GTM Performance Engineering: VQ37VHR Twin Supercharger System

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?

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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.