complete engine overhaul questions.

FL 4Motion

I just don't see 500whp coming out of an n/a 370z, regardless of what's done to the motor (assuming it's still the original modded motor, not an lsx swap etc). I think it's a question of diminishing returns to certain extent, increasing the displacement should, in theory gain hp, but beyond a certain point, not so much as to even make the effort ($$$) even remotely worth it.

In short, I can see 400whp with a stroked and massaged vq37 (n/a build) happening at some point but not more than that, def not more on pump gas.

chii370

How is it so inconceivable, I see mags and shows on tv for example "top gear" that feature cars like a WRX, an EVO, or a RX7 or any of those cars ALL of which have a much smaller displacement engine, and in the case of the top gear pep it was a 1000 HP EVO 8 I believe. YES I understand that's AFTER it was turboed, but you expect me to believe that the turbo alone is producing 600 of those horses? U have to be about retarded. And then say a motor that's ALMOST double it's size can't make half of that on it's own? It doesn't take much. Mine dinoed at 368 FWHP bone stock. Bolt on stuff ALONE would get it close to 380-390 if I did all bolt ons available. Just puting a good pair of heads on an engine helps dramatically. Or at least it does with a old V8. and guess what? It's the same dame thing, minus 2 cylinders.

I think that vvel **** would probably be a tuning issue and would probably have to be worked around entirely IMO but all it really is, is an electronicly "ecu" operated and timed variable opening and closing of the valves. regardless of cam lobe being more aggressive "because thats the difference in a race cam" and keeping the valves open longer or opening them faster its just a matter of tuning the rest of the system to accept the new variables and tolerances . but other then that this is clearly a hypothetical question as it stands. And who cares what it costs? I'm asking if it can be done and if anyone has a real professional opinion about it, not your opinion on financing. My situation is simply time sensitive, and if you must know I'm going army special forces next may. But paying for the car UNTIL then is the issue, not after.

I didn't say I don't know how a transmission works or a clutch or anything else, I told you I'm old school muscle car. Have a question about a torqueflight trany? How about a ford 9in rear? Or whether you can put 351 windser heads on a 302 "Aka boss" then Im the man to ask. But if you ask me about all this new ****? viscis rears, quad disk dampened clutches and all this other ********? No I DONT know much about it. It's called learning, so how about a little respect and not insta flame someone because they may not know something you do? How about trying a nifty technique called teaching.

I see no reason to even doubt it can be done, I simply asked if anyone knew how.... And where to aquire the parts to do it. It's not like I can just call up JEGS or summit, for some reason the Japanese car tuner market feels it needs to be far more exclusive and complicated to work on these prissy picky *** cars. It's like babysitting an autistic child trying to work on these things.

Did u ever think that maybe I was ok with investing time and money into trying to figure it Out like a true mechanic rather then be a ******* instant gratification whore and go the easiest route possible because of any lack of real knowledge? Aka turbo solution. Most people talk big, but don't actually know what it really takes to build a race engine. Not just a stock engine that's blown, procharged or turboed.

chii370

So in a nut shell, what I'm hearing is that you think you can't gain 100-150 more horse out of heads, pistons, cam, crank, bore, intake, fuel system. Doing the SAME thing to an old v8 of any kind doesn't matter, that say... Made 330hp from the factory, like an old 383 or a 440. using a CARB and running on 93 pump gas you can easily build one that makes 750-775hp . I should know, I have a 1974 AMC hornet with a 401 bored 10 over that puts 800 on the ground. it runs low 9s. And thats on a road legal cheater slick, cars not tubed, full interior, all original sheet metal. So it just so happens I know my way around a performance engine or two, but not the new stuff. If you want pix I will upload a few, I know how people tend not to believe each other behind a vale of anonymity.

http://s1222.photobucket.com/albums/...t=IMG_0574.jpg

http://s1222.photobucket.com/albums/...t=IMG_0573.jpg

sorry about the quality, an ipod isnt the best for taking pics

(self correction, since this car doesnt have what you could conciser a traditional camshaft with lobes, i take back that statement. ) but from what i gather on how the VVEL works with the opposing rocker arms in place of lobes and stuff its all down to tuning. im sure theres tolerance limits to the stock system but from what i see it has potential to be FAR more versatile then having to swap in a cam thats physically different. its all operated and changed on the fly by the computer for the opening and closing duration and speed. thats some seriously complex stuff right there, but just like everything else it can be replicated and designed to be more performance oriented.

Rui Z

Just call GTM and ask them what needs to happen in order to get 500 rwhp on a normally aspirated 4.5 liter stroker kit engine.

And no i dont believe you when you say you can get 850 whp naturally aspirated on amc 360 for <$10,000.

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chii370

I already did, emailed them though.... Takes a few days for them to get back to ya.

And I don't care what you believe, I have one. I'm not going to lose any sleep over it. AMC engines are particularly cheap to build if your not an idiot. And if U bothered to notice my hornet has a 401, not a 360. the 360 850whp claim may be a little ambitious, but for that amount it's going to be pretty close. Don't know about you, but I have friends that fab these parts and tune this stuff so it's not like I'm picking up a summit racing mag every time I want to buy a part. That would be stupid, and would cost 3 times more buying everything brand new retail of the shelf like a good little sheep consumer. The 401 that's in the car actually came from a junkyard for 350$ use your head and you can shave a lot of money off the top of a build like that. I have less in the entire car then some people do in there engine, and I'm running the same times. Believe me or not, I don't give two ***** I still have my car and I'm still happy.

Jeffblue

you asked about an EVO or WRX getting 1000hp... and you said it that huge difference in HP from stock can't just be from the turbo... i hate to burst your bubble but that's exactly what its from. much of those upgraded engine components are there specifically for the purpose of being able to run higher boost. The big difference between a 500whp supra and a 1000 whp supra is how much boost they are running. a lot of these crazy HP/small displacement cars, while they do have upgraded cams, headers, valve jobs and every other upgrade in the book... they are also running like 30-40psi.

FI makes a much bigger difference then marginally increasing the displacement of an engine.

all those old muscle cars you mention, and how they made 330hp stock just like the 370z... well the reason they could easily make that extra hp when you put work into them was because there was a lot of headroom in those cars. The 370z was tuned and designed very well to eek out almost every hp there was from the stock motor. Nissan didn't leave an extra 150 horsepower on tap... they squeezed almost everything they could out of the vq37hr. that's why gains from bolt ons are so minimal.

To try and figure out a realistic gain from what you are talking about we should compare the stock 300zx with a VG30DE (non turbo) to a full bolt on 370z with full bolt ons. The difference in displacement between these two engines is roughly the difference between the 3.7 and your hypothetical 4.5L stroker motor. and we'll give you the benefit of the doubt and say that what you would do to this engine would be the equivalent of 15-20 years of Nissan engineering.

1. STOCK 300zx NA = 222bhp (188whp)
2. STOCK 370z = 332 bhp (290whp)
3. FBO/Tune 370z = 380bhp (330whp) (this is based on the supposed whp numbers people getting from FBO and TUNE... which IMO are pretty exaggerated but if anything it helps your argument.)

4. Net gain in WHP from adding .7L, a lot of advanced engineering, full bolt ons and a tune = ~158bhp (142whp)

so what you are saying is you want to get a 330bhp motor to the 500WHP mark (which is ~590bhp) that is a gain of almost 260bhp or 210whp. Nissan only managed to get 158bhp out of adding .7 liters and a lot of advancement in engineering WITH everyone's aftermarket bolt ons... so how could you possibly expect to get 260bhp out of adding .8 liters? (even with all the upgraded engine components you mention.)

roy'sz

One important factor this guy who's going into the army is failing to realize. Imports are way different a beast to deal with than Americal Muscle. And yes buddy it does take A turbo and sometimes two to gain 600 hp. The 8second skyline is tt. Look at the bugati...TT. Ranting and raving about your 50 year old led sled isn't going to get you anywhere in comparison to these caliber of cars, apples and oranges my friend. You would be lucky to get 350-400 with bolt ons and that is with the stock internals as is. Maybe you shold read up on the car before you make any extreme decisions!

Skeeterbop

I've been wanting to do something similar to the OP, except I'm not shooting for a HP goal. I plan on staying NA and trying to make the engine as responsive as possible while also being able to safely bump the RPMs to 8500-9000. I think with a lot of time, trial and error, and money. 500whp is doable. I think you would need to ditch the VVEL and go to a traditional intake cam though. And obviously a Standalone EMS. I also think it would require race gas to reach that number as well.

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theDreamer

There was a 350z in Japan (limited run) that revved to above 8k but they dropped the displacement from 3.5 to 3.3. It was designed to alter the powerband for track setups.

Now onto the OP, you must remove the ideas from American V8 motors when dealing with the JDM engines. The Japanese prefer smaller displacement cars which rev higher and occasionally throw turbo(s) on. Now this is great for certain things, but NA power it is very limited and even with engine upgrades you are very restricted. Also, this motor is very 'tech' oriented which is also a negative as just throwing upgrades at the motor will not directly lead to results.

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wstar

JeffBlue's number is about right in that 330rwhp is the best reasonable number you could hope for with NA, full bolt-ons, and a very high-reading happy dyno on a really cold day. Assuming you could easily bump the car from a 3.7 to a 4.5, a rough horribly inaccurate estimate would be about 425rwhp (330 * (4.5/3.7)). That's assuming you can get VVEL to play nice with you, but so far it seems to be mostly self-adapting within that sort of power range, given appropriate UpRev tune with a decent timing starting point and fueling. I like the idea of doing that, but I really don't expect it to be cheap or easy on this car unfortunately. It would be simpler and cheaper to slap on an SC setup and just use pulley size and ECU tuning to pick your sweet spot anywhere between around 350-500-ish rwhp.

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chii370

Wstar, your the first person in a long time that has mentioned SC on this car. From what I have heard and read over and over on forums, people are getting screwed going the SC route, not even receiving the SC factory claim of horsepower gains "which isn't even close to TT" let alone a respectable whp number in the 500-550 range which I would EXPECT with a $7000 investment.

I wouldn't have minded going SC, no lag, and it just feels like a stupid sounding NA engine with more power which is all fine and great. But did they figure out the problems yet? I've heard quite a few stories so far about how people bought one from stillin or gtm and only saw gains of 125-150 FWHP. IMO 125 whp isn't worth 7 grand just on the forced induction side of things, because now you have spent a lot of money and done NOTHING to your stock motor to ready it for that. Instead why not spend the money on the motor itself.

I'm starting to understand a little more about the differences in these cars with more research and Talkin to you guys. VVEL is what it is, I think its limited by design, that problem aside though there are a LOT of things on the motor that can be improved, and I understand it took years and millions from Nissan to develope it..... But there's one crucial thing your missing. THEY WEREN'T BUILDING A RACE CAR!! They have to get the most power they can AND worry about maximum reliability, fuel economy, emissions, engine life, transmission and differential limits... I mean the list goes on and on.

To say it's at it's max NA HP rating is naive, it is for what they were trying to design yes. But I understand what you were getting at. Ok so let's assume you can't get 500 out of it, but as it sits right now mines 368 at the crank so 450 crank seem unreasonable? I just think the main problem with this entire subject is that no one has tryed it yet, to expensive, not enough parts, and untreated territory.

Everyone I've ever talked to has always just TT, SC, or put on an exhaust with headers "3 in" and slapped in a cold air with k&n filters. That seems to be the average extent of experimentation and knowledge am I wrong? But even the guys with the exhaust, headers, intake, tune, filters are seeing 40+ gains crank depending what Dino u use. Hell I've done one thing to mine, I put k&n panel filters in and it made a average powerband gain of 4.5 horse with a max of 11.5 at 6krpm.

What does that tell me? This engine has a lot of room to grow on the intake side of things, as it sits from the factory it's struggling to breathe. So a bigger intake manifold "perhaps one from the gtr" huge heads, bigger injectors, and a tune that makes it work and I bet you could match or BETTER the gains from all your boltons and then you can still bolt on all that stuff after for even MORE gains. Little things here and there help too. Light weight flywheel, forged aluminum heads "saves weight" forged aluminum pistons.... I mean it starts to add up pretty fast and they are always gains. By pretty conservative calculations for average projected gains on each part the engine dips in the 450 crank area with relative ease..... And this is without considering an increase of volume to 4.5 or whatever you choose.... Which yet again will have decent gains by itself. Hell that was already backed up in theory by the 300zx vs 370z full bolt on base HP compairison. not all, but a lot of that extra power can be contributed by the increase in displacement IMO probably most of it.

theDreamer

Wow, you need to spent some time reading about this motor and other threads.
You are just 'assuming' a lot of information and ignoring those trying to help.

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Skeeterbop

I still think that unless VVEL gets cracked that it will hamper any all out build but if you do this I'll be subscribed. My plan is to eventually get a short block and build that up. Then when I'm ready swap engines and keep the stock one as a back up in case something goes wrong with the built engine.

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Red__Zed

theDreamer

And to answer some of your question:
I have a Stage I SC from GTM making 100% claimed power GTM stated. I am sitting at 400whp and I started at 270whp bone stock. Not sure where you are reading or getting your information, but both Stillen & GTM have provided exactly whay they claimed with their SC kits.

For 7k, 130whp is a pretty good bargain compared to other parts you can buy. You would spend easily 20k doing your NA build and honestly you will not see 500whp, 500 crank might be possible but then you are down to 450whp or less which makes for a horrible investment compared to what other options there are.

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