think they'd use that one.


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