GTM Performance Engineering: VQ37VHR Twin Supercharger System

chii370

yes "make" is a bit too literal in this sense. take a north american nismo, and put everything it lacks from the JDM version on the car, reading between the lines is a useful trick. I had mentioned both of those parts in the post, but i also assumed everyone who owned a z, or at the very least a NISMO would know what i was referring too. my bad, next time i will clarify.

and i will have to admit the comment about there not being more than one was kinda half sarcasm. i was "hoping" there was. especially since the product is put up for purchase...... but you cant have it. durp.

timp

Thanks for keeping us updated. I have ordered the kit and waiting for shipment. Good things are worth waiting for.

chii370

before anyone says "ask sam" i have an inquiry in que, hes a busy man. so im going to ask here. mainly because i know their are members that have done this so know the answer..... If i were to buy a 4.2 or 4.5L short block. can i use the stock heads, cams, and intake. you can buy a stroker kit, with pistons, rods, and crank. and race cams from Z1. but i noticed no one sells damn "stage" cylinder heads for the VQ37...wtf? basically what i want to know is, if i buy the short block, what do i need. i will be doing the install myself but really have no "modern" engine experience, im used to building up 60s-70s motors lol. back in the old time days when they still used push rods and timing CHAINS. not all this new witchcraft..... :P I figured it would be a much cheaper alternative than payin 4k for the parts and then another 5k to have someone else put it in. my plan is to prep the car one part at a time for EVENTUALLY buying this kit, as i want it to make big power. so the stroker, lightweight pistons, race cams, hopefully heads if i can find them, M370 intake or anything better at the time, fuel system, engine managment, clutch, 4.08 gears, and a nismo GT pro rear end. i wont be able to afford the 30k it will cost to have a damn twin supercharger installed for quite some time :P not fortunate enough to have been born with a silver spoon in my mouth.

Chuck33079

GTM has staged head packages from what I remember. If you build the motor for boost, and then run it NA for a while you may be really disappointed with the performance. The CR is going to be too low for a NA car. If you're going for big power you don't want 4.08 gears either. You would want to go the other way. And 30k for the sc kit and install is way off.

__________________
2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent

chii370

yeah, kinda durp on the gears. but way off on the price? its 10k just for the kit itself. then with all the SC supporting mods, not talking about clutch and stuff. just ENGINE. such as fuel return, pump, oil cooler, and everything including installation. i cant imagine 30k is really all that far off. hell, if i knew how to tune a modern vehicle i would do it all myself. mechs these days think their time is worth hundreds per hour, when honestly the works not that hard. done it for the better part of 10 years, hell my first car at 16 was a 68 cougar 302, boss clone with 351 windsor mods putting out 400 horse that i built myself on weekends with NO prior knowledge, just reading big thick *** manuals and having mechanical understanding. time consuming, yes, hard? no not at all. i understand its a business, and ultimately i will STFU and reluctantly hand over my money to have them do it, but i see no real reason why it should costs as much as the parts to have it installed. there are 2 sides of this fence. the people who can just "afford it" and therefore dont care. and the ones that cant, but have in depth mechanical knowledge and fully understand what the work really entails. im an ENGINEER and i dont even get paid what auto shops charge per hour to have a mech install something. engineers just a fancy overglorified way to say mech that works on everything lol.

I fully agree with you, building up the motor for FI and running it NA will be horrible. especially with the race cams in it. having a super tall agressive cam that makes the car sound like a badass has a HUGE flaw. you lose a lot in the low end, they are designed to make big power in a specific band. thats why big NA V8 drag cars run a "stall" or "stutter box" they launch at 4k not because they want to, they HAVE too. when you get in the 600+ na range those motors are absolutely garbage at low RPM, but once in their band run like a scalded dog. ive seen tons of hot rod builders make that mistake. next time you go to the strip, find a big v8 muscle car making about 700 na horse, and ask him if he will do a pass from 0 RPM without his stall and watch carefully what happens. it will fall on its face until the engine revs and then it will take off like a bat out of hell. 90% of the time we drive our cars on the road, so its usually in the **** band. im fully aware of what happens. i plan to put all the parts in at the same time, im just getting all my ducks in a row and buying it bit by bit and needed to know what i have to buy. available parts for the 370 are somewhat shrouded in a veil of mystery, random manufactures make random parts, and GTM's site is ...... weird. people say these parts exist, and im sure they do. but im not seeing them on the site lol, its all 350 stuff. some of them say OR, but the heads dont. are the parts SO similar to the 350 that literally all nissan did was change bolt patterns and increase displacement? i mean come on..... if motordyne can get away with re selling a 350z intake for the 370 by only changing some bolts for 800 bucks...... im getting suspicious that this is the story with the heads, pistons, rods, probably the fuel system..... and many more.

my overall goal isnt just horsepower. im primarily concerned about torque. i want to make a VERY snappy responsive torque monster. bad platform to start with, but it CAN be done. when im done with it, i want that thing to rev like a damn F1 car. ive seen some interesting results from FI builds in the FI thread. some people dont get **** for gains, others get SUPER high HP and SHITTY torque, and some get pretty decent hp and AWESOME torque. and the weirdest part is..... 99% of them use the exact same kits. my goal is 550 RWHP at 425-440 RWTQ and violent as hell off the line. not looking for a paper numbers, nice neat perfection machine. i want it to be an "event" when i drive this car. I know it can be done, V8 V6 or 4 cylinder, mechanical principles still remain about the same.

Chuck33079

Yes. For just a sc kit, 30k is way too high. How much do you think supporting mods cost? What do you consider supporting mods? Fuel pump should be included in the kit. Adding the return system is <1k. Oil cooler is around $500. Another $500 for gauges, etc. Install will be around 30 hours or so at around $100/hr. If the kit is 10k, and ~3k for the install, I can see maybe another 5-7k in supporting mods. That's $20k. Where's the other 10 coming from?

__________________
2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent

chii370

cams, crank, pistons, rods, fly wheel, valve train, block just to mention the motor. then sub supporting mods like clutch, and rear end. the tune is literally the ONLY thing holding me back from installing all of it myself and saving myself like 5-6k. thats a LOT of money ;( also, just to ask, what gear ratio have most of the FI builds been using? if im not mistaken the nismo is already like.... 3.7 or 3.8 something right? need to be taller than that? im not looking for this thing to go 200 mph, im looking for maximum torque and responsiveness, so i have to find a happy median. longer gears would take more advantage of the extra power yes, but shorter gears would make the available power easier for the engine to convert to mechanical power on the ground, hence "mechanical advantage" but i dont want them TOO short, or then it would so easily overpower itself it would be literally impossible to drive, and first and second gear would be like .5 nano seconds long before shift.

someone please remind me how a dyno calculates again? wouldnt having 4.08 gears technically allow your engine to more efficiently put "more" power on the ground, or does the calculation compensate for gear ratio? in my mind its an artificial way for the engine to help make up for torque. but im positive im wrong about that.

i miss the days you could just throw these parts in an engine, time the engine with a gun and your distributer, fiddle with your 4 barrol carb for a bit and BAM, engine tuned. computers made cars infinitely more complicated. better yes..... but not required. i could make that old "inferior tech" 302 run RINGS around a BUILT 370z motor with about 5-6 grand. and all i had to do to the rest of the car was....... absolutely nothing at all. the rear end, transmission could already hold its own. slap some big *** tires under the wells and you got yourself a bored and stroked 500 horse NA MONSTER that runs 11 second quarters. 302 is pushing it..... but point remains. tried to compare it as closely as possible to displacement. 302=5L to a 370z's 4.5L stroker.

Chuck33079

Ok, if you consider a built motor as a "supporting mod", then you're too low on costs. You can put the kit on and build the motor later, if you even need to at all. The car can easily handle 500 whp without a built motor. You may find that's enough in this car. The jury's out on the twin sc kit, but in general sc is not the correct path for an all-out big power build. Install it yourself and have someone else tune it. It'll come with a canned tune that's very good. 4.08 gears on a FI build will convert the power into tire smoke, not forward momentum. There's a 3.3 rear end if you're going for 600whp+.

__________________
2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent

chii370

i HATE to mention this in a gtm thread "sorry sam" but would it be a better idea to go with the fast intentions TT? ive never seen turbo numbers like that before, its making 450RWHP at 3k rpm!!! WTF. i thought the low rpm range was supercharger territory lol. 10psi, 550 hp, 485 tq......... thats absolutely insane. if they can get the fuel issue worked out, which i would guess just cant keep up with how quickly the car needs it, not pressure, VOLUME. you can put more pressure on a small pipe to flow more, but will still have pressure drop if the demand exceeds the delivery. increased pressure doesnt linearly equate to higher volume of gas when using a mechanical pump. the kits 9 grand..... thats cheaper than the TSC, and MAN is it clean. all you can even see from under the hood is the intakes, and to an untrained eye that would just look like you had some retarded long tube CA intakes on it. cant even see the damn intercooler unless you look straight through the front of the car, its about as hidden as the oil cooler lol.

your not the first to say that this car can hold 500+ stock..... im starting to believe it. also, random question since ive mentioned so many mods...... does anyone sell a CF driveshaft for the 370? i took the one on my old 09 off for various reasons i wont disclose..... and dear GOD its heavy. and ive even heard rumors that its actually partially carbon fiber ALREADY? really? i dont remember CF weighing a million pounds.

Chuck33079

All of the 370 sc kits are centrifugal, so they're going to shine in higher rpm. It's not a roots blower. There are a lot of guys running 500whp with no issues. It's all in the tune. Yes, the driveshaft is composite already. No need for the cf driveshaft.

__________________
2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent

m3chhawk

I won't get into the turbo manufacturer debate, because it's been beat to death in countless threads. You will find all you need to know there without hijacking a GTM thread.

500-550 is the norm on stock internals. Some have pushed 550-600 reliably.

The driveshaft is a composite (that contains some carbon fiber material), not full CF.

__________________

SS_Firehawk

Man oh man where do I begin... Read Z owners! There are cheaper ways to make power. The Stage 2 SC is the cheaper way if you are supercharging. I bought this because the long tube header clearance issues with a low mounted SC. If you are running stock or shorties, there are cheaper ways. Remember GTM sells their Garret TT kits and the MHI kit. No need to ask about a competing vendor on this thread. Chili, unless you plan on pushing serious power, you don't need a built motor. If you are looking for torque, go TT's, if you are looking for response, get a SC unless you don't mind waiting for the half second it takes (maybe less) for the turbos to spin. If you are looking for instant torque and response, sorry, there is no twin screw or roots blower options here.

__________________

chii370

wish someone would make one...... and make some kind of low profile blower that could sit under a ram air style hood so it doesnt have a giant stupid looking blower intake sitting in the way of what i usually need to see while driving :P wasnt tryin to jack the thread, sorry about that. its just that this is a big choice, i dont have an EXTRA 10g to press the reset button if i **** up the first time. normally, i want response. and normally i dont consider turbos..... but DAMN already over 450rwhp at 3k rpm..... if thats what you call turbo lag? i will take it. not to mention its not using the usual 9587645976 PSI required for a typical TT to produce big power that early so my engine wont explode after 50k miles. clean oem look....... ok i will stop now.

although ive been following this thread for like..... EVER. since the last guy wimped out when his car didnt make big *** power on its very first dyno run and put it back to stock..... that was a good half a year wasted waiting to see some damn results. one would EXPECT this kit to go far and above what a single sc, and maybe even what their stage 2 TT can do for how much it costs, and how complex the installation is. but we shall see. believe it or not, im actually rooting for this thing to be the next sliced bread 2.0.

KaienZ34

GTM TT Nismo... This doesn't look stealthy and stock? You could even go with black tubing and inner cooler for even more stealth.

__________________

chii370

u got me..... that looks pretty damn good. but then we would be getting into a GTM VS FI TT kit flamewar..... and thats not for this thread. money spent/gains achieved = numbers between them dont match. nuff said.