Jumbo Boost

jumbosrule

jumbosrule

Fully FX Invested
Premium
Location
Redondo Beach, CA
Car
2003 FX35T
Name
Brad
Awwwww yeah. It's time to lock down the parts and the kit. Been blogging a bit about my learning experience - pretty much talking to all the other forums out there representing the other VQ35DE communities. I've learned that I'm going to be doing this in steps. My goals for this install are on the conservative side, with an eye for future expansion. I want to keep costs down and plan to keep all stock engine internals in place, with no need to pull the engine for the boost install.

First step will be to install the turbo kit on the stock engine internals. I'll be upgrading the fuel delivery (pump & injectors) and installing a TT kit with a new EMU. My goals will be for 7-9 psi boost at 375 whp. Community experience says there are plenty of VQs out there running on stock internals up to 420 whp. Some have bent rods under this whp, but with a good tuning, I believe this risk is small.

I'll be looking to size the turbos so I can have some forward expansion when I build the engine in the future. We're probably talking a year or more after I install the turbo kit initially, but it will include pistons, rods, cams, valve springs, fuel rail & bigger injectors.

The EMU I go with will be whatever my install shop is skilled at tuning. I'll make sure the EMU will take me from the intial install through the future expansion so I don't have to re-buy that component.

The JWT TT kits are a possibility 500bb or 700bb kits - but I can only consider these only if the local shops that I talk to are certified to install it. If not, then a Greddy TT is probably going to be the way I go. I'll begin by looking at a pair of 18g or maybe 20g turbos.
 
it's going to be hard to properly size the turbos for the initial stage, & then continue to use them in the second stage of your plan I think. if you properly size them for the after then they will be too big initially & vice versa

sizing turbos is pretty tricky stuff. if you plan on determining your own turbo requirement then you'll find Garrett's website extremely helpful in understanding the engineering & calculations you'll need to make. unless you actually go & do the calculations & then plot the target points against the compressor maps your just at the guessing stage, & little differences in the A/R or the compressor/exducer properties make a difference overall in how the turbo setup is going to respond, where it will start to choke, & how efficient it'll be, & where your torque curves wind up lying...

I'd recommend at the very least you don't just adapt a 350z intercooler to the fx, the fx has so much more potential for a more efficient intercooler with less pressure drop than a severely limited 350z application. with the right intercooler you can def do so much better & this will of course also change your actual turbo requirements too.

start here & learn some In's & outs: http://www.turbobygarrett.com/turbobygarrett/tech_center/turbo_systems_tech_center.html

also, I hate to say it, but virtually all the turbo kits out there for the z are not ideal... they are all compromises built with the extreme limitations of space available to a 350z built into the design, where the fx does not have these kinds of restrictions & a turbo kit built with the fx in mind can have way more efficiency & less pressure drop than a 350z application. just food for thought, I mean yeah, I guess it's so much easier to just buy a ready made kit & adapt it to the fx, but for the same money you can build a much better twin turbo setup that is better all around by utilizing the extra under hood space the fx has available. it is relatively easy to build headers to put the turbos up front instead of tucked in tight to the sides of the block connected to a cast log type manifold, & the much better turbo positioning will improve all other aspects of the turbo system, from having the room for external waste gates to reducing the plumbing restrictions to & from the turbo's & intercoolers...

another good read is a book by corky bell tittled maximum boost. once you learn what turbo's like & don't like I think someone like you will appreciate the difference in the amount of compromises a standard off the shelf 350z TT setup imposes. on the other hand like I said, it is probably a lot easier to just go with an off the shelf setup, & of course they can & do work too, but just throwing out some food for thought:smile:
 
All good input - I'll definitely continue my education throughout the build. Made it through all three of the Turbo tech "classes" on that site - cool stuff. Thanks for the post.

In terms of sizing the turbos I might have to concede application specific sizes for my first install with the intent to upgrade later on. Meaning - I'll size my turbos for my my current boost and whp goals. It might cost more to buy bigger turbos later on, but I can offset part of that cost with the turbos I'm replacing. This is really future planning. It's more important for me to set up an expandable platform even if the turbos themselves are not part of that plan. If they could serve both purposes, great - but I wont expect that after understanding how to calculate manifold pressure requirements for target horsepower.

I absolutely understand and agree about adapted off the shelf kits, but I don't plan on using the piping, manifolds or intercooler provided to do exactly as you suggest - take advantage of the FX engine bay space. I plan to start with an OTS kit to identify all the components, then pick and choose parts to keep & reject for my specific application. I have yet to determine how cost effective this will be - might end up buying all components individually instead of buying a kit and then selling/buying parts to arrive at my design. But starting with a kit meant for the 350Z will allow me to see a bunch of built examples already installed and what I can expect out of the kit in terms of performance.

A more efficient intercooler and turbo layout might increase the potential power of a particular kit meant for the Z, but the FX probably won't make the same power with the same kit due to weight & drivetrain loss.

If anybody has alternative kit ideas or component suggestions, I'm listening. That probably extends to just finding a great deal on a particular component.
 
the piping & the manifolds & the intercooler pretty much are the kit... once your not using that stuff then buying a kit is very wasteful IMHO. you're much better off sourcing your own stuff. first of all you'll be able to get much more value for your dollar, & you'll be able to source the best product for the job rather than settling for whatever is bundled into a kit trying to keep it cost effective & profitable to the kit provider.

you should be able to get a stand alone ecu like a haltech, a pair of boe water cooled real deal Garrett BB turbo's specifically catered to your own calculations, a much much much better set of tial or turbonetics dual external wastegate setup than the commonly used in kit form internal wastegate setup all for less than a kit that will not be as good nor as expensive. the 'waste' of the components that won't be used can go towards better components that you will use & def get you more bang for the buck & a better setup for the same $$ as starting with a kit.

it's like building a stereo. easy to just get the whole bundled out of the box experience, but a compromise on many levels... always going to be better to source the individual components yourself & get the best of each component, making the whole "system" that much better. best receiver, best amp, best processor & best speakers etc, where a bundled "kit" is going to compromise big time to just make the kit "complete" & to meet a price point. once your going to consider replacing the speakers & the amp & the processor anyway it makes no sense to buy a complete stereo out of the box setup at all, here is about the same thing I think
 
the whole problem is that the kits available are all designed around constraints that we just don't have at all. if they had the luxury of building the kit the way we can in the fx believe me they would, but they just can't... the target market for the fx alone is never going to be enough for jim wolf or gtm to design a totally different kit for the fx, but if they could then it would be very different from the z design. the z design adapted to the fx is just a convienience thing... again it will work, but it could be so much better
 
turbocad6 said:
the piping & the manifolds & the intercooler pretty much are the kit... once your not using that stuff then buying a kit is very wasteful IMHO. you're much better off sourcing your own stuff. first of all you'll be able to get much more value for your dollar, & you'll be able to source the best product for the job rather than settling for whatever is bundled into a kit trying to keep it cost effective & profitable to the kit provider.
Click to expand...

The kit really can't be beat for value if I do use it off the shelf, which would still give me all the performance goals I want. Remember, I'm just boosting to approach the stock internals limitations here - no more. The available 350Z kits will need to be restricted and tuned back to safe my stock engine. Ideally I'd like to customize the piping and manifolds but that might not be the direction I end up going.

Could I do better? Yes - but not without time and energy, plus making and correcting potentially expensive mistakes along the way. Most of the guess work is already done if I stay with a kit and don't change out the intercooler, piping & manifolds. Same goes for the stereo in a box analogy you made - you can't beat the price for all the components together, even if some are under-powered or lacking in quality. If the system delivers everything you want, better is the enemy of good enough in terms of cost and schedule. This thinking doesn't sit well with technical perfectionists, but it does with project managers for risk mitigation and the bottom line.

I have a big picture in mind that doesn't require quite so much work - making compromises is part of the plan and I don't think it will be difficult to reach my goals with what is already available out there.

This is still discussion and a plan under development so it's all good. I have an appointment with a local shop this Friday and want to meet with the other two competitors here in Houston before deciding where to have the build done. The shops have mentioned they already have some parts in stock and this might cause me to adjust my plan or the "kit" I buy based on the benefits and prices each shop can offer. same goes for engine management. I'll be going with what the install shop wants to use, or what is provided in the kit I buy.
 
I agree completely, & like you said, the complete out of the box setup is usually perfectly adequate, more than enough for most, & is usually what most would really want or need anyway. I in no way meant to imply that it was inadequate or a bad route to go, in most ways it's the most sane & direct route to what your looking for, just wanted to throw some more info & ideas your way for consideration & to add another point of view & options that you may or may not have considered really, weather it's right for you to even consider is of course your own choice. about the only thing I really recommend considering that deviates from the simple kit form is the intercooler itself. there I see a lot of room for potential, but even that, if you went with a 350z application of course it would also do the job. if you go with like a greedy setup I think it doesn't include an intercooler anyway, so there you'd have the liberty of choosing what might work best for your application without any waste. this is one nice thing about turbo's in general. even if there not set up under ideal conditions in the end they still can be very effective at increasing intake pressure & volume anyway, sts is a perfect example of that... almost everything done contrary to normal accepted good practice with turbo system design, but still very effective none the less...
 
turbocad6 said:
the piping & the manifolds & the intercooler pretty much are the kit... once your not using that stuff then buying a kit is very wasteful IMHO. you're much better off sourcing your own stuff. first of all you'll be able to get much more value for your dollar, & you'll be able to source the best product for the job rather than settling for whatever is bundled into a kit trying to keep it cost effective & profitable to the kit provider.

you should be able to get a stand alone ecu like a haltech, a pair of boe water cooled real deal Garrett BB turbo's specifically catered to your own calculations, a much much much better set of tial or turbonetics dual external wastegate setup than the commonly used in kit form internal wastegate setup all for less than a kit that will not be as good nor as expensive. the 'waste' of the components that won't be used can go towards better components that you will use & def get you more bang for the buck & a better setup for the same $$ as starting with a kit.

it's like building a stereo. easy to just get the whole bundled out of the box experience, but a compromise on many levels... always going to be better to source the individual components yourself & get the best of each component, making the whole "system" that much better. best receiver, best amp, best processor & best speakers etc, where a bundled "kit" is going to compromise big time to just make the kit "complete" & to meet a price point. once your going to consider replacing the speakers & the amp & the processor anyway it makes no sense to buy a complete stereo out of the box setup at all, here is about the same thing I think
Click to expand...

+1

Go all custom. Save money. Get EXACTLY what you want ;)
 
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Have it installed at the shop if you must, but if we don't get a "Jumbo's sweet ass turbo kit" write-up afterward with lots of pics I'm gonna be miffed. :tongue:
 
You've probably been checking them out already but there are three shops for you...

Secret Services Auto
JTran Studios
Powerfab - they did the suspension on my FX and they have a lot of G35s there

Not so local...
Boostlogic in Austin. I keep hearing great things about them. Not so long ago they finished Powell's 996TT and its truly beastly!!!!
 
SexualChocolate said:
You've probably been checking them out already but there are three shops for you...

Secret Services Auto
JTran Studios
Powerfab - they did the suspension on my FX and they have a lot of G35s there

Not so local...
Boostlogic in Austin. I keep hearing great things about them. Not so long ago they finished Powell's 996TT and its truly beastly!!!!
Click to expand...

Haha - funny you should mention these three - I'm going to Powerfab and JTran tomorrow afternoon. I called up Secret Services a few months ago and they seemed interested in working with me, but then didn't return a couple phone calls and emails, so I gave up. Might try again once I see where things are settling out.

---------------------

So in the Turbo tech link that John posted earlier in the thread, I read about and have been messing around with airflow calculations. I'm using a bunch of formulas, but don't have some specific information for the VQ35DE engine. Wondering if anybody has seen this info or knows where to look to confirm it?

Stuff I found on other forums but am not sure if it's correct:

VQ35DE non Rev-up
Engine displacement = 3.5 L = 213.57 cubic inches
Maximum RPM = 7000
Air to Fuel (A/F) ratio = 11.5
Brake Specific fuel consumption (BSFC) = .62
Engine Volumetric efficiency (stock) = .92

If the BSFC and EVC are off, the whole calculation gets thrown off. No idea what these numbers really are for the FX.
 
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Paradigm shift

So after meeting with both shops today, I'm now thinking single turbo - maybe twin scroll. Think I will end up going custom manifolds and piping, plus the Haltech EMU. All custom parts, with the build goal staying 400whp.

I'll have general parts lists from both shops and I'll be talking with both of them again before I decide which way I want to go. Probably going to end up being price because both shops really seemed solid to me. Both suggested Haltech and the same size injectors (650cc), along with a fuel pump.

One of the shops offered to give me a free dyno tune - with the implied understanding I'd be going there for the FI install. Which I would. There were many Zs and Gs at that shop, which I liked. The dyno tune would be huge - I'll find out Monday what that entails and what the benefits are. But if I was understanding correctly, it is exactly the same as the Technosquare tune, except more specific to the mods on my car. If that's really the case, he bought my loyalty until he proves otherwise. Looking forward to picking parts and starting a search to see if I can beat the shop prices.
 
SexualChocolate said:
I am guessing Powerfab...
I could be wrong though.
Click to expand...

So I'm still letting things soak in and I really don't have enough of the details nailed down. Both shops have a starting point and I have asked them to pick the parts based on what I want. I'm not set on going to either shop per se - but Jtran offered me the free dyno tune and that's a pretty big faith gesture. Dyno tune should be better than the Technosquare mail-in tune, which is not cheap. I'm not counting out Powerfab yet because I'd be stupid not to see what kind of set-up they propose and for what price. I have about the same level of confidence in each shop. I know this isn't going to be cheap so I want to love the plan and the parts list. That's right - I said love. I get emotional-n-shit.

tchuck said:
5. The equation for Ve is: (Avf / Tvf) x 100%
where Avf = Actual volumetric air flow (CFM)
and Tvf = Theoretical volumetric air flow (CFM)
The Tvf is 432.36CFM @ 7K rpms
The Avf requires a measurement of your specific engine, and is then calculated using equations 1 & 2 on this PAGE (<-- That's a link).
Click to expand...

This calculation is how I got to the number I posted. The Avf can be estimated using a formula which is what I did. The question I'm asking is, for a VQ engine, does this number look right to others that have already done this? I guess I'm looking for an real world adjustment because I had to calculate Avf and want to use the "known value" for our engine.

I'm using stock conditions, as this is an airflow calculation for a particular horsepower based on engine displacement. Mods don't impact the calculation. They might impact flow efficiency - but this is for sizing a compressor. Flow is a different topic and for me it will be based on the custom piping fabbed for this install - TBD when my parts known and the layout is determined.

------------

Having slept on the idea of a single, quality turbo set-up - I like it more and more. The more I try to narrow down my build, the more I realize that future expansion will NOT be my focus. I need to build for one goal and that goal is going to be maximizing the engine on stock internals. Spool time is important to me - I want throttle response. Two small twins driven by three cylinders each won't spool as quickly as a properly sized single turbo driven by six cylinders. And if I go for a higher quality twin scroll turbo - then it will be even more efficient than the standard singles out there. My concern is the turbo manifold fabrication. That will be a project all by iteself.

Once again, tuning is everything. The computer needs to be the Haltech, so no matter what custom set-up and/or kit I go with, I can go buy that now.
 
From what I hear both shops are good. I have been out of the game too long and really have no friends that currently work in the field/own a shop to lend you any assistance.

I wouldn't count out Secret Services though, from the pictures I have seen their facility is impressive and I read somewhere they are working on Dr Robs TT Viper. Plus they have done an FX already and are familiar with them (in fact didn't they fix everything the other shop screwed him on?). Powerfab on the other hand was improving an STS TT C6...and they posted some nice gains at the same or lower boost level.

Although I am envious I wouldn't want o be in your shoes at this point. We're talking some serious work, time, and expense. When all things are said and done my opinion is go with the most solid shop...around here that would be BoostLogic in Austin. This is the same BoostLogic that is world renouned for their bad ass Supras. Why you might ask? Well I have seen many come and go in the last 14 years...even the cream of the crop doesn't last. I would want the backing of a very stable performance outfit behind my build (whether it is big or small). At the very least they would be worth checking out.
 
Appreciate the advice - I will check them out.

The time and money don't outweigh how much I enjoy doing this and my car in general. I feel like I have pretty realistic expectations and conservative goals. I'm doing this whole thing for me - for fun. No other reasons. It would be nicer if it were less expensive but saving up for the build is an accomplishment I'm proud of by itself! This is definitely the most I have ever dropped on a non-essential. A few years ago if you told me I would one day be spending this kind of money on a car there was nothing wrong with, I would have laughed.
 
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