I want a built shortblock but....
 

information is hard to come by. Of course I want to do the project in stages. I'm hoping to start the project around November/December. I've researched all over the web and I've checked out many 350z engine builds.

Right now I'm looking to keep it N/A and just build the shortblock. I plan on going F.I. after law school but I love an N/A motor. So I have a few questions.

Can I build the shortblock and then do the heads say 6 months later? I don't drive the car often so I wouldn't mind building the block and then the heads, I can be patient and rather have it done properly in stages.

I am shooting for 12.5:1 compression, any idea what kind of #'s I'd be looking at the wheels? My euro mechanic built his e46 M3 motor. He put down 340whp and redlines to 8500, his car is a monster and he's always in the powerband. With added displacement I'm sure a built VQ37 would put out similar if not greater numbers.

This is an introductory research attempt. If you have negative comments like just go S/C right now, clearly your missing the picture and didn't read the thread. Someone has to build a shortblock and I wouldn't mind being the first, any and all info appreciated.

Added note, I live literally down the block from Vinny Ten, a well known builder of 350z's on the Island so I might not even need to outsource. Still before I go knocking on his door I need to be informed so let the discussion begin.

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Thats funny I had a talked with Sam today about building my block, also another buddy of mine wants to do the same. Sam would be the guy to talk to because he knows the VQ37 motor better than anyone at this point in the ball game.

I plan on doing a short block too. I want to lower the compression and up the boost.

:excited:

Do you plan to rebuild again before boosting it? 12.5:1 CR plus any significant amount of boost is not achievable without race gas. It may work with little or no detonation, but I wouldn't trust it.

I'm honestly not sure you'd want to waste that much money building an engine to N/A specs that will be completely nullified once you boost it. Piston ring end gaps will have to change, piston-to-cylinder-wall clearance will have to loosen (a bunch if you're running 2618 alloy pistons, and you'll probably want to drop the compression ratio to 10:1-ish in the end.

The gains of building a VHR for N/A power probably aren't substantial enough to justify the cost. It's amazing how efficient this engine is right out of the box - without making it undriveable on the street, I cannot imagine squeezing more than 340 WHP out of it.

Just my $0.02 based upon what I've worked on before.

Yes, I know it would require a rebuild before boosting it to drop compression. The other option would be to build an N/A 4.5L long block with the stroker kit. Its well documented that S/C's and TT's are the way to go. Personally I won't TT it until I build the motor, the dream would be to do a build like bullitt. Any guess on what a 4.5L N/A build would put out? If it indeed comes to be that a built shortblock isn't going to put out more than 350whp then I might just go with an N/A longblock.

I gave pretty much all the input I have to give, but I'm just curious - if you know the costs involved in doing a proper N/A build, why not just get a turn-key turbo kit from GTM and make 3x the power on stock internals?

You would be the first dude! Why don't you make it happen and we can all find out. :happydance:

I know you don't want others to say ,"Just go turbo or sc" so I am going to appologize ahead of time.





Yeah I think if it was a v8, going N/A would not be a crazy idea; but, its not a TORQUEY v8. But insted a somewhat refined v6. It only makes sence to go in the ways of boost. hahahaha plus its just much funner.....





Edit: I can't believe I just said funner

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You guys might be right, I'm keeping all my options open it'll be a big investment so I don't want to regret it. This forum has always been the spot to get quick quality info, you guys haven't disappointed. I still think its to early to get into the SC game, GTM still hasn't been able to hold above 6psi with F.I. LTH's which I have and love. Stillen is also having issues, that's why I set my timetable around christmas...give the tuners time to figure things out. Lastly, Top Secret is working on their Z, in my opinion they would be the best (and most expensive) so it's kind of hard to see what the limit is since they haven't released their kit yet.

Looks like I'm going to have to stay patient, but keep the info coming!

I know no one has blown apart their motor yet...but I feel going that route would create an expensive ticking time bomb. F.I. is still new to the z34. I know for a fact that forged was working on a s1 shortblock but due to drama they took down their thread. Anyone know how that turned out?

Bladez, I think if you want to go built motor I would suggest TT kit over a SC kit.
My plan from the get go was LTH with a stage 1 for a simple power bump, but from the sounds of it you want to go a bit more.

Hopefully with JB already having a TT (stage 2) kit and wanting a built motor you could use him to your advantage. ;)

Dreamer, we're Z veterans (not to take away with anyone else). I've been an avid follower on this forum for awhile now and the reality is that you're never going to need more than 600hp on the streets. I should probably clarify my goal, that is maximum power SAFELY. I've had a boosted 04 Mustang Gt and frankly, whether it be immaturity or being niave, I never worried about blowing up my motor. With the auto industry switching over to aluminum blocks, I no longer have the safety blanket of heavy but durable engines. That would be why I didn't get an Evo X, I didn't trust the aluminum block, if they kept the older evo's iron block...

I'm waiting on you bro, if GTM makes their SC kit work with your LTH's I'll be boosted in time to race Santa's Sleigh.

Well, dyno run tomorrow to see how the kit is doing and then data set off to Sam. :tup:

Did you use a local shop for the install? How much did the install run you? Did they include dyno time in the install price?

Baker Tuning is handling all my work, not 100% sure on pricing on things as they are handling it all currently.

I always try to remind people of a few things when talking about dreams of being boosted or higher output of their current power levels. See, most people have this majic little hp number inwhich they have in their little heads that will satisfiy them if they hit it. 90% of my buds end up hitting this little number and, suddenly it becomes unsatisfactory once the goal was met. Almost like a "Hit it and Quit it" type deal. My opinion, is that you will prolly....not be happy with the power/to/price ratio of going N/A.

These prices reflect labor:
1. N/A for about 6-12k depending on how you build it out (Low power output with a high price tag)
2. Turbo for about 11-15k (High output and scalable on the fly to ones needs)
3. SC for about 8-9k (Mid-range power output but not scalable AKA: Stuck with what you got but; for a sweet price)

With a supercharger you really are getting your money worth and some. Turbo is not for everyone and can cost a 3rd more but power can be adjusted on the fly. Going fully built N/A on a VQ37 has never really been done so I can't start to make assumptions. It my be worth it, but something tells me it is not. Just my 2cents

Generically speaking, an NA engine makes its power because of 2 things, increased compression (requires full-race fuel) to increase torque. but there is little point going beyond 12.5:1 because of the exotic fuels required, and increased revs to shift the torque up the rev curve and therefore increase HP.

The former requires stronger pistons. gas-flowed heads (inlet and exhaust) and better head clamping to withstand a bigger "bang" which means more torque, and the latter requires a stronger crank/rods/fasteners and possibly block to decelerate and accelerate the piston as they rotate thru top and bottom dead centre and hold everything in the proper spot so the engine does not self-destruct.

"If" the heads will flow enough air at elevated rpm's, then you can consider 120-150bhp/litre if everything is radical (re-engineered oiling system to support elevated rev's, big-port heads, cams to match the objectives, port matched inlet and exhaust, improved coolling ot handle additional heat rejection, blah, blah).

The real question is "what are you after" - a dyno pull number, a car you can still drive on the street, a race car ????

I have been racing sports cars for 40 years ... and an NA big-power engine is always a compromise - in terms of ulitmate driveability, absolute levels of power and the reliability that goes with it ..... so the first thing is to establish exactly what you are looking for.

Then you can figure out the next step.

Most s/c will increase torque of a std engine by 50%, dead easy and simple. If you don;t drive it at WOT all the time, it will probably live for a while

Most Turbo systems that do not drop the compression will give infinitely adjustable torque for a relatively short time before detonation or a melted piston turns the engine to custard.

A fully engineered turbo installation can offer a heap, but they are expensive if not OEM engineered, as you are sometimes forced to do the engineering R&D yourself, and by fully engineered, I mean crank, pistons, rods, bearing package, heads and head gaskets, electronics to manage detonation risk etc).

Have fun - you are talking about ground breaking .... with NA

i dont mean to thread jack or at least thats not my intention, but ppl on posting on this seem to know a great deal. I am also looking for n/a tuning options. I've always liked revving the nuts of n/a car. i'm looking for high engine response and controllability.

yea im kind of curious why you want a really high compression when you plan on doing FI

Honestly if your going to do N/A stick with N/A don't go FI. Thacker and logistics are a nightmare. I tried it with my s2000 and wish I would have just went FI first... If your going N/A talk to Sam @ GTM since he has the best stroker kit out there and I know that's what your wanting. Seriously, there is ALOT that goes into a big motor build like mine. You have to run a full standalone ecu... I will have a stock ecu with a special tune so I can pass emissions but that's it. Literally a tune to get me to the testing facility and pass the obd 2 scans and then unplug it for the ride back home :D

Bullitt, will running a standalone ecu finally allow you to mess with vvel?? You know what it is man, the Z aftermarket is still growing, it's a big investment that I won't want to rush, shortchange, and regret. I appreciate guys like you bullitt and dreamer being the Z pioneers.

bullitt, you've been following my responses. Yeah man I want the stroker, the thing is that I don't want the TT kit. I know it's what produces the most power but I want to keep the Z streetable for now (meaning atleast the next 3 years). I love my Z and I have a hell of a strong motor, she made 296.4whp with test pipes only! That was the last of 3 dyno runs. Since then I've put on my homemade bazooka exhaust and LTH's. I think I'll go S/C but I don't want less than 450whp safely. I'm trying to decide what's the best way to go about it.

Stroker won't yield the 450rwhp you want unless you drop a sh*t load of money onto your stroker motor. If you do try you will be like us pioneering the way. If you don't wanna go ridiculous on the power do the stroker then custom supercharger from GTM ;)

Why is a turbo not "streetable". Ok So I understand that you want to keep your LTH's, done. So that knocks Turbo out of the equation. Also LTH's make you lose boost on a S/C, so that is an "ify". So I see why you would want to go N/A. But trust me brother I don't think this is the smart route, but I could be wrong. Fitting those LTH's into this equation is going to be hard but not impossible. As soon as dreamer gets his B!tch @$$ on the dyno we with know more about if LTH's are worth buying if considering a sc setup.

I am forsure not going to beat a dead horse, so this will for sure be fun to see what a fully built VQ37 in the N/A mode can do. And I promise I wont take your dyno graph and the the final cost, and make a power to cost ratio :happydance:

This might even be cheaper and faster than building a na VQ37 :stirthepot:

http://i199.photobucket.com/albums/a...er43411868.jpg

the bench racing number for a 4.5l with bolt ons is about 360 wheel, and i think you add 5% per point of increased compression can't quite remember off hand

^^ Are you speaking from personal experience or did you find that info somewhere? With your figures you're looking at 380whp at the wheels.

Yeah the LTH's are a sticking point but it's more then that. S/C kits, while not generating as much heat as TT's, will still eventually destroy stock equipment ie. stock cats. I think the inability to match LTH's with current SC kits is more the limitations of the kit than the increased flow of the headers. I'd be willing to guess that if you ran a kit with a full standalone, where you'd be able to tune VVEL, the headers wouldn't be a problem.

JB, your car is a monster man, but a TT isn't for me right now. I'm sure I'll change my mind a million times before I make the decision but I'm leaning toward an SC kit and maybe down the line if and when I do a full stroker build going TT. Hopefully by then I'll have enough $ where it won't be a limiting factor, not all of us can spend like bullitt right now.

I'll be keeping a sharp eye on the progress of the GTM and Stillen kits, RCZ loves his stillen kit and he's running headers and HFC's in time I'm sure it'll all get figured out.

This thread has been filled with informative facts and opinions thus far...keep them coming!

I've been contemplating the same things you have. You can't beat the powerband of a NA motor, and boost is definitely easier. With that being said, the aftermarket on the VQ37 motor hasn't really picked up it's full potential yet. If there were a cam and VVEL tuning available, I would definitely have gone for it, but the way things have been going it doesn't seem very likely that this will happen. You won't be able to uncork the full potential of an NA VQ37 unless someone can crack the VVEL and do the legwork on cams/shims etc.

With the TT/supercharged route it seems easy to just up the boost and be done with it. If your boost isn't substantial you can always have a reliable platform.

NA power is always harder and cheaper to obtain the same HP numbers with.

Be patient my friend. Two companies are coming up with supercharger kits by the end of the year. Two TT kits are also coming out by January. Its still a new car. This is why I am waiting. I am in the same shows your are in. I honestly believe supercharger is that best way to go for a streetable car and a daily driver. Planning on going with LTH and supercharger just waiting on production.