Engine Build / Stroker before FI - Thoughts and Questions
 

So after a year or so of saving up money from work, I finally have the funds available for a forced induction kit. I had my heart set on the Boosted Performance kit, because I would be installing it myself and it seemed the easiest, as well as a very good performing kit, but I also took notice of the newly released GTM twin MHI turbo kit, which is priced so amazingly.

After a few back and forth discussions with a couple of friends however, I was also tossing around building and possibly stroking the motor before forced induction. I never plan to sell this car, since I already own a civic as a daily (d16 non vtec, what), and it dawned on me that if I could build and stroke the motor, I would have room for a crazy power build down the line. I also thought that if I were to stroke the motor with GTM's 4.2 / 4.5 kit, I would make a huge power increase N/A for the meantime, and that would hold me off till next year.

I know it's dreaming big, considering the prices listed on GTM's website for the stroker kit, as well as building the motor in general, but did you guys have any thoughts about what the costs and misc. stuff that would be required? Also, any thoughts on specifics like brand of forged internals, compression ratio, etc. Like I said, I will never get rid of the car, so I have plenty of time to figure out both saving up, as well as time that I'm without the Z.

My main concerns would be the cost of doing the stroker kit, as well as if the car would retain it's driveablity, so to speak. That would include VVEL working, as well as Synchro-Rev Match, reliability, and fuel economy. I drive my car like it's meant to be driven, so I want something that I can depend on. I figure a built motor will be more reliable than a stock motor on boost.

Any thoughts on this would be appreciated. I really do want to give this a serious try, if the price isn't crazy. I'll be calling GTM later this week. ^^ I'm kinda expecting that this is gonna cost a fortune. :icon17:

Why bother stroking it if you are willing to build it and go FI? Displacement will help you make more power, but the issue with stroking is going to be all the additional heat generated by the longer stroke as well as piston speed stress. If I had your budget, I would just build the engine at the standard displacement and hang some big Garrett turbos off it!

I agree with Nix. I think stroker is not worth it.

Would be more easier to build the motor and go with a stage 2 or 3 kit. You could also save big money building it yourself. The complete built engines on Gtm site seem priced really high.

Also built motor could be usable on the street. The only stroker kit I seem with FI is at like 1k hp. Must be extremely hard to plant that kinda power on the street.

I'm in south Florida also. If u ever finish this build I'd love to see it!
Good luck!

Oh yeah, of course. Plus if the block was sleeved, the heat would be crazy, I would need at least the CSF/Mishimoto radiator, possibly multiple oil coolers, mandatory meth injection, and hood venting. I wish my budget was a sky-is-the-limit budget, I'd dream of having the next 1k hp 370z. :icon17:

Mechanically speaking, stroker kits seem like they would be more prone to crankshaft failure than leaving stock displacement, correct? It probably also creates issues at high rpm, since piston speed per revolution must increase.

Mmhmm, the White Dragon Z, haha. The whole reason I thought of stroking the motor was if that maybe a deal could be worked out that it could be affordable enough, I'd love to invest in the stroker kit as well as a fully forged block, even if it took me until the end of this year to save for it.

Looking at GTM's website made me sick. :roflpuke2: It's so pricey! I'd definitely have a shop build my car for me, and just have parts ordered. I'm curious what goes into the stroker kits. AFAIK, no one besides the UAM car has one installed.

South FL, woop woop! I'm in Boca Raton myself. Where about in Broward are you? Maybe I've seen the car, who knows.
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Thinking about it, with my current funds, I'd say if I needed $8k or so to build the motor at stock displacement (at least without labor costs involved), I'd have to wait till around the end of summer or a little later to begin the build. To be honest, I haven't really built a car or owned a car with this much capability as the Z before, but I live by the adage that you do things right the first time, rather than cheaping out. :tup: I really wanna do this car right, and I sure do have plenty of time to figure it out. ^^

But, that being said, looking on GTM's website, the stroker kits are priced at $6k, and include the crank, rods, and pistons. Separately, what do you think they would run without a stroker crank?

I read an older thread about how much an engine build costs, hypothetically speaking, but there weren't really any concrete answers, let alone ballpark figures. Any thoughts?

I'm in Sunrise now. I'm boosted also. 540hp/500 tq.. Already difficult to plant this power down.. But I'm stanced also lol. I've been in HIN car show that was at Miami beach convention center and few others if u go to the shows.

Cost on a full engine build? I'd say around 8-10k. Maybe less if u do it on ur own.
I've dropped some good coin in my ride so far. Built motor is my last thing on the to-do list. So far I'm enjoying the ride so I'm not in a rush. I'd say I dropped about 15-18k so far. ****, don't remind me!

GTM is making a v8 swap kit (or w/e they wanna call it). Oh the badassery. Going for a stroker kit will be cool and all, but if you plan on doing FI later, compression would be lower than a NA stroker. But I agree with the others that a good FI kit is a better purchase. You can remove that and sell it, increase power with a touch of a button, it's cheaper, and faster to install and go.

Very nice! That's actually exactly the same numbers my original goal with FI was, give or take. It honestly must be a blast to have that much power, haha. Do you ever go to the towers meets on friday? I don't know of any others really down this far south.

I was at HIN. ^^ Didn't make the roll in though, couldn't plan logistics with the girlfriend and all. I had a few friends with Team Sunworks and a buddy who had a car at the HPLogic stand. Only other show I recently went to was in Daytona, which was Simply Clean. Do you have any pictures of the G?

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But anyhoo, considering the motor build, I was thinking around $8k, which may be a lot, but in the long run, that will hold all the power I need. When you mean do it yourself, do you mean at home kinda-thing? I didn't really think it was possible. :ugh2: All the work done on my car was done by me, and I'm never afraid to try new things, but is it actually possible to build the car in my garage? I store my car in a one-car garage at home, and just drive the Civic to work and school, so it's no pressure if it just sits on stands for weeks or months even.

Considering having a shop build it, I know HPLogic does lots of stuff with Z's, and they are in WPB. Rev Works is a member on this forum too, and they are in Orlando I believe. Still though, I'm treading very shallow waters when it comes to engine work.

I'm doing almost the same thing. I've talked with GTM about their 4.2L upgrade. I was told to avoid the 4.5L due to what they have to do to the engine and could be a pain...meaning it's really for tracking and not DD. I'm going to buy the whole engine including the block. That way I have a back up engine and they run about 16k for the whole engine but it's rated for up to 800hp. Oh choices.....when your done pulling your hair deciding which way to go let us know and good luck with your build!!

Well lets lay down your plan:
-What do you plan to do with the car?
-Do you want more low end power or more of a go for the HP king?
-Do you want DD reliability & driving or purely focus on weekend toy?

You have no idea how badly I'm thinking about pulling the trigger on ordering a kit. :icon17: Considering the compression, I know guys that build them drop the compression, and I was thinking about 9:1 or even 10:1. Of course, it's all speculation, I'd have to talk to GTM or someone with experience about it.

Bet you can't wait for the twin SC, by the way.

Hmm, interesting. I wish I could swallow the cost for a long block, haha. I'll be calling them hopefully tomorrow if time permits, and get some more concrete information. 800whp is auch a nice number. ^^ Go big or go home, right?

Thanks for the support, by the way!
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If I had a shop build my car, I would probably also at that time have a clutch / flywheel installed too, so that's about another grand in parts. Hopefully I'll be able to follow through with all this, I really want to get this build started!

Good questions that will help us answer.


OP, you might also look at ditching the VHR heads if you have big plans. Much easier to accomplish big power reliably without VVEL.

I really plan to drive the car for myself, possibly participate in HPDE or drag strip type stuff, but it's mostly for me. My dream ever since I got into modifying cars was to have a full interior car with leather, ICE, AC, the works, that looks great on the exterior, full suspension mods and whatnot, all while having a crazy amount of power. I don't plan on stripping the car out and becoming a race car. :driving:

Honestly, I prefer a balance of power, I'm not looking to be a dyno-queen or anything. I feel with a larger turbo kit, I could make pretty good hp and tq numbers, and it won't become an all out HP race. Or should I? ;D

I'm kinda weird on this point. Where it stands now, I drive the Z irregularly as a day car. Most days, if I'm just going to work or school, I'll drive the Civic, but some days I just take the Z for thr whole day, or if I'm going to a car meet or something. Heck, some days I run home and switch cars halfway through the day! So I'm definitely looking for some DD reliability, since it's not strictly a weekend toy.

HP KING!!! I hope...

I remember seeing that someone was doing an HR head swap - did that ever go through?

Thinking about now, I don't think the stroker kit, let alone any internals kit should affect the heads in any way, right? Maybe the VVEL could be tuned in conjunction with the increased piston speed, alongside timing control for some good power gains.

VVEL tuning is still in the beta phases and only pro tuners have access currently. They could tune it for you but might be best to wait for more information to come out.
On your build, I would skip the stroker kit as it would be a waste. Focus on building a reliable engine that can achieve the power & performance you want/need. Be that power under the curve, very specific HP/TQ, etc.

A good starting place is: http://www.the370z.com/forced-induct...ld-thread.html

I figure hopefully VVEL will have progressed further by the end of this year. Possibly Haltech will have released their 370z PnP as well!

Considering ultimate power, do you think a built, stock displacement block will be able to handle crazt power, such as 800+? I know it's a crazy number, but hey, if I'm gonna keep the car forever, it would be nice to have loads of headroom.

I've read that thread lots of times - plenty of good info in there. I think once I make some calls to shops and whatnot, I'll be able to come back with some hard numbers.

if you build it, 4.2 is preferred because it's a square setup and no need to sleeve.

I don't doubt a 3.7 can hit those numbers, but it's waiting for the boost to build up that will really show. With the larger displacement, the turbo spools up quicker, that's the nice perk. Drivability will be compromised if you are waiting on the turbos.

That's definitely one of the reasons behind the stroker - less overall lag.

Do you think a nice tune will alleviate the problems behind driveability? Considering all the internals will be balanced, coated, etc., would there be a reason that it would be less driveable until boost?

What shop do u have in mind to do the work for you?

I listed earlier that all I really know is Rev Works in Orlando and HPLogic in WPB, but to be honest, I honestly don't know what shop to go to down in FL. I was almost tempted to drive my car all the way to Z1 if it guaranteed that a good build would be done. Do you have any recommendations?

I only say that because the power curve will start looking like a 4 banger with a big turbo lol, just not as bad. Waiting, waiting, waiting, waiting, waiting, OOOOOMMMMMMMFFFFFGGGG!!!!!!! SHIFT OOOOOOMMMMMMMMFFFFFFGGGGGG!!!!

I'm no expert, but I would say if you are chasing over 700whp, go for the 4.2. Most don't play around over 550whp just because the price for power goes way up.

When I'm ready (almost there) I'll be goin to Z1. I have heard too many horror stories when it comes to HP logic. I didnt know they built motors. Thought they just tuned.

Ur best bet would be Z1. I'm actually gonna call em tomorrow n have a chat about my build list.

Yeah, most builds I see are about 550whp or less, to be safe. Mr. Squeeze is doing 700whp though, it's very impressive!

I hope I'll be able to make this a reality. Alongside the stroker kit, I'll be wanting to do clutch/flywheel/CSC work, as well as possibly doing a fuel return system. I don't think I'll need valvetrain work since the car won't be revving any faster than stock or anything like that. According to list prices, this would come out to a little over $8k in parts alone, but maybe a deal could be worked out, you know? :tup:

Apparently they do some motor work - I heard that a few GT-R's are being built by Jack over there, but I don't have concrete information. I've also heard bad and good things there, so it's wishy-washy. What was your plan for Z1? Drive the car there and fly back for the meantime? I was thinking something along those lines.

Yea that was my plan haha. Haven't heard back from them yet so I'm jus waiting. Will try to call them tmrw.

No need for a 4.2 for 700whp it can be done on the 3.7 I am close myself,and trust me when I tell you there is not waiting for power.

Sometimes people get to caught up in spool time and power at 2000-3000rpm's. What goo is a tone of power that low if all your going to do is light the tires up, there has to be a balance.

The stroker really isn't necessary at all man. The 4.5 especially has some heat issues. Theres a car on here that claims 1000whp but no one can produce a sheet over 8??whp and its barely been driven since all the work.

The initial thought of having that much power is cool and all, but you wind up with a fortune invested on a trailer/dyno queen that isn't good for anything.

I'd like to add a few things in here if I may.

The main reason people are concerned with piston speed is not so much the actual speed itself, but the derivative of it (velocity more specifically): acceleration. At top dead center on the exhaust stroke, the piston has to come to a complete stop and reverse direction with no resistance from any gas in the chamber working against it. That puts all the load on the connecting rods. The lower the rod ratio is, the higher this acceleration is at TDC. Generally, people look at a lot of documentation pertaining to OEM limits on piston speed. However, one of the factors in all this is the mass of the piston itself as well as the materials the connecting rod, wrist pin and piston are made of. The higher the tensile strength of the connecting rod, the higher the acceleration can be before the rod starts experiencing fatigue.

The bottom line here is that when we designed our stroker kits, we made sure that the tensile strength of the billet chromoly rods was high enough to withstand the inertial loads generated by the rod ratio at redline as well as the mass of the pistons we use. Also, there is a limit on how high you can rev the stroker engine. Basically, you should not rev it beyond the stock redline for maximum longevity.

One of the many advantages of our stroker kit is the oiling system in our crankshaft. We use a straight shot oiling system as opposed to the factory cross drilled oiling system. The straight shot oiling system improves oil flow to the rod bearings at high rpm while the centripetal forces in the cross drilled crank makes it more difficult for the oil to reach the rod bearings at high rpm.

All that said, when planning a build, it is important to recognize that you have to specify the compression ratio when you build the engine. That means if your plan is to build a forced induction car, you'll need to specify a lower compression ratio. The flip side is that if you do that and don't put a forced induction system on the engine, it'll be a complete dog as a naturally aspirated setup. At the same time, if you decide to go higher compression and then end up putting forced induction on there later, down the road, then you won't be able to run the turbos/superchargers at higher boost where they are more efficient and flow the most air.

Typically, if you have to choose between a built motor and a forced induction kit, I recommend getting the forced induction system first and doing the built motor later on. That way, you can enjoy the additional power on a stock engine then crank it up once you've built the motor and gotten all the additional supporting modifications for the extra horsepower.

Just my $0.02

Lol, I was looking at your dyno again Squeeze, it's still surprising to see your car build power the way it does. Freak of engineering.

Gotcha Mike. I appreciate you going into the details of the inner mechanics of the motor - ME student here. :icon17:

I'm worried about longevity with forced induction on the stock block - I know many of us think that the block is quite strong all the way up to 550+ whp or so, and what, 500tq? But, my concern is my driving style and how well that will affect the health of my motor, before I get it built. I'd say each time I take my car out, I'll give it a good working out at least once, and especially when I'll be going to the drag strip, or to local meets.

Granted, I do drive my beater car most of the time, so that does put less miles on the Z. Do you think I could sit at 500-550 whp for an extended amount of time safely? I also understand part, if not most of the safety of the car relies on the tune as well.

Also, I want to contact you about the MHI TT forced induction kit. I'll send you an email shortly about that, unless there is a better way to contact you. :driving:

Thanks man :tup:

I really feel like there is no reason why the 3.7 cant make good power just like the 3.8 in the GTR. Now I will kindly trade some bottom end power for some for top end like that graph. That car still has 500 torque at 4000 rpm's


Bellow is a GTR with GTX 2867R turbos still 3.8


http://imageshack.us/a/img707/2444/gtx2867.jpg

Thank you Mike for stepping in and explaining why the stroker kit works the way it does. Too many people here assume they know what they're saying as fact when it's all just opinion. Guys please, most of that information that Mike just put out on this thread is damn near word for word on the GTM website. Opinions are nice, but for the love of God also know the facts that they put out on their product! It seems almost a wasted effort that people don't want to take the time to read a few paragraphs of the product they're interested in only to take the opinions of others as gospel. GTM is a highly respected and well engineered company, I doubt Mike would let anything out of his shop that has such serious compromises as what was assumed here in this thread. That's a slap to the face IMHO.

We're sorry. We didn't realize our opinions counted in your eyes. Next time we will ask you before we post something. Thanks for straightening us out. :facepalm:

Hahahahahaha

I read you want to use the car for track or HPDE? I have a close friend who races SCCA autocross and has taken numerous HPDE days and has raced multiple times at Road America... I can tell you right now that you should develop your skills with the car. I would highly recommend, based on advice given, that you learn to reliably and consistently push the limits of the car in it's current form (given some suspension upgrades) before trying to push a short-wheelbase, tail-happy, relatively-lightweight car around a track with 500+ wheel horse and 450+ wheel torque.

If anything, I would go for FI kit and aim for 500 wheel, then build it if you are absolutely confident you can take more power. I'm not trying to condescend, but you're not exactly a race driver at the moment, and the skill it requires to control a 800+ horsepower time attack car, despite all the downforce and grippy tire, boggles my mind.

That would be a welcome thing! Please feel free to know the facts about the item under discussion or well thought out opinions instead of hearsay, wives tales, and grossly misplaced assumptions. If you want to back up your point Tower74 with facts vice elementary trolling please do.:happydance::tup:

I think I'm going to get my hands dirty on this one. Nismodean, everyone here offered suggestions and thoughts. Others have experience, and a lot is common knowledge. To say everyone who tried to help just blurted out useless information is crap. You just waltz in here and preach about the greatness of Mikes post and crapping on everyone else. I like Mike and GTM and his input is invaluable. But it does not devalue the input of the community. You can't dictate what is relevent, that's the OP's job. You know, the guy who opened the thread. He didn't compain. I have a hard time blaming Tower74 for poking you with a stick. I'm not sure what benefit your posting had.

So can we get back to what the thread was about? I want moar displacement! I don't remember where I read it, but it's better to have peak torque higher in the powerband. Can't remember specifically what was said, something about the engine being able to handle the stresses better at high rpm rather than down low. This may be something to look further in to. Also flexing 500+whp for extended periods of time involves a serious amount of cooling. Outside of that tuning is key to the longevity of the engine.

I'm going to get in on this as well.................

Since when does nut hugging on someone else's post make your post valid or fact filled / valid. Last time I checked, GTM is not the be all end all of VQ related products. They do have a good deal of expertise when it comes to working on or with the VQ platform, but damn! A couple posts from GTM and this dude wants to use their experience to get snippy. If you see mis-information, post the facts that refute the bad information instead of be a ****-bag.

/on-topic

I went with boost first and plan to build around the end of the year (if not sooner). Of course I have looked at the GTM products, but I will only go with them if I have to. That is not a stab at them, but I think a combination of the Fanboys AND some of the events that have come to light in the last 3 years have made me shy away. That is why, Zerolift did my GREDDY TT install and UPREV did my tuning. Since I am on that piece, Fast Intentions is going to be my first choice for TT revamp if I go that route. They will also be my first choice for ANY exhaust work and AAM (yup, that's right) is my backup custom modification provider. More than likely, I will go back to Zerolift for my engine build when the time comes, but I may go with KR Motorsport (local to Killeen/Fort Hood) or whoever UPREV uses for that service (per OMAR). If I were near GA, I would go with Z1 or Forged, but that is a 14-15 hour drive from my current location and 8-10 hours from home. Take it for what it's worth dudes!